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Browse subject: coastal forests
Number of records: 50

Presettlement and modern disturbance regimes in coast redwood forests: Implications for the conservation of old-growth stands
About this Resource: Coast redwood (Sequoia sempervirens), a western North American conifer of ancient lineage, has a paradoxical combination of late-successional characteristics and strong adaptations to disturbance. Despite its shade tolerance and heavy dominance of the canopy on many sites, redwood saplings are uncommon in upland old-growth stands. Information needed to ensure the conservation of old-growth redwood forests has been limited. In this review paper, we integrate evidence on redwood biology with data on the historic and modern disturbance regimes to help clarify the degree to which key attributes of redwood forests may have been dependent upon periodic disturbance. Available evidence suggests that episodes of fire, flooding, and slope failure prior to European settlement were frequent but predominantly of low to moderate severity and extent, resulting in broadly uneven-aged forests. The majority of fires prior to European settlement were apparently of human origin. Frequency and severity of the major disturbance agents have been radically changed in modern times. Fires have been largely excluded, and flooding has been altered in ways that have often been detrimental to old-growth redwoods on alluvial terraces. However, because of the apparent anthropogenic origin of most presettlement fires, the long-term evolutionary role of fire for coast redwood is ecologically ambiguous. With fire exclusion, redwood possibly could be displaced to some extent on upland sites by increasing abundance of fire-sensitive competitors. Alternatively, redwood may be able to maintain dominance by vegetative sprouting and new seedling establishment on root-wad mounds, fallen logs, and on soil exposed by slope failure. Future research priorities are suggested that will help resolve some of the current ambiguities.

Broad-Scale Classification and Mapping of Tree Size and Density Attributes in Productive Old-Growth Forests in Southeast Alaska's Tongass National Forest
About this Resource: The forest classification and mapping system currently used in managing the Tongass National Forest (NF) is based largely on an economic forest measure, net board foot volume per acre. Although useful for timber economic modeling, this forest measure poorly differentiates old-growth forest types in a way that is meaningful to ecological and social concerns. In 2005, we published an article presenting a proposed tree size and tree density mapping model for the Tongass NF. We claimed the model would provide better information on the structural patterns in old-growth forests than did the current mapping models based on net board foot volume per acre. We also stated that further testing of our proposed model is required before it can be fully integrated into forest management plans and landscape analysis. In this article, we used independent field data to evaluate our proposed tree size and density model and better define its accuracy. Results showed differences among mapping classes similar to differences observed in the development stages of the model. Results also showed mapping accuracy estimates between 60 and 80%. We used the model in a forest management application by comparing the representation of old-growth forest types within a landscape to the representation within a management-defined subset of that landscape.

Winter Bird Population Studies and Project Prairie Birds for Surveying Grassland Birds
About this Resource: We compared 2 survey methods for assessing winter bird communities in temperate grasslands: Winter Bird Population Study surveys are area-searches that have long been used in a variety of habitats whereas Project Prairie Bird surveys employ active-flushing techniques on strip-transects and are intended for use in grasslands. We used both methods to survey birds on 14 herbaceous-reforested sites and 9 coastal pine savannas during winter and compared resultant estimates of species richness and relative abundance. These techniques did not yield similar estimates of avian populations. We found Winter Bird Population Studies consistently produced higher estimates of species richness, whereas Project Prairie Birds produced higher estimates of avian abundance for some species. When it is important to identify all species within the winter bird community, Winter Bird Population Studies should be the survey method of choice. If estimates of the abundance of relatively secretive grassland bird species are desired, the use of Project Prairie Birds protocols is warranted. However, we suggest that both survey techniques, as currently employed, are deficient and recommend distance-based survey methods that provide species-specific estimates of detection probabilities be incorporated into these survey methods.

Predation of gypsy moth (Lepidoptera: Lymantriidae) pupae in three ecosystems along the southern edge of infestation
About this Resource: The predation potential of small mammals, in particular mice, Peromyscus spp., and invertebrates, was evaluated from 1992 to 1995 near the leading edge of gypsy moth, Lymantria dispar (L.), spread into the southeastern United States. Two study sites were established in each of three geographic areas: the coastal plain, Piedmont, and mountains. All sites were mixed hardwood stands with varying amounts of oak, Quercus spp., and all were classified for gypsy moth susceptibility. Small mammal density was estimated using Sherman live-traps and pitfall traps within these 4.68-ha sites in early and late summer. Each site contained 75 trapping stations located on a 25-m grid. Predation was measured by offering freeze-dried gypsy moth pupae near trapping stations at four heights (0, 0.25, 1.0, and 2.0 m) on different tree boles. Pupal predation was monitored for three consecutive nights. Vertebrate predation was positively correlated with good mast production in the previous autumn. Predation data showed that when mice were at high densities they were the major source of pupal predation. However, within these southern sites, when densities of Peromyscus spp. were low, predation by invertebrates was occasionally greater than predation by vertebrates. These data suggest that in some years invertebrates may retard gypsy moth buildup when small mammals are scarce due to mast crop failures.

Oligocene terrestrial strata of northwestern Ethiopia: a preliminary report on paleoenvironments and paleontology
About this Resource: The Paleogene record of Afro-Arabia is represented by few fossil localities, most of which are coastal. Here we report sedimentological and paleontological data from continental Oligocene strata in northwestern Ethiopia. These have produced abundant plant fossils and unique assemblages of vertebrates, thus filling a gap in what is known of Paleogene interior Afro-Arabia. The study area is approximately 60 km west of Gondar, Chilga Woreda; covers about 100 km2; and represents as few as 1 Myr based on radiometric dates and paleomagnetic chronostratigraphy. The sedimentary strata are 150 m thick, and dominated by kaolinitic and smectitic mudstones and airfall tuff deposits. Five main paleosol types are interpreted as representing Protosols (gleyed or ferric), Histosols, Gleysols, Vertisols, and Argillisols. Varied, poor drainage conditions produced lateral variation in paleosols, and stratigraphic variation probably resulted from lateral changes in drainage conditions through time. Vertebrate fossils occur in sediments associated with ferric Protosols and occur with fruits, seeds, and leaf impressions. Plant fossils also occur as in situ forests on interfluves, leaf and flower compressions associated with in situ carbonized trees in overbank deposits (Gleyed Protosols), and compressions of leaves, twigs and seeds in tuffs. Plant fossil assemblages document diverse forests, from 20-35 m tall, of locally heterogeneous composition, and representing families occurring commonly (legumes) or uncommonly (palms) in forests today. Sedimentological and paleobotanical data are consistent with a nearly flat landscape where a meandering river and ample rainfall supported lush vegetation. Over time, the region was subject to intermittent ashfalls. A unique fauna of archaic mammalian endemics, such as arsinoitheres and primitive hyracoids, lived here with the earliest deinotheres.

An assessment of dead wood patterns and their relationships with biophysical characteristics in two landscapes with different disturbance histories in coastal Oregon, USA
About this Resource: Understanding the relative importance of landscape history, topography, vegetation, and climate to dead wood patterns is important for assessing pattern-process relationships related to dead wood and associated biodiversity. We sampled dead wood at four topographic positions in two landscapes (1400-2100 km2) that experienced different wildfire and salvage histories in coastal Oregon. Study objectives were to (i) determine whether and how the landscapes differed in dead wood amounts and characteristics and (ii) evaluate relationships between dead wood characteristics and potentially related biophysical variables associated with historical and current vegetation, topography, climate, soils, and ecoregion. Despite differences in history, the two landscapes differed little in total dead wood volume; however, they differed in dead wood volume by structural type, decay class, and source (legacy/nonlegacy). Dead wood varied by topographic position, and topography was of greatest importance compared with other factors. In this mountainous region, upper topographic positions may be source areas for dead wood and riparian areas and streams sinks for dead wood. Climate explained more variance in dead wood in the landscape that burned earlier and was not salvaged. Landscape-scale patterns of dead wood are evident in landscapes with different disturbance histories and despite finer-scale variation in topography, vegetation, and other biophysical attributes.

Habitat Selection by American Martens in Coastal California
About this Resource: We investigated habitat selection using single- and mixed-scale modeling at 2 spatial scales, stand and home range, by the only known population of American martens (Martes americana) remaining in the historical range of the Humboldt subspecies (M. a. humboldtensis) in California, USA. During 2000 and 2001, we sampled a 12 x 14 grid with 2-km spacing, using 2 sooted track plates at each grid point. We detected martens at 26 of the 159 grid points. We used resource selection probability functions and an information-theoretic method to model habitat at detection locations. At the stand scale, martens selected conifer-dominated stands with dense, spatially extensive shrub cover (average = 74% cover, SE = 4) in the oldest developmental stage. At the home-range scale, martens selected the largest available patches ( average = 181 ha, SE = 14) of old-growth, old-growth and late-mature, or serpentine habitat. Mixed-scale models revealed that habitat characteristics from both scales best explained marten occurrence compared to one scale alone. Dense, spatially extensive shrub cover is a key habitat element for martens in coastal forests. Dense shrubs provide refuge from predators, cover for prey, and may also deter larger-bodied competitors. Managers can increase the likelihood of marten population persistence and encourage expansion in coastal forests by maintaining and restoring late-mature and old-growth, conifer-dominated forests with dense shrub cover in large, contiguous patches.

Forest dynamics in Oregon landscapes: Evaluation and application of an individual-based model
About this Resource: The FORCLIM model of forest dynamics was tested against field survey data for its ability to simulate basal area and composition of old forests across broad climatic gradients in western Oregon, USA. The model was also tested for its ability to capture successional trends in ecoregions of the west Cascade Range. It was then applied to simulate present and future (1990-2050) forest landscape dynamics of a watershed in the west Cascades. Various regimes of climate change and harvesting in the watershed were considered in the landscape application. The model was able to capture much of the variation in forest basal area and composition in western Oregon even though temperature and precipitation were the only inputs that were varied among simulated sites. The measured decline in total basal area from tall coastal forests eastward to interior steppe was matched by simulations. Changes in simulated forest dominants also approximated those in the actual data. Simulated abundances of a few minor species did not match actual abundances, however. Subsequent projections of climate change and harvest effects in a west Cascades landscape indicated no change in forest dominance as of 2050. Yet, climate-driven shifts in the distributions of some species were projected. The simulation of both stand-replacing and partial-stand disturbances across western Oregon improved agreement between simulated and actual data. Simulations with fire as an agent of partial disturbance suggested that frequent fires of low severity can alter forest composition and structure as much or more than severe fires at historic frequencies.

Transmission of Phytophthora ramorum in mixed-evergreen forest in California.
About this Resource: During 2001 to 2003, the transmission biology of Phytophthora ramorum, the causal agent of sudden oak death, was studied in mixed-evergreen forest, a common forest type in northern, coastal California. Investigation of the sources of spore production focused on coast live oak (Quercus agrifolia) and bay laurel (Umbellularia californica), dominant hosts that comprised 39.7 and 46.2% of the individuals at the study site, respectively. All tests for inoculum production from the surface of infected coast live oak bark or exudates from cankers were negative. In contrast, sporangia and chlamydospores were produced on the surface of infected bay laurel leaves. Mean number of zoospores produced from infected bay laurel leaves under natural field conditions during rainstorms was 1,173.0 +/- SE 301.48, and ranged as high as 5,200 spores/leaf. P. ramorum was recovered from rainwater, soil, litter, and streamwater during the mid- to late rainy season in all 3 years of the study. P. ramorum was not recovered from sporadic summer rains or soil and litter during the hot, dry summer months. Concentrations of inoculum in rainwater varied significantly from year to year and increased as the rainy season progressed for the two complete seasons that were studied. Potential dispersal distances were investigated for rainwater, soil, and streamwater. In rainwater, inoculum moved 5 and 10 m from the inoculum source. For soil, transmission of inoculum was demonstrated from infested soil to bay laurel green leaf litter, and from bay laurel green leaf litter to aerial leaves of bay laurel seedlings. One-third to one-half of the hikers tested at the study site during the rainy season also were carrying infested soil on their shoes. In streamwater, P. ramorum was recovered from an unforested site in pasture approximately equal to 1 km downstream of forest with inoculum sources. In total, these studies provide details on the production and spread of P. ramorum inoculum in mixed-evergreen forest to aid forecasting and managing disease transmission of this environmentally destructive pathogen.

Assessment of C-band synthetic aperture radar data for mapping and monitoring Coastal Plain forested wetlands in the Mid-Atlantic Region, U.S.A.
About this Resource: Multi-temporal C-band SAR data (C-HH and C-VV), collected by ERS-2 and ENVISAT satellite systems, are compared with field observations of hydrology (i.e., inundation and soil moisture) and National Wetland Inventory maps (U.S. Fish and Wildlife Service) of a large forested wetland complex adjacent to the Patuxent and Middle Patuxent Rivers, tributaries of the Chesapeake Bay. Multi-temporal C-band SAR data were shown to be capable of mapping forested wetlands and monitoring hydroperiod (i.e., temporal fluctuations in inundation and soil moisture) at the study site, and the discrimination of wetland from upland was improved with 10 m digital elevation data. Principal component analysis was used to summarize the multi-temporal SAR data sets and to isolate the dominant temporal trend in inundation and soil moisture (i.e., relative hydroperiod). Significant positive, linear correlations were found between the first principal component and percent area flooded and soil moisture. The correlation (r2) between the first principal component (PC1) of multi-temporal C-HH SAR data and average soil moisture was 0.88 (p = < .0001) during the leaf-off season and 0.87 (p = < .0001) during the leaf-on season, while the correlation between PC1 and average percent area inundated was 0.82 (p = < .0001) and 0.47 (p = .0016) during the leaf-off and leaf-on seasons, respectively. When compared to field data, the SAR forested wetland maps identified areas that were flooded for 25% of the time with 63-96% agreement and areas flooded for 5% of the time with 44-89% agreement, depending on polarization and time of year. The results are encouraging and justify further studies to attempt to quantify the relative SAR-derived hydroperiod classes in terms of physical variables and also to test the application of SAR data to more diverse landscapes at a broader scale. The present evidence suggests that the SAR data will significantly improve routine wooded wetland mapping.

Foraging Ecology of Pileated Woodpeckers in Coastal Forests of Washington
About this Resource: In the Pacific Northwest, providing adequate habitat for pileated woodpeckers (Dryocopus pileatus) has been a key component of federal forest management strategies for over 20 years. Although their nesting and roosting ecology has been well studied, information on their foraging ecology is limited. From 1990 to 1995, we studied food habits of pileated woodpeckers in coastal forests (with scat analysis); estimated the relative abundance of their primary prey, carpenter ants (Camponotus spp.), associated with logs and cut stumps; and investigated selection of forest structures and site characteristics used by pileated woodpeckers for foraging. Pileated woodpeckers primarily consumed carpenter ants (54% of diet), but round-headed beetle larvae (Coleoptera, Cerambycidae) and dampwood termites (Isoptera, Termopsidae) were important food items during the breeding season (Mar-Jun). Selection of foraging structures was related to wood characteristics and microsite conditions that influence the presence and abundance of arthropod prey. Pileated woodpeckers foraged almost exclusively (95%) on standing structures, selecting tall, large-diameter snags in early to moderate stages of decay. Contrary to previous studies, pileated woodpeckers rarely (2%) foraged on logs. Carpenter ants were scarce at logs in closed-canopy habitats, which suggested that in coastal forests logs are too cool and wet to support abundant populations of carpenter ants. Selection of foraging sites by pileated woodpeckers was influenced by the abundance of potential foraging structures; 0.4-ha plots with recent foraging activity had greater densities of large snags (>51 cm dbh and 7.5 m tall) than plots without recent foraging. The efficacy of management strategies designed to provide habitat for pileated woodpeckers would be enhanced if they included specific provisions for foraging habitat and accounted for regional differences in the types of structures that provide suitable conditions for wood-dwelling arthropods.

Long-term fire incidence in coastal forests of British Columbia: (Corrected and reprinted from Northwest Science, volume 72, special issue 2, pages 64-66, 1998)
About this Resource: Long-term fire incidence in coastal forests of British Columbia: (Corrected and reprinted from Northwest Science, volume 72, special issue 2, pages 64-66, 1998)

Genetic variation in fall cold hardiness in coastal Douglas-fir in western Oregon and Washington
About this Resource: Genetic variation in fall cold damage in coastal Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) was measured by exposing excised branches of seedlings from 666 source locations grown in a common garden to freezing temperatures in a programmable freezer. Considerable variation was found among populations in fall cold hardiness of stems, needles, and buds compared with bud burst, bud set, and biomass growth after 2 years. Variation in fall cold hardiness was strongly correlated (r = 0.67) with cold-season temperatures of the source environment. Large population differences corresponding with environmental gradients are evidence that natural selection has been important in determining genetic variation in fall cold hardiness, much more so than in traits of bud burst (a surrogate for spring cold hardiness), bud set, and growth. Seed movement guidelines and breeding zones may be more restrictive when considering genetic variation in fall cold hardiness compared with growth, phenology, or spring cold hardiness. A regional stratification system based on ecoregions with latitudinal and elevational divisions, and roughly corresponding with breeding zones used in Oregon and Washington, appeared to be adequate for minimizing population differences within regions for growth and phenology, but perhaps not fall cold hardiness. Although cold hardiness varied among populations, within-population and within-region variation is sufficiently large that responses to natural or artificial selection may be readily achieved.

Cold oceans enhance terrestrial new-particle formation in near-coastal forests
About this Resource: The world&apos;s forests produce atmospheric aerosol by emitting volatile organic compounds (VOC) which, after being oxidized in the atmosphere, readily condense on the omnipresent nanometer-sized nuclei and grow them to climatically relevant sizes. The cooling effect of aerosols is the greatest uncertainty in current climate models and estimates of radiative forcing. Therefore, identifying the environmental factors influencing the biogenic formation of aerosols is crucial. We show that, in addition to local meteorological factors in the forest, the magnitude of evaporation from oceans hundreds of kilometers upwind can effectively suppress or enhance new-particle formation. Our findings indicate that, unlike warm waters, the cold polar oceans provide excellent clean and dry background air that enhances aerosol formation above near-coastal forests in Fennoscandia and South-East Australia.

Seven new species of Cephennium Müller & Kunze (Coleoptera, Staphylinidae, Scydmaeninae, Cephenniini) from California with a key to native North American species
About this Resource: Seven new species of Cephennium from California are described and illustrated - C. celsifrons, n. sp., C. mariposae, n. sp., C. grandarboreum, n. sp., C. canestroi, n. sp., C. gilberti, n. sp., C. urbanum, n. sp. and C. aridum, n. sp. The single known native Nearctic species, C. anophthalmicum Brendel, was known only from moist coastal forests around the San Francisco Bay area. The new species greatly expand the distribution of the genus, through central and southern California, occurring in the central the Sierra Nevada, south through the coast ranges and Sierra Nevada to the Santa Monica Mountains and desert foothills of the San Bernardino and San Jacinto Mountains. A key to all eight species (the entire native Nearctic fauna) of Cephennium occurring in California is provided.

Sudden oak death and Phytophthora ramorum in the USA: a management challenge
About this Resource: Oaks and tanoaks in California and Oregon coastal forests are being ravaged by sudden oak death. The exotic causal agent, Phytophthora ramorum, is an oomycete in the Straminipile group, a relative of diatoms and algae. P. ramorum also infects many popular horticultural plants (i.e. camellia and rhododendron), causing ramorum blight, with symptoms expressed as leaf spots, twig blight and shoot dieback. P. ramorum has raised important biosecurity issues, which continue to reverberate through the agriculture, forestry and horticulture industries as well as associated government management, regulatory and scientific agencies. The continued spread of this and other new Phytophthora spp. presents significant impetus for adjustments in the management and regulation of forest pathogens and nursery stock.

Use of woody debris piles by birds and small mammals in a riparian corridor
About this Resource: Woody debris piles, a natural component of rivers draining the coastal forests of the Pacific Northwest, provide a unique resource in the riparian-river corridor. We describe the distribution of woody debris piles on the Skykomish River, Washington, and examine their use by birds and small mammals. We found an average of one debris pile per 15 m of river bank; the inside of these piles was significantly cooler than the ambient environment. Over sixteen bird species were observed using the debris piles while other bird species in the area were never observed on the debris piles. The overall species richness of small mammals was greater at debris piles (9 species) than at reference sites in nearby areas without woody debris (4 species). On cobble bars, there was a greater abundance of small mammals at debris piles than at reference sites. We conclude that debris piles may provide valuable resources to both birds and small mammals particularly on otherwise barren cobble bars

Litterfall and litter nutrient content in two Brazilian Tropical Forests
About this Resource: Litterfall and transfer of nutrients was estimated in two tropical coastal forests of Brazil - the Atlantic and the Restinga Forests at Cardoso Island, São Paulo. Samples were collected monthly, from June 1990 to May 1991, using thirty 0.25 m2 traps. There were significant differences in litter production between the Atlantic Forest (6.3 t.ha-1.year-1) and the Restinga Forest (3.9 t.ha-1.year-1). Litterfall was continuous throughout the year with maximum in the beginning of the rainy season in both sites. The annual return of mineral elements through litter in the Atlantic Forest was (kg.ha-1): 101.8 N, 3.8 P, 20.3 K, 60.0 Ca, 18.0 Mg, and 14.6 S and in the Restinga Forest was: 27.5 N, 1.0 P, 6.5 K, 30.0 Ca, 10.9 Mg, and 6.6 S. The return, although small, is relevant due to the low fertility of the soils in those ecosystems, especially in Restinga. The Restinga Forest seems to be an ecosystem well adapted to oligotrophic conditions, lying among those presenting higher nutrient use efficiency.

Litterfall and litter nutrient content in two Brazilian Tropical Forests
About this Resource: Litterfall and transfer of nutrients was estimated in two tropical coastal forests of Brazil - the Atlantic and the Restinga Forests at Cardoso Island, São Paulo. Samples were collected monthly, from June 1990 to May 1991, using thirty 0.25 m2 traps. There were significant differences in litter production between the Atlantic Forest (6.3 t.ha-1.year-1) and the Restinga Forest (3.9 t.ha-1.year-1). Litterfall was continuous throughout the year with maximum in the beginning of the rainy season in both sites. The annual return of mineral elements through litter in the Atlantic Forest was (kg.ha-1): 101.8 N, 3.8 P, 20.3 K, 60.0 Ca, 18.0 Mg, and 14.6 S and in the Restinga Forest was: 27.5 N, 1.0 P, 6.5 K, 30.0 Ca, 10.9 Mg, and 6.6 S. The return, although small, is relevant due to the low fertility of the soils in those ecosystems, especially in Restinga. The Restinga Forest seems to be an ecosystem well adapted to oligotrophic conditions, lying among those presenting higher nutrient use efficiency.

Manuka Oil and Phoebe Oil are Attractive Baits for Xyleborus glabratus (Coleoptera: Scolytinae), the Vector of Laurel Wilt
About this Resource: Redbay ambrosia beetle, Xyleborus glabratus Eichhoff, is a native of Southeast Asia recently established in coastal forests of Georgia, SC and Florida. It vectors a wilt fungus, Raffaelea sp., lethal to redbay trees, Persea borbonia L. Spreng, and certain other Lauraceae. No practical monitoring system exists for this beetle so we conducted studies to identify host attractants and develop lures. Volatiles were collected from redbay wood and bark by steam distillation, direct solvent extraction, and dynamic headspace sampling with a Poropak Q cartridge. Steam, methanol, and pentane extracts were tested as baits in trapping trials but were not attractive to X. glabratus. Major constituents in Poropak aerations identified by gas chromatography-mass spectrometry included α-pinene, β-pinene, δ-3-carene, eucalyptol, p-cymene, α-copaene, terpinene-4-ol, linalool, calamenene, and nonanoic acid. We assayed several of these compounds (including eucalyptol, p-cymene, terpinene-4-ol, linalool, nonanoic acid, and caryophyllene oxide) both individually and in combination, but none were attractive at tested doses. Two other redbay odor components, α-copaene and calamenene, were unavailable in sufficient quantities commercially so we substituted manuka oil, the essential oil extracted from Leptospermum scoparium Forst. and Forst., which contains high proportions of both compounds. Manuka oil was equally attractive as redbay wood to X. glabratus, but increasing release rates >10-fold did not enhance its activity. Phoebe oil, an extract of Brazilian walnut (Phoebe porosa Mez.), which contains significant quantities of α-copaene and calamenene, was also attractive. Fractions of manuka oil were not more attractive than the whole oil. Manuka and phoebe oil are readily available and are good alternatives to redbay wood as a trap bait for monitoring X. glabratus distribution and population trends.

Northern temperate coastal Sitka spruce forests with special emphasis on canopies: Studying arthropods in an unexplored frontier
About this Resource: Northern temperate coastal Sitka spruce forests with special emphasis on canopies: Studying arthropods in an unexplored frontier

Use of small streams and forest gaps for breeding habitats by winter wrens in Coastal British Columbia
About this Resource: Few studies have examined the value of riparian areas adjacent to streams <=10-m wide as habitat for forest birds. In mature (80-120 years) and young (40-60 years) coastal forests of southern British Columbia, Canada, we examined the habitat values for male winter wrens [Troglodytes troglodytes] of riparian areas adjacent to small streams and areas upslope of these streams. In both riparian and upslope areas, wrens preferentially located nests (n=47) and song perches (n=77) in disturbed sites with fewer trees than randomly located sites. Hydrological processes associated with streams, mortality of dominant canopy trees or uprooted trees can produce these disturbed sites. In mature forest, winter wrens chose stream banks and upturned root masses when available for building their nests with most nest substrates located within 5 m of small streams. In both young and mature forests, they also chose areas near small streams as locations for song perches. Winter wrens may use areas closer to streams when available because channel morphology, the associated heterogeneous forest structure, and microclimate likely provide optimal nesting and foraging habitat. Our research supports operational efforts by forest managers to conserve structures near small streams and in upslope areas because these structures maintain long-term habitat values for wildlife such as winter wrens.

Life history and habitat associations of the broad wood cockroach, Parcoblatta lata (Blattaria: Blattellidae) and other native cockroaches in the Coastal Plain of South Carolina
About this Resource: Wood cockroaches (Blattaria: Blattellidae) are important prey of the red-cockaded woodpecker, Picoides borealis Wilson (Piciformes: Picidae), an endangered species inhabiting pine (Pinus spp.) forests in the southern United States. These woodpeckers forage on the boles of live pine trees, but their prey consists of a high proportion of wood cockroaches, Parcoblatta spp., that are more commonly associated with dead plant material. Consequently, we sampled large woody debris, logs and standing dead trees (snags), in a South Carolina pine forest to determine densities of wood cockroaches in these habitats. Nearly 80% of the 662 wood cockroaches we collected from woody debris were found in snags. However, when we estimated the number of wood cockroaches per hectare, we found that the two habitats contained approximately equal numbers because logs are more abundant than snags. The broad wood cockroach, Parcoblatta lata Brunner, was the most common cockroach on live pine boles constituting 46% of the wood cockroaches. Males were present from late April to late July in field studies suggesting that P. lata has only one generation per year, which is consistent with laboratory studies in which males lived an average of 91.3 d. Female P. lata lived almost twice as long (158.2 d) and produced an average of 12.6 oothecae/female (SE = 3.4) or approximately equal to 517 offspring/female. Although P. lata were common on boles of live trees, our results show that snags and logs also are important habitats of these wood cockroaches in pine forests.

Chronological dating of high-elevation dead and dying trees on northern Vancouver Island, British Columbia
About this Resource: Tree rings were analysed in order to determine the time of death for 18 moribund and dead trees of 3 species used as roosts by bats on the upper slopes (700-1500 m altitude) of Mt. Cain, northern Vancouver Island, Canada. The species were yellow cedar (Chamaecyparis nootkatensis), western hemlock (Tsuga heterophylla) and western white pine (Pinus monticola). Some 29 increment core samples were crossdated with tree-ring chronologies of living trees to estimate when the trees died. After they die, yellow cedar trees deteriorate slowly and remain standing for as long as 200 years. In contrast, few western hemlock and western white pine snags persist longer than 100 years. The ages at which the sampled trees died were highly variable, with western white pine, western hemlock, and yellow cedar exhibiting the narrowest to widest range of ages, respectively. The findings highlight the long persistence of snags in high-altitude coastal forests and the centuries of ecological service that these trees provide to snag-dependent wildlife.

Detection of Phytophthora ramorum blight in Oregon nurseries and completion of Koch's postulates on Pieris Rhododendron, Viburnum, and Camellia
About this Resource: Phytophthora ramorum, the cause of sudden oak death in California and Oregon coastal forests and ramorum blight in European nurseries and landscapes (1), was detected in six Oregon nurseries in Jackson, Clackamas, and Washington counties from May to June 2003. The pathogen was isolated from: Viburnum bodnantense 'Dawn', V. plicatum var. tomentosum 'Mariesii', Pieris japonica x formosa 'Forest Flame', P. japonica 'Variegata' and 'Flaming Silver', P. floribunda x japonica 'Brouwer's Beauty', Camellia sasanqua 'Bonanza' and other cultivars, C. japonica, and Rhododendron x 'Unique'. Samples of symptomatic tissues were plated on a Phytophthora-selective medium (PARP) and tested by polymerase chain reaction (PCR) (3). All samples positive for P. ramorum with PCR yielded P. ramorum isolates in culture. The isolates have the European genotype, mating type A1, except for the Camellia spp. isolates, which have the North American genotype, mating type A2 (2). Isolates are deposited in the American Type Culture Collection. Koch's postulates for this pathogen have been completed on V. bodnantense and C. japonica (1). To confirm pathogenicity on the new hosts, isolates from V. plicatum var. tomentosum 'Mariesii', Pieris x 'Forest Flame', Pieris x 'Brouwer's Beauty', and P. japonica 'Variegata' and 'Flaming Silver' were used to inoculate healthy plants of the same cultivars. For isolates from Rhododendron x 'Unique' and C. sasanqua 'Bonanza', pathogenicity was tested on Rhododendron x 'Nova Zembla' and C. sasanqua 'Sutsugekka' and 'Kanjiro'. Three to five plants of each cultivar were inoculated and three to five were noninoculated. Zoospore inoculum was prepared on dilute V8 agar for one isolate from each host. Foliage of plants growing in 10-cm pots was dipped for 5 sec in a zoospore suspension (3 x 10(4) zoospores per ml) or sprayed to runoff with a hand mister (6 x 10(4) zoospores per ml). Control plants were dipped in or sprayed with sterile water. C. sasanqua plants were also inoculated by placing 6-mm mycelial plugs on individual leaves that had been wounded by piercing with a pin. Control leaves were wounded but not inoculated. Foliage was enclosed in plastic bags to retain humidity and the pathogen, and plants were incubated in a locked growth chamber (21 to 23°C). After 21 days, plants were examined for symptoms, and isolations onto PARP were made. All inoculated plants showed foliar symptoms, and P. ramorum was consistently isolated from inoculated plants, but not from asymptomatic control plants. On Rhododendron x 'Nova Zembla', nearly all leaves were wilted and dead, as were terminal buds and stems. Pieris spp. cultivars exhibited leaf and stem necrosis and defoliation. On V. plicatum var. tomentosum 'Mariesii', necrotic leaf lesions and defoliation of the lower leaves were observed. On C. sasanqua, necrotic lesions developed only on wounded leaves inoculated with mycelial plugs; these leaves abscised. Our results confirm the pathogenicity of Oregon nursery isolates of P. ramorum on V. plicatum var. tomentosum 'Mariesii', P. japonica x formosa 'Forest Flame', P. japonica 'Variegata' and 'Flaming Silver', P. floribunda x japonica 'Brouwer's Beauty', C. sasanqua and Rhododendron and complete Koch's postulates for several new hosts.

Three new species of Ceralocyna Viana, 1971 from Mexico and Ecuador (Cerambycidae: Cerambycinae, Trachyderini, Ancylocerina)
About this Resource: Three new species are described herein, one from coastal lowland deciduous forests of western M exico (Jalisco), one from coastal lowland deciduous scrub in western Ecuador (Manabi), and one from upper Amazonian Ecuador (Napo).

Habitat associations of saproxylic beetles in the southeastern United States: A comparison of forest types, tree species and wood postures
About this Resource: Saproxylic beetles are highly sensitive to forest management practices that reduce the abundance and variety of dead wood. However, this diverse fauna continues to receive little attention in the southeastern United States even though this region supports some of the most diverse, productive and intensively managed forests in North America. In this replicated three-way factorial experiment, we investigated the habitat associations of saproxylic beetles on the coastal plain of South Carolina. The factors of interest were forest type (upland pine-dominated vs. bottomland hardwood), tree species (Quercus nigra L., Pinus taeda L. and Liquidambar styraciflua L.) and wood posture (standing and downed dead wood, i.e., snags and logs). Wood samples were taken at four positions along each log and snag (lower bole, middle bole, upper bole and crown) ~11 months after the trees were killed and placed in rearing bags to collect emerging beetles. Overall, 33,457 specimens from 52 families and >=250 species emerged. Based on an analysis of covariance, with surface area and bark coverage as covariates, saproxylic beetle species richness differed significantly between forest types as well as between wood postures. There were no significant interactions. Species richness was significantly higher in the upland pine-dominated stand than the bottomland hardwood forest, possibly due to higher light exposure and temperature in upland forests. Although L. styraciflua yielded more beetle species (152) than either Q. nigra (122) or P. taeda (125), there were no significant differences in species richness among tree species. There were also no relationships evident between relative tree abundance and observed or expected beetle species richness. Significantly more beetle species emerged from logs than from snags. However snags had a distinct fauna including several potential canopy specialists. Our results suggest that conservation practices that retain or create entire snags as opposed to high stumps or logs alone will most greatly benefit saproxylic beetles in southeastern forests.

Amphibian and reptile community response to coarse woody debris manipulations in upland loblolly pine (Pinus taeda) forests
About this Resource: Coarse woody debris (CWD) has been identified as a key microhabitat component for groups that are moisture and temperature sensitive such as amphibians and reptiles. However, few experimental manipulations have quantitatively assessed amphibian and reptile response to varying CWD volumes within forested environments. We assessed amphibian and reptile response to large-scale, CWD manipulation within managed loblolly pine stands in the southeastern Coastal Plain of the United States from 1998 to 2005. Our study consisted of two treatment phases: Phase I treatments included downed CWD removal (removal of all downed CWD), all CWD removal (removal of all downed and standing CWD), pre-treatment snag, and control; Phase II treatments included downed CWD addition (downed CWD volume increased 5-fold), snag addition (standing CWD volume increased 10-fold), all CWD removal (all CWD removed), and control. Amphibian and anuran capture rates were greater in control than all CWD removal plots during study Phase I. In Phase II, reptile diversity and richness were greater in downed CWD addition and all CWD removal than snag addition treatments. Capture rate of Rana sphenocephala was greater in all CWD removal treatment than downed CWD addition treatment. The dominant amphibian and snake species captured are adapted to burrowing in sandy soil or taking refuge under leaf litter. Amphibian and reptile species endemic to upland southeastern Coastal Plain pine forests may not have evolved to rely on CWD because the humid climate and short fire return interval have resulted in historically low volumes of CWD.

Physical and Biological Responses of Forests to Tropical Cyclones Affecting the United States Atlantic Ocean and Gulf of Mexico Coasts
About this Resource: Problem Statement: Natural resources within the southern United States have repeatedly been subjected to the impact of tropical cyclones. While the frequency of tropical cyclones hitting either coast varies from year to year, it is crucial for natural resource managers and land owners to be prepared for the damage resulting from such storms. The goal of this review paper is to synthesize previous research and assess how hurricanes impact coastal forests. Approach: In order to understand the impact on forests in this region, an extensive literature review was preformed. The literature review focused primarily on the southern United States’ forests but included information from other areas that was pertinent in understanding the impact of strong wind events on forests. Results: Although the literature is not entirely consistent in arriving at factors that can be used to describe or predict potential damage to forests, a number of trends were obvious. Forest damage was found to be a function of tree species, proximity to the eye of the hurricane, stand and site characteristics, species-specific responses to storm surges, and topographic exposure. Each of these factors was found to be critical in developing and understanding potential hurricane damage to forest and wildlife values. Conclusions/Recommendations: Such a review paper was found to be a valuable tool for informing natural resource managers and forest land owners of the potential impacts of hurricanes on the forest of the southern United States. This information will help land managers develop a response plan related to hurricane damage.

Soricid response to coarse woody debris manipulations in Coastal Plain loblolly pine forests
About this Resource: We assessed shrew (soricids) response to coarse woody debris (CWD) manipulations in managed upland loblolly pine (Pinus taeda) stands in the upper Coastal Plain of South Carolina over multiple years and seasons. Using a completely randomized block design, we assigned one of the following treatments to 12, 9.3-ha plots: removal (n =3; all CWD>=10cm in diameter and >=60cm long removed), downed (n =3; 5-fold increase in volume of down CWD), snag (n =3; 12-fold increase in standing dead CWD), and control (n =3; unmanipulated). Therein, we sampled shrews during winter, spring, and summer seasons, 2003-2005, using drift-fence pitfall arrays. During 1680 drift-fence plot nights we captured 253 Blarina carolinensis, 154 Sorex longirostris, and 51 Cryptotis parva. Blarina carolinensis capture rate was greater in control than in snag treatments. Sorex longirostris capture rate was lower in removal than downed and control plots in 2005 whereas C. parva capture rate did not differ among treatments. Overall, the CWD input treatments failed to elicit the positive soricid response we had expected. Lack of a positive response by soricid populations to our downed treatments may be attributable to the early CWD decay stage within these plots or an indication that within fire-adapted pine-dominated systems of the Southeast, reliance on CWD is less than in other forest types.

Fire history of white fir forests in the coastal mountains of northwestern California
About this Resource: Fire intervals are presented for white fir (Abies concolor var. lowiana) forests in the coastal mountains of northwestern California (USA). Fire dates and tree establishment dates were derived using dendrochronological analysis of stumps with fire scars from 28 logged sampling sites spread across an area approximately 125 km by 30 km. Pre-suppression median fire intervals ranged from 12 to 161 years. The median fire interval for the pre-suppression period (27 years) was significantly shorter than for the suppression period (74 years). There were no significant differences in median fire intervals among vegetation series. There were also no significant regressions of median fire interval with distance from the ocean, latitude, or elevation. Most sampling sites were multi-aged and had experienced multiple surface fires. Some sites had experienced stand-replacing fires. Fire suppression has increased stand density, increased the density of shade tolerant tree species, and decreased the density of shade intolerant tree species.

Western equatorial African forest-savanna mosaics: a legacy of late Holocene climatic change?
About this Resource: Past vegetation and climate changes reconstructed using two pollen records from Lakes Maridor and Nguène, Gabon, provide new insights into the environmental history of western equatorial African rainforests during the last 4500 cal yr BP. The Lake Maridor pollen record indicates that the coastal savannas of western equatorial Africa did not exist during the mid-Holocene and instead the region was covered by evergreen rainforests. In the Lake Nguène pollen record, a rapid decline of hygrophilous evergreen rainforest occurred around 4000 cal yr BP, synchronously with grassland expansion around Lake Maridor. The establishment of coastal savannas in Gabon suggests decreasing humidity at the onset of the late Holocene. The marked reduction in evergreen rainforest and subsequent savanna expansion was associated with the colonization of secondary forests dominated by the palm, &lt;i&gt;Elaeis guineensis&lt;/i&gt;, in the coastal region and the shrub, &lt;i&gt;Alchornea cordifolia&lt;/i&gt;, further inland. A return to wetter climatic conditions from about 1400 cal yr BP led to the renewed spread of evergreen rainforest inland, whereas a forest-savanna mosaic still persists in the coastal region. There is no evidence to suggest that the major environmental changes observed are driven by human impact.

Natural history and morphometry of the Cuban iguana (Cyclura nubila Gray, 1831) in Cayo Sijú, Cuba
About this Resource: Natural history and morphometry of the Cuban iguana (Cyclura nubila Gray, 1831) in Cayo Sijú, Cuba.— The report presents data about the Cuban iguana population (Cyclura nubila nubila) inhabiting Cayo Sijú, an 88 ha island off the southwest coast of Cuba. Population densities estimated using strip transects were higher in xerophytic coastal scrub (6.72 ± 6.25 iguanas/ha) than in typical sand vegetation (3.63 ± 2.71 iguanas/ha) and mangrove forests (2.9 ± 2.9 iguanas/ha). The total population for the cay was estimated at 350 individuals with an adult biomass of approximately 11.67 kg/ha. Densities varied minimally between three habitat types and between the wet and dry seasons. No significant density fluctuations were found one month after Hurricane Ivan affected the cay. Iguana burrows were encountered most frequently in beach dunes. Analysis of 30 scat samples revealed eight species of plants, with the fruits of Chrysobalanum icaco and the leaves of Batis maritima being the most frequently identified items. The remains of crab (Cardisoma guandhumi) and insects of the order Hemiptera were also present in scat samples. Sexual dimorphism was evident in this population, with males being significantly larger in eight morphological variables. The snout–vent length measurements were larger in this population than in those reported in two cays off the south coast of Cuba.

Land Cover in a Managed Forest Ecosystem: Mexican Shade Coffee
About this Resource: Managed forest ecosystems—agroforestry systems in which crops such as coffee and bananas are planted side-by-side with woody perennials—are being touted as a means of safeguarding forests along with the ecological services they provide. Yet we know little about the determinants of land cover in such systems, information needed to design effective forest conservation policies. This paper presents a firstever spatial regression analysis of land cover in a managed forest ecosystem—a shade coffee region of coastal Mexico. Using high-resolution land cover data derived from aerial photographs, along with data on the institutional, geophysical, socioeconomic, and agronomic characteristics of the study area, we find that plots in close proximity to urban centers are less likely to be cleared, all other things equal. This finding contrasts sharply with the literature on natural forests. In addition, we find that membership in coffee marketing cooperatives, farm size, and certain soil types are associated with forest cover, while common property, proximity to small town centers, and the prevalence of indigenous peoples are associated with forest clearing.

Migration Patterns of the Emerging Plant Pathogen Phytophthora ramorum on the West Coast of the United States of America
About this Resource: Phytophthora ramorum (oomycetes) is the causal agent of sudden oak death and ramorum blight on trees, shrubs, and woody ornamentals in the forests of coastal California and southwestern Oregon and in nurseries of California, Oregon, and Washington. In this study, we investigated the genetic structure of P. ramorum on the West Coast of the United States, focusing particularly on population differentiation potentially indicative of gene flow. In total, 576 isolates recovered from 2001 to 2005 were genotyped at 10 microsatellite loci. Our analyses of genetic diversity and inferences of reproductive mode confirm previous results for the Oregon and California populations, with the strong majority of the genotypes belonging to the NA1 clonal lineage and showing no evidence for sexual reproduction. The high incidence of genotypes shared among populations and the lack of genetic structure among populations show that important large-scale, interpopulation genetic exchanges have occurred. This emphasizes the importance of human activity in shaping the current structure of the P. ramorum population on the West Coast of the United States.

Evaluation of SWAT manual calibration and input parameter sensitivity in the Little River Watershed
About this Resource: The watershed-scale effects of agricultural conservation practices are not well understood. A baseline calibration and an input parameter sensitivity analysis were conducted for simulation of watershed-scale hydrology in the Little River Experimental Watershed (LREW) in the Coastal Plain near Tifton, Georgia. The Soil and Water Assessment Tool (SWAT) was manually calibrated to simulate the hydrologic budget components measured for the 16.9 km 2 subwatershed K of the LREW from 1995 to 2004. A local sensitivity analysis was performed on 16 input variables. The sum of squares of the differences between observed and simulated annual averages for baseflow, stormflow, evapotranspiration, and deep percolation was 19 mm 2 ; average annual precipitation was 1136 mm. The monthly Nash-Sutcliffe model efficiency (NSE) for total water yield (TWYLD) was 0.79 for the ten-year period. Daily NSE for TWYLD was 0.42. The monthly NSE for three years with above-average rainfall was 0.89, while monthly NSE was 0.59 for seven years with below annual average rainfall, indicating that SWAT's predictive capabilities are less well-suited for drier conditions. Monthly average TWYLD for the high-flow winter to early spring season was underpredicted, while the low-flow late summer to autumn TWYLD was overpredicted. Results were negatively influenced when seasonal tropical storms occurred during a dry year. The most sensitive parameters for TWYLD were curve number for crop land (CN2(crop)), soil available water content (SOL_AWC), and soil evaporation compensation factor (ESCO). The most sensitive parameters for stormflow were CN2(crop), curve number for forested land (CN2(forest)), soil bulk density (SOL_BD), and SOL_AWC. The most sensitive parameters for baseflow were CN2(crop), CN2(forest), ESCO, and SOL_AWC. Identification of the sensitive SWAT parameters in the LREW provides modelers in the Coastal Plain physiographic region with focus for SWAT calibration.

Litterfall in the hardwood forest of a minor alluvial-floodplain
About this Resource: Within mature deciduous forests, annual development of foliar biomass is a major component of aboveground net primary production and nutrient demand. As litterfall, this same foliage becomes a dominant annual transfer of biomass and nutrients to the detritus pathway. We report litterfall transfers of a mature bottomland hardwood forest in a minor alluvial-floodplain within the middle Coastal Plain physiographic province of central Louisiana, USA. Climate is humid subtropical. Floodplain forests of minor alluvial-streams may account for nearly half the remaining acreage of bottomland forests in the Southeastern USA and differ markedly from those of major alluvial-rivers and deep-water swamps. For a 3-year period, litterfall magnitude, components, leaf species, and timing were monitored by monthly collection of materials from litterfall collectors. Variations in litterfall transfers across 10 study-plots and their relationships to forest parameters are evaluated. Mean transfers of total litterfall, leaf fall, reproductive structures, fine wood, and other litterfall were 816, 512, 130, 98, and 76 g m-2 year-1, respectively. Quercus pagoda Raf., Q. nigra L., and Liquidambar styraciflua L. accounted for an average of 49% of annual leaf fall, with 11 tree species and canopy vines accounting for 94% of total annual leaf fall. A total of 38 species and genera contributed to total leaf fall. Variation in total litterfall and leaf fall transfers across the alluvial bottom were related to size of overstory trees and their species composition. Higher and more consistent mass transfers of reproductive structures were observed than previously reported for upland hardwood stands.

Effect of Forest Site Preparation and Livestock Grazing on Stormflow and Water Quality in the South East
About this Resource: The commercial forestlands of East Texas and Louisiana are the most water-efficient producing areas of the two states. Current and projected water shortages for Texas makes this water-rich area extremely important to future growth and development of Texas. However, little is known about the influence of intensive forest practices or livestock grazing on water quality, yield or site productivity in Texas. This is the only instrumented watershed study in Texas or Louisiana that is currently evaluating the influence of livestock grazing on water and the second study evaluating the impact of intensive forest practices on water. This research is providing information that will enable forest managers, state and federal agencies to select livestock grazing and/or forest management practices that will maintain a productive forest environment and minimize off-site water quality impacts. It is imperative that if Texas in the next 30 years is: 1) to help meet the timber product demand that is projected to be placed on the Southeast, and 2) to meet the projected water shortages we need to understand the impact of intensive forest and livestock grazing practices on site productivity and water. This research is helping provide the basic information needed to manage Southeast forestlands for timber products, red meat and water. The southern states are currently producing half of the nation's wood supply with large demands to increase timber production expected in the next 20 years. The challenge facing forestry in the South is in developing technology and management to meet this increased demand and maintain an acceptable forest environment in the face of increased taxes, rising labor, equipment and energy costs. The intensive forest management practices of harvesting and site preparation have been identified as causing potential declines in site production and as sources of nonpoint pollution. The Clean Water Act (PL 92-500 and PL 95-217) requires identification and control of silvicultural activities and livestock grazing which contribute to nonpoint source pollution. Implementation of "best management practices", either voluntary or mandatory, are the suggested means for maintaining water quality and site productivity. Hydrologic impacts of livestock grazing result primarily from the interactions of climate, vegetation, soil, and intensity and duration of livestock use. Thus, grazing impacts will vary naturally from area to area due to the normal variability of these factors. Few studies have attempted to account for these natural variations. Documentation of the intensity and duration of livestock grazing has been poor or completely ignored in most studies. In East Texas, the impact of livestock grazing on water quality has had no research effort. Most research regarding the impact of grazing upon water quality has been conducted outside the Southern Region and, more importantly, outside of the Gulf Coastal Plains. Because geology, soils , topography, climate, etc. are different, extensions of that research to the East Texas and Louisiana areas may be misleading.

COMPARATIVE ECOLOGY OF THE INVASIVE RUBUS PHOENICOLASIUS AND THE NATIVE RUBUS ARGUTUS
About this Resource: Invasive species are one of the most significant factors in human influenced global change. Management actions that prevent the spread and impacts of invasive species require knowledge of their ecological characteristics. The characteristics of the invasive wine raspberry (Rubus phoenicolasius Maxim.) and the native sawtooth blackberry (Rubus argutus Link) were examined in two forest habitats on the Maryland Coastal Plain. The invasive had greater negative effects on a common herbaceous plant (Duchesnea indica Andr. Focke) than the native. The invasive, R. phoenicolasius had higher leaf nitrogen concentrations (Nleaf), greater specific leaf areas (SLA) and higher maximal rates of photosynthesis (Amax) for a given dark respiration rate (Rd) than R. argutus. R. phoenicolasius depended less upon pollinators for fruit development and had higher fruiting rates with more seeds per fruit than the native species. In addition, seeds of R. phoenicolasius had higher germination rates. Survival of invasive seedlings was negatively affected by leaf litter additions, but seedling growth was not negatively influenced by shading. R. phoenicolasius seedlings grown in a greenhouse and inoculated with arbuscular mycorrhizal fungi produced less biomass than seedlings that were not inoculated. The distribution of R. phoenicolasius may be affected by leaf litter, but presence of AMF is probably not necessary for seedling success. A three year demographic study showed that both species were negatively impacted by drought, but the invasive recovered faster than the native species in the higher light forest. Overall, results of these studies indicate that the invasive R. phoenicolasius was more likely to competitively exclude understory herbs which can coexist with the native R. argutus. The ability of R. phoenicolasius to adapt physiologically to different light levels helps explain its ability to form dense populations under varying environmental conditions. The combination of high fruit production, plasticity and lower mortality in high light habitats is in agreement with previous studies on invasive species. The combined characteristics demonstrated by R. phoenicolasius allow this invader to spread, expand and persist in mid-successional forests in the Coastal Plain of Maryland.

Interactions among vegetation and ozone, water and nitrogen fluxes in a coastal Mediterranean maquis ecosystem
About this Resource: Ozone, water and energy fluxes were measured over a Mediterranean maquis ecosystem from 5 May until 31 July 2007 by means of the eddy covariance technique. Additional measurements of NO&lt;sub&gt;x&lt;/sub&gt; fluxes were performed by the aerodynamic gradient technique. Stomatal ozone fluxes were obtained from water fluxes by a Dry Deposition Inferential Method based on a big leaf concept. &lt;br&gt;&lt;br&gt; The maquis ecosystem acted as a net sink for ozone. The different water availability between late spring and summer was the major cause of the changes observed in stomatal fluxes, which decreased, together with evapotranspiration, when the season became drier. &lt;br&gt;&lt;br&gt; NO&lt;sub&gt;x&lt;/sub&gt; concentrations were significantly dependent on the local meteorology. NO&lt;sub&gt;x&lt;/sub&gt; fluxes resulted less intense than the ozone fluxes. However an average upward flux of both NO and NO&lt;sub&gt;2&lt;/sub&gt; was measured. &lt;br&gt;&lt;br&gt; The non-stomatal pathways of ozone deposition were investigated. A correlation of non-stomatal deposition with air humidity and, in a minor way, with NO&lt;sub&gt;2&lt;/sub&gt; fluxes was found. &lt;br&gt;&lt;br&gt; Ozone risk assessment was performed by comparing the exposure and the dose metrics: AOT40 (Accumulated dose over a threshold of 40 ppb) and AF&lt;sub&gt;&lt;i&gt;st&lt;/i&gt;&lt;/sub&gt;1.6 (Accumulated stomatal flux of ozone over a threshold of 1.6 nmol m&lt;sup&gt;&minus;2&lt;/sup&gt; s&lt;sup&gt;&minus;1&lt;/sup&gt;). AOT40, both at the measurement height and at canopy height was greater than the Critical Level for the protection of forests and semi-natural vegetation (5000 ppb h) adopted by UN-ECE. Also the AF&lt;sub&gt;&lt;i&gt;st&lt;/i&gt;&lt;/sub&gt;1.6 value (12.6 mmol m&lt;sup&gt;&minus;2&lt;/sup&gt; PLA, Projected Leaf Area) was higher than the provisional critical dose of 4 mmol m&lt;sup&gt;&minus;2&lt;/sup&gt; PLA for forests. The cumulated dose showed two different growth rates in the spring and in the summer periods, while the exposure showed a more irregular behavior in both periods.

Nitrogen uptake in riparian plant communities across a sharp ecological boundary of salmon density
About this Resource: Abstract Background Recent studies of anadromous salmon (Oncorhynchus spp.) on the Pacific Coast of North America indicate an important and previously unrecognized role of salmonid nutrients to terrestrial biota. However, the extent of this uptake by primary producers and consumers and the influences on community structure remain poorly described. We examine here the contribution of salmon nutrients to multiple taxa of riparian vegetation (Blechnum spicant, Menziesii ferruginea, Oplopanax horridus, Rubus spectabilis, Vaccinium alaskaense, V. parvifolium, Tsuga heterophylla) and measure foliar &#948;15N, total %N and plant community structure at two geographically separated watersheds in coastal British Columbia. To reduce potentially confounding effects of precipitation, substrate and other abiotic variables, we made comparisons across a sharp ecological boundary of salmon density that resulted from a waterfall barrier to salmon migration. Results &#948;15N and %N in foliage, and %cover of soil nitrogen indicators differed across the waterfall barrier to salmon at each watershed. &#948;15N values were enriched by 1.4&#8240; to 9.0&#8240; below the falls depending on species and watershed, providing a relative contribution of marine-derived nitrogen (MDN) to vegetation of 10% to 60%. %N in foliar tissues was slightly higher below the falls, with the majority of variance occurring between vegetation species. Community structure also differed with higher incidence of nitrogen-rich soil indicator species below the waterfalls. Conclusions Measures of &#948;15N, %N and vegetation cover indicate a consistent difference in the riparian community across a sharp ecological boundary of salmon density. The additional N source that salmon provide to nitrogen-limited habitats appears to have significant impacts on the N budget of riparian vegetation, which may increase primary productivity, and result in community shifts between sites with and without salmon access. This, in turn, may have cascading ecosystem effects in forests adjacent to salmon streams.

The arid and dry plant formations of south America and their floristic connections: new data, new interpretation?
About this Resource: In this study we aimed at testing two hypothesis about the biogeography of South America: (1) the existence of a marked discontinuity in the Andes of central Peru that separates the floras of northern and southern South America and (2) the occurrence of a more or less continuous semi-deciduous forest in South America during the Pleistocene. We conducted a search for different sources of published information on the flora (inventories) of 19 dry regions in South America as well as one region in Central America and another in North America. In order to analyze the data, we employed ordination and classification techniques, which give a more objective picture of the phytogeographical relationships. Additionally, we evaluated similarity scores between the regions. We found 1,421 woody and herbaceous genera for the 21 regions. These regions form two groups: one mostly in northern South America and the other one restricted to the southern half of the hemisphere. Within the latter, further subdivisions are discernible. Almost all the northern group is made up of tall, deciduous and semi-deciduous forest types. The southern group regions mainly range from very dry forests to desert scrub. Our results support the existence of a floristic discontinuity in relation to the drier flora of the Andes. The southern flora (from southern Peru to northern Argentina and Chile) constitutes a floristic group quite different from that of northern South America. The Chaco region, although more floristically related to the southern group, seems to constitute the connecting link between these northern and southern floras. Within the flora of southern South America, the coastal desert seems to be the connection between hot and cold semi-deserts. Our data also support the hypothesis of the existence of pleistocenic lowland forests in most parts of South America which, however, probably extended up to Mexico.

Fish communities in coastal freshwater ecosystems: the role of the physical and chemical setting
About this Resource: Abstract Background We explored how embayment watershed inputs, morphometry, and hydrology influence fish community structure among eight embayments located along the southeastern shoreline of Lake Ontario, New York, USA. Embayments differed in surface area and depth, varied in their connections to Lake Ontario and their watersheds, and drained watersheds representing a gradient of agricultural to forested land use. Results We related various physicochemical factors, including total phosphorus load, embayment area, and submerged vegetation, to differences in fish species diversity and community relative abundance, biomass, and size structure both among and within embayments. Yellow perch (Perca flavescens) and centrarchids numerically dominated most embayment fish communities. Biomass was dominated by piscivorous fishes including brown bullhead (Ameiurus nebulosus), bowfin (Amia calva), and northern pike (Esox lucius). Phosphorus loading influenced relative biomass, but not species diversity or relative abundance. Fish relative abundance differed among embayments; within embayments, fish abundance at individual sampling stations increased significantly with submerged vegetative cover. Relative biomass differed among embayments and was positively related to total phophorus loading and embayment area. Fish community size structure, based on size spectra analysis, differed among embayments, with the frequency of smaller-bodied fishes positively related to percent vegetation. Conclusion The importance of total phosphorus loading and vegetation in structuring fish communities has implications for anthropogenic impacts to embayment fish communities through activities such as farming and residential development, reduction of cultural eutrophication, and shoreline development and maintenance.

Hydrodynamical, hydrochemical and isotopic characterization of the Kourimat aquifer system (Essaouira basin, Morocco)
About this Resource: The synclinal basin of Kourimat, subdivided in two sub-basins (Igounzar in the North, and Zeltene in the South), is situated in the oriental part of Essaouira basin shelters a carbonate aquifer system contained in the limestones and dolomitic limestones of the Cenomanian and the Turonian. These ground waters represent the only drinking water and irrigation resource for the region.The geological formations outcropping in the studied area, start with the clay and marly formations of the terminal Jurassic in the south of Zelten watershed, and end with the sandy and loamy Quaternary formations in coastal areas in the Low Qsob watershed. The Middle and Upper Cretaceous (marl, fractured limestone, and dolomites) represent the rest of the stratigraphic series especially in the areas of the Igrounzar watershed (up to 85% of the outcrops) and in Zelten (up to 50%).The field occupation is not very significant. It basically consists of three types: 1) cultures (essentially cereals) where it is possible (on the marly soils of the Cretaceous, the Quaternary and the Eocene); 2) uncovered areas corresponding to the fissured and karstic limestone outcrops of the Cretaceous and the Jurassic formations, and 3) forests (coniferous trees) in the downstream part of the catchments area (Plio-quaternary soils and mountainous reinforcements of the Western High Atlas). Like for other undeveloped areas of Morocco, the Meskala basin is also subjected to an intensive deforestation (wood for heating and cooking).The study undertaken on the Cenomano-turonian aquifer has allowed us to characterize it from the hydrodynamical, hydrogeological and hydrogeochemical point of view. The piezometric map of the two regrouped aquifer levels shows water flow senses from the SE to the NW. The hydraulic gradient varies from upstream to downstream, being weak n the central zone relative to the best hydrodynamic characteristics. The time evolution of the piezometry shows annual and seasonal fluctuations in connection with the variations of precipitations. Hydrodynamic characteristics have been calculated by means of the interpretation of data of pumping tests, performed in the region by the General Hydraulic Administration of Morocco.On the hydrochemical point of view, results of chemical analyses have allowed us to determine the chemical facies of waters of the two aquifers, their interaction and their quality for the human consumption and their use in agriculture.To better understand the functioning modalities of the Meskala-Kourimat aquifer system, an isotopic study has been performed that showed the variations relative to the altitude of the recharge zones of the different channels. The altitudinal gradient in O18, estimated to 0,25&#226;&#128;&#176; every 100 m confirms the validity of this result at a regional scale. The oxyg&#232;ne-18/deut&#233;rium relationship (&#206;&#180;2H = 7,74*(&#206;&#180;18O) + 10,83) indicates an Atlantic system of the precipitation without evaporation. This suggests a quick infiltration, also confirmed by the importance of the fracturation developed in limestones and dolomitic limestones of the Cenomano-turonian aquifer of Meskala-Kourimat.La cuvette synclinale de Kourimat comprenant deux sous bassins celui de Zelt&#232;ne et d&#226;&#128;&#153;Igrounzar, est situ&#233;e dans la partie orientale du bassin d&#226;&#128;&#153;Essaouira, abrite un syst&#232;me aquif&#232;re carbonat&#233;, repr&#233;sent&#233; par les calcaires du C&#233;nomanien et les calcaires dolomitiques du Turonien. Les eaux de cet aquif&#232;re constituent l&#226;&#128;&#153;unique ressource pour la r&#233;gion tant pour l&#226;&#128;&#153;alimentation en eau potable que pour l&#226;&#128;&#153;irrigation.Le Jurassique plus pr&#233;pond&#233;rant dans le sous bassin du Zelt&#232;ne est caract&#233;ris&#233; par une dominance des formations plut&#244;t &#233;tanches (marnes argiles rouges, etc.). Les formations carbonat&#233;es du Cr&#233;tac&#233;, d&#226;&#128;&#153;extension spatiale fort dominante, repr&#233;sentent &#224; peu pr&#232;s de 50% de la superficie du Zelt&#232;ne et presque 85% de celle d&#226;&#128;&#153;Igrounzar. Il s&#226;&#128;&#153;agit de calcaires dolomitiques, calcaires marneux et de marno-calcaires et marnes calcaires tr&#232;s fractur&#233;s &#224; karstqiques. L&#226;&#128;&#153;occupation des sols est assez sommaire. Elle se r&#233;sume en gros &#224; trois types de couverts : 1) des cultures (c&#233;r&#233;aliculture) sur les terrains marneux d&#226;&#128;&#153;age cr&#233;tac&#233;, sur le Plio-Quaternaire et l&#226;&#128;&#153;Eoc&#232;ne ; 2) des terrains nus correspondant aux affleurements des dalles calcaires fissur&#233;es et karstiques du Cr&#233;tac&#233; et aux formations jurassiques, et 3) des for&#234;ts (r&#233;sineux) dans la partie aval du bassin versant sur les terrains d&#226;&#128;&#153;age plio-quaternaire et sur les renforts montagneux du Haut Atlas Occidental. A l&#226;&#128;&#153;instar de toutes les r&#233;gions d&#233;favoris&#233;es du Royaume, le bassin du Qsob est lui aussi soumis &#224; un d&#233;boisement intensif (bois de chauffe et de cuisson).L&#226;&#128;&#153;apport de cet article a permis de caract&#233;riser l&#226;&#128;&#153;aquif&#232;re C&#233;nomano-turonien du point de vue hydrodynamique, hydrog&#233;ologique et hydrog&#233;ochimique. La carte pi&#233;zom&#233;trique repr&#233;sentant deux niveaux aquif&#232;res regroup&#233;s montre un sens d&#226;&#128;&#153;&#233;coulement des eaux souterraines du sud-est vers le nord-ouest. Le gradient hydraulique varie de l&#226;&#128;&#153;amont vers l&#226;&#128;&#153;aval ; il est faible dans la zone centrale en relation avec de meilleures caract&#233;ristiques hydrodynamiques. L&#226;&#128;&#153;&#233;volution de la pi&#233;zom&#233;trie dans le temps montre des fluctuations interannuelles et saisonni&#232;res en relation avec les variations pluviom&#233;triques. Les caract&#233;ristiques hydrodynamiques ont &#233;t&#233; calcul&#233;es par le biais de l&#226;&#128;&#153;interpr&#233;tation des donn&#233;es des pompages d&#226;&#128;&#153;essais, r&#233;alis&#233;s dans la r&#233;gion par l&#226;&#128;&#153;Agence G&#233;n&#233;rale de l&#226;&#128;&#153;Hydraulique.Sur le plan hydrochimique, les r&#233;sultats des analyses physico-chimiques ont permis de d&#233;terminer les faci&#232;s chimiques des eaux des deux nappes, leur interaction et leur qualit&#233; pour la consommation humaine et l&#226;&#128;&#153;utilisation en agriculture.Pour mieux comprendre les modalit&#233;s de fonctionnement du syst&#232;me aquif&#232;re de Meskala-Kourimat, l&#226;&#128;&#153;&#233;tude isotopique entreprise a montr&#233; la variation des teneurs en O18 des points d&#226;&#128;&#153;eau avec l&#226;&#128;&#153;altitude des zones de recharge des diff&#233;rents exutoires. Le gradient altitudinal en O18, estim&#233; &#224; 0,25&#226;&#128;&#176; par 100 m confirme par ailleurs la validit&#233; r&#233;gionale de celui-ci par d&#226;&#128;&#153;autres auteurs. La relation oxyg&#232;ne-18/deut&#233;rium &#206;&#180;2H = 7,74*(&#206;&#180;18O) + 10,83 traduit un r&#233;gime atlantique des pr&#233;cipitation sans &#233;vaporation qui sugg&#232;re une infiltration rapide, confirm&#233;e &#233;galement par l&#226;&#128;&#153;importante fracturation des calcaires et calcaires dolomitiques de l&#226;&#128;&#153;aquif&#232;re c&#233;nomano-turonien de Meskala-Kourimat.

Spatio-Temporal Analysis of Xyleborus glabratus (Coleoptera: Circulionidae: Scolytinae) Invasion in Eastern U.S. Forests
About this Resource: The non-native redbay ambrosia beetle, Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae: Scolytinae), has recently emerged as a significant pest of southeastern U.S. coastal forests. Specifically, a fungal symbiont (Raffaelea sp.) of X. glabratus has caused mortality of redbay (Persea borbonia) and sassafras (Sassafras albidum) trees in the region; several other Lauraceae species also seem susceptible. Although the range of X. glabratus continues to expand rapidly, little is known about the species' biology and behavior. In turn, there has been no broad-scale assessment of the threat it poses to eastern U.S. forests. To provide a basic information framework, we performed analyses exploiting relevant spatio-temporal data available for X. glabratus. First, we mapped the densities of redbay and sassafras from forest inventory data. Second, we used climate matching to delineate potential geographic limits for X. glabratus. Third, we used county infestation data to estimate the rate of spread and modeled spread through time, incorporating host density as a weighting factor. Our results suggest that (1) key areas with high concentrations of redbay have yet to be invaded, but some are immediately threatened; (2) climatic conditions may serve to constrain X. glabratus to the southeastern U.S. coastal region; and (3) if unchecked, X. glabratus may spread throughout the range of redbay in <40 yr. Disruption of anthropogenic, long-distance dispersal could reduce the likelihood of this outcome.

Survival and growth of 31 Populus clones in South Carolina
About this Resource: Populus species and hybrids have many practical applications, but clonal performance is relatively undocumented in the southeastern United States outside of the Mississippi River alluvial floodplain. In spring 2001, 31 Populus clones were planted on two sites in South Carolina, USA. The sandy, upland site received irrigation and fertilization throughout the growing season, while the bottomland site received granular fertilizer yearly and irrigation in the first two years only. Over three growing seasons, tree survival and growth differed significantly among clones at both sites. Hybrid clones I45/51, Eridano, and NM6 had very high survival at both sites, while pure eastern cottonwood (P. deltoides) clones consistently had the lowest survival. Nearly all mortality occurred during the first year. The P. deltoides clone WV416 grew well at both sites, P. deltoides clones S13C20 and Kentucky 8 grew well at the bottomland site, and hybrids 184-411 and 52-225 grew well at the upland site. Based on both survival and growth, clones 311-93, S7C15, 184-411, and WV416 may warrant additional testing in the upper coastal plain region of the southeastern US. Kentucky 8 and S13C20 had excellent growth rates, but initial survival was low. However, this was likely due to planting stock quality. We emphasize this is preliminary information, and that clones should be followed through an entire rotation before large-scale deployment.

Composição florística e estrutura do componente epifítico vascular em floresta da planície litorânea na Ilha do Mel, Paraná, Brasil
About this Resource: O estudo das epífitas vasculares foi realizado em uma área de 3.000 m² de floresta na planície litorânea na Ilha do Mel (25°30? S 48°23? W); o levantamento qualitativo foi realizado em toda a área; para o estudo quantitativo, foram sorteados 100 forófitos, divididos em intervalos de 2 m a partir do solo. Em cada intervalo, registraram-se todas as espécies epifíticas ocorrentes, sendo estimado o valor de importância epifítico a partir das freqüências nos estratos, nos forófitos e nas espécies forofíticas. No levantamento total, foram encontradas 77 espécies (16 de Pteridophyta, 53 de Liliopsida e 8 de Magnoliopsida), das quais 70 foram amostradas nos forófitos analisados. As famílias mais ricas foram Orchidaceae, Bromeliaceae e Polypodiaceae e os gêneros foram Vriesea, Encyclia e Maxillaria. A área com maior similaridade florística com este estudo localiza-se no Município de Torres (RS). As espécies mais importantes quantitativamente foram Microgramma vaccinifolia, Codonanthe gracilis, Epidendrum latilabre e E. rigidum. As espécies amostradas foram agrupadas em três categorias quanto à preferência por intervalos de altura: exclusivas, preferenciais e indiferentes. O número de ocorrências de epífitos em um mesmo forófito variou de 1 a 35, enquanto o número de espécies variou de 1 a 21 (médias 14 ± 7,6 e 10 ± 4,6, respectivamente). Os primeiros estratos (0-2 m, 2-4 m e 4-6 m) foram os mais ricos em espécies epifíticas. As espécies forofíticas com maior número de ocorrências foram Andira fraxinifolia e Ternstroemia brasiliensis, e com maior número de espécies Ocotea pulchella e Guapira opposita. Quanto à fidelidade sobre espécies forofíticas, foram encontradas espécies epifíticas exclusivas, preferenciais e generalistas, esta incluindo a maioria das espécies amostradas.

Tree Species Survival in the Homestead Forests of Salt Affected Areas: A Perception Analysis for Bangladesh
About this Resource: One of the major problems in the coastal zone of developing countries is salinity intrusion. It is increasing in those countries due to natural and anthropogenic reasons. Soil salinity is causing decline in soil productivity and crop yield, which result in severe degradation of bio-environment and ecology. The effect of salinity on the agriculture crop is well understood even in developing countries but the effect on ecology is less explored. So in Bangladesh a perception analysis has been made on the effect of soil salinity on the homestead gardens of the worst salinity affected district Satkhira (21°36`-22°54` N and 88 ° 54`-89 ° 20` E). It has been found that the people have recognized salinity as a problem and construction of shrimp enclosures and maritime influence as the main reasons. Salinity increase results in reduction of crop production (2.50% per year), tree growth (2% per year) and vegetation coverage (1.87% per year). Tree species are disappearing due to salinity (three main species are Swietenia macrophylla King>Achras zapota Linn.>Spondias pinnata (Linn. f.) Kurz). The remaining trees are affected by diseases, like, top dying, leaf shedding and root rot. The main salt tolerant species are Acacia nilotica (Linn.) Willd. ex Del., Cocos nucifera Linn. and Phoenix sylvestris Roxb.

Root dynamics in bottomland hardwood forests of the Southeastern United States Coastal Plain
About this Resource: Effects of flooding on root dynamics appear nonlinear and therefore difficult to predict, leading to disparate and often contradictory reports of flooding impacts on production in bottomland hardwood forests. We explored root dynamics in two adjacent wetland habitats by comparing results obtained from several methods of estimating root processes. Also, we tested the influence of flooding on root dynamics of cherrybark, overcup, water and swamp chestnut oaks. Fine root biomass in the laurel oak habitat was greater (α< 0.05) than in the swamp tupelo habitat (5.7 vs. 2.4 Mg ha-1), as was fine root necromass (2.4 vs. 1.3 Mg ha-1), productivity (2.3 vs. 0.3 Mg ha-1 yr-1 when the sum of significant increments method was used, 5.6 vs. 2.5 Mg ha -1 yr-1 when the maximum minus minimum method was used, and 1.2 vs. 1.0 Mg ha-1 yr -1, when the root screen method was used), and turnover (40% and 12% per year). Mortality estimates were lower in the laurel oak habitat (1.3 and 1.2 Mg ha-1 yr-1) than in the swamp tupelo community (2.8 and 2.1 Mg ha-1 yr-1) when significant increment and maximum minus minimum methods were used, respectively. This apparent contradiction between estimates of production and mortality may be due to more rapid decomposition rates in the more aerated soil of the laurel oak than in the swamp tupelo forest type. Roots in the swamp tupelo habitat appeared to be longer-lived than in the laurel oak habitat. We concluded that there was greater investment in roots in the laurel oak habitat, where a shallow rooting zone and episodes of flooding and drought required drastic changes in root structure and physiology. In contrast, the swamp tupelo habitat had a deeper rooting zone and more consistently moist to flooded hydroperiod, allowing flood adapted roots to persist. The four oak species varied in their phenology of root production and response to flooding, from no difference among treatments for overcup oak to dramatic reductions in root growth during and after flooding for cherrybark oak. Flooding enhanced or at least did not negatively influence root growth in overcup oak, but seriously impacted root growth and survival of cherrybark oak and swamp chestnut oak. Different responses were attributed to the timing of root production: root growth began early for cherrybark oak so spring flooding severely affected this species. Growth in overcup oak began later and ended earlier than the other species tested, allowing the species a means of avoiding flood stress.