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Browse subject: montane forests
Number of records: 46

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.

Evaluation of site impacts associated with three silvicultural prescriptions in an upland hardwood stand in northern Alabama, USA
About this Resource: Soil disturbance patterns and associated changes in soil physical status were measured in a study that evaluated the implementation of three alternative management prescriptions in an upland hardwood stand in northern Alabama, USA. Management prescriptions applied in this study consisted of a clear-cut, strip cut, and deferment cut that were compared to a non-harvested control. Final tabulations of disturbance types indicated disturbance to be similar in clear-cut and deferment cut treatments with less disturbance in strip cut sites. Soil physical response varied by soil property but, in general, as disturbance intensity increased, soil physical properties responded accordingly. Bulk densities were elevated to the highest degree in the clear-cut sites while soil strength as indicated by cone index measurements attained its highest levels in the deferment cut. These differences were thought to be due to differences in trafficking patterns related to the implementation of each management prescription.

Holocene records of Dendroctonus bark beetles in high elevation pine forests of Idaho and Montana, USA
About this Resource: Paleoecological reconstructions from two lakes in the U.S. northern Rocky Mountain region of Idaho and Montana revealed the presence of bark beetle elytra and head capsules (cf. Dendroctonus spp., most likely D. ponderosae, mountain pine beetle). Occurrence of these macrofossils during the period of time associated with the 1920/1930 a.d. mountain pine beetle outbreak at Baker Lake, Montana suggest that when beetle populations reach epidemic levels, beetle remains may be found in the lake sediments. In addition to the beetle remains found at Baker Lake during the 20th century, remains were also identified from ca. 8331, 8410, and 8529 cal yr BP. At Hoodoo Lake, Idaho remains were found at ca. 7954 and 8163 cal yr BP. These Holocene records suggest the infestations occurred during a period when climate changed rapidly to cooler and effectively wetter than present in forests dominated by whitebark pine. These two lake records provide the first preliminary data for understanding the long-term history of climatic influences on Dendroctonus bark beetle activity, which may be useful for predicting climate and stand conditions when mountain pine beetle activity occurs.

Long-term development of above- and below-ground carbon stocks following land-use change in subalpine ecosystems of the Swiss National Park
About this Resource: Vegetation changes following agricultural land abandonment at high elevation --- which is frequent in Europe --- could have a major impact on carbon (C) sequestration. However, most information on the effects of vegetation changes on ecosystem C stocks originates from low-elevation studies on reforestation or early successional forests, and little is known about how these stocks change during long-term secondary forest succession and at high elevation. We assessed aboveground, belowground, and ecosystem organic matter and C stocks in high-elevation ecosystems that represent the long-term development (centuries) following land abandonment: short- and tall-grass pastures, Swiss mountain pine (Pinus mugo Turra), mixed-conifer, and Swiss stone pine (Pinus cembra L.) -- European larch (Larix decidua P. Mill.) forests. Aboveground C stocks were lowest in the short-grass pastures (0.1 Mg C·ha-1) and reached a maximum in the mixed-conifer and stone pine - larch forests (166 Mg C·ha-1). Belowground C stocks did not differ among the ecosystems studied. We only detected ecosystem C sequestration during reforestation; whereas no significant differences in ecosystem C stocks were found during long-term secondary forest development. Our calculations showed that only an additional 1733-3032 Mg C·year-1 would be sequestered owing to natural reforestation in high-elevation Switzerland, which likely can be considered negligible compared with total annual C sequestration calculated for Swiss forests in other studies.

Historical fires in Douglas-fir dominated riparian forests of the southern Cascades, Oregon
About this Resource: Despite the ecological importance of fire in Pacific Northwest forests, its role in riparian forests is just beginning to be documented. This study reconstructed the historical occurrence of fire within riparian forests along different stream sizes in coast Douglas-fir (Pseudotsuga menziesii var. menziesii [Mirbel] Franco) dominated forests within the drier western hemlock (Tsuga heterophylla [Raf.] Sarg.) forest series of the Upper Steamboat Creek watershed of the Umpqua National Forest, Oregon. Fire dates were determined from a total of 194 firescarred wedges from stumps sampled at 15 riparian and 13 upslope one-hectare plots. Fire was common historically in both the riparian zones and upslope forests of this study area. Riparian Weibull median probability fire return intervals (WMPIs) were somewhat longer (ranging from 35-39 years, with fire return intervals ranging from 4-167 years) than upslope WMPIs (ranging from 27-36 years, with fire return intervals ranging from 2-110 years), but these differences were not significant. Fires were probably mixed in severity and likely patchy, considering the high incidence of fires occurring only at a riparian plot or only at an upslope plot within a pair, but not at both. Finally, fire return intervals showed a non-significant trend of decreasing length from west to east to north aspects. An increased sampling effort may have shown this decrease to be significant. Based on the results from this study, it is evident that restoring fire will be necessary to protect riparian forest health in this study area. Historical recruitment of large woody debris was likely patchy and pulsed for these mixed-severity fire regime forests.

Carbon exchange and venting anomalies in an upland deciduous forest in northern Wisconsin, USA
About this Resource: Turbulent fluxes of carbon, water vapor, and temperature were continuously measured above an upland forest in north central Wisconsin during 1999 and 2000 using the eddy covariance method. Maple (Acer saccharum), basswood (Tilia americana), and green ash (Fraxinus pennsylvanica) species found in this forest also comprise a substantial portion of the landscape in the northern Great Lakes region and area, and it has been hypothesized that forests of this age (60-80 years) are responsible for net uptake of atmospheric CO2 over North America. Mean CO2, water vapor, and temperature profile measurements were used to improve flux estimates during periods of low turbulence, and were effective for friction velocities (u*) >0.3 m s-1. Unique observations at this site included nighttime and early morning venting anomalies that seemed to originate from a seemingly homogenous area within the forest. These elevated NEE measurements, some as high as 80 mol m-2 s-1, appeared in valid turbulent flux observations for hours at a time, and provided circumstantial evidence for preferential venting and/or existence of pooled CO2 in low-lying areas. We observed that the forest was a moderate sink for atmospheric carbon, and cumulative NEE of CO2 was estimated to be -334 g C m-2 year-1 during 2000. Sensitivity to low-turbulence flux corrections was very small (21 g C m-2 year-1), and discrepancies between annual estimates of NEE and NEP were similar to other sites. A normalized measure of ecosystem respiration, the free energy of activation, was presented and its seasonal variations were analyzed. Gross ecosystem production (GEP) was high (1165 g C m-2 year-1) and ecosystem respiration (ER) was low (817 g C m-2 year-1) in comparison to spatially integrated, landscape-scale observations from WLEF (914 and 1005 g C m-2 yea-1, respectively), a 477 m tower located 22 km to the northeast [Glob. Change Biol. 9 (2003) 1278]. Forest transpiration was responsible for most of the water released to the atmosphere. Stomata closed under intense sunlight and high vapor pressure deficits (VPD > 1.5 kPa). Effect of stomotal closure on annual CO2 uptake was minimal due to adequate soil moisture and moderate VPD during the growing season.

Invasive plants transform the three-dimensional structure of rain forests
About this Resource: Biological invasions contribute to global environmental change, but the dynamics and consequences of most invasions are difficult to assess at regional scales. We deployed an airborne remote sensing system that mapped the location and impacts of five highly invasive plant species across 221,875 ha of Hawaiian ecosystems, identifying four distinct ways that these species transform the three-dimensional (3D) structure of native rain forests. In lowland to montane forests, three invasive tree species replace native midcanopy and understory plants, whereas one understory invader excludes native species at the ground level. A fifth invasive nitrogen-fixing tree, in combination with a midcanopy alien tree, replaces native plants at all canopy levels in lowland forests. We conclude that this diverse array of alien plant species, each representing a different growth form or functional type, is changing the fundamental 3D structure of native Hawaiian rain forests. Our work also demonstrates how an airborne mapping strategy can identify and track the spread of certain invasive plant species, determine ecological consequences of their proliferation, and provide detailed geographic information to conservation and management efforts.

Dynamics of wood in stream networks of the western Cascades Range, Oregon
About this Resource: We develop and test a conceptual model of wood dynamics in stream networks that considers legacies of forest management practices, floods, and debris flows. We combine an observational study of wood in 25 km of 2nd- through 5th-order streams in a steep, forested watershed of the western Cascade Range of Oregon with whole-network studies of forest cutting, roads, and geomorphic processes over the preceding 50 years. Statistical and simple mass balance analyses show that natural process and forest management effects on wood input, transport processes, and decomposition account for observed patterns of wood in the stream network. Forest practices reduced wood amounts throughout the network; in headwater streams these effects are fixed in stream segments bordered by cuts and roads, but in larger channels they are diffused along the channel by fluvial transport of wood. Landforms and roads limited delivery of wood by debris flows to mainstem channels. Network dynamics studies and watershed management plans should include spatial patterns of debris flow initiation and runout, flood redistribution, and reduction of wood in the network by forest cutting and intentional wood removal from channels on time scales of forest succession and recurrence of major floods.

Influences of climate on fire regimes in montane forests of north-western Mexico
About this Resource: To identify the influence of interannual and interdecadal climate variation on the occurrence and extent of fires in montane conifer forests of north-western Mexico. This study was conducted in Jeffrey pine (Pinus jeffreyi Grev. & Balf.)-dominated mixed-conifer forests in the central and northern plateau of the Sierra San Pedro Mártir, Baja California, Mexico. Fire occurrence was reconstructed for 12 dispersed sites for a 290-year period (1700-1990) from cross-dated fire-scarred samples extracted from live trees, snags and logs. Superposed epoch analysis was used to examine the relationships of tree-ring reconstructions of drought, the El Niño/Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO) with fire occurrence and extent. Years with no recorded fire scars were wetter than average. In contrast, years of widespread fires were dry and associated with phase changes of the PDO, usually from positive (warm) to negative (cold). The influence of the PDO was most evident during the La Niña phase of the ENSO. Widespread fires were also associated with warm/wet conditions 5 years before the fire. We hypothesize that the 5-year lag between warm/wet conditions and widespread fires may be associated with the time necessary to build up sufficient quantity and continuity of needle litter to support widespread fires. Two periods of unusually high fire activity (1770-1800 and 1920-1950) were each followed by several decades of unusually low fire activity. The switch in each case was associated with strong phase changes in both PDO and ENSO. Climate strongly influences fire regimes in the mountains of north-western Mexico. Wet/warm years are associated with little fire activity. However, these years may contribute to subsequent fire years by encouraging the production of sufficient needle litter to support more widespread fires that occur in dry/cool years.

Changes in conifer and deciduous forest foliar and forest floor chemistry and basal area tree growth across a nitrogen (N) deposition gradient in the northeastern US
About this Resource: We evaluated foliar and forest floor chemistry across a gradient of N deposition in the Northeast at 11 red spruce (Picea rubens Sarg.) sites in 1987/1988 and foliar and forest floor chemistry and basal area growth at six paired spruce and deciduous sites in 1999. The six red spruce plots were a subset of the original 1987/1988 spruce sites. In 1999, we observed a significant correlation between mean growing season temperature and red spruce basal area growth. Red spruce and deciduous foliar %N correlated significantly with N deposition. Although N deposition has not changed significantly from 1987/1988 to 1999, net nitrification potential decreased significantly at Whiteface. This decrease in net potential nitrification is not consistent with the N saturation hypothesis and suggests that non-N deposition controls, such as climatic factors and immobilization of down dead wood, might have limited N cycling. Data from the 1999 remeasurement of the red spruce forests suggest that N deposition, to some extent, is continuing to influence red spruce across the northeastern US as illustrated by a significant correlation between N deposition and red spruce foliar %N. Our data also suggest that the decrease in forest floor %N and net nitrification potential across sites from 1987 to 1999 may be due to factors other than N deposition, such as climatic factors and N immobilization in fine woody material (<5 cm diameter).

Seed Invasion Filters and Forest Fire Severity
About this Resource: Forest seed dispersal is altered after fire. Using seed traps, we studied impacts of fire severity on timing of seed dispersal, total seed rain, and seed rain richness in patches of high and low severity fire and unburned Douglas-fir (Pseudotsuga menziesii) forests in the Fischer and Tyee fire complexes in the eastern Washington Cascades. Unburned plots had the lowest average seed production. The high severity fire patches in the Fischer Fire Complex had a higher total seed production than low severity fire patches of the same complex. At the Tyee Fire Complex, the total seed production for each of the two fire severities was similar, but the period of maximum seed dispersal was later for high severity than low severity fire. Seed rain at the Fischer Fire patches (sampled one year after the fire) was predominantly composed of annual species, while that of the Tyee Fire patches (sampled nine years after fire) was predominantly perennial species. Seed rain richness was greater in Tyee high severity patches than paired low severity fire patches. In these paired Tyee patches the average number of new seed species (species not found in the extant plot vegetation) was greater for high severity than low severity fire. Our results suggest that high severity fire plots are more porous to seed rain than low severity plots. Intact forest canopies may filter seed rain and reduce seed influx, while high severity fires are more open to invasion by seed dispersal.

Forest Fires in the Insular Caribbean
About this Resource: This paper presents a summary of the forest fire reports in the insular Caribbean derived from both management reports and an analysis of publicly available Moderate Resolution Imaging Spectrodiometer (MODIS) satellite active fire products from the region. A vast difference between the amount of fires reported by land managers and fire points in the MODIS Fire Information for Resource Management System data can be observed. Future research is recommended to better understand the nature of these differences. While there is a general lack of available statistical data on forest fires in the Caribbean, a few general observations can be made: Forest fires occur mainly in dry forest types (500 to 1000 mm of mean annual rainfall). These are also the areas where most human settlements are located. Lowland high forests and montane forests with higher rainfall (1000 and more mm y-1) are less susceptible to forest fire, but they can burn in exceptionally dry years. Most of the dry forest ecosystems in the Caribbean can be considered to be fire-sensitive ecosystems, while the pine forests in the Caribbean (Cuba, Dominican Republic, and the Bahamas) are maintained by wildfires. In fire-sensitive ecosystems, uncontrolled burning often encourages the spread of alien invasive species. A Caribbean Fire Management Cooperation Strategy was developed between 2005 and 2006 under auspices of the Food and Agriculture Organization of the United Nations. This regional strategy aims to strengthen Caribbean fire management networking by encouraging closer collaboration among countries with similar ecological conditions. The strategy for the Caribbean identifies a number of research, training, and management activities to improve wildfire management capacity in the Caribbean.

Effects of Off-Highway Vehicle Use on the American Marten
About this Resource: Motorized recreation in North American wildlands is increasing, and technological developments in the power and range of vehicles has increased access to high-elevation habitats. The American marten (Martes americana) is vulnerable to this disturbance because martens, like other residents of high-elevation forests, are associated with remote wilderness conditions where the presence of motorized vehicles is a recent phenomenon. We evaluated the effects of vehicles at 2 study sites in California, USA, by comparing marten occupancy rates and probabilities of detection in areas where recreational vehicle use is legal and encouraged (use areas) with wilderness areas where vehicles are prohibited (non-use areas). We sampled vehicle occurrence in nearby use and non-use areas using sound level meters and determined marten occurrence using track and camera stations. We also included 2 secondary measures of potential effects of vehicles on martens: sex ratio and circadian pattern of activity. Martens were ubiquitous in use and non-use areas in both study sites, and there was no effect of vehicle use on marten occupancy or probability of detection. We predicted that females might be less common and martens more nocturnal in use than in nonuse areas, but neither occurred. Martens were exposed to low levels of disturbance in our study sites. We estimated that a marten might be exposed to 0.5 vehicle passes/hour and that this exposure had the greatest effect on ,20% of a typical home range area. Furthermore, vehicle use usually occurred when martens were inactive. We did not measure behavioral, physiological, or demographic responses, so it is possible that vehicles may have effects, alone or in concert with other threats (e.g., timber harvest), that we did not quantify. We encourage additional studies to determine whether other montane species that are year-round residents demonstrate the same response to motorized vehicles.

Hydrology of tropical montane cloud forests: A Reassessment
About this Resource: Extending an earlier review of the literature (Bruijnzeel and Proctor, 1995), this paper incorporates the results obtained by post-1993 hydrological and hydrometeorological studies in tropical montane cloud forests (TMCF) situated mostly in Latin America and the Caribbean. Based on the presently available information on the hydrological functioning of TMCF, the most pressing gaps in our understanding are highlighted and suggestions offered as to where and how these could be addressed.

Carbon pools and productivity in a 1-km² heterogeneous forest and peatland mosaic in Minnesota, USA
About this Resource: Determining the magnitude of carbon (C) storage in forests and peatlands is an important step towards predicting how regional carbon balance will respond to climate change. However, spatial heterogeneity of dominant forest and peatland cover types can inhibit accurate C storage estimates. We evaluated ecosystem C pools and productivity in the Marcell Experimental Forest (MEF), in northern Minnesota, USA, using a network of plots that were evenly spaced across a heterogeneous 1-km² mosaic composed of a mix of upland forests and peatlands. Using a nested plot design, we estimated the standing C stock of vegetation, coarse detrital wood and soil pools. We also estimated aboveground net primary production (ANPP) as well as coarse root production. Additionally we evaluated how vegetation cover types within the study area differed in C storage. The total ecosystem C pool did not vary significantly among upland areas dominated by aspen (160±13MgCha⁻¹), mixed hardwoods (153±19MgCha⁻¹), and conifers (197±23MgCha⁻¹). Live vegetation accounted for approximately 50% of the total ecosystem C pool in these upland areas, and soil (including forest floor) accounted for another 35-40%, with remaining C stored as detrital wood. Compared to upland areas, total C stored in peatlands was much greater, 1286±125MgCha⁻¹, with 90-99% of that C found in peat soils that ranged from 1 to 5m in depth. Forested areas ranged from 2.6 to 2.9MgCha⁻¹ in ANPP, which was highest in conifer-dominated upland areas. In alder-dominated and black spruce-dominated peatland areas, ANPP averaged 2.8MgCha⁻¹, and in open peatlands, ANPP averaged 1.5MgCha⁻¹. In treed areas of forest and peatlands, our estimates of coarse root production ranged from 0.1 to 0.2MgCha⁻¹. Despite the lower production in open peatlands, all peatlands have acted as long-term C sinks over hundreds to thousands of years and store significantly more C per unit area than is stored in uplands. Despite occupying only 13% of our study area, peatlands store almost 50% of the C contained within it. Because C storage in peatlands depends largely on climatic drivers, the impact of climate changes on peatlands may have important ramifications for C budgets of the western Great Lakes region.

Fruit Production in Mature and Recently Regenerated Forests of the Appalachians
About this Resource: Fleshy fruit is a key food resource for both game and nongame wildlife, and it may be especially important for migratory birds during fall and for resident birds and mammals during winter. Land managers need to know how land uses affect the quantities and species of fruit produced in different forest types and how fruit production varies seasonally and as young stands mature. During June 1999-April 2004, we quantified fleshy fruit abundance monthly in 31 0.1-ha plots in 2 silvicultural treatments: 1) young 2-age stands with low basal area retention, created by shelterwood-with-reserves regeneration cuts (R; harvested 1998-1999); and 2) uncut mature closed-canopy stands (M) in 2 common southern Appalachian, USA, forest types (upland hardwood and cove hardwood [CH] forests). Over the 5-year study period, total dry pulp biomass production was low and relatively constant in both M forest types ( = 0.5-2.0 kg/ha). In contrast, fruit production increased each year in R, and it was 5.0 to 19.6 times greater in R than in M stands beginning 3-5 years postharvest. Two disturbance-associated species, pokeweed (Phytolacca americana) and blackberry (Rubus allegheniensis), produced a large proportion of fruit in R but showed different patterns of establishment and decline. Huckleberry (Gaylussacia ursina) recovered rapidly after harvest and was a major producer in both silvicultural treatments and forest types each year. Several herbaceous species that are not associated with disturbance produced more fruit in CHR. Few species produced more fruit in M than in R. Fruit production by most tree species was similar between R and M, due to fruiting by stump sprouts in R within 1-3 years postharvest. Fruit availability was highest during summer and early fall. American holly (Ilex opaca), sumac (Rhus spp.), and greenbriar (Smilax spp.) retained fruit during winter months but were patchy in distribution. In the southern Appalachians, young recently regenerated stands provide abundant fruit compared to mature forest stands and represent an important source of food for wildlife for several years after harvest. Fruit availability differs temporally and spatially because of differences in species composition, fruiting phenology, and the dynamic process of colonization and recovery in recently harvested stands. Land managers could enhance fruit availability for many game and nongame species by creating or maintaining young stands within forests.

Current and Historical Composition and Size Structure of Upland Forests Across a Soil Gradient in North Mississippi
About this Resource: Comparisons of current and historical tree species composition and size structure along natural productivity gradients are useful for inferring effects of disturbance regimes and productivity on patterns of succession. We tabulated occurrences and estimated diameters of 3483 General Land Office bearing trees across 19 survey townships along an upland soil texture and organic matter gradient in north Mississippi. We then contrasted this presettlement composition and structure with that of 2998 trees in sampling plots within present-day mature (>100 years old) upland forests contained within the survey townships. Presettlement upland communities appeared to consist of non-successional communities, in which the most abundant trees were shade-intolerant, fire-tolerant trees (e.g., Quercus marilandica [blackjack oak]) in both large and small size classes across the entire soil gradient. These fire-prone pre-settlement assemblages differed greatly from present-day mature uplands, which were transitional assemblages of upland and floodplain trees, with mesophytic floodplain species (both early and late-successional) dominating the smaller size classes.

Soil organic carbon quality in forested mineral wetlands at different mean annual temperature
About this Resource: Forested mineral soil wetlands (FMSW) store large stocks of soil organic carbon (SOC), but little is known on: (i) whether the quality of SOC stored in these soils (proportion of active versus more resistant SOC compounds) differs from SOC in upland soils; (ii) how the quality of SOC in FMSW varies with mean annual temperature (MAT); and (iii) whether SOC decomposition rates in these environments respond to warming and drying more strongly than those observed in upland soils. To address this substantial knowledge gap, we identified nine FMSW and fifteen paired upland forest sites across three bioregions in North America (sub-alpine in Colorado; north-temperate in Minnesota; and south-temperate in South Carolina) to test the following three hypotheses. First, FMSW store a higher proportion of active SOC compared with upland systems because long anaerobic periods favor the accumulation of labile substrates. Second, in FMSW, SOC quality decreases from cold to warm bioregions because high quality detritus accumulates preferentially at cool sites where decomposition is slow. Finally, decomposition of SOC in FMSW will respond more strongly to warming under aerobic conditions than SOC from upland forest soils because of higher accumulation of active SOC in FMSW. To test these hypotheses, we incubated FMSW and upland forest soils at two constant temperatures (10 and 30 °C) for 525-d under aerobic conditions and constant moisture. In contrast to our first hypothesis, we observed similarly rapid depletion of active SOC compounds at initial stages of incubation across FMSW and upland sites, and across the 525-d incubations we observed overall lower SOC decomposition rates in our FMSW soils. In line with our second hypothesis, and across FMWS and upland soils, we found greater SOC loss in the sub-alpine bioregion than both temperate regions. In contrast to our last hypothesis, we found no difference in the temperature sensitivity (Q10) of SOC decomposition in FMSW and upland forest soils. Critically, total SOC loss (g SOC per g soil) was larger in FMSW because of the large amount of SOC stored in these ecosystems, indicating that despite a lack of difference between FMSW and upland responses, the total release of C from FMSW that could result from global warming may be large.

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.

Disturbance changes arbuscular mycorrhizal fungal phenology and soil glomalin concentrations but not fungal spore composition in montane rainforests in Veracruz and Chiapas, Mexico
About this Resource: Mexican montane rainforests and adjacent disturbed areas were studied for disturbance-related spatio-temporal changes to the arbuscular mycorrhizal fungal (AMF) community and soil glomalin concentration. The AMF community functions to both improve plant growth and soil conditions and is thus an important component to the restoration of this forest type to disturbed areas. The study areas included mature rainforests that were converted to pine forests, milpas, pastures and shrub/herbaceous plant communities via burning and logging. Seasonal patterns in AMF spore species richness and sporulation significantly differed across disturbance types at two of the three sites surveyed. Contrasting patterns of sporulation among AMF families across different disturbance types helped to explain how species richness and composition were maintained despite dramatic changes to the host plant community. Meaning, in most cases, disturbance induced changes in when different AMF taxa sporulated but not what taxa sporulated. Only conversion from mature pine-oak-Liquidambar-Persea forests to pine-dominated stands severely reduced AMF spore richness and total sporulation. Surprisingly, in pine-dominant stands no concomitant negative impacts on soil glomalin (MAb32B11 immunoreactive soil protein) concentrations were detected. However, soils of mature forests containing no pines had the highest concentration of glomalin. Conversion to pasture and milpa (diverse cornfield) had a strong negative impact on the concentration of soil glomalin concentrations. In sharp contrast, the same disturbance types improved AMF sporulation and AMF spore richness. It appears that disturbance type, and not AMF community measures used herein, best predicts changes in soil glomalin concentration.

The influence of fuels treatment and landscape arrangement on simulated fire behavior, Southern Cascade range, California
About this Resource: Wildfire behavior can be modified by altering the quantity, structure, and arrangement of fuel (flammable vegetation) by silvicultural treatments such as forest thinning and prescribed burning. The type and arrangement (including landscape location) of treated areas have been demonstrated to influence wildfire behavior. This study analyzes the response of several key fire behavior variables to variation in the type, amount, and spatial arrangement of fuel treatments for simulated wildfires in mixed-conifer forests of the southern Cascades in the Goosenest Adaptive Management Area (GAMA). NEXUS and BehavePlus were used to simulate pre- and post-treatment stand-level fire behavior. Fire area simulator (FARSITE) was used to simulate landscape-level wildfire behavior in both untreated and treated forest landscapes. In the forest landscape, treatment areas were placed in the landscape according to two strategically designed arrangements and one random treatment arrangement. Treatments included thinning by prescribed burning (burn-only), mechanical thinning (mechanical-only), mechanical thinning followed by burning (mechanical-burn), and no treatment (control). At the stand level, the mechanical-burn treatment most effectively reduced both surface fire (e.g., decreased flame length) and crown fire behavior (e.g., torching index). At the landscape level, treatment type, amount, and arrangement had important effects on both fire spread and fire intensity. In this landscape the most effective treatment arrangement was Finney's optimal SPLATs design. This study shows that there is potential to efficiently reduce high-intensity fire behavior while treating less area by relying on strategically placed treatments.

Understory structure in a 23-year-old Acacia koa forest and 2-year growth responses to silvicultural treatments
About this Resource: Restoration of degraded Acacia koa forests in Hawaii often involves mechanical scarification to stimulate germination of seed buried in the soil and to suppress vegetation that competes with shade intolerant A. koa. Resulting even-age stands are gradually colonized by other plant species, but understory structure is poorly quantified, and the effects of management on understory vegetation are unknown. We examined the structure of the dominant understory species 23 years after stand initiation and determined their subsequent 2-year growth responses to silvicultural treatments prescribed to improve growth of koa. Release thinning, chemical control of introduced grasses, and phosphorus fertilization were applied in a split-plot experimental design. Results for DBH and height class distributions indicated that recruitment for most tree species began within a few years of stand initiation. By 23 years understory trees made up only 14% of total stand basal area, but they added greatly to native plant biodiversity. Alien grasses covered 92% of the forest floor and averaged 1.35Mgha⁻¹. Of the four most abundant native understory tree species, only shade intolerant Myoporum sandwicense grew faster in response to the treatments. P-fertilizer combined with grass control significantly increased production of the native shrub, Rubus hawaiiensis. Notably, alien grass biomass did not increase in response to thinning, and actually declined in P-fertilized plots. Only, where P-fertilizer was applied were P concentrations of understory leaves elevated. Foliar concentrations of other nutrients were generally unaffected by treatments. Our findings suggest that the conservative silvicultural treatments we used can be applied without adversely impacting the capacity of aggrading A. koa forests to support a diversity of native understory plants. Lack of an increase in alien grass biomass, and in the case of P fertilization, a reduction in grass biomass, indicates that treatments should not increase competition with native species.

Scale-dependent environmental controls over species composition in Alaskan black spruce communities
About this Resource: The boreal forest is the second largest terrestrial biome, and the black spruce (Picea mariana (Mill.) BSP) forest type occupies a large extent of boreal North America. Black spruce communities occur in a variety of environmental conditions and are especially important in the context of climate change because of underlain permafrost in much of the northern black spruce forests, as well as their adaptation to fire disturbance. We used a classification and ordination approach to describe and name Alaskan black spruce communities and relate them to key environmental variables. We analyzed the relationship of species richness with topographic position and with soil pH using both univariate and multivariate analyses of variance. We also explored the variability in structural, physical, and soil characteristics. We described three black spruce community types and five subtypes based purely on floristic composition. Paludification and topography were the most important gradients explaining species composition for the Fairbanks region (61% variance explained). However, at the scale of interior Alaska, pH, drainage, and productivity were the strongest environmental gradients (81% variance explained). We conclude that species composition of mature black spruce forests in interior Alaska results from the complex interaction of landscape and fire history, soil pH, paludification, permafrost, and topographic position.

Reconciling divergent interpretations of quaking aspen decline on the northern Colorado Front Range
About this Resource: Ecologists have debated over the past 65 years whether quaking aspen (Populus tremuloides Michx.) has or has not declined in abundance, vigor, or regeneration in western North America. Many studies have provided divergent interpretations of the condition of aspen forests, leading to difficulty in translating this ecological information into management recommendations. To reconcile these contrasting conclusions and to test the hypothesis that multiple types of aspen decline and persistence occur simultaneously on heterogeneous landscapes, we assessed 91 aspen stands across the northern Colorado Front Range to determine the range of ecological conditions that underlie aspen decline or persistence. Approximately 15% of aspen forest area in our sample exhibited dieback of mature stems coupled with a lack of young trees indicative of declining stands, most often at lower elevations where elk browsing is heavy and chronic, and where effects of fire exclusion have been most significant. However, 52% of the area sampled had multiple cohorts indicative of self-replacing or persistent stands. Conifer dominance was increasing in over 33% of all aspen forest area sampled, most often at high elevations among lodgepole pine (Pinus contorta var. latifolia Englem. ex Wats.) forests. Reconstructions of relative basal area and density of aspen and lodgepole pine in these stands suggest cyclical dominance of these species, where conifers gradually replace aspen over long fire intervals, and aspen vigorously re-establish following stand-replacing fires. The diversity of ecological contexts across the northern Colorado Front Range creates a variety of aspen dynamics leading to decline or persistence, and no single trend describes the general condition of aspen forests in appropriate detail for managers. Active management may be useful in preserving individual stands at fine scales, but management prescriptions should reflect specific drivers of decline in these stands.

Riparian communities associated with Pacific Northwest headwater streams: assemblages, processes, and uniqueness
About this Resource: Riparian areas of large streams provide important habitat to many species and control many instream processes - but is the same true for the margins of small streams? This review considers riparian areas alongside small streams in forested, mountainous areas of the Pacific Northwest and asks if there are fundamental ecological differences from larger streams and from other regions and if there are consequences for management from any differences. In the moist forests along many small streams of the Pacific Northwest, the contrast between the streamside and upslope forest is not as strong as that found in drier regions. Small streams typically lack floodplains, and the riparian area is often constrained by the hillslope. Nevertheless, riparian-associated organisms, some unique to headwater areas, are found along small streams. Disturbance of hillslopes and stream channels and microclimatic effects of streams on the riparian area provide great heterogeneity in processes and diversity of habitats. The tight coupling of the terrestrial riparian area with the aquatic system results from the closed canopy and high edge-to-area ratio for small streams. Riparian areas of the temperate, conifer dominated forests of the Pacific Northwest provide a unique environment. Forest management guidelines for small streams vary widely, and there has been little evaluation of the local or downstream consequences of forest practices along small streams.

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.

Los Andes de Mérida, una nueva subprovincia fitogeográfica de la provincia de los Andes del Norte
About this Resource: The Andean Cordillera belongs to two different florístics kingdoms in the Takhtajan´s phytogeographical system of clasification: To the south the antartic or Holartic Kingdom and towards the North of Chile the Neotropical one. This last it is subdivided as well in two provinces: the Central Andes, from the North of Chile to the North of Peru, and the Northern Andes from the North of Peru to Venezuela. This one comprising the vegetal formations above the limit of the subtropical forests including in the upper altitudinal belts the Puna, the Jalca and the Paramo. Such province possesses floristical, vegetational, geological and climatical characteristics heterogeneous, for which reason many authors have subdivided it in diverse regions attending to diverse criteria. As a result of the phytogeographical comparison of the flora of the Superpáramos of the Andes of Mérida along the Andes, it was found that 37% of its taxa were determined as propious of these formations, emphasizing the Espeletiinae as quasi endemics (including the presence of endemics genera like Coespeletia) and Helleria (Festuca s. l.), in addition to the presence of other endemics genera of lower vegetational belts like Ruilopezia and Carramboa. The singularity of the Andes of Merida due to the floristic peculiarity of the altimontanous vegetational belt is emphasized with the floristic peculiarities of the montane forests in which more than 143 angiosperm species, that reach their limit of distribution in Tamá and are found in Colombia and more to the South, are absent in the Andes of Merida beyond the north of the tectonic depression of the Táchira. This florístic singularity corresponds as well with paleoecollogical, climatics fisiographics an geological criteria. For this reason the definition of a new phytogeographic subprovince named Subprovince of the Andes of Merida as a subunit of the North Andes Province is justified. This one comprise the vegetal formations above 1.500 m a.s.l., lower limit of the montane forests, until the limit of perpetual snows, between the tectonics depressions of the Táchira and Barquisimeto.

Why financial incentives can destroy economically valuable biodiversity in Ethiopia
About this Resource: Ethiopian montane rainforests are economically valuable repositories of biodiversity, especially of wild Coffea arabica populations, and they are vanishing at accelerating rates. Our research results confirm theory which explains biodiversity loss by diverging private and social net benefits from land conversion. Poor farmers basically live from hand-to-mouth and manage resources with very short term planning horizons. In such circumstances they cannot afford to carry the cost burden of conservation from which the broader national and global society benefits. Society, on the other hand, highly values the biodiversity of Ethiopia's montane rainforests, but has not managed to put mechanisms in place which enable to pay for the conservation of these values and conservation policies are in place but are not implemented. While it is economically rational for the farmer to convert forests into agricultural land and thereby improve his income (the financial incentive we refer to here), it is economically irrational for national and global society not to pay for conservation. The core reasons for such divergence is that institutions for conservation and sustainable use are not in place. We identify the most important ones and recommend changes for the Ethiopian case.

Montane forest diversity influencing pioneer flora on natural landslides at the Western side of Podacarpus National Park, South Ecuador
About this Resource: The present study comprises a comparison of the biodiversity of montane forests and its influence on natural disturbances,especially landslides. A total of 412 plant species, belonging to 185 genera and 75 families were registered in naturalforests. A high endemism, with 58 endemic species, was found in the montane forest and paramo “ecotone” between 2600-2800 m, and around 3200m. Natural landslides were colonized by 218 species of 180 genera and 51 families. The mainspecies diversity was grouped around 2700 m. Five different soil profiles with a median depth of 60 cm were dug. Theycontained three main types: Dystropepts, reddish to yellowish soil with high kaolinitic and geothitic clay content, sometimeswith gibesite. Blackish soils, especially in humid, cold areas, of lighter color in humid areas of lower zones. Crayquets, richin organic matter, were encountered at altitudes from 3000 - 34000 m. The soils of landslides were very acidic, withmedium to very high nitrogen content, and median to low content of phosphorous and potassium. The TWINSPAN analysisof floristic affinity arranged the 170 landslide and 19 natural vegetation plots into three vegetation communities with 13landscape units. A CANOCO analysis indicated that community I was determined by a high content soil organic matter andcomprised undisturbed vegetation. Community II was delineated according to its soil acidity, exposition, and sandy-claysoils, and included mostly disturbed vegetation types at lower altitudes as well as two forest areas in Cajanuma (at 2500 m,wetern slopes) and Sabanilla (2800 m, estaren slopes). Community III was delineated by its clay soils and concentrated onthe western side of the research area, including the forests of San Francisco at 2100 m. Colonization on both sides of theAndean chain is patchy, with different forest types functioning as genetic reservoirs for colonization. At this point theinfluence of the soil seed banks has not been studied.

Ten new species of Telipogon (Orchidaceae, Oncidiinae) from southern Peru
About this Resource: Ten new species of Telipogon, T. antisuyuensis, T. austroperuvianus, T. casadevalliae, T. farfanii, T. javiercastroviejoi, T. kosnipatensis, T. marleneae, T. mesotropicalis, T. santiagocastroviejoi, and T. tupayachii are described and illustrated. These are terrestrial or epiphytes of the montane humid forests from Andean valleys of southern Peru. Diagnostic morphological characters are discussed for each species. A key is provided for the species of the genus found in southern Peru. The number of Telipogon species currently recognized for the Peruvian flora is 46.Se describen e ilustran diez especies nuevas de Telipogon –T. antisuyuensis, T. austroperuvianus, T. casadevalliae, T. farfanii, T. javiercastroviejoi, T. kosnipatensis, T. marleneae, T. mesotropicalis, T. santiagocastroviejoi y T. tupayachii. Éstas son plantas terrestres o epífitas de los bosques húmedos montanos de los valles andinos del sur de Perú. Se discuten sus caracteres morfológicos diagnósticos y se propone una clave dicotómica para diferenciar las especies que crecen en el sur del país. El número de especies de Telipogon actualmente reconocidas para la flora peruana es de 46.

Fire history of Douglas-fir forests in the Morse Creek drainage of Olympic National Park, Washington
About this Resource: In the Morse Creek drainage of the northeastern Olympic Mountains in Washington state, USA, montane forests dominated by Douglas fir (Pseudotsuga menziesii) owe their prominence to a complex fire regime that incorporates high severity stand-replacing fires and low/moderate severity ground fires. The fire history of these forests was quantified using dendrochronological methods to determine the role played by wildfire to favour dominance of Douglas fir rather than late-successional western hemlock (Tsuga heterophylla). Three matrix forest types reflect the influence of past wildfires. The youngest matrix type was 300 yr old. Germination dates and fire release markers were identified on increment cores from 318 Douglas firs, and used to date past fire events. A 600-yr fire history was developed for this 2500-ha area. Periods characterized by many small-scale, low and moderate severity fires were interrupted by 2 high severity, stand-replacing burning periods in 1687-1720 and 1897-1904. Mean fire return intervals (FRI) were calculated for various land units. The most informative size was 200 ha, the approximate mean size of lateral tributaries to Morse Creek. FRI was 21 yr at this spatial scale. For the entire 2500 ha drainage, mean FRI was estimated at 3 yr. Similar to Douglas-fir forests in central Oregon and northern California, small patchy fires were much more common in the eastern Olympics than previously thought. Instead of fire exclusion, a policy that uses management fires to burn many small patches of forest each year would approach the kind of fire regime typical of these forests.

The soil seed bank during Atlantic Forest regeneration in Southeast Brazil
About this Resource: A survey was conducted to determine the density and species composition of viable seeds buried in four stands of a tropical montane forest at Parque Estadual Intervales, Brazil. The objective was to understand: (1) how numbers and composition of the soil seed bank change as the forest regrows, and (2) how such changes affect the species available for regeneration if forests of different ages are cut down. In each forest stand (5, 18, 27-yr-old and a mature forest), 57 soil samples were collected (0-2.5 and 2.5-5 cm deep). Viable seed density of herbaceous species ranged between 11,003 seeds. m-2 (5-yr-old vegetation) and 482 (mature forest), and between 25 (5-yr-old vegetation) and 389 seeds. m-2 (mature forest) for woody plant species in the 0-5 cm soil layer, suggesting a decrease in seed stocks in the course of forest regeneration. Seeds buried in the 0-2.5 cm soil layer represented between 56.9% and 67.4% of all viable seeds. Most of the viable seeds belonged to weeds of Asteraceae, Poaceae, Malvaceae and Solanaceae. The results provide evidence that, in forests of different ages, the soil does not store seeds of the same key ecological groups involved in the regeneration of Atlantic forest. Allochthonous seeds from remaining patches of forest, as well as their vertebrate dispersers, are needed for forest regeneration since the soil seed bank does not store large seeds of shade-tolerant species.

Legacy retention versus thinning: Influences on small mammals
About this Resource: Management strategies for promoting late-seral attributes in second-growth forest need evaluation for their efficacy in maintaining biodiversity, including complete forest-floor, small-mammal communities. Two common strategies in the Pacific Northwest are (1) management with thinnings to promote large trees with developed understories and (2) retention of legacies, defined as live trees, logs, and snags from the preceding forest, at harvest, followed by protection but not thinnings of the new stand. We compared small-mammal communities resulting from >65 yr of application of these strategies in the Puget Trough, Washington. We also compared these communities with the small-mammal communities found in old-growth, naturally young, and extensively managed forests elsewhere in western Washington. Forests managed with thinnings had 1.5 times the individual mammals and 1.7 times the mammal biomass of forests managed with legacies of coarse woody debris and snags-differences similar to those between old-growth and naturally young forest (1.2 times more individuals in old-growth) and old-growth and extensively managed forest (1.6 times more individuals in old-growth). Management strategy had a profound impact on community structure, with the Columbian mouse (Peromyscus oreas), the small mammal mostassociated with old growth, much reduced in Puget Trough forests (absent from most stands) and the creeping vole (Microtus oregoni) (a species commonly associated with early seral stages, but found in all seral stages in Washington) third-ranked in thinned stands but seventh ranked in legacy stands. The montane shrew (Sorex monticolus) was second-ranked, after Trowbridge's shrew (S. trowbridgii), in marked contrast to codominance by the southern red-backed vole (Clethrionomys gapperi), S. monticolus, and P. oreas in old growth. Thus, neither strategy produced communities typical of late-seral forests

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.

Transpiration of montane Pinus sylvestris L. and Quercus pubescens Willd. forest stands measured with sap flow sensors in NE Spain
About this Resource: Stand transpiration was measured during the 2003 and 2004 growing seasons using heat dissipation sap flow sensors in a Scots pine (Pinus sylvestris L.) and a pubescent oak (Quercus pubescens Willd.) forests located in a montane area of the Eastern Pyrenees (NE Spain). The first aim of the study was to assess the differences in quantitative estimates of transpiration (Ec) and the response to evaporative demand of the two stands. Over the studied period of 2003, characterised by a severe drought episode during the summer, the oak stand (Ec was only 110 mm compared to the 239 mm transpired by the Scots pine stand, although the ratio of transpiration to reference evapotranspiration (Ec/ET0) in the oak stand compares well with the expected values predicted for low leaf area index (LAI) oak forests in southern Europe. Scots pine showed a strong reduction in (Ec/ET0 as the drought developed, whereas pubescent oak was less affected by soil moisture deficits in the upper soil. As a second objective, and given the contrasting meteorological conditions between 2003 and 2004 summer periods, the interannual variability of transpiration was studied in the Scots pine plot. Rainfall during the summer months (June-September) in 2003 was almost 40% less than in the same interval in 2004. Accordingly, transpiration was also reduced about 25% in 2003. Finally, Scots pine data from 2003 and 2004 was used to calibrate a simple transpiration model using ET0 and soil moisture deficit (SMD) as input variables, and implicitly including stomatal responses to high vapour pressure deficits (Dd) and soil water status.

Species-specific response to climate reconstruction in upper-elevation mixed-conifer forests of the western Sierra Nevada, California
About this Resource: Dendrochronology climate reconstruction studies often sample dominant, open-grown trees to reduce competition effects and isolate annual climate influences on radial increment growth. However, there has been no examination of how species respond as stand densities increase or which species in mixed-conifer forests provide a better record of past climate. We sampled 579 trees representing five upper montane mixed-conifer species at the Teakettle Experimental Forest in California's southern Sierra Nevada to determine species-specific responses to annual climatic fluctuations. Using the Kalman filter, we examined the affect of local stand density on growth response and whether the growth-climate relationship improved with a time lag. The Kalman filter iteratively calculates error for predicted versus actual radial growth and accounts for this variation in the corrector equation. Under current high-density conditions, shade-tolerant white fir (Abies concolor (Gord. & Glend.) Lindl.) provided the best model for climate reconstruction. Shade-intolerant Jeffrey pine (Pinus jeffreyi Grev. & Balf.) had a lagged response to annual climatic fluctuations, possibly because its roots may tap water reserves in granitic bedrock fissures. Open-grown trees provided more accurate records of climate. Changes in forest density in this forest may have resulted in changes in species-specific response to annual climatic fluctuations.

Proximity to a stand edge influences growth of advance and planted Pacific silver fir seedlings
About this Resource: Growth and physiology of advance regeneration, present in the understorey before harvest, and planted seedlings of Pacific silver fir (Abies amabilis) were compared in three environments created by increasing distance from an edge of a montane clearcut on Vancouver Island, British Columbia, Canada. The objective was to quantify growth limitations and their underlying mechanisms in relation to light and nutrient availability. The site was clearcut in 1989. In 1993, plots were established 5-10 m inside the north-east facing stand edge, and 12-17 and 60-65 m into the adjoining clearcut. Microclimate data were collected, and biomass allocation, specific leaf area, and net photosynthesis of advance and planted seedlings in the plots were measured in 1993. Height growth and foliar nitrogen concentration of advance and planted seedlings were measured over a 5 year period. Light and air temperature increased from the inside edge environment into the clearcut. Soil moisture did not differ greatly among environments. Seedlings of both regeneration types grew tallest in the clearcut, and specific leaf areas were lower in the clearcut. In 1993, root:shoot ratios and rates of net photosynthesis were greater in advance than planted seedlings. Planted seedlings were significantly taller than advance regeneration by 1998, 5 years after establishment, however, this size difference was due mainly to the larger starting size of planted seedlings. By 1998, foliar nitrogen concentrations did not differ between regeneration types. Foliar nitrogen concentrations were low in all environments, which supports the contention that growth check of Pacific silver fir in montane clearcuts is associated with nitrogen deficiency.

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.

Diurnal Habitat Relationships of Canada Lynx in an Intensively Managed Private Forest Landscape in Northern Maine
About this Resource: In March 2000, Canada lynx (Lynx canadensis) were listed as a federally threatened species in 14 states at the southern periphery of their range, where lynx habitat is disjunct and snowshoe hare (Lepus americanus) densities are low. Forest conditions vary across lynx range; thus, region-specific data on the habitat requirements of lynx are needed. We studied lynx in northern Maine, USA, from 1999 to 2004 to assess quality and potential for forests in Maine to sustain lynx populations. We trapped and radiocollared 43 lynx (21 M, 22 F) during this period and evaluated diurnal habitat selection by 16 resident adult lynx (9 M, 7 F) monitored in 2002. We evaluated lynx selection of 8 habitats at multiple spatial scales, and related lynx habitat selection to snowshoe hare abundance. Lynx preferred conifer-dominated sapling stands, which supported the highest hare densities on our study site ( = 2.4 hares/ha), over all other habitats. The habitats where lynx placed their home ranges did not differ by sex. However, within their home ranges, males not only preferred conifer-dominated sapling stands, but also preferred mature conifer, whereas females singularly preferred conifer-dominated sapling stands. Approximately one-third of Maine's spruce-fir forest and nearly 50% of our study area was regenerating conifer or mixed-sapling forest, resulting from a disease event and intensive forest management (e.g., large clear-cuts). Our findings suggest that current habitat conditions in Maine are better than western montane regions and approach conditions in boreal forests during periods of hare abundance. We recommend that forest landowners maintain a mosaic of different-aged conifer stands to ensure a component of regenerating conifer-dominated forest on the landscape.

Activity budgets in a group of Sichuan snub-nosed monkeys in Shennongjia Nature Reserve, China
About this Resource: We examined time allocation by Sichuan snub-nosed monkeys Rhinopithecus roxellana in the montane, temperate and highly seasonal forests of the Shennongjia Nature Reserve in China, in order to improve our understanding of the ecological and social influences on monkey behavior. We collected data on activity budgets in relation to food availability in a group of monkeys from July 2003 to September 2004 (except February 2004), using instantaneous scan samples. The monkeys spent 36.21% of daytime moving (n = 21,269 records), 24.39% foraging, 9.33% inactive, 11.7% performing social behaviors, and 18.38% performing other behaviors. There were seasonal and annual variations in the proportions of time devoted to some activities. These variations were largely attributed to seasonal or annual fluctuations in the distribution and quality of food resources. Adult males spent more time moving, searching, and displaying other behaviors, but less time feeding and performing social behaviors than adult females. Adults performed other behaviors more often and moving less often than juveniles. These differences in activity budgets may reflect fundamental differences in reproductive biology, parental investment, and development among the different age/sex classes[Current Zoology 55(3):–2009].

Micromamiferos andinos holocenicos del sitio arqueologico Inca Cueva 5, Ju Juy, Argentina: tafonomia, zoogeografia y reconstruccion paleoambiental
About this Resource: A micromammal archaeological sequence (2120 f 120 to 780 f 100 years BP) from Inca Cueva 5 site (23" 05' S - 65" 27' W; 3700 m.a.s.l., Jujuy Province, Argentina) was studied. The following mammalian taxa were recorded: Order Didelphimorphia, Family Didelphidae, Thylamys cf. T. pallidior; Order Rodentia, Family Muridae, Akodon cf. A. albiventer, Andinomys edax, Auliscomys sublimis, Calomys lepidus, Neotomys ebriosus, Phyllotis sp.; Family Caviidae, Cavia cf. C. tschudii, Galea musteloides; Family Abrocomidae, Abrocoma cinerea; Family Chinchillidae, Lagidium viscacia; Family Octodontidae, Octodontomys gliroides. The taphonomy indicates that the sequence is an owl pellet accumulation inside the cave. The general landscape corresponds to the oriental border of the Puna steppe, with scattered shrub and low brush vegetation. Near the site there are small tree groups of Polylepis australis as well as small streams covered with grass and ciperaceous vegetation known as &#194;&#171;vegas&#194;&#187;. Al1 the recorded taxa at Inca Cueva 5 exist today in Puna and Prepuna environments from Jujuy and Salta Provinces and southem Bolivia, excepting Cavia cf. C. tschudii. The modem records of this species in northem Argentina and southern Bolivia come from localities with high montane bunchgrass prairies and forests of the humid Yungas phytogeographical region. The presence of this species in the sequence suggests wetter climatic conditions on this region when the archaeological site was originated. Later drier conditions, caused probably by anthropic influence in the last 500 years, produced the retraction of Cavia tschudii to the moist eastern side of the Andes and its disappeareance of the Puna areas.El sitio arqueol&#243;gico Inca Cueva 5 se encuentra en la provincia de Jujuy, Argentina, en el borde oriental de la regi&#243;n de la Puna (23" 05' S - 65" 27' W; 3700 m s n m) y est&#225; fechado entre 2120 f 120 y 780 f 100 a&#241;os radiocarb&#243;nicos AP. El estudio de una peque&#241;a muestra de micromam&#237;feros permiti&#243; reconocer la presencia de los siguientes taxa: Orden Didelphimorphia, Familia Didelphidae, Thylamys cf. T. pallidior; Orden Rodentia, Familia Muridae, Akodon cf. A. albiventer, Andinomys edax, Auliscomys sublimis, Calomys lepidus, Neotomys ebriosus, Phyllotis sp.; Familia Caviidae, Cavia cf. C. tschudii, Galea musteloides; Familia Abrocomidae, Abrocoma cinerea; Familia Chinchillidae, Lagidium viscacia; Familia Octodontidae, Octodontomys gliroides. La tafonom&#237;a indica que el agregado tuvo su origen en la depositaci&#243;n de egagr&#243;pilas de lechuza (Aves, Strigiformes) en el contexto de la cueva. El ambiente general actual en la zona corresponde a la estepa pune&#241;a, con arbustos y matorrales bajos y dispersos. En el fondo del valle hay bosquecillos de Polylepis australis, un curso de agua y vegas peque&#241;as y circunscritas. Todas las especies registradas en Inca Cueva 5 habitan actualmente en ambientes de Puna y Prepuna de Salta, Jujuy y sur de Bolivia, a excepci&#243;n de Cavia cf. C. tschudii. Los registros actuales de esta especie en el noroeste de Argentina y sur de Bolivia corresponden a localidades ubicadas en pastizales de altura y bosques subtropicales de Yungas. La presencia de este tax&#243;n en la secuencia sugiere condiciones de mayor humedad que las actuales para la regi&#243;n durante el lapso considerado. Condiciones posteriores de mayor aridez, probablemente asociadas al impacto antr&#243;pico de los &#250;ltimos 500 a&#241;os, habr&#237;an redundado en la desaparici&#243;n de Cavia tschudii de &#225;reas pune&#241;as y en su retracci&#243;n a los cordones orientales h&#250;medos de los Andes.

Kam Guilzhouh nyim Guangxxih di Benxtux Wenchual nyim Zihyuanc dih Gonxliix
About this Resource: Kam Guilzhouh nyim Guangxxih di Benxtux Wenchual nyim Zihyuanc dih Gonxliix: Kam Local Indigenous Knowledge and Sustainable Resource Management in Guizhou and Guangxi Provinces. Historically, the Han Chinese forcibly displaced Kam people from the best agricultural land. Today, the Kam cultural landscape largely encompasses the border regions of Guizhou, Hunan and Guangxi Provinces, in which lie verdant riverine mountains and valleys. Sufficient water resources support Kam rice cultivation and the broadleaf and evergreen forests of the humid subtropical montane ecosystem. The Kam have dwelled in this diverse environment for approximately 2,000 years developing unique livelihood strategies of harvesting fish and grain from paddy fields, integrating agroforestry and agriculture on mountain slopes and applying specialized knowledge and skills in utilizing local natural resources. Kam people believe that spirits inhabit elements in nature and the world around them, thus great respect should be given to these supernatural beings. Kam resource management practices support regional vegetation where hillside pastureland and forage for domestic animals are ample. Kam rice paddies and fishponds have been judiciously maintained, contributing to Kam cultural survival and development.

Activity areas of female long-eared myotis in coniferous forests in Western Oregon
About this Resource: We used radiotelemetry to investigate the temporal patterns of activity, characteristics of activity areas, and the spatial relationships among activity areas, day roosts, and water for female long-eared myotis (Myotis evotis). We tracked 12 adult female long-eared myotis for 23 nights from June to August, 1996 and 1997, on the western slope of the Cascade Mountains in Oregon, USA. The activity areas of nine bats (n=11 nights) averaged 38.3 ha and were centred an average of 518 m from the day roost (SE=60 m) and 73 m from water (SE=10 m); centres of activity were significantly closer to water than random points (P<0.001). Odds of an area being used decreased with distance to available water (P=0.0001). Activity areas typically encompassed water but did not include the day roost. Activity areas did not significantly differ in forest composition as determined from randomly selected circular plots. Bodies of open water appear to function as important centres of activity for long-eared myotis. We contend that management of habitats for bats should consider spatial relationships among activity areas, day roosts and water.

Reforestation and topography affect montane soil properties, nitrogen pools, and nitrogen transformations in Hawaii
About this Resource: Land use changes, such as deforestation and reforestation, modify not only the organisms inhabiting affected areas, but also above-and belowground environments. Topography further influences local vegetation and environment. Effects of topography and re-establishment of N-fixing koa (Acacia koa A. Gray) trees in +100-yr-old montane grassland on surface soil properties, N pools, and N transformations were assessed using standard and 15N-isotope pool dilution methods. Data were collected for soils on slopes and in drainage bottoms located in grassland, under 9- to 11-yr-old planted koa, and in nearby old-growth koa-ohia (Metrosideros polymorpha Gaud.) forest. Soil under planted koa had significantly lower fine soil bulk density and pH than soil in grassland, and had concentrations of total C, total N, and extractable Mg and C/N ratio intermediate between grassland and forest. Topographic position affected pH and concentrations of total C, total N, and extractable P. Ten years after koa trees were re-introduced to grassland, the concentration of soil NH4(+)-N had increased above levels found even in intact forest, and the concentration of NO3(-)-N was intermediate between forest and grassland. Ammonium dominated the inorganic N pools in grassland soil and NO3(-) dominated in forest soil. Under planted koa, NH4(+) domination was beginning to give way to NO3(-) domination. Soil microorganisms were potentially strong competitors for inorganic N on grassland slopes where they immobilized nearly all the inorganic N that was produced during short- and medium-term field incubations, thus leaving little for plant growth. Re-establishment of koa trees increased soil N availability.

Canopy Dieback and Successional Processes in Pacific Forests
About this Resource: Massive tree dieback has occurred periodically in the Hawaiian montane rain forest. The species mainly involved is Metrosideros polymorpha, which is the prevailing upper canopy tree species throughout most of this forest on all high Hawaiian islands. The canopy dieback occurs in stands over the entire spectrum of sites, from well-drained lava flows over nutritionally rich volcanic ash to permanently wet bogs with toxic soils. A biotic agent could not be found to cause this dieback. Five main dieback patterns have been recognized, and all are site-specific. These patterns suggest certain causal mechanisms, but they explain only a fraction of the dieback syndrome. A number of additional facts were established which have led to a new dieback theory involving a chain-reaction process: (1) cohort senescing as a predisposing factor; (2) a dieback trigger, which can be either internal (a species characteristic) or external (a fluctuating and recurring site-specific perturbation), and (3) a dieback hastening (biotic agents) or stalling mechanism. It is believed that the dieback phenomenon is not restricted to Hawaii but occurs also in other, functionally similar Pacific forests. A corollary to the Hawaiian dieback etiology is a new succession theory, which explains the temporally recurring dieback as a pattern and process sequence in primary succession. The larger dieback patterns are considered a consequence of catastrophic disturbances in the past, such as lava flows, ash blanket deposits, or landslides, which gave rise to large cohorts. Canopy dieback of these large cohorts during their senescing stage then gives rise to new cohorts. However, these become successively smaller and more patchy with each dieback cycle. Concomitantly with the dieback cycles a turnover of successional races or ecotypes appears to occur within the Metrosideros polymorpha species complex. This may allow us to determine pioneer, seral, and near-climax races within this species complex.