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Browse subject: agroforestry
Number of records: 179

Glossary for Agroforestry
About this Resource: The Glossary for Agroforestry contains terms relating to agroforestry organized alphabetically. Clicking on a letter of the alphabet leads to all the terms in the glossary that begin with that letter. The website provides a link to a library with factsheets, publications, and newsletters. There is also information about the Eastern Arc Mountains and country profiles of Kenya, Tanzania, Uganda, and Africa.

Overstory- International Journal for Agroforestry
About this Resource: Overstory is a free e-mail journal focusing on trees and crops in agroforestry. This site provides previous issues of Overstory, as well as comments by the readers, subscription information.

Agroforestry Advantage
About this Resource: This page features the Center for Integrated Natural Resources and Agricultural Management's newsletter. Through this site users can access past issues of the newsletter.

Agroforestry in British Columbia
About this Resource: This website from the Government of British Columbia gives people information about different aspects of agroforestry in British Columbia. There is information on finances, industry, and government as well as fact sheets and publications.

agroforestry.net
About this Resource: Agroforestry Net, Inc. is a nonprofit organization dedicated to providing educational resources about agroforestry, trees, and sustainable stewardship of land and water. The site contains current project information, publications, and links to other resources on the web.

agroforester.com
About this Resource: Agroforester.com is a site that provides information on tropical forestry and agroforestry. The site provides publications, information on services, training, and education, and links to other resources.

Resource Centre on Urban Agriculture and Forestry
About this Resource: Reducing poverty, generating employment and improving food security are primary goals at the Resource Center on Urban Agriculture and Forestry (RUAF). Working as a global network with the six regional organizations, this website details RUAF's regional activities. The Centre's magazine, Urban Agriculture Magazines, is online in seven different languages. A bibliographic database of shared resources, pools information from: the International Development Research Center, the Urban Agriculture Network, the Food and Agriculture Organization of the United Nations and the African Studies Centre.

Agroforestry Learning Communities in the Northeast
About this Resource: This website provides information on agroforestry in the Northeast United States. The site contains information on crops, forest farming, small farms, and crop tree management. Links to agroforestry related sites are also provided.

Non-timber Forest Products and Agroforestry
About this Resource: This website offers users access to many non-timber forest products and agroforestry websites. There are links to basic information about forests as well as articles and resources about more specific topics.

University of Minnesota - Environment and Natural Resources
About this Resource: A link that identifies resources relating to the relationship of humans to the land. Coverage on environmental protection and management, forests and wood products, water quality, urban and rural development, shoreland protection, waste management and expanding populations.

University of Missouri Center for Agroforestry
About this Resource: The University of Missouri Center for Agroforestry is an interdisciplinary research, teaching and technology transfer program that draws on the expertise of MU faculty in forestry, fisheries and wildlife, entomology, plant pathology, agronomy, animal science, agricultural economics, rural sociology and horticulture. The website features news and information about the Center, as well as general agroforestry information. There is also information about agroforestry in Missouri, research projects, events, and nuts and health. The site also provides publications and other online resources.

Methods to prioritize placement of riparian buffers for improved water quality
About this Resource: Agroforestry buffers in riparian zones can improve stream water quality, provided they intercept and remove contaminants from surface runoff and/or shallow groundwater. Soils, topography, surficial geology, and hydrology determine the capability of forest buffers to intercept and treat these flows. This paper describes two landscape analysis techniques for identifying and mapping locations where agroforestry buffers can effectively improve water quality. One technique employs soil survey information to rank soil map units for how effectively a buffer, when sited on them, would trap sediment from adjacent cropped fields. Results allow soil map units to be compared for relative effectiveness of buffers for improving water quality and, thereby, to prioritize locations for buffer establishment. A second technique uses topographic and streamflow information to help identify locations where buffers are most likely to intercept water moving towards streams. For example, the topographic wetness index, an indicator of potential soil saturation on given terrain, identifies where buffers can readily intercept surface runoff and/or shallow groundwater flows. Maps based on this index can be useful for site-specific buffer placement at farm and small-watershed scales. A case study utilizing this technique shows that riparian forests likely have the greatest potential to improve water quality along first-order streams, rather than larger streams. The two methods are complementary and could be combined, pending the outcome of future research. Both approaches also use data that are publicly available in the US. The information can guide projects and programs at scales ranging from farm-scale planning to regional policy implementation.

World Agroforestry Centre
About this Resource: A CGIAR Research Center and a home page link for the World Agroforestry Center. The Center - headquarters in Kenya - works to improve human welfare by reducing poverty, improving food and nutritional security, and enhancing environmental resillance in the tropics. Employing both strategic and applied research, the Centers' main focus is on sustainability and productive land use. This involves: restoring soil fertility, regenerating degraded land, developing market-driven tree cultivation systems, improving watershed protection, biodiversity conservation and research into carbon sequestration. Finally, the Center intends to develop capacity for agroforest research. A CGIAR Research Center, this home page is a source for graeter understanding.

Forestscience.info
About this Resource: ForestScience.info is an online information resource for forest and wood science. Subject coverage includes agroforestry, community forestry, forest management, forests, nonwood forest products, and wood technology. The database is updated weekly and contains content from 1939 to the present. The site also includes links to the Global Forest Information Service (GFIS) and BIOME, a guide to resources in health and life sciences. There is a link to the Society of American Foresters homepage and information on the Forestry compendium.

Nut-yield variations and yield-diameter relationships in open-canopy black walnut trees in southern USA
About this Resource: Many landowners in the United States have little knowledge of the potential economic returns from agroforestry practices. Economic simulators for temperate agroforestry practices have been generated; yet, there are few data sets on yields of timber and other products to validate and refine such models. The objectives of this study were to characterize variations in nut yields among open canopy eastern black walnut (Juglans nigra L.) trees and apply this information to the development of predictive equations between tree diameter at breast height (DBH) and nut yields. Three data sets were analyzed that included results from Tennessee; Chetopa, Kansas; and Mt Vernon, Missouri. Tree-to-tree variation in nut yields was high within each data set, with coefficients of variation for nut yields typically exceeding 50%. Averaging nut yields over several consecutive years reduced coefficients of variation. Nearly half of the high nut producing trees exhibited an alternate, biennial nut bearing pattern. Trees with low average nut yields had either sporadic or irregular patterns of nut bearing. The regression coefficients for equations relating stem diameter and nut yields varied considerably. Averaging nut yields over consecutive years, and averaging stem diameter and nut yields over a number of trees increased regression coefficients of such equations. These results indicate that predicting nut yields of a tree stand over a several year-period will be easier than predicting yields for a specific tree in a specific year.

An Evaluation of the Contribution of Cultivated Allspice (Pimenta Dioca) to Vertebrate Biodiversity Conservation in Nicaragua
About this Resource: Tropical deforestation has emerged as one of the most important conservation challenges of our time, both because of the high species diversity and rates of endemism of tropical forests, and because of the rapid rate at which this process is proceeding. Recent studies indicate that areas of low-intensity agroforestry have similar levels of vertebrate diversity as some primary habitats, leading some researchers and conservationists to conclude that this type of commodity production could contribute to the conservation of biodiversity. We compared the composition of bird, mammal and herpetofaunal communities in primary forest, secondary forest, and pasture--and within the allspice productive systems that have replaced pasture. We found that mammal species richness was higher in primary forest than all other habitats; however for resident and migrant birds, amphibians and reptiles, species richness was similar between primary forest and the other habitats. Despite similarities in overall numbers of species, there were numerous species that were encountered only in primary habitats. We conclude that the cultivation of allspice in a mixed productive system can offset some of the losses to biodiversity; however it should be complemented by the establishment and maintenance of protected areas to accommodate populations of primary forest specialists that are unable to persist in altered habitats.

Silvicultural systems design with emphasis on the forest canopy
About this Resource: Silvicultural systems design with emphasis on the forest canopy

Botanical composition and forage production in an emulated silvopasture.
About this Resource: Integrating trees into pasture may increase pasture production and improve nutritive value by altering both species composition and productivity. Our objective was to determine forage yield and botanical composition in response to tree species, tree density, and slope position in an emulated silvopasture (the site had no animals). In 1995, black walnut (Juglans nigra L.) and honey locust (Gleditisia triacanthos L.) trees were planted within plots (r = 3) of predominantly tall fescue (Festuca arundinacea Schreb.) pasture. Trees were planted down slopes in rows to create low, medium, and high tree densities at shoulder-, mid-, and toe-slope positions. Sampling sites (n = 54) under field treatment combinations were harvested May to October at 35-d intervals in 2002 and 2003. Before spring, summer, and fall harvests, plots were subsampled for botanical composition. Tree species did not affect botanical composition when compared over the two seasons. Plots under honey locust trees tended to have more fescue in a dry year (2002) and more legumes and less dead herbage in a wet year (2003). Greater percentages of warm-season grasses and fewer weeds were observed at low tree density sites in 2003. Forage mass (5280, 6130, and 4970 kg ha(-1) at low, medium, and high tree densities) was 16% greater under medium-density trees. Plots under black walnut yielded 13% more forage than those under honey locust (5790 vs. 5130 kg ha(-1)). Appropriately spaced trees have potential to positively alter botanical composition and can support greater forage production in a southern Appalachian silvopasture.

Farmers' objectives toward their woodlands in the upper Midwest of the United States: implications for woodland volumes and diversity
About this Resource: This paper reports the results of a study that explores the relationship between farm woodland owners' stated intentions for owning woodland, and the structure and composition of these woodlands in the states of Illinois, Indiana and Iowa in the upper Midwest of the United States. Data from two sample-based inventories conducted by the USDA Forest Service, Forest Inventory and Analysis (FIA) program were combined for this analysis--the FIA forest resources inventory and the National Woodland Owner Survey (NWOS). We looked for relationships between product value and investment in woodlands, as reflected in volumes and tree quality. We also examined whether measures of diversity reflected specific management focus. Our results partially supported our hypotheses. Woodland-focused ownership reasons were found to have larger volumes and individual tree sizes. We found that a passive woodland ownership reason--that woods were “part of the farm”--generally had lower volumes per hectare. Although we were not able to differentiate between different forest product classes and measures of volume, we did find that those landowners who harvested veneer had more volume than those who harvested for firewood. Woodland owners who salvage-harvested their woodlands--a harvesting reason that is more reactive than proactive--exhibited lower volumes per hectare than those who harvested for more proactive, product-focused reasons. Biodiversity was also found to be related to the ownership focus and harvest intent. Generally, there was lower diversity in overstory species when the woodland was viewed merely as “part of the farm,” when the product harvested was fence posts and when timber was harvested for salvage or land clearing. The small sample size limits our analysis, but we can conclude that focusing the woodland owners on management of their woodlands--regardless of what the specific management goals might be--should increase productivity and biodiversity of those woodlands.

Women and Agroforestry: A Human Ecology Approach to Understanding The Needs and Priorities of Women Farmers in Africa
About this Resource: This study examined rural Ugandan women’s lives to discover reasons why they may or may not practice agroforestry. These women are responsible for the triple roles of reproduction, production and community maintenance work, all carried out within the context of a gendered social environment. From the perspective of the social manifestations of gender, six key factors were identified. The findings were used to create a theoretical model of the interaction between rural women’s lives and agroforestry systems. The model shows that agroforestry is not only a biophysical farming system; There is a human component in that interacts with other components to determine the success or failure of an agroforestry initiative. The model can be used to identify and understand the human component of the agroforestry system on an individual and community level.

JOINT MODELING AND SIMULATION OF AUTOCORRELATED NON-NORMAL TIME SERIES: AN APPLICATION TO RISK AND RETURN ANALYSIS
About this Resource: This study presents a technique that can jointly model and simulate the expected values, variances, and covariances of sets of correlated time-series dependent variables that are autocorrelated and non-normal (right or left skewed and/or kurtotic). It illustrates the method by applying it to risk analysis of diversified tropical agroforestry systems.

Towards A National Agribusiness System: A Conceptual Framework
About this Resource: This paper examines today's challenges to the agribusiness sector. Through the Resource-Based View approach, we explore the potential roles and linkages between national public policies and local strategies in order to enhance the competitiveness and sustainability of a national agribusiness system. The main goal is to achieve a strategic alignment between the actions of multiple stakeholders, like firms, research centers, consumers, government, and the society in general. The essence of the paper is synthesized in a framework, which highlights the need for coordination of agribusiness systems by a National Strategy.

Yield components and nutritive value of Robinia pseudoacacia and Albizia julibrissin in Arkansas, USA
About this Resource: Ranchers need alternative livestock feeds when herbaceous forages become limiting in summer. Our objectives were to determine: (1) leaf and stem biomass components, (2) nutritive value [in vitro dry matter digestibility (IVDMD), total nonstructural carbohydrate (TNC), N, and N digestibility] of leaves for animal browse, (3) concentration of the secondary metabolites robinin and mimosine, and (4) in vitro leaf and bark toxicity for black locust (Robinia pseudoacacia L.) and mimosa (Albizia julibrissin Durz.), respectively, pollarded at 50 cm in Arkansas, USA. Black locust exceeded mimosa for every yield component (leaf mass tree-¹, leaves shoot-¹, shoots tree-¹, shoot mass tree-¹, stem basal area, and biomass tree-¹) except mass leaf-¹. Projected yields were 1,900 and 1,600 kg leaves ha-¹ for black locust and mimosa, respectively, assuming a population of 12,300 trees ha-¹. Mimosa leaves had greater IVDMD, TNC, and N digestibility than black locust. Mimosa leaves exceeded the nutritional N requirements of growing cattle (Bos taurus L.) and goats (Capra hircus L.), but protein supplementation would be needed for growing goats grazing black locust leaves. Tissue concentrations of secondary metabolites robinin and mimosine were below detectable limits in black locust and mimosa, respectively. The extract of black locust bark, but not leaves, was toxic to bioassayed African green monkey (Cercopithecus aethiops L.) cells. Either black locust or mimosa could provide moderate quantities of high quality, rotationally grazed forage for goats during summer months when herbaceous forage may in short supply.

Hedgerow Pruning Effects on Light Interception, Water Relations and Yield in Alley-Cropped Maize
About this Resource: In alley cropping, trees and crops compete for light, nutrients, and water. However, there is little information on how hedgerow pruning would impact light interception, water relations, and yield in a maize (Zea mays L.)-mimosa (Albizia julibrissin Durazz) alley-cropping system. Competition between mimosa hedgerows and maize was measured under alley cropping on a compass loam sand in Shorter, AL. Treatments were established in a randomized complete block design and consisted of no pruning or pruning at 30, 30+60 and 30+90 days after maize planting (DAP) and at 5 cm and 50 cm pruning heights. To minimize competition for nutrients, 189 kg N ha-1, 9 kg P ha-1, and 73 kg K ha-1 were applied. Reduction in photosynthetically active radiation (PAR) was assessed periodically. Water status in maize was assessed using a steady state porometer to measure maize leaf stomatal conductance and transpiration rate. PAR was lower in maize rows closest to hedgerows (ROW1) than in second maize rows from hedgerows (ROW2)especially after 60 DAP. After the 90 DAP pruning, 30+90 DAP pruning treatment gave significantly lower stomatal conductance (CD) and transpiration rate (TR) in maize leaves than did 30 DAP or 30 + 60 DAP treatments. ROW1 had high CD and TR, which suggests greater water loss that might reduce final yields. Pruning increased PAR, maize grain and stover yields compared to no-pruning plots. Pruning twice gave higher grain and stover yields than did no-pruning controls. Pruning at 5 cm height gave higher maize yield than pruning at 50 cm. On average, ROW1 had 24% lower yield than did ROW2. Interaction of treatment by row was highly significant. Yield in ROW1 was more affected by pruning treatments than in ROW2. After 90 DAP, 30+90 DAP pruning treatment had lowest shade, followed by pruning treatment 30 + 60 DAP at 5 cm height. Pruning at 90 DAP and pruning at 5 cmheight reduced competition for water and light. Hedgerow pruning can increase light interception and reduce water stress in the maize crop.

Effect of Loblolly Pine Root Pruning on Alley Cropped Herbage Production and Tree Growth
About this Resource: Tillage to disrupt (prune) tree roots is an intensive practice which could improve herbage productivity at the crop-tree interface by reducing competition for water. We compared tillage effects on 9- to 11-yr-old loblolly pine (Pinus taeda L.) growth and herbage yields of annual ryegrass (Lolium multiflorum Lam.) and pearl millet [Pennisetum glaucum (L.) R. Br.] on a fragipan soil in Arkansas. Alley crops were rotationally grown in a 9.7-m wide alley (main plot) between bordering trees on one of three tillage treatments: control (surface tillage), rip followed by surface tillage, and trench plus root barrier followed by surface tillage. Topsoil water in May through September, herbage mass, and nutritive value were measured for each crop for 2 or 3 yr in three subplots systematically arrayed (north, middle, and south) across the alley. Diameter at breast height (DBH, measured 1.3 m above soil surface) and height of border trees were measured annually. Trenching resulted in a more uniform distribution of topsoil water among subplots compared to the other tillage treatments. Annual ryegrass yield did not show a tillage response, but pearl millet yielded more herbage in the rip (6760 kg ha-1 in 2003) and trench (3300 kg ha-1 in 2005) than the control treatment (4990 and 1260 kg ha-1 for 2003 and 2005, respectively). Ripping and trenching significantly reduced loblolly pine DBH and height compared to the control. Similarly configured alley cropping practices probably have little potential for annual herbage production even with root pruning.

Soil phosphorus and water effects on growth, nutrient and carbohydrate concentrations, δ¹³C, and nodulation of mimosa (Albizia julibrissin Durz.) on a highly weathered soil
About this Resource: Growth and physiological performance of multipurpose tree species can be severely constrained by low phosphorus (P) availability in highly weathered soils. Limitations to plant growth are accentuated by seasonal dry periods. The overall objective of this study was to examine P fertilization and irrigation effects on survival, growth, biomass partitioning, foliar nutrients, intrinsic water-use efficiency (WUE) indexed by δ¹³C, Rhizobium nodulation, and carbohydrate content as an indicator of resprouting potential, of mimosa (Albizia julibrissin Durz.), a N₂-fixing tree species being tested for browse in agroforestry practices in south-central USA. In a field experiment carried out during two growing seasons near Booneville, Arkansas, USA, mimosa had a strong growth response to irrigation. The trial was arranged in a split plot design with three replications with irrigation as main plot treatment and P as sub-plot treatment. Mean total plant aboveground biomass at the end of the second growing season was 9.8 and 44.1 g plant⁻¹ for the rainfed treatment without and with 300 mm of irrigation water, respectively. Placed P fertilization increased mean total aboveground biomass from 19 g plant⁻¹ for the 0-P treatment to 69 g plant⁻¹ for the treatment with 90 kg P ha⁻¹ year⁻¹. Similarly, irrigation consistently increased stem basal diameter, total height, survival, root, stem, foliar and total aboveground biomass, and number of nodules per plant. Phosphorus fertilization increased basal diameter, and root and stem biomass in both irrigation treatments, survival and nodulation in the rainfed treatment, and foliar and total aboveground biomass in the rainfed +300 mm irrigation treatment. There was a decrease of foliar δ¹³C suggesting that WUE decreased with P fertilization. In a pot experiment, seedlings were subjected to a factorial combination of two irrigation treatments and six P levels in a randomized complete block design. Irrigation increased basal diameter, root, stem, foliar and total biomass, leaf area and nodulation, whereas P fertilization (i.e., levels from 0 to 3.68 g P kg⁻¹ soil) had similar effect in all the above variables except foliar biomass. Foliar P concentration to obtain 90% of the maximum total plant biomass (critical level) was estimated at 0.157%. Total nonstructural and water soluble carbohydrate, and starch concentrations increased non-linearly with irrigation and P addition suggesting impaired re-growth potential after defoliation of seedlings with reduced water supply and at low soil P availability. Results of this study indicated strong limitations for growth and regrowth potential of mimosa on a highly weathered soil with very low P availability and seasonal water content shortages. Placed (i.e., near the plant base) application of P appeared to be a good strategy to fertilize perennial woody plants.

Methodology for comparative analysis of sustainability in agroforestry systems
About this Resource: The work analyzes the political/institutional links and technological formats of agroforestry systems in the Caí and Taquari river valleys of the Brazilian state of Rio Grande do Sul in an effort to determine a value for their ability to endure: their sustainability. Sustainability indicators are created for the analysis of these systems. The indicator values will be used to create a Sustainability Index (SI) for each studied agroforestry system and to identify each system?s sustainability pattern. The different agroforestry systems will also be classified according to their structural characteristics. Analysis of the identified patterns and indexes will reveal the adequacy of the methodology employed and the consequence of each system?s institutional arrangement, technological format, and sustainability pattern. The agro forestry system that combines exotic forest species with watermelon and the system that combines native forest species with citrus fruit stand out as being most sustainable while, from an institutional perspective, those systems that were linked in an "associative" arrangement had the highest sustainability index values.

ECONOMICS OF AGROFORESTRY PRODUCTION IN IRRIGATED AGRICULTURE
About this Resource: A dynamic optimization model for agroforestry management is developed where tree biomass and soil salinity evolve over time in response to harvests and irrigation water quantity and quality. The model is applied to agroforestry production in the San Joaquin Valley of California. Optimal water applications are at first increasing in soil salinity, then decreasing, while the harvest decision is relatively robust to changes in most of the underlying economic and physical parameters. Drainwater reuse for agroforestry production also appears promising: both net reuse volumes and the implied net returns to agroforestry are substantial.

Dale Bumpers Small Farms Research Center. USDA-ARS.
About this Resource: USDA-ARS's Dale Bumpers Small Farms Research Center (DBSFRC) seeks to develop enhanced small farm production systems. This website describes the Centers' research programs and introduces its' staff.

Soil and litter fauna of cacao agroforestry systems in Bahia, Brazil
About this Resource: Agroforestry systems deposit great amounts of plant residues on soil and this leads to high levels of soil organic matter content and has increased soil biodiversity and improved its conservation. This study compares the distribution of meso and macrofaunal communities in soil and litter under cacao agroforestry systems and in a natural forest in the southern Bahia state of Brazil. Soil and litter samples were obtained in September 2003, February 2004, and August 2004 in five cacao agroforestry systems. The systems evaluated included: cacao renewed under Erythrina sp. (Erythrina poeppigiana) (CRE); cacao renewed under natural forest (Cabruca, CRF); an old cacao system under Erythrina sp. (OCE); an old cacao system under a natural forest system (Cabruca, OCF) and a cacao germplasm collection area (CGC). As a reference soil and litter under a natural forest (NF) was included. Organisms were collected over a 15-day period with a Berlese-Tullgren apparatus. The density and richness of total fauna varied distinctly according to sites, sampling time and material sampled (soil and litter). 16,409 of fauna were recovered from soil and litter samples and the density of total fauna was 2,094 individuals m⁻² in the litter and 641 individuals m⁻² in the soil. The richness was 11.8 in the litter and 7.5 in the soil. The cacao agroforestry systems adopted for growing cacao in the southern Bahia region of Brazil have beneficial effects on the soil and litter faunal communities, and such systems of cacao cultivation could be considered as a conservation system for soil fauna. The development of a litter layer resulted in higher abundance and diversity of soil fauna.

Response of woodland-planted ramps to surface-applied calcium, planting density, and bulb preparation
About this Resource: Concern about over-harvesting wild populations of ramps (Allium tricoccum Ait.) has led to interest in planting ramps as an under-story agroforestry crop. To see if ramps would respond to Ca amendments in an acidic site, we planted three types of ramps bulbs and broadcast slaked lime (3316 kg.ha(-1)) or gypsum (7704 kg.ha(-1)) on a Rayne silt loam (fine-loamy, mixed, mesic Typic Hapludults). After 3 years, surface-applied slaked lime raised Ca levels as deep as the 22.5 to 30 cm layer, which showed an increase of 0.34 cmol(c).kg(-1), and increased pH in the 2.5 to 5.0 cm layer from 3.96 to 4.67. Gypsum application raised Ca concentration in the 22.5 to 30 cm layer from 0.2 in the control to 0.7 cmol(c).kg(-1), but had little effect on pH anywhere in the profile. In plots harvested after 2 years, both amendments increased plant survival and per-plant weight, compared to controls. In plots harvested after 3 years, ramps grown in the slaked lime treatment were heavier than in the gypsum treatment indicating that slaked lime, which raised pH as well as supplied Ca, was probably the better amendment. Single or joined bulbs survived better than bulbs obtained by breaking joined bulbs in two. While more research is needed to overcome limitations to commercial planting of ramps in acidic sites, our data show that Ca application is beneficial to growth and survival of ramps.

Birds as predators in tropical agroforestry systems
About this Resource: Insectivorous birds reduce arthropod abundances and their damage to plants in some, but not all, studies where predation by birds has been assessed. The variation in bird effects may be due to characteristics such as plant productivity or quality, habitat complexity, and/or species diversity of predator and prey assemblages. Since agroforestry systems vary in such characteristics, these systems provide a good starting point for understanding when and where we can expect predation by birds to be important. We analyze data from bird exclosure studies in forests and agroforestry systems to ask whether birds consistently reduce their arthropod prey base and whether bird predation differs between forests and agroforestry systems. Further, we focus on agroforestry systems to ask whether the magnitude of bird predation (1) differs between canopy trees and understory plants, (2) differs when migratory birds are present or absent, and (3) correlates with bird abundance and diversity. We found that, across all studies, birds reduce all arthropods, herbivores, carnivores, and plant damage. We observed no difference in the magnitude of bird effects between agroforestry systems and forests despite simplified habitat structure and plant diversity in agroforests. Within agroforestry systems, bird reduction of arthropods was greater in the canopy than the crop layer. Top-down effects of bird predation were especially strong during censuses when migratory birds were present in agroforestry systems. Importantly, the diversity of the predator assemblage correlated with the magnitude of predator effects; where the diversity of birds, especially migratory birds, was greater, birds reduced arthropod densities to a greater extent. We outline potential mechanisms for relationships between bird predator, insect prey, and habitat characteristics, and we suggest future studies using tropical agroforests as a model system to further test these areas of ecological theory.

AGROFOREST SYSTEM INVESTMENT ANALYSIS UNDER RISK
About this Resource: Agroforestry System is the ecological and economical interaction of the use of the land, with the combination ofagriculture, livestock and forest production, in temporary sequence and in a simultaneous way. The studies of investments in projectsassume the existence of risks and uncertainties. An alternative to reduce the risk in the forest investment is the association with theagricultural. This work analyzed the situations of risk of a system agroflorestal. Monte Carlo s method comes from the theory ofsimulations and stands out as a powerful and useful tool to provide a distribution of probabilities for the analysis of decision. A totalof 10,000 interactions of the Net Present Value (VPL), of Internal Rate of Return (TIR) and of the Equivalent Periodic Benefit (BPE)were made in order to establish the probability distribution. The results presented 78.65% of chance of VPL being US$ 1,410.00;77.56% of chance of TIR being 36.36%, and; 75.39% of chance of BPE being US$ 309.70; the agroforestry system presented lowinvestment risk; and the livestock is the main product of the agrossilvopastoril system, followed by charcoal.

Soil carbon and tree litter dynamics in a red cedar-scotch pine shelterbelt
About this Resource: Carbon sequestration in the woody biomass of shelterbelts has been investigated but there have been no measurements of the C stocks in soil and tree litter under this agroforestry practice. The objective of this study was to quantify C stored in surface soil layers and tree litter within and adjacent to a 35-year-old shelterbelt in eastern Nebraska, USA. The 2-row shelterbelt was composed of eastern red cedar (Juniperus virginiana) and scotch pine (Pinus sylvestris). A sampling grid was established across a section of the shelterbelt on Tomek silt loam (fine, smectitic, mesic Pachic Argiudolls). Four soil cores were collected at each grid point, divided into 0-7.5 and 7.5-15 cm depth increments, and composited by depth. Soil samples were analyzed for total, organic, and inorganic C, total N, texture, pH, and nutrient content. Under the shelterbelt, all surface litter in a 0.5 x 0.5 m² area at each grid point was collected prior to soil sampling, dried, weighed, sorted, and analyzed for total C and N. Average soil organic carbon (SOC) in the 0-15 cm layer within the shelterbelt (3,994 g m-²) was significantly greater than in the cultivated fields (3,623 g m-²). The tree litter contained an additional ~1,300 g C m-². Patterns of litter mass and soil pH and texture suggested increased organic inputs by tree litter and deposition of wind-blown sediment may be responsible for greater SOC beneath the shelterbelt. Further research is needed to identify the mechanism(s) responsible for the observed patterns of SOC within and adjacent to the shelterbelt and to quantify the C in biomass and deeper soil layers.

DEFORESTATION AND AGROFORESTRY ADOPTION IN TROPICAL FORESTS: CAN WE GENERALIZE? SOME RESULTS FROM CAMPECHE, MEXICO AND RONDONIA, BRAZIL
About this Resource: The adoption of sustainable agriculture and other sustainable forestry methods that can help to reduce tropical deforestation have received a great deal of attention in the literature (Adesina and Zinnah 1993, Akinola and Young 1985, Feder and Slade 1984, Holden 1993, Kebede et al. 1990). Although results from different studies can be compared in an absolute sense, there are very few individual studies that compare results and determine, through empirical analysis, whether policy can be universally applied. This paper uses farm-level data to determine whether some universal conclusions can be drawn about the adoption of agroforestry by peasant farmers in developing countries by comparing the land use choices of farmers in Rondônia, Brazil and Campeche, Mexico. The empirical results indicate that education level and the degree of exposure to information about agroforestry significantly influence the adoption of agroforestry and that deforestation levels for farmers in both nations are influenced by the size of the farm lots. The two communities used in the analysis differ in terms of tradition, history, geography, and economics but both experience a link between deforestation and imperfect information. Policies that address imperfect information in developing countries are likely to decrease deforestation as well as improve the well being of residents.

Methodology for comparative analysis of sustainability in agroforestry systems
About this Resource: The work analyzes the political/institutional links and technological formats of agroforestry systems in the Caí and Taquari river valleys of the Brazilian state of Rio Grande do Sul in an effort to determine a value for their ability to endure: their sustainability. Sustainability indicators are created for the analysis of these systems. The indicator values will be used to create a Sustainability Index (SI) for each studied agroforestry system and to identify each systems sustainability pattern. The different agroforestry systems will also be classified according to their structural characteristics. Analysis of the identified patterns and indexes will reveal the adequacy of the methodology employed and the consequence of each systems institutional arrangement, technological format, and sustainability pattern. The agro forestry system that combines exotic forest species with watermelon and the system that combines native forest species with citrus fruit stand out as being most sustainable while, from an institutional perspective, those systems that were linked in an "associative" arrangement had the highest sustainability index values.

ASSESSING THE FINANCIAL RISKS OF DIVERSIFIED COFFEE PRODUCTION SYSTEMS: AN ALTERNATIVE NONNORMAL CDF ESTIMATION APPROACH
About this Resource: Recently developed techniques are adapted and combined for the modeling and simulation of crop yields and prices that can be mutually correlated, exhibit heteroskedasticity or autocorrelation, and follow nonnormal probability density functions. The techniques are applied to the modeling and simulation of probability distribution functions for the returns of three tropical agroforestry systems for coffee production. The importance of using distribution functions that can more closely reflect the statistical behavior of yields and prices for risk analysis is discussed and illustrated.

RISK ANALYSIS UNDER CORRELATED, NON-NORMAL PRICE AND YIELD PROBABILITY DISTRIBUTIONS
About this Resource: Recently developed techniques are combined for modeling mutually correlated crop yields and prices that exhibit heteroscedasticity and autocorrelation, respectively, and follow non-normal probability density functions (pdf's). The importance rigorously modeling these pdf's for financial risk analysis is illustrated through a case study of tropical agroforestry systems for coffee production.

MANAGEMENT STRATEGIES FOR INDONESIAN SMALL-HOLDER RUBBER PRODUCTION IN SOUTH SUMATRA: A BIOECONOMIC ANALYSIS
About this Resource: A simplified version of the BEAM Rubber Agroforestry Model is embedded in a dynamic economic model to examine the impact of uncertainty about prices and climate on decision variables. Solutions, in terms of optimal levels for decision variables are found using a Monte Carlo stochastic framework. These solutions were used to derive risk-efficient frontiers corresponding to different levels of the decision variables. The results underline the importance of including uncertainty in dynamic bioeconomic systems since profits under uncertainty turned out to be quite different from those obtained with prices and climate assumed to be constant.

Proceedings of the Sustainable Taro Culture for the Pacific Conference / Colocasia Taro on Pohnpei Island
About this Resource: Using legends and history, the origin of Colocasia taro on Pohnpei is examined, and its importance culturally and nutritionally is summarized. The most common method of growing taro, integration into the traditional agroforestry system, is described, and a summary of future research needs for Colocasia taro is presented.

Proceedings of the Sustainable Taro Culture for the Pacific Conference / Potentials for Shade Management in Agroforestry Systems for Taro Cropping
About this Resource: This paper discusses the potential benefits from shade management in agroforestry systems for taro cropping. Trial work to evaluate weed growth, taro production, and cultivar responses to shade levels are reviewed. It is concluded that weed growth can be reduced in tree-shaded plots without reducing corm production. Higher crop biomass is obtained when taro is grown under fifty percent shade compared to full sunlight. Furthermore, there is a shade/cultivar interaction which indicates the need to select cultivars appropriate to the shade levels found in farmers' fields. Tree shade in agroforestry plots provides a pleasant environment to carry out heavy tasks such as crop planting and weeding, possibly improving productivity from labor.

Land Dispute Resolution in Mozambique: institutions and evidence of agroforestry technology adoption
About this Resource: Successful adoption of natural resource management technologies requires that important fundamentals of property rights be established. Because disputes over property rights occur universally, the ability to successfully defend one’s rights to property exercises a central influence on the tenure security necessary for technology adoption. However, defending rights to property rests upon the possession of evidence that is readily available and widely regarded as legitimate. This paper presents work carried out in postwar Mozambique on the availability and legitimacy of evidence pertaining to land tenure dispute resolution. What is unusual about the Mozambique case is that the physical presence of a natural resource management technology—agroforestry trees in this case—also serves as one of the most widely available and legitimate forms of evidence in the postwar period. Such an arrangement reveals important aspects about the reverse relationship between property rights and technology adoption. While such an evidence role for a technology may at first appear to encourage further adoption of agroforestry, important influences on property rights in the postwar setting serve to discourage full adoption and jeopardize the long-term presence of existing agroforestry trees. It remains to be seen if recent legislative changes regarding property rights will successfully engage customary forms of evidence and encourage full adoption of agroforestry in Mozambique.

REGIONAL DRAINWATER MANAGEMENT: SOURCE CONTROL, AGROFORESTRY, AND EVAPORATION PONDS
About this Resource: Source control is one way to address salinity and drainage problems in irrigated agriculture, and reuse of drainage flows on salt-tolerant crops or trees in agroforestry production is another. A regional model of agricultural production with drainwater reuse and disposal is developed. Deep percolation flows are controlled through choice of crop areas, irrigation systems, and applied-water quantities. Crop drainwater may by reused in agroforestry production, and residual emissions are disposed of in an evaporation pond. A significant role for both source control and reuse is found. Sensitivity to various cost and revenue parameters is also analyzed.

Economic Incentives for Entry and Exit in Gum Arabic Agroforestry System in Sudan
About this Resource: The gum tree (Acacia senegal) in the Sahel-Sudan zone has many environmental benign functions. An important function is to control desertification. In this paper we analyze farmers’ economic incentives to preserve the existing gum trees and their incentives to create new plantations using a real options approach. Results indicate that agricultural crops provide higher economic benefits as compared to gum agroforestry system. However, on the one hand, as gum arabic is produced during the dry period and land is abundant, there are low incentives for deforestation. Instead, farmers’ tend to leave the land idle and let the tree growing. On the other hand, our results suggest that an increase in the prices of gum arabic of about 330 per cent is needed to induce entry and a shift in land use system from continuous agricultural production to gum agroforestry system.

Comparing Profitability and Cash Flows of Agroforestry and Agriculture on Australian Farms
About this Resource: This paper is a summary of a project that compared the relative profitability of existing, emerging and prospective agroforestry systems with profitability of conventional agricultural land uses in the cropping zones of Western Australia and New South Wales. The project explored the economic boundary conditions under which several promising agroforestry systems may be viable in the lower rainfall zones. Partial budgeting and discounted cash flow techniques were used to conduct the comparative analysis of alternative land use scenarios. The profitability, cash flows and debt associated with each of the scenario are reported. The analysis underpinning this research provides estimates of the economic value of the temporal and spatial interaction effects of trees on agricultural crops and pastures.

PROPOSAL OF A MINIMUM SET OF BIOPHYSICAL INDICATORS FOR MONITORING THE SUSTAINABILITY IN AGROFORESTRY SYSTEMS
About this Resource: Agroforestry Systems are considered sustainable alternatives to intensive production systems and due to the scarcity of research work related to the evaluation of sustainability of Agroforestry Systems, selection criteria are proposed which were applied to indicators already known in the pertinent literature. The objective of this paper comprised therefore the use of the smallest group of indicators which would be able to satisfy the requirements for monitoring environmental sustainability of Agroforestry Systems including or not the animal component. The main conclusions were: the category of endogenous resources involved the greatest number of indicators in the biophysical component; the greatest concentration of indicators in the category of endogenous resources is located in the fauna, flora and soil components; the element technical management showed the major occurrence of indicators in the category of operation of the system; all elements of the category of exogenous resources showed about the same number of indicators; the animal component of the Agroforestry Systems require greater number of indicators; the majority of the indicators suggested in this paper depend only upon the direct observations and only a small number need laboratorial analyses; most indicators suggested is cheap and easy to apply; Agroforestry Systems without the animal component are easier and cheapes to monitor.

Eucalipto em Sistemas Agrossilvipastoris (Eucalyptus in Agricultural-forestry-pasture Systems)
About this Resource: ResumenA produção pecuária Brasileira hoje em dia tem de competir com diversas outras culturas que podem proporcionam maiores rentabilidades e para que isso não ocorra, a maximização da produtividade tem de ser intensificada. Uma maneira ambientalmente correta de aumento da renda é a utilização de sistemas agroflorestais. Os sistemas agroflorestais são utilizados para produção de materiais como madeira, alimentos para o homem e também para os animais promovendo a sustentabilidade do sistema. Nesta revisão são abordados aspectos quanto à utilização do Eucalipto em sistemas agroflorestais com objetivo de maximização da produtividade. SummaryThe Brazilian cattle production nowadays compete with many others crops that can be more rentable and to this don’t occur, the maximization of the system must be done. A correct environmental way for increasing rentability is the use of agroforestry systems. The agroforestry systems are used to produce materials like wood, timber, food for people and also feed for the animals. In this review aspects about the use of eucalyptus in agroforestry systems with the intention of increase productivity are.

Could carbon payments be a solution to deforestation? Empirical evidence from Indonesia
About this Resource: Up to 25 percent of all anthropogenic greenhouse gas emissions are caused by deforestation, and Indonesia is the third largest emitter worldwide due to land use change and deforestation. On the island of Sulawesi in the vicinity of the Lore Lindu National Park, smallholders contribute to conversion processes at the forest margin as a result of their agricultural practices. Specifically the area dedicated to cocoa plantations has increased from zero in 1979 to nearly 18,000 hectares in 2001. Some of these plots have been established inside the 220,000 hectares of the National Park. An intensification process is observed with a consequent reduction of the shade tree density. This study focuses on the impact of carbon sequestration payments for forest management systems on smallholder households. The level of incentives is determined which motivates farmers to desist from further deforestation and land use intensification activities. Household behaviour and resource allocation is analysed with a comparative static linear programming model. As these models prove to be a reliable tool for policy analysis, the output can indicate the adjustments in resource allocation and land use shifts when introducing compensation payments. The data was collected in a household survey in six villages around the Lore Lindu National Park. Four household categories were identified according to their dominant agroforestry systems. With carbon credit prices up to €32 tCO2e-1 an incentive can be provided for the majority of the households to adopt the more sustainable shade intensive agroforestry systems. The results show that with current carbon prices the deforestation activities of the majority of households could be stopped. A win-win situation seems to appear, whereby, when targeting only the shade intensive agroforestry systems with carbon payments, the poorest households economically benefit the most, the vicious circle of deforestation can be interrupted and land use systems with high environmental benefits are promoted.

Soil enzyme activities and physical properties in a watershed managed under agroforestry and row-crop systems
About this Resource: The proportion of water-stable aggregates (WSA) and a diverse microbial activity influence soil quality, crop growth, nutrient retention, water infiltration, and surface runoff. The objective of the study was to test the hypothesis that permanent vegetative buffers increase WSA and contribute to increased soil enzyme activity. Soil samples (5cm diameter and 10cm long) from agroforestry (AG), grass buffer (GB), grass waterway (GWW) and crop (CS) areas were collected from summit, middle, and lower landscape positions at the Paired Watershed Study, near Novelty, MO. Water-stable aggregates (>250μm diameter; wet-sieving method), soil carbon, and soil enzyme activity were determined and data were statistically analyzed. Soils under permanent vegetative buffers and GWW had significantly lower bulk density and more WSA than the crop areas. Soil carbon contents were highest in the GWW and lowest in the CS treatments. Fluorescein diacetate (FDA) hydrolase, β-glucosidase, and glucosaminadase enzyme activities were higher in AG, GB, and GWW soils than CS soils. Dehydrogenase activity differed between grass buffer or GWW and crop areas. The results of the study show that WSA, soil carbon, and functional diversity of enzyme activity increased due to establishment of buffers with trees and grass. It can be speculated that increased diversity of functional enzymes associated with cycling of key soil nutrients and improved soil physical properties may reduce nonpoint source pollution (NPSP) from row-crop agriculture watersheds thus improving overall environmental quality.

VALUING AGROFORESTRY IN THE PRESENCE OF LAND DEGRADATION
About this Resource: Agroforestry can help prevent land degradation while allowing continuing use of land to produce crops and livestock. A problem with the evaluation of agroforestry using long-run static models and traditional discounting techniques is that the present value of the forestry enterprise is generally much lower than that of other production activities. This problem is common with Australian native species which tend to have a high environmental value but a low market value. This paper presents an economic analysis of an agroforestry operation in land prone to degradation and in the presence of positive externalities provided by trees. The value of the land is estimated based on the present value of expected returns in perpetuity under optimal management. Simulation analysis is used to evaluate the loss in land value caused by dryland salinity. A nonlinear programming model is developed and used to study the effects of timber prices and forest planting costs on optimal forest area and the level of salinity. Elasticities of relevant variables with respect to prices and costs are derived and policy implications of results are discussed.