Types Of Agroforestry Systems Research Articles

Revisiting IPCC Tier 1 coefficients for soil organic and biomass carbon storage in agroforestry systems

Agroforestry systems comprise trees and crops, or trees and pastures within the same field. Globally, they cover approximately 1 billion hectares of land and contribute to the livelihoods of over 900 million people. Agroforestry systems have the capacity to sequester large quantities of carbon (C) in both soil and biomass. However, these systems have not yet been fully considered in the approach to C accounting developed by the Intergovernmental Panel on Climate Change, largely due to the high diversity of agroforestry systems and scarcity of relevant data. Our literature review identified a total of 72 scientific, peer-reviewed articles associated with biomass C storage (50) and with soil organic carbon (SOC) (122), containing a total of 542 observations (324 and 218, respectively). Based on a synthesis of the reported observations, we are presenting a set of Tier 1 coefficients for biomass C storage for each of the eight main agroforestry systems identified, including alley cropping, fallows, hedgerows, multistrata, parklands, shaded perennial-crop, silvoarable and silvopastoral systems, disaggregated by climate and region. Using the same agroforestry classification, we are presenting a set of stock change factors (FLU) and SOC accumulation/loss rates for three main land use changes (LUCs): cropland to agroforestry; forest to agroforestry; and grassland to agroforestry. Globally, the mean SOC stock change factors (± confidence intervals) were estimated to be 1.25 ± 0.04, 0.89 ± 0.07, and 1.19 ± 0.10, for the three main LUCs, respectively. However, these average coefficients hide huge disparities across and within different climates, regions, and types of agroforestry systems, highlighting the necessity to adopt the more disaggregated coefficients provided herein. We encourage national governments to synthesize data from local field experiments to generate country-specific factors for more robust estimation of biomass and SOC storage.

Carbon stock in the development of different designs of biodiverse agroforestry systems

ABSTRACT The objective of this study was to estimate the carbon stock in the different designs of biodiverse agroforestry systems (AFSs) in the region of the Environmental Protection Area (EPA) of Pratigi, Bahia, Brazil. Phytosociology aspects related to the potentiality of carbon stock of 10 farms were evaluated using plots of 10 x 50 m allocated in each AFS, inventorying 928 individuals of 17 families and 37 species, established in 2013. The biomass above and below the soil of the arboreal individuals were estimated by indirect method, using specific allometric equations for each species or group of species, with diameter above 1 cm. Carbon stock (CS) was estimated from the biomass. Cacao (Theobroma cacao) and rubber tree (Hevea brasiliensis) were the dominant species in all of the designs, which also contained fruit trees, and native and exotic shade trees. There was variation of the estimate of carbon stock (8.01-1.42 Mg ha-1) between the types of AFSs. The designs with a larger relative density of fruit and shade trees led to larger carbon storage, influenced by the wealth and diversity of species in the initial phase of establishment of biodiverse AFSs.

Los agroecosistemas cafetaleros modernos y su relación con la conservación de mariposas en paisajes fragmentados

Land use change by the intensification of agriculture contributes to tropical forest fragmentation and biodiversity loss. In this sense, in comparison with traditional agroforestry systems (AFS), modern AFS are considered irrelevant for the conservation of biodiversity of tropical forest fragments. However, there is an increasing trend toward the establishment of different types of modern AFS. Owing to the sensitivity to environmental changes, we evaluated the biodiversity of butterflies in AFS with Coffea arabica and Erythrina poeppigiana (CP), and intermixed with Musa spp. (CPM) or Cordia alliodora (the only native species of AFS) (CPL), as well as premontane very humid forest fragments in the Volcánica Central-Talamanca Biological Corridor, Costa Rica. In six representative sites of each system we set up three parallel 80 m line-transects, separated by a distance of 25 m. Each coffee farm and forest fragment (FR) was surveyed during 1.5 hours to record butterflies. All sites were sampled once a month from May to July 2007. We obtained 4.5 hours of sampling/site, and 27 hours of sampling/habitat. Both CP and CPM together had a butterflies’ species composition which differed from CPL and FR. The indicator species of both CP and CPM together were Hermeuptychia hermes and Anartia jatrophae which are typical of open areas. CPL resulted with the species of secondary forests Heliconius erato petiverana and Pareuptychia ocirrhoe as indicators. In contrast, FR resulted with several indicator species typical of closed canopy forests such as Pierella helvina incanescens, Caligo eurilochus, and Morpho peleides limpida. Moreover, the richness of species was similar among coffee AFS. Furthermore, the richness of species of each coffee AFS was lower in comparison with FR. However, among coffee AFS, CPL harbored higher diversity (Exp(H’)) of forest butterflies than CP. Also, CPM was higher in abundance of frugivorous butterflies in relation with CP and CPL. In fragmented forests, coffee farms with exotic shade species combined at least with a native tree or fruit species, can be a better habitat for forest butterflies than those dominated by an exotic monospecific shade.

Which agroforestry options give the greatest soil and above ground carbon benefits in different world regions?

Climate change mitigation and food security are two of the main challenges of human society. Agroforestry systems, defined as the presence of trees on external and internal boundaries, cropland, or on any other available niche of farmland, can provide both climate change mitigation and food. There are several types of agroforestry systems with different rates of above ground and soil carbon (C) sequestration. The amount of carbon sequestered can depend on the type of system, climate, time since land use change and previous land use. Data was collected from a total of 86 published and peer reviewed studies on soil and above ground carbon sequestration for different agroforestry systems, climates and regions in the world. The objective was to understand which agroforestry systems provide the greatest benefits, and what are the main factors influencing, soil and above ground carbon sequestration. The results show that, on average, more soil carbon sequestration occurs in agroforestry systems classified as silvopastoral (4.38tCha−1yr−1), and more above ground carbon sequestration occurs in improved fallows (11.29tCha−1yr−1). On average, carbon benefits are greater in agroforestry systems Tropical climates when compared to agroforestry systems located in other climates, both in terms of soil (2.23tCha−1yr−1) and above ground (4.85tCha−1yr−1). In terms of land use change, the greatest above ground carbon sequestration (12.8tCha−1yr−1) occurs when degraded land is replaced by improved fallow and the greatest soil carbon sequestration (4.38tCha−1yr−1) results from the transition of a grassland system to a silvopastoral system. Time since the change is implemented was the main factor influencing above ground carbon sequestration, while climate mainly influences soil carbon sequestration most. The results of the analysis may be used to inform practitioners and policy makers on the most effective agroforestry system for carbon sequestration. The lack of data on carbon stocks before the implementation land use change and the lack of reporting on soil sampling design and variances were the main limitations in the data. The need to report this data should be considered in future studies if agroforestry systems are expected to play an important role as a climate change mitigation strategy.

Spatial similarities between European agroforestry systems and ecosystem services at the landscape scale

Agroforestry systems are known to provide ecosystem services which differ in quantity and quality from conventional agricultural practices and could enhance rural landscapes. In this study we compared ecosystem services provision of agroforestry and non-agroforestry landscapes in case study regions from three European biogeographical regions: Mediterranean (montado and dehesa), Continental (orchards and wooded pasture) and Atlantic agroforestry systems (chestnut soutos and hedgerows systems). Seven ecosystem service indicators (two provisioning and five regulating services) were mapped, modelled and assessed. Clear variations in amount and provision of ecosystem services were found between different types of agroforestry systems. Nonetheless regulating ecosystems services were improved in all agroforestry landscapes, with reduced nitrate losses, higher carbon sequestration, reduced soil losses, higher functional biodiversity focussed on pollination and greater habitat diversity reflected in a high proportion of semi-natural habitats. The results for provisioning services were inconsistent. While the annual biomass yield and the groundwater recharge rate tended to be higher in agricultural landscapes without agroforestry systems, the total biomass stock was reduced. These broad relationships were observed within and across the case study regions regardless of the agroforestry type or biogeographical region. Overall our study underlines the positive influence of agroforestry systems on the supply of regulating services and their role to enhance landscape structure.

How local stakeholders perceive agroforestry systems: an Italian perspective

This paper reports the results of a study conducted in Italy, within the AGFORWARD (2014–2017) project, aimed at promoting innovative agroforestry practices in Europe. Agroforestry offers a means for maintaining food production whilst addressing some of the negative environmental effects of intensive agriculture. This study aims to elicit the positive and negative points of view and perceptions of local stakeholders in Italy in relation to three types of agroforestry systems. The Participatory Research and Network Development was implemented in three workshops conducted in Sardinia, Umbria, and Veneto regions, and applied adopting a common methodological protocol. Qualitative data were obtained using open discussions with stakeholders on key issues, challenges and innovations. Quantitative data were obtained from stakeholders completing questionnaires during the workshops. A statistical analysis was applied to elicit the differences in stakeholders’ positive and negative perceptions in relation to production, management, environment and socio-economy aspects. Although the participants in the study came from different geographical and socioeconomic contexts with varied educational and cultural backgrounds, the different professional groups (farmers, policy-makers and researchers) and the three workshops generally shared similar perceptions of the benefits and constraints. The effects of agroforestry on production and the environment were generally perceived as positive, whilst those related to management were generally negative. The process of bringing the groups together seemed to be an effective means for identifying the key research gaps that need to be addressed in order to promote the uptake and maintenance of agroforestry.

Agroforestry Systems as Alternative Land-Use Options in the Arid Zone of Thal, Pakistan

Agroforestry offers unique opportunities for increasing biodiversity, preventing land degradation, and alleviating poverty, particularly in developing countries, but factors explaining the adoption by farmers are not well understood. A survey of 524 farm households was conducted in Bhakkar district of Punjab, Pakistan to study factors that determine the adoption of agroforestry on the sand dunes in the resource-deficient region of Thal. Two types of agroforestry systems were studied: intercropping and border cropping (also known as boundary or perimeter planting). Both agroforestry systems included irrigated cultivation of the timber trees Eucalyptus camaldulensis (local name: sufeda) and Tamarix aphylla (local name: sars) with wheat, chickpeas (Cicer arietinum) (local name: chana) or cluster beans (Cyamous tetragocalobe) (local name: guars). The majority of the farmers was in favour of intercropping and border cropping. Most farmers reported the protection of nearby crops from dust storms as the most important positive perception about both agroforestry systems. Age, education, and farm to market distance were significant determinants of agroforestry adoption. Older and less-educated farmers, with farms closer to markets were less likely to adopt tree planting or border cropping in Thal. In general, the agroforestry systems examined were more likely to be adopted by farmers who can wait 3–4 years for harvesting crop outputs, but not by poorer farmers who are totally dependent on subsistence agriculture and cannot afford the high initial cost of agroforestry establishment, nor can they wait for crop output for extended periods. Furthermore, the adoption of both agroforestry systems was more likely in remote marginal areas than in areas close to markets. To increase agroforestry adoption rates, government policies should strengthen farmers’ knowledge of every stage of agroforestry through extension services, focusing particularly among the prime prospects, i.e. farmers who will be most likely to adopt agroforestry. Once the prime prospects have adopted it, the older, less-educated, and poor farmers of the rural population can be also focused on to motivate adoption.

Agroforestry Systems as Habitat for Avian Species: Assessing Its Role in Conservation

In the current scenario of rapid conversion of tropical forests into human-dominated activities landscape, the present study was undertaken to understand the role of existing agroforestry systems in conservation of avian species. Three types of agroforestry systems namely tea gardens, homegardens and agrisilviculture were selected in the Brahmaputra North Bank Landscape of Assam, northeast India for the study. A total of 468 point counts revealed 164 bird species belonging to 51 families and 18 orders across all the three different types of agroforestry systems. Tea gardens showed significantly higher bird species richness followed by homegardens and agrisilviculture systems. As per IUCN, four species were categorized as Near Threatened and one species was categorized as Vulnerable. Out of 164 species recorded, 68.3% species were residents, 30.5% species were winter visitors and remaining were summer visitors (1.2%). Majority of the species (45.7%) were common to all the three types of selected agroforestry systems. The feeding guilds revealed that most of the species were insectivorous (50.0%) in habit. A total of 167 tree species belonging to 54 families and 24 orders was recorded across all the three different types of agroforestry systems. The highest tree species richness was recorded in the homegardens (160), followed by agrisilviculture systems (19) and least in tea gardens (11). No statistically significant correlation was found among bird species richness and patch size, tree species richness and number of bird species individuals. The selected agroforestry systems have provided shelter, nesting space, feeding and foraging grounds for birds during the winter season. This data can be useful for the policy makers, tea garden managers, homegarden owners for framing conservation policies of avian species in an era of natural wildlife habitat loss and degradation.

Effect of grazing on carbon sequestration and tree growth that is developed in a silvopastoral system under wild cherry (Prunus avium L.)

Silvopastoral systems have been considered a good tool for carbon sequestration by taking up atmospheric carbon dioxide and storing it in the soil. The effect of animal presence on carbon sequestration in this type of agroforestry system has been studied recently. However, the soil carbon storage in these systems is influenced by the stocking rate. In addition, soil fractions have been known to influence carbon storage. This study was undertaken in order to examine the effects of livestock grazing at two different stocking rates [Light Stocking Rate (LS; 4sheepha−1) and Heavy Stocking Rate (HS; 8sheepha−1)]. This was compared with the soil chemical and physical properties of No Grazing (NG) pastures, the amount of C stored in the whole soil, in three different soil fractions (250–2000, 53–250, and <53μm), at each of four soil depths (0–25, 25–50, 50–75, and 75–100cm), and the tree growth in a silvopastoral system under Prunus avium L. The presence of animals in silvopastoral systems plays an important role in carbon sequestration by the direct or indirect modifications of the pH, the soil bulk density, and the soil fraction proportions. The LS treatment promoted carbon sequestration linked to macroaggregates in the upper soil layers when compared with the HS treatment and the NG treatment. However, in deep horizons, the NG treatment enhanced the soil organic carbon storage more than did the grazing treatments and this carbon was linked to microaggregates, increasing the soil density. A better carbon concentration was found when 1m of soil depth was evaluated in an LS treatment, but no differences were apparent in the carbon storage per hectare that were found due to a high soil bulk density in an NG treatment.

Timber yield from smallholder agroforestry systems in Nicaragua and Honduras

The importance of tropical timber is increasing worldwide. However, the timber supply of tropical forests has been greatly impacted by growing deforestation associated with complex and restrictive timber harvest laws. In Central America, as well as in other developing regions, reforestation programs have often fallen short of expectations. In these cases, agroforestry proves to be a useful strategy for providing tropical timber supplies for smallholder farmers, rural development and environmental services. Timber yields and their potential revenues in four types of agroforestry systems (silvopastoral, coffee, cocoa and living fences) were researched in Nicaragua and Honduras. The results suggest that smallholder timber production in agroforestry systems is a profitable activity despite lower market prices than commanded by timber from forests. The net value from timber sales represents 11–49 % of the total revenue from agroforestry systems. However, this amount could be 58 % higher if farmers were able to improve management practices. Encouraging the knowledge and adoption of silvicultural practices in agroforestry systems is important to increasing timber revenues among smallholder farmers in Central America.

Climate diversity in line with agroforestry systems: studying technicalities of agroforestry systems and allied components in two diverse climatic regions (Warm climate vs. cold climate) (Case study: Kazeroun & Sepidan in Fars Province, I.R.Iran)

There has been some decline in the land potential capacity in many developing countries, and depending on location,the multi objective management strategy of Agroforestry can make effective use of natural resources to be feasible.Environmental principles which are effective on Agroforestry systems and their components, together with climaticfactors, are the important parameters which been evaluated in this study. Two cities, Kazeroun (with warm climate) andSepidan (with cold climate) in Fars province, were chosen for the purpose of this research, and after proper identificationand classification of the Agroforestry systems, the effects of climatic factors were analyzed. Nineteen points wereidentified in these two cities by field investigations, with each type of Agroforestry systems and their correspondingcomponents determined in each point. From the results, most of the systems in Kazeroun, characterized with warmclimate, were Agrosilvopastoral, while Sepidan with a characteristic cold climate was the Agrosilvicultural system. Also,the components of each system clearly changed with change in climate, owing to the great importance of the livestock andcrop components in Kazeroun and Sepidan, respectively. In general, it can be concluded that the impact of climatic factorson Agroforestry systems and their components has been approved in this study, and the results can be applied indeveloping these systems in other regions.

Estimation of Economic Value of Agroforestry Systems at the Local Scale in Eastern Sudan

The objective of this paper is to institute farmers’ own perceptions of the on-and off-farm benefits of agroforestry systems (AFS). Using use value approach, this paper presents empirical evidence on the use values of three types of AFS practiced by the refugees and their hosting communities in Eastern Sudan. The total economic value (TEV) was applied as a framework to estimate the ecosystem values of AFS under study. Goods values were estimated using specific market values, while the services values were qualitatively described according to local perceived values of the local communities. Perceived TEV of AFS includes marketable and non-marketable goods and services. The main direct marketable and sustainable high value products include: food, cash crops, firewood, gum, fodder, NTFPs medicine, fodder, and honey. The valuation results reveal that AFS in the project sites have significantly contributed to the livelihoods of the local communities. Overall, the average net direct-use value of marketable products across all sites was estimated at 7,346,000.0 SDG (1,335,636.36 US$) HH/annum. Gum Arabic alone accounted for 38%, followed by sorghum grain and fodder 35%, and cash crops (sesame) 18%. This value would be many time higher if other indirect values (non-marketable) services such as shade, aesthetic and recreation, environmental protection, biodiversity and carbon sequestration are quantified. The goods and services mentioned above provide sustainable income to the farmer directly and viable benefits to the region indirectly. Hence, AFS in the study sites shows the way to reconcile two conflicting goals: short-term food and livelihood needs with long-term environmental conservation and improvement. The study provides evidence that the high local perceived values of AFS in the study sites constitute a central means of livelihood, whereas its contribution to the local economy. The study stresses the need to quantify the monetary values of non-marketed products to consistently account for resource availability and usage to further sound policy decisions. Tenure security, farmer support services and human capital development were major areas identified for policy development.

Physical Feasibility Study of Agroforestry Farm Systems to Support Sustainable Agriculture in Konaweha Sub Watershed of Southeast Sulawesi

The farming systems in Konaweha watershed are mostly mixed garden that are partly managed intensively as wellas traditionally. The objectives of this research were to identify and classify agroforestry systems that were practicedby farmers, to study the effect of the agroforestry systems on soil properties, hydrological indicators, and erosion,as well as to analyze farm management feasibility of agroforestry systems to establish sustainable agriculturesystem. The study was carried out in Konaweha watershed, Southeast Sulawesi. The results indicated thatagroforestry systems in this area were devided into four types i.e. sylvopastoral-perennial crops with pasture,agrosylvicultural-perennial crops, agrosylvicultural-multystrata systems, and sylvopastoral-multystrata systems.The four types of agroforestry systems significantly increased the soil aggregate stability, soil porosity at 30 cm indepth, organic matter, soil organic carbon, and microorganisms population. In addition, the agroforestry haddecreased runoff and erosion significantly. Therefore, the erosion rate from the four types of agroforestry systemwas below the value of tolerated soil loss (TSL), except that of agrosylvicultural-perennial crops with an elevationof &gt; 30%. The best quality of soil and environment was found at sylvopastoral-multystrata systems.Keywords: Agroforestry; erosion; soil properties; sustainable agriculture[How to Cite: Marwah S. 2012. Physical Feasibility Study of Agroforestry Farm Systems to Support Sustainable Agriculture in Konaweha Sub Watershed of Southeast Sulawesi. J Trop Soils, 17 (3) : 275-282. doi: 10.5400/jts.2012.17.3.275][Permalink/DOI: www.dx.doi.org/10.5400/jts.2012.17.3.275]

Carbon outcomes of major land-cover transitions in SE Asia: great uncertainties and REDD+ policy implications.

Policy makers across the tropics propose that carbon finance could provide incentives for forest frontier communities to transition away from swidden agriculture (slash-and-burn or shifting cultivation) to other systems that potentially reduce emissions and/or increase carbon sequestration. However, there is little certainty regarding the carbon outcomes of many key land-use transitions at the center of current policy debates. Our meta-analysis of over 250 studies reporting above- and below-ground carbon estimates for different land-use types indicates great uncertainty in the net total ecosystem carbon changes that can be expected from many transitions, including the replacement of various types of swidden agriculture with oil palm, rubber, or some other types of agroforestry systems. These transitions are underway throughout Southeast Asia, and are at the heart of REDD+ debates. Exceptions of unambiguous carbon outcomes are the abandonment of any type of agriculture to allow forest regeneration (a certain positive carbon outcome) and expansion of agriculture into mature forest (a certain negative carbon outcome). With respect to swiddening, our meta-analysis supports a reassessment of policies that encourage land-cover conversion away from these [especially long-fallow] systems to other more cash-crop-oriented systems producing ambiguous carbon stock changes - including oil palm and rubber. In some instances, lengthening fallow periods of an existing swidden system may produce substantial carbon benefits, as would conversion from intensely cultivated lands to high-biomass plantations and some other types of agroforestry. More field studies are needed to provide better data of above- and below-ground carbon stocks before informed recommendations or policy decisions can be made regarding which land-use regimes optimize or increase carbon sequestration. As some transitions may negatively impact other ecosystem services, food security, and local livelihoods, the entire carbon and noncarbon benefit stream should also be taken into account before prescribing transitions with ambiguous carbon benefits.

Evolution of agroforestry based farming systems: a study of Dhanusha District, Nepal

This paper examines how agroforestry-based farming systems evolved in the Dhanusha district of Nepal following the conversion of forest into agriculture during the early 1950s. Some data are from two focus group discussions with agroforestry farmers and one meeting with agroforestry experts. The farmers’ discussion traced the development of farming practices from 1950 to 2010 to identify the drivers of land use change. The experts’ discussion resulted in a scale to differentiate the prevailing farming systems in the study area considering five key components of agroforestry: agricultural crops, livestock, forest tree crops, fruit tree crops and vegetable crops. Data related to the system components were collected from the randomly selected households. The study reveals that land use had generally changed from very simple agriculture to agroforestry, triggered by infrastructure development, technological innovations, institutional support (subsidies and buy-back guarantees) and extension programs. A range of farming systems with varying degrees of integration was evident in the study area: simple agriculture; less integrated agroforestry; semi-integrated agroforestry and highly integrated agroforestry. The three types of agroforestry systems, which are the focus of this study, varied significantly in terms of farm size, cropping intensity, use of farm inputs, tree species diversity, tree density, home to forest distance and agricultural labour force.

Tree Growth Prediction in Relation to Simple Set of Site Quality Indicators for Six Native Tree Species in the Philippines

The gain in precision to explain the variation on tree growth performance as a function of a set of site indicators was analysed in a stepwise form, increasing its complexity and costs. Six native timber tree species were commonly found on farmer's fields and planted under different types of agroforestry systems. Localization of trees to be used for measurement was achieved through individual interviews to assess timing of introduction of trees. Results proved that native tree species planted on farmers' fields have similar growth rate other exotic timber species asSwietenia macrophyllathat are widely spread in the Philippines. Nevertheless, the large fraction of the variation in tree performance that could not be explained by the biophysical site indicators measured implies that farmers take considerable risk in planting trees on the basis of current “scientific” knowledge. The complement of “site characteristics” is probably “management”, and the low determination of tree growth by site properties may in fact be good news for the farmers.

Mineralization Dynamics of Nitrogen and Phosphorus in Areca Catechu L.–Based Traditional Agroforestry System

Areca catechu L.–based agroforestry system is practiced by local farmers in which a variety of crops are cultivated along with trees to maximize harvest security. Most farmers do not use inorganic fertilizers to improve crop yields, mainly because they cannot afford to purchase these fertilizers, and for this reason cycling of nutrients through the decomposition of plant residues becomes an important phenomenon in this type of agroforestry system. In this context, a study was carried out to estimate in situ nitrogen (N) and phosphorus (P) mineralization as influenced by soil type and management system. Net N and P mineralization rates were studied on the basis of final concentrations of ammonia, nitrate, and P in soil using a buried‐bag technique for one cropping cycle to examine temporal and depth variations across the three different sites (Harmutty, Nirjuli, and Doimukh). A significant variation in N mineralization was recorded among the three sites. Seasonal changes in N and P mineralization were also observed. The Harmutty site had highest rates of N mineralization during the rainy season and immobilization during spring. Phosphorus mineralization rate was higher during autumn at Doimukh and during winter in Harmutty and Nirjuli sites, whereas greater immobilization was recorded during the rainy season. The Harmutty site recorded a greater ammonification rate during September and immobilization during November and March months, the Nirjuli site recorded maximum ammonification during January and immobilization during November and March, and the Doimukh site had greater immobilization during March and ammonification during January. Nutrient dynamics may prove productive if managed properly in synchronization with mineralization that could result in fairly good crop productivity.

Influence of specific gravity on wood species selection for agroforestry in some Local Government Areas of Oyo State, Nigeria

Specific gravity (SG) of wood has not been adequately reported to be a factor directly or indirectly influencing its selection for incorporation into or retention in some of the agroforestry systems. In this study, the SG of twelve wood species that top the priority ranking of respondents in Akinyele and Ido Local Government Areas (LGAs), Oyo State, Nigeria, where the predominant type of agroforestry system practiced is that of scattered trees in croplands, were evaluated and found to range between 0.42 and 0.85 with eleven of the species having values > 0.60. Ranking pattern by the respondents in the two LGAs was found not to be significantly different using Friedman chi-square analysis (χ2 = 2.17, p 0.80, p < 0.05) between SG and cumulative ranking values in the two LGAs. Conclusion and recommendations were made in line with the outcome of the study. Key words: Agroforestry technologies, wood specific gravity, species selection, natural resources, indigenous knowledge.

Agroforestry systems conserve species-rich but modified assemblages of tropical birds and bats

Although an increasing number of studies have shown that diverse, multi-strata agroforestry systems can contribute to the conservation of tropical biodiversity, there is still debate about how the biodiversity within agroforestry systems compares to that of intact forest and alternative land uses. In order to assess the relative importance of agroforestry systems for biodiversity conservation, we characterized bat and bird assemblages occurring in forests, two types of agroforestry systems (cacao and banana) and plantain monocultures in the indigenous reserves of Talamanca, Costa Rica. A total of 2,678 bats of 45 species were captured, and 3,056 birds of 224 species were observed. Agroforestry systems maintained bat assemblages that were as (or more) species-rich, abundant and diverse as forests, had the same basic suite of dominant species, but contained more nectarivorous bats than forests. Agroforestry systems also contained bird assemblages that were as abundant, species-rich and diverse as forests; however the species composition of these assemblages was highly modified, with fewer forest dependent species, more open area species and different dominant species. The plantain monocultures had highly modified and depauperate assemblages of both birds and bats. Across land uses, bird diversity and species richness were more closely correlated with the structural and floristic characteristics than were bats, suggesting potential taxon-specific responses to different land uses. Our results indicate that diverse cacao and banana agroforestry systems contribute to conservation efforts by serving as habitats to high numbers of bird and bat species, including some, but not all, forest-dependent species and species of known conservation concern. However, because the animal assemblages in agroforestry systems differ from those in forests, the maintenance of forests within the agricultural landscape is critical for conserving intact assemblages at the landscape level.

Selección de especies y efecto del ciervo (Cervus elaphus L.) sobre arbustedos y matorrales de los Montes de Toledo, España central

Los sistemas agroforestales (mosaicos de bosques, arbustedos, matorrales, pastos herbáceos y cultivos) dedicados a la caza del ciervo constituyen una forma rentable y creciente de uso territorial en la España mediterránea desde la década de 1960. Como consecuencia, las cargas cinegéticas han aumentado mucho y sobrepasan con frecuencia los 50 individuos/km2. Ello origina un nuevo problema de sustentabilidad para esos nuevos sistemas agroforestales. Este trabajo analiza la selección de especies leñosas por el ciervo y el efecto de sus poblaciones sobre arbustedos y matorrales de los Montes de Toledo. Se obtuvieron índices de selección para 33 especies leñosas comparando sus porcentajes de utilización (ramoneo) con los de disponibilidad. Phillyrea angustifolia, Arbutus unedo y Quercus faginea presentaron los máximos índices mientras que Thymus mastichina, Daphne gnidium y Pinus pinea exhibieron los más bajos. Las preferencias alimenticias no varíaron significativamente al hacerlo las cargas cinegéticas. El efecto de una carga del orden de 35 ciervos/km2 parece superar el límite de sustentabilidad, incluso teniendo en cuenta que en el área de estudio existen pastos sembrados y cultivos disponibles para los ciervos.