Fergus L. Sinclair

PATTERNS OF ANIMAL DIVERSITY IN DIFFERENT FORMS OF TREE COVER IN AGRICULTURAL LANDSCAPES

As tropical regions are converted to agriculture, conservation of biodiversity will depend not only on the maintenance of protected forest areas, but also on the scope for conservation within the agricultural matrix in which they are embedded. Tree cover typically retained in agricultural landscapes in the neotropics may provide resources and habitats for animals, but little is known about the extent to which it contributes to conservation of animal species. Here, we explore the animal diversity associated with different forms of tree cover for birds, bats, butterflies, and dung beetles in a pastoral landscape in Nicaragua. We measured species richness and abundance of these four animal taxa in riparian and secondary forest, forest fallows, live fences, and pastures with high and low tree cover. We recorded over 20,000 individuals of 189 species including 14 endangered bird species. Mean abundance and species richness of birds and bats, but not dung beetles or butterflies, were significantly different among forms of tree cover. Species richness of bats and birds was positively correlated with tree species richness. While the greatest numbers of bird species were associated with riparian and secondary forest, forest fallows, and pastures with >15% tree cover, the greatest numbers of bat species were found in live fences and riparian forest. Species assemblages of all animal taxa were different among tree cover types, so that maintaining a diversity of forms of tree cover led to conservation of more animal species in the landscape as a whole. Overall, the findings indicate that retaining tree cover within agricultural landscapes can help conserve animal diversity, but that conservation efforts need to target forms of tree cover that conserve the taxa that are of interest locally. Preventing the degradation of remaining forest fragments is a priority, but encouraging farmers to maintain tree cover in pastures and along boundaries may also make an important contribution to animal conservation.

Trees, crops and soil fertility concepts and research methods.

Successful agroforestry requires an understanding of the complex relationship between trees, crops and soils. This book provides a review of both social and biophysical aspects of soil use and research in agroforestry in the tropics, with an emphasis on nutrient-poor forest and savanna soils. Key topics covered include decomposition, nutrient cycling and leaching, soil structure, and soil biological processes. The book combines theory and a review of methods used in research.

Productivity and profitability of multistrata organic versus conventional coffee farms in Costa Rica

In areas where traditional multistrata coffee systems have been transformed to systems with patchy or no shade at all, often dependent on high chemical inputs, ecological and socioeconomic degradation has become an increasing issue. During the 1990s, rising environmental and health concerns have promoted the interest in organic production systems and their environmental services for natural resource conservation. This study compared productivity, profitability, producer-defined constraints, and goals and research priorities between ten individually paired organic and conventional coffee farms in Costa Rica. Although five of the organic farms matched or exceeded the production of their conventional counterparts, the three-year mean yield of the organic farms as a group was 22% lower than that of the conventional farms. However, excluding organic certification costs, mean variable costs and net income (NI) were similar for both groups, mainly because organic price premiums received by the farmers compensated for lower yields. If current organic certification costs are included, the price premiums paid to organic producers would have to increase to 38% in order to equal the NI from conventional coffee. Conventional farmers indentified low and unstable prices as the main constraints to sustained production and stated further intensification of production as their main goal. In contrast, the key issues for future development of the organic group centered on farm diversification, agroecological self-sufficiency, and agronomic practices that permit organic farm management.

A general classification of agroforestry practice

Present classification schemes confuse agroforestry practices, where trees are intimately associated with agricultural components at a field scale, with the whole farm and forest systems of which they form a part. In fact, it is common for farming systems to involve the integration of several reasonably discrete agroforestry practices, on different types of land. The purpose of a general classification is to identify different types of agroforestry and to group those that are similar, thereby facilitating communication and the organized storage of information. A new scheme is proposed that uses the ‘practice’ rather than the ‘system’ as the unit of classification. This allows an efficient grouping of practices that have a similar underlying ecology and prospects for management. A two stage definition of agroforestry is proposed that distinguishes an interdisciplinary approach to land use from a set of integrated land use practices. Four levels of organization are recognized through analysis of the role of trees in agricultural landscapes: the land use system, categories of land use within systems, discrete groups of components (trees, crops, animals) managed together, and functionally connected groups of such discrete practices in time and space. Precedents for this form of analysis are found in the literature and it conforms with generally accepted methods of systems analysis. Classification of major types of agroforestry practice proceeds primarily according to the components involved and the predominant usage of land. A secondary scheme further classifies these in terms of the arrangement, density and diversity of the tree components involved.

Soil organic nitrogen mineralization across a global latitudinal gradient

[1] Understanding and accurately predicting the fate of carbon and nitrogen in the terrestrial biosphere remains a central goal in ecosystem science. Amino acids represent a key pool of C and N in soil, and their availability to plants and microorganisms has been implicated as a major driver in regulating ecosystem functioning. Because of potential differences in biological diversity and litter quality, it has been thought that soils from different latitudes and plant communities may possess intrinsically different capacities to perform key functions such as the turnover of amino acids. In this study we measured the soil solution concentration and microbial mineralization of amino acids in soils collected from 40 latitudinal points from the Arctic through to Antarctica. Our results showed that soil solution amino acid concentrations were relatively similar between sites and not strongly related to latitude. In addition, when constraints of temperature and moisture were removed, we demonstrate that soils worldwide possess a similar innate capacity to rapidly mineralize amino acids. Similarly, we show that the internal partitioning of amino acid-C into catabolic and anabolic processes is conservative in microbial communities and independent of global position. This supports the view that the conversion of high molecular weight (MW) organic matter to low MW compounds is the rate limiting step in organic matter breakdown in most ecosystems.

Incorporation of indigenous knowledge and perspectives in agroforestry development

Calls for the effective integration of indigenous knowledge and perspective into agroforestry are increasingly familiar in agroforestry programmes. This is the result of a need to better target research, ethical concerns about participation and power and the recognition that indigenous knowledge is a potentially powerful source of understanding that may often be complementary to scientific knowledge.

A systems approach to comparing indigenous and scientific knowledge: consistency and discriminatory power of indigenous and laboratory assessment of the nutritive value of tree fodder

Abstract In recent years, the assumption in agricultural R&D that scientific knowledge can and should displace local knowledge and practice has been challenged by an emerging view of local knowledge as a key component of an agricultural system. This paper describes a study of the discriminatory powers of assessment by farmers and by laboratory techniques, of the nutritive value of tree fodder found in the middle hills of Nepal. The two systems of nutritive value assessment for tree fodder are described and evaluated through detailed investigation of eight types of tree fodder (one leguminous and seven non-leguminous), used to supplement crop residue-based diets for cattle during the dry season. Both systems are shown to provide means of discriminating fodder sources in terms of their nutritive value that are comparable in terms of discriminatory power and consistency. This research suggests that laboratory assessment of the feed quality of tropical tree fodder may be used to build on and enhance rather than replace local classification.

The role of local knowledge in determining shade composition of multistrata coffee systems in Chiapas, Mexico

This research explores interactions between farmers’ knowledge and socioeconomic circumstances and the floristic composition of multistrata coffee plantations in Chiapas, Mexico. Interviews with 24 individual farmers with accompanying vegetation transects and two community level participatory workshops were carried out. The frequency, density, dominance, utility and importance value for all tree species surveyed were obtained. Farmers were grouped by cluster analysis on the basis of their land area, time producing coffee and the age of their coffee farms but the dominant shade species in their coffee plantations was not influenced by socioeconomic status (p<0.05). A total of 74 shade species were recorded and classified as temporary, suitable, or unsuitable as shade species by farmers, based on attributes such as leaf phenology, foliage density, crown shape and the amount and timing of litter decomposition, as well as their overall impact on coffee yield. Principal component and cluster analysis using these attributes confirmed the consistency of the farmers’ classification system. A group of preferred species was identified, but less than half the trees recorded on farms were of these species, showing that farmers retained a wide range of trees and shrubs in their plantations, taking into account not only commercial interests but also their contribution to ecosystem functions. Farmers harnessed the forces of secondary succession by retaining pioneers as temporary shade, knowing that they would naturally be succeeded, while at the same time promoting and tolerating other longer living native species that they considered more suitable as coffee shade. Managing diverse secondary succession instead of establishing monospecific shade was an efficient way for farmers to achieve acceptable coffee yields while contributing to biodiversity and landscape conservation that could allow them access to niche markets.

The basis of indigenous knowledge of tree fodder quality and its implications for improving the use of tree fodder in developing countries.

Many interventions generated by research with the aim of improving the nutritional status of livestock in developing countries have failed to realize their apparent potential when implemented on farms. It is now widely accepted that this is because farmers try to meet a wide range of objectives in feeding their animals. Their decision making can be supported by a sophisticated, indigenous knowledge. When researcher-developed technologies fail to account for this, they may be deemed unacceptable by the farmer. This paper explores one example of an indigenous knowledge system that relates to the quality of tree fodder used by farmers in Nepal. Our results suggest that the knowledge of tree fodder quality possessed by the farmers is quite consistent with the level of information that may be generated from the laboratory analyses that are commonly used by nutritional researchers for the same purpose. Of the two distinct indigenous knowledge systems from Nepal used, one (obanopan) appeared to relate to digestibility of tree fodder (as predicted by an in vitro test) and the other (posilopan) that was perceived as an indicator of general nutritional quality may relate to the ability of a tree fodder to promote the supply of protein at the duodenum. However, the relationship between obanopan and in vitro digestibility indicated that Nepalese farmers, in preferring to use obano fodder, also preferred less digestible fodder due to its ability to fill animals in times of feed shortage. This observation ‐ and the fact that recommendations derived

Incorporation of indigenous knowledge and perspectives in agroforestry development. I: Review of methods and their application

Calls for the effective integration of indigenous knowledge and perspective into agroforestry are increasingly familiar in agroforestry programmes. This is the result of a need to better target research, ethical concerns about participation and power and the recognition that indigenous knowledge is a potentially powerful source of understanding that may often be complementary to scientific knowledge.Incorporating indigenous knowledge into development may be achieved through farmer participation in research planning and implementation, external survey of local needs as a basis for planning research or the active synthesis of indigenous and scientific knowledge (in addition to collaboration between the scientist and the farmer) in order to capitalise on their potential complementarity.It is argued that active synthesis has received inadequate attention. In part this is because it demands rigorous analysis of indigenous and scientific knowledge. This is an exacting process and requires effective means of explicatly representing the knowledge concerned. An approach to this task is briefly introduced. A case study description and evaluation can be found in the accompanying paper [Thapa et al., 1995 (this issue)].