| Agroforestry in the Pacific Islands: Systems for Sustainability (1993) |
Context of the study
In much of the tropical world, agriculture and forests compete for the use of land, with agriculture usually the winner. The defeat of forests in this competition is the continuation, at a faster rate than ever before, of one of the most ancient relationships between humanity and the environment - the replacement of wildlands with human domesticates, including humans themselves (Janzen 1990, xi). Now, because a near total loss of tropical forest is foreseen and because newly cleared as well as older agricultural lands suffer increasing degradation, governments, funding agencies, and scientists seek ways to rehabilitate the damaged interface of agriculture and forests and to prevent further deterioration.
To achieve these goals, attention has turned strongly to "agroforestry," a term and concept that became widely known after the publication in 1977 of the seminal work Trees, Food and People: Land Management in the Tropics by Bene, Beall, and Cote, who recommended the establishment of what became the International Council for Research in Agroforestry (ICRAF). Since then, interest in agroforestry has greatly increased, and the concept has now been brought into prominence under the banner of "sustainable development." Researchers now specialize in the discipline of agroforestry; many conferences have focused on agroforestry; and a rapidly growing literature has been published - e.g., the ICRAF journal Agroforestry Systems, many articles in other journals, and at least 16 books, manuals, or conference proceedings in the past 6 years (Baumer 1990;
Beets 1989; Buck 1989; Budd et al. 1990; Gholz 1987; Gregersen et al. 1989; Kartasubrata et al. 1990; MacDicken and Vergara 1990; Nair 1989b; Raintree 1987a, 1987b; Rocheleau et al. 1989; Steppler and Nair 1987; Vergara and Briones 1987; Withington et al. 1988; Wood and Burley 1991).
Examination of this literature reveals that there are two distinct, although not always entirely separated, approaches to agroforestry: the modern, institutional; and the traditional, or indigenous. Institutional agroforestry relies on modern agronomic science and field experimentation for such purposes as assessing yields of crops, trees, and animals in varying combinations and under varying conditions; determining competition or complementarily of system components; seeking maximization of aggregate production; or determining which leguminous tree species produce the green manure supportive of the greatest nitrogen mineralization. The approach that focuses on traditional or indigenous agroforestry (Denevan et al. 1984) arises from cultural geography and ecological anthropology; it seeks to record the attributes of traditional or non-institutionalized agroforestry systems that are in use now and that may have been practiced by tropical peoples for centuries or millennia. Some cultural-ecological studies derive purely from ethnographic interest but most are now also motivated by the belief that the traditional or non-institutionalized systems are worthy of preservation and dispersal. The present study, written by geographers, mainly follows the cultural-ecological approach rather than the quantitatively analytic agronomic approach, but our interest extends beyond the ethnographic to the applied, for we believe that the past and present agroforestry systems that have been empirically developed by Pacific peoples have much to offer in the search for sustainable development.
A merit of the indigenous systems is that they are based on indigenous trees, which are familiar and useful to local people and already adapted to local climatic and soil conditions (Montagnini 1990, 5051). Further, though any particular local agroforestry system probably yields less than its potential maximum, its technologies are adapted to local conditions by virtue of empirical experimentation and have already been adopted by local people. In many cases, the system could be improved by tinkering based on analytic agronomic knowledge but it does not have to be invented anew. It is in place and it works.
The value of the indigenous systems is acknowledged by most agroforestry researchers, and the antiquity of agroforestry among tribal and peasant peoples is widely recognized (e.g., King 1989). One of ICRAF's projects, launched in the early 1980s, was a systematic inventory of agroforestry systems (Nair 1987): an effort that showed "there was a bewildering array of agroforestry systems worldwide" with more than 2,000 species of multi-purpose trees in use (Steppler 1987, 15). None the less, most government-supported, aid-funded projects in agroforestry follow the institutional approach, which usually requires the introduction of unfamiliar, non-indigenous trees and associated slow, complex experimentation. In discussing the difficulty of gaining scientific understanding of the large number of agroforestry systems, Steppler (1987, 17) noted:
Any one system undergoing experimentation would include, at a minimum, a tree species and a crop species. Each of these could have variation in genotype and management such as spatial arrangement, maturity type for crop and harvesting methods (e.g., lopping and coppicing timing for the tree). It quickly becomes apparent that we are dealing with a multifactor design with many combinations. As we add species of trees and/or crops or introduce animals, the experiment grows in size logarithmically.... The other dimension to the problem is the fact that we have combined long-lived woody perennials with annuals, short-lived perennials and/or animals. Ideally, experiments should continue for the life of the longest-lived component; this could be upwards of 40 years and we cannot wait that long. Thus, we must also devise tests and methods of prediction that will have acceptable levels of confidence in predicting long-term effects.
These sorts of difficulties suggest to some planners and students of agroforestry that, while there is a need to build institutionalized analytic capacity, it should be recognized that "many of the problems which are addressed by agroforestry do not have clear and explicit objectives associated with them. That is, the task is not necessarily one of solving a problem, but rather one of establishing a context in which social learning can take place" (Budd et al. 1990, 332-333).
The existence of so many site-specific indigenous agroforestry systems and the information that is available about them makes it less necessary to seek "valid" scientific findings by means of long experimentation with a fixed set of variables according to a strict problem-solving paradigm. As Nair (1984, 73) says, such luxuries cannot be afforded in agroforestry research at this stage. Existing indigenous systems already satisfy, to varying degrees, the three basic criteria that Raintree (1990, 58) argues should be built into the design of a good agroforestry system: productivity, sustainability, and adoptability. That the systems have remained in use shows that local farmers are convinced of the adequacy of their production in relation to inputs. The presence of trees in the system lengthens the time-span of production and protection and provides an inherent basis for sustainability. That the local people have already adopted the system meets the requirement - increasingly recognized as basic to the success of any project to ameliorate living conditions - that the intended users accept the project and be active participants in its design, trial, evaluation, and redesign. The indigenous systems have already been well tested by local farmers from season to season and generation to generation and so provide a strong locally based framework for sound management and incremental agro-ecological innovation (Gliessman 1990, 36; Richards 1985).
In their review of institutional agroforestry in the South Pacific region, Vergara and Nair (1985, 377) comment that, "in general, trees may be considered suitable to agroforestry if they complement and support rather than compete with the interplanted food crops.... Unfortunately, out of the over 2000 species that satisfy these characteristics, only a handful have been tested and used in agroforestry, such as Leucaena, Albizia, Gliricidia, and Calliandra. The rest remain untried and therefore their potentials unrealized."
In contrast, our point is that in the Pacific- and elsewhere, as in the Peruvian Amazon (Denevan and Padoch 1988; Denevan et al. 1984) - many or most of the indigenous trees suitable to agroforestry have already been tried and their potentials at least partially realized in traditional systems, even if they have not yet been the subject of institutional agronomic experiments.
Our purpose in this book is to tap this already-existing knowledge by offering details on the wide range of non-institutional, informal agroforestry systems practiced in the Pacific Islands, now or previously. We hope this information will be of applied use in the further adaptation and diffusion of agroforestry practices, whether institutional or developed informally. We do include some details about institutional agroforestry developments in the Pacific (chapter 9), but emphasize the traditional or indigenous systems because we believe that Pacific landscapes themselves and the agroforestry systems they already contain are the most useful drawing-board from which to move agroforestry into the landscapes of the future.