6-1MIW LQ-b\hbd& CL pbbwp l<d&Q ! man Influences on Biodiversity - . McNEELY, M. GADGIL, C. LEVEQUE, C. PADOCH, K. REDFORD edford (Chapter 11.4) rtmann, M. Freudenberger, G. Frisvold, A. Ghosh, D. Ghosh, H. Gjosaeter, Glasser, M.G. Gogte, N. Goodwin, A. Hails, J. Hamre, R. Heal3 S. Hecht, hcock, J. Hodges, K. Hindar, B. Jonsson, A. Kothari, L. Laikre, R. Leemans, laret, K.C. Malhotra, C. Martinet, J. Matowanyiko, J. Mehta, J.L. Munro, s, R. Norgaard, G. Olssen, E. Ostrom, N. Peluso, I;: Popper, D. Popper, C. Rosseland, N. Ryman, Safina, OX Sandlund, l? Waggoner . ... - -. " - ,.. -. ." c_ __ ~~ ~ Itzj7uetzce.s oti Biodiversity 783 - be decade, $42.6 billion had been flowing to developing In the dynamics of underlying causes, no agreement yet countries.) Between 1986 and 1993 developing countries exists on the level at which adequate explanation is paid $1253 billion to serve a growing foreign debt that achieved. For example, some may consider that e. Losses in reached around $1550 billion in 1994 (IMF, 1994). If the deforestation by agricultural expansion is driven by ioil. developing countries continue to be shut out of markets, population growth, while others would contend that deprived of access to technology, and burdened with debt, Pace on our agricultural expansion helps to cause population growth; they will have neither the means nor the incentive to ing, leading others will suggest that population growth needs to be their resources for the future. explained in terms of the socio-political and economic iaged more conditions that promote it. Ehrlich and Ehrlich (1990) have 11.2.4 Conclusions attempted to provide a single comprehensive approach to xessures to The major cause of biodiversity loss in recent historical the question of driving forces, using the equation I = PAT iserve their times is human action, primarily land use that alters and where I represents environmental impact, as the product of degrades habitat to serve human needs (Pimm and P (population), A (affluence) and T (technology). Thus, Gilpen1989; Freedman 1989). Yet the ability to forecast nan actions human impact is a product of the number of people, the the impact of specific actions on biodiversity is not yet ever, some level at which they consume, and the character of material well developed, and practical techniques for conducting and energy flows in production and consumption. Meyer i influence; such analyses are at only a very preliminary stage (OTA and Turner (1992) have pointed out that this formula umans (for 1987; Soulé and Kohm 1989). Machlis and Forester (1992) suffers from the handicap of a mismatch between its have pointed out that while a large number of conceptual categories of driving forces and the categories customarily revalent on and predictive models of the interactions between humans used in the social sciences, Neither ‘affluence’ nor ibit highly and nature exist, explicit models of biodiversity loss are ‘technology’ is associated with a substantial body of social hand, their sparse and incomplete. While many of the generic models science theory. inations of treat ‘environmental change’ or ‘ecosystem alteration’ as Today’s pressures on the natural world mean that the have been the dependent variable, it is not at all clear that genetic diversity of many species is being reduced because I biodiversity loss can simply be substituted for these more the total sizes of populations are decreasing and they are general factors. Biodiversity loss a special case of ierty rights is often being split into small, widely separated, subgroups environmental change, and the socioeconomic factors that /n property which cannot interbreed. Others might argue that this is one influence it may not have generic impacts. For example, a ;e goods to of the processes of speciation, with humans serving as biodiversity loss measured as a reduction in species new isolating mechanism. ‘ order and Ights work richness may be so dependent upon the original number of species at a specific locale that certain generic models will types. The fail to explain, much less predict, even the most dramatic 11.3 Information requirements for the sustainable use Id so forth, levels of biodiversity loss. The importance of habitat in the of biodiversity devices of preservation of biodiversity may suggest that spatial benefit of 11.3.1 Introduction relationships at the local scale will play a more significant Effective action must be based on accurate information. Iole in biodiversity models than, say, models of climate and the more widely shared the information, the more likely it is that individuals and institutions will agree on the However, it seems apparent that the issue of scale is definition of problems and solutions. However, the current lhe continue( crucial, as biodiversity loss is embedded in a complex state of knowledge is still largely inadequate to evaluate human/environment system that operates at several precisely what are the impacts of human activities in hierarchial levels; socioeconomic factors important at one different ecosystems, and to understand what are the scale may be less important at another, and at each different relationships between economic activities, development scale, new variables and relationships may emerge as and conservation of biodiversity. Gaps in knowledge may cqtical driving forces. have at least three origins. ’ The driving forces of human-induced change will vary First, the lack of information resulting from an With the type of change involved, and forces that drive insufficient research effort, especially for the inventory of Some changes may lessen others (Meyer and Turner 1992). species and ecosystems (see 11.3.2.4), for understanding For example, rising agricultural prices may provide an how components of ecosystems fit together and interact incentive for clearing forests, while also providing an with one another, for information on traditional use and incentive to adopt soil conservation measures. Second, the knowledge of biodiversity, and for changes in ecosystem Same kind of land-cover change can have different sources use. A significant increase in funding and man-power could in different areas, with deforestation in some areas fill most of these gaps. However, while some scientists Primarily for timber extraction, in others for shifting argue that until we understand the natural environment, it cultivation, and in others for establishment of plantations. will be difficult to understand how human societies interact .*>- I 784 Human Influences on Biodive,&+ with these systems, it is not realistic to wait for many years socioeconomic changes. One of the greatest diffic for conservation action. What to do in a situation of is to distinguish the effects of natural fluctuation uncertainty? changes from the effects of human-made distur The second major source of gaps derives from the Another question still partly unanswered is what complexity of the natural environment and the complexity should be monitored. Distribution and abundanc, ~~ of the interactions between human societies, their activities selected species? Changes in ecosystem structure, and the natural world. Natural and social sciences evolved composition, functions and processes? Distribut independently, but better interaction between them is area of different land-use classes, habitats, bi needed to understand the nature and strength of their ecosystems? relationships. The long-term preservation of biodiversity depends on management strategies and modes of 11.3.2.1 Long-term monitoring development, but it is very difficult to forecast changes in Most of the questions asked of scientists by human behaviour. This uncertainty makes it difficult to concern our ability to detect changes in the predict changes in the environment and the expected chemical or biological state of the environment, and consequences for biodiversity, and it reinforces the need to distinguish cause from effect. We need data sets from monitor biodiversity carefully in order to respond with regional, long-term monitoring to provide decision- corrective action. with convincing data on environmental changes d The third set of gaps involves access to information and adverse impact (see Section 5). The selection of sit how to use what we already know. How can technological long-term monitoring depends on the questions solutions be applied on a large scale? While useful investigated, but in selecting sites, a good knowle concepts such as ‘sustainable development’ and ‘integrated their management history is most relevant management’ are available, we need guidelines for action, understanding of the processes of change. However, supported by reliable observations and experiences. The term data collection programmes face problem effective implementation of biodiversity action plans relies continuity of the variables measured, continuity of on improved methodologies and tools. and comparability of data as analytical methods cha In general, research must be expanded and strengthened- Monitoring programmes are also faced wit to improve our understanding of biodiversity and its difficulties in the interpretation of data. For e potential role in building sustainable human societies. species extinctions and ecosystem changes do not al We need to understand a great deal more about how, why result from a single disturbance but rather fro and where human activities affect biodiversity, in order cumulative effects of many different disturbances, to provide accurate information to politicians and not always