Modern industrial agriculture is not sustainable because of its heavy reliance on petroleum, a non-renewable source of the energy used in farming, and because of pollution caused by petroleum products such as fertilizers and pesticides. A systems analysis of farming suggests that agriculture will be more sustainable when services of nature, such as nutrient recycling by soil micro-organisms and natural controls of insects, replace the services now provided by energy from petroleum. Examples are drawn from the Southeastern USA, but lessons learned can be applied worldwide.

Research in tropical forestry is confronted with the task of finding strategies to alleviate pressure on remaining forests, and techniques to enhance forest regeneration and restore abandoned lands, using productive alternatives that can be attractive to local human populations. In addition, sustainable forestry in tropical countries must be supported by adequate policies to promote and maintain specific activities at local and regional scales.

Here, a multi-disciplinary approach is presented, to better the understanding of tropical forest ecology, as a necessary step in developing adequate strategies for conservation and management. The authors have long experience in both academic and practical matters related to tropical forest ecology and management.

This work evaluates the merits of a widely-used approach to natural resource management, participatory action research (PAR), an approach to resource management that strives to link researchers with farmers and other local residents whose lives are effected by long-range conservation programmes. The authors begin the book with the history of PAR, and then use a variety of case studies that chronicle sustainable development efforts in Brazil. They evaluate the strengths and weaknesses of these efforts and suggest specific ways to improve on future PAR efforts.

Modern industrial agriculture is not sustainable because of its heavy reliance on petroleum, a non-renewable source of the energy used in farming, and because of pollution caused by petroleum products such as fertilizers and pesticides. A systems analysis of farming suggests that agriculture will be more sustainable when services of nature, such as nutrient recycling by soil micro-organisms and natural controls of insects, replace the services now provided by energy from petroleum. Examples are drawn from the Southeastern USA, but lessons learned can be applied worldwide.

DEVELOPMENT AND DISTURBANCE IN AMAZON FORESTS Contrasting Impressions 6 2 The rain forests of the Amazon Basin cover approximately 5.8 x 10 km (Salati and Vose 1984). Flying over even just part of this basin, one gazes hour after hour upon this seemingly infinite blanket of green. The impression of immen sity is similar when viewed from the Amazon River itself, or from its tributar ies. From a hammock on the shaded deck of a riverboat, the immensity of the forest presents an incredible monotony as one view of the shoreline blends unnoticeably into another. From both perspectives, the overwhelming reaction to the sea of trees that stretches from horizon to horizon is a sense of the vastness of the rain forest. In September 1985, I got a different impression of the rain forest. Several students and I journeyed in a self-propelled car along the single-track railroad that stretches almost 1000 km from the Carajas iron ore mine in the rain forest of Para State, Brazil, all the way to Sao Luis on the coast (Fig. 1.1)."

Research in tropical forestry is confronted with the task of finding strategies to alleviate pressure on remaining forests, and techniques to enhance forest regeneration and restore abandoned lands, using productive alternatives that can be attractive to local human populations. In addition, sustainable forestry in tropical countries must be supported by adequate policies to promote and maintain specific activities at local and regional scales.

Here, a multi-disciplinary approach is presented, to better the understanding of tropical forest ecology, as a necessary step in developing adequate strategies for conservation and management. The authors have long experience in both academic and practical matters related to tropical forest ecology and management.

Survival of the fittest" is a tautology, because those that are "fit" are the ones that survive, but to survive, a species must be "fit". Modern evolutionary theory avoids the problem by defining fitness as reproductive success, but the complexity of life that we see today could not have evolved based on selection that favors only reproductive ability. There is nothing inherent in reproductive success alone that could result in higher forms of life. Evolution from a Thermodynamic Perspective presents a non-circular definition of fitness and a thermodynamic definition of evolution. Fitness means maximization of power output, necessary to survive in a competitive world. Evolution is the "storage of entropy". "Entropy storage" means that solar energy, instead of dissipating as heat in the Earth, is stored in the structure of living organisms and ecosystems. Part one explains this in terms comprehensible to a scientific audience beyond biophysicists and ecosystem modelers. Part two applies thermodynamic theory in non-esoteric language to sustainability of agriculture, and to conservation of endangered species. While natural systems are stabilized by feedback, agricultural systems remain in a mode of perpetual growth, pressured by balance of trade and by a swelling population. The constraints imposed by thermodynamic laws are being increasingly felt as economic expansion destabilizes resource systems on which expansion depends.

This work looks at an alternative approach to resource production systems, taking the view that many environmental problems associated with conventional resource management are avoidable if we work with nature instead of trying to dominate it. Jordan argues that achieving sustainability in production systems is best accomplished by encouraging a change in the relationship between humans and nature - from one of exploitation through control to one of sustainability through cooperation.