The destruction of forest ecosystems appears economically rational because many of the values of intact ecosystems are not recognized in land-use decisions. Many authors have suggested that the conservation of intact ecosystems requires that markets be extended to increase economic benefits derived from the standing forest to the point where they out-compete alternative, destructive land-uses. Three such strategies for market-oriented forest conservation are natural forest management for high-value timber, the collection of non-timber forest products, and biodiversity prospecting. In each case the proposed use of the ecosystem is likely to prove socially and economically unsustainable, or to generate significant alterations in ecosystem structure which endanger its diversity, or both. The success of market-oriented conservation requires that sustainable extraction of useful organisms over the long term yields more profit than destructive activities. The market-oriented conservation strategies examined, however, appear to yield too little profit to out-perform alternatives such as agricultural production or the replacement of forests by pastures or plantations. In each case, key factors limit profits. The slow growth rates of natural forests combined with discounting hinders natural forest management. In the case of non-timber forest products, the typically low density of resources in tropical forests creates disincentives for sustainable commercial production. The profitability of biodiversity prospecting is undermined by the low probability of discovering species with medicinal properties and developing countries' inability to capture the information value of the genetic content of species. Furthermore, each of the three strategies also has potentially negative ecological impacts. In the drive to increase profits, each is likely to degrade ecosystems through over-exploitation of the resource, and prompt simplification of the ecosystem through forest management designed to increase the density of profitable species. Ultimately, such activities are likely to lead to the loss of biodiversity.

Several conditions must be met for market-oriented conservation to be effective. Scientific understanding of forest ecosystems, and the ecological knowledge of both users and regulators must be sufficiently advanced to allow appropriate management regimes to be designed to assure maintenance of the forest ecosystem despite alterations caused by resource harvesting. The natural reproduction rate of the harvested resource must also be sufficiently rapid to justify leaving most of the resource undisturbed to guarantee its reproduction. Furthermore, the resource must be more cheaply and reliably produced in a natural forest than in a plantation, than by a synthetic substitute, or replacement through domestication. Finally, even where ecological and economic conditions support market-oriented conservation, those making land-use decisions must be in a position to benefit from the sustainable harvest of forest resources. If they are unable to enforce exclusive rights to the forests, the conservation effect of market-oriented strategies is likely to prove elusive.

Nevertheless, strategies for market-oriented forest conservation are a vital component of efforts to conserve biodiversity, and they must be improved to harness their full conservation potential. Resource management regulations, strong enforcement, and stable and secure property rights are essential preconditions. In addition, land-use planning should identify ecosystems with lower biological diversity where marketable products are concentrated at economic densities. Areas of high biological diversity will require non-market mechanisms to ensure their protection. In this context, there is no substitute for fully protected areas, and their expansion is vital.

Increasingly, natural areas are exposed to people who come to view, study or photograph wildlife. In order to develop appropriate management plans for both avian and human use of natural environments it is essential to understand how people affect foraging birds. The foraging behaviour of five species of water-birds at Loxahatchee (Arthur B. Marshall National Wildlife Refuge), part of the Everglades, in Southern Florida was observed, between 1992 and 1994, from a dike that received many visitors. Species examined included common gallinule (Gallinula chloropus), sora rail (Porzana carolina), glossy ibis (Plegadis falcinellus), little blue heron (Egretta caerulea) and Louisiana heron (E. tricolor). These birds were observed before people were near, while people were present, and following the departure of people. Variation in feeding behaviour was largely explained by whether people were present, the number of people present, and the amount of noise made by the people. For all species, time devoted to feeding and number of strikes or pecks decreased while people were present. The percentage of time spent foraging and the number of strikes decreased as the noise made by people increased. Birds that were closer to the path flew away from people more often than birds that were further away. Birds usually swam or flew away from the path while people were present.

Bushmeat consumption and trade is the greatest threat to biodiversity conservation in African forest regions. In many areas cable snaring is the principal hunting method employed by subsistence and commercial hunters. Methods for studying cable snaring and bushmeat markets were compared at a single site in the Central African Republic, in order to identify the relative strengths and weaknesses of the methods. Dependence upon any single method results in incomplete information on the ecological impacts of cable snare hunting and bushmeat marketing.

Taxus baccata L. subsp. wallichiana (Zucc.) Pilger has come into prominence in recent times due to its uncontrolled harvesting from the Himalayan wilds for the extraction of the anti-cancer drug Taxol. It is a very slow growing tree with poor regeneration, and the extent of canopy damage is likely to have serious consequences on biomass yield, plant survival and natural regeneration by affecting 'seed' output. The present study in the Jageshwar area of the Central Himalaya aimed to determine the stand and canopy structure, microsite characteristics, extent of canopy removal, and regeneration in human-disturbed and undisturbed sites. The number of trees, saplings and seedlings varied amongst plots. Leaf area index and canopy volume increased with increasing circumference at breast height. Of the total canopy volume, 57.4% was found to have been removed from the study area (9.54 ha; representing about 8% of the total T. baccata habitat). Regeneration of the species was found to be better in moist and shady microsites at undisturbed locations than in disturbed sites. Efforts made thus far for its conservation, and future strategies are discussed.

New legislation has encouraged regulatory biologists in the UK to examine the impacts of eutrophication in rivers for the first time. The principal tools for this have been new indices based on macrophyte and diatom communities. The use of such indices is placed within an appropriate theoretical framework. The importance of recognizing the upper limit of sensitivity of such indices, as well as factors such as organic pollution, which can confuse interpretation, is discussed. Despite their limitations, community-based indices are valuable tools for reconnaissance studies and, in the long-term, as indicators of the extent to which nutrient reductions have led to an ecological response. Some general guidelines for monitoring eutrophication in rivers are proposed.

Common lands, being a significant form of natural resource endowment in many developing countries, play a vital role in maintaining the ecological balance, and more particularly in supporting the people, especially the rural poor, in eking out their livelihood. However, the contributions of common lands to the rural economy and ecology have remained unappreciated which has led to the depletion and degradation of these lands. In an attempt to examine the nature and extent of contribution of common lands to household economies, 432 sample households from eight sample villages across four ecological regions in Haryana, northwest India, were surveyed using a structured questionnaire during 1995. We found that common lands still hold an important place in the household economy of rural people of this state. A significant proportion of the sample households obtained substantial biomass resources, income and employment from common lands. The contributions of these lands in terms of variety and extent were many times higher in the households belonging to less developed than developed regions, and those households belonging to poor than wealthy classes. Hence, there is an immediate need to develop effective strategies for the regeneration and sustainable use and management of common lands.

Trees in cities face a severe limitation of plantable space and an exceptionally stressful growing environment. In Hong Kong, shortage of developable land has relegated trees to a lower priority and intensified urban impacts on them, relative to other cities. The vicissitudes of urban growth and trees since the founding of Hong Kong are reviewed, and eleven specific conflicts between urbanization and trees in Hong Kong are described. Redevelopment of existing buildings has raised site coverage by impervious surface and taken away ground-level planting space within and around affected lots. Infilling of relatively low-density areas mainly for government and institutional land-uses has increased development density and removed existing greenery and planting spaces. Road construction and improvement has widely damaged roadside trees and removed valuable and conspicuous greenery. Proliferation of underground utilities has fuelled the contest for usable space and precluded planting in many places. Widespread and frequent roadside trenching, associated with utilities and the laying of cable television and telecommunication networks has incurred massive root damage at roadsides. Poor soil quality commonly beset by chemical and physical constraints has caused chronic poor tree performance. Intrusion into urban parks and other green enclaves by buildings and roads has usurped the limited stock of green spaces. Encroachment into peri-urban woodlands has deprived the city of fringing mature greenery with conservation, landscape and amenity worth. Plantable space in reclaimed lands has been intensively used with inadequate allocation for trees. Protection and preservation of champion specimens has lacked statutory means and a coordinated policy. Reinforcement and demolition of stone walls has destroyed many large trees on unique mural habitats. Quality of arboricultural practice is poor, particularly in the private sector. Possible solutions to these limitations in Hong Kong are suggested, and have implications for other cities facing similar problems.

Farm forestry is increasingly promoted in many countries as a land-use option which is likely to provide benefits in terms of improving the viability of agriculture, developing additional timber resources for industry, and enhancing regional development. This paper draws upon experiences of farm forestry in Australia to identify some lessons for its development that may be relevant to other countries. The paper provides an overview of farm forestry in the Australian context and reports on a recent review of leading case studies to provide some insights into means of future development. Three case studies are included to illustrate the diverse nature, and multiple benefits sought, of farm forestry. The important requirements of landholders pioneering farm forestry relate to: managing risks, participating in research and development, contributing to information exchange, addressing key farm issues, developing in-depth farm knowledge, establishing links with government and/or industry, and contributing to long-term community values.

Wild animals often destroy standing crops and prey on livestock, causing economic losses to farmers. Crop and wildlife damage are becoming serious for many Indian protected areas, and this study aimed to characterize the problem in villages in and around the Sariska Tiger Reserve (STR), Rajasthan, India. Data were collected using a semi-structured questionnaire in 37 villages followed by a semi-structured questionnaire administered to 180 households, quadrat sampling and focus group discussions. Crop and livestock depredation evidently affected nearly half of the households in villages adjacent to the STR, but damage varied considerably amongst villages and with distance from the Reserve border. Wild animal distribution and protection measures which people adopted also influenced the damage. Nilgai (Boselaphus tragocamelus() and wild boar ((Sus scrofa() were reported to be responsible for at least half of the total damage to the major crops caused by wild animals. Tigers and leopards were the main livestock predators; the former preyed mostly on larger livestock and the latter on smaller animals such as goats and sheep. More than two-thirds of the villagers spent considerable time and money guarding crops and protecting livestock. Guarding was the most popular means followed by physical fences around fields. In spite of damage to crops and livestock, the local people still had a positive attitude towards the STR, because of tangible benefits derived from the Reserve in terms of fodder and fuelwood, and cultural/religious attitudes towards wild animals. Settlement of rights to collect fuelwood and fodder within the Reserve appears to be one acceptable measure to compensate for losses besides an immediate review of hunting policy. Suggestions given by local people to minimize losses have implications for the long term sustainability of the STR as a protected area.

Attitudes of local people to wildlife, and particularly to large animals, are an increasingly important element of conservation work, but attitudes may vary within a community according to gender, and prior experience of wildlife. Data were collected by questionnaire and informal interviews with 59 men and 57 women living on the southern edge of the Budongo Forest Reserve, Uganda, to assess the influence of these factors in attitudes towards elephants, in an area from which they are now absent, and to conservation in general. It was hypothesized that prior experience of elephants might influence people's perceptions of them, and that this in turn might influence their attitudes towards the issue of elephant conservation. The results of this study did not generally support this. There was no evidence that people with prior experience of elephants were any more likely to support their conservation than were people who did not have prior experience of them. Within this community men and women expressed very different views as to the behaviour of elephants. Women were more likely than men to report that elephants were dangerous, irrespective of whether they had seen an elephant or not. Locally, conservation was considered to be particularly important and beneficial as a strategy because it 'should help ensure protection of people and their crops from marauding elephants and other animals'. Attitudes to, and expectations of, conservation as a strategy also varied between members of this community with respect to gender, but age and ethnic group were not good predictors of whether people were likely to be supportive of conservation issues or not.

Madagascar's biodiversity is of extremely high international significance, yet comprehensive efforts to assess current knowledge and set priorities have been absent until recently. Beginning in April 1995, a major participatory effort to assess the country's scientific and conservation priorities was undertaken in Madagascar. This process laid important groundwork for the revision of Madagascar's National Environmental Action Plan. The first stage of the process was a scientific priority-setting workshop. Over one hundred experts, organized in thematic groups, reached consensus on biodiversity priorities for the island, based on cross-discipline comparisons. A principal finding of the workshop is that many areas of outstanding biodiversity and research importance are located outside protected areas. Participants also agreed that corridors needed to be created between the high-priority protected areas in order to maintain gene flow and exchange of species. The second stage of the process was a stakeholder consultation which integrated scientific findings, national priorities, local stakeholder views, and donor input. The stakeholder consultation concluded that a collaborative, regional approach was needed to augment site-based conservation activities. Participants also emphasized that institutional strengthening in forestry and parks agencies needed much higher priority. The net result of the process was the adoption of a landscape approach to conservation which integrates regional planning, biodiversity monitoring and institutional strengthening.

The Rif mountains of northern Morocco represent a region of international significance from the standpoint of plant biodiversity with Abies maroccana amongst the endemic species; forest clearance, soil erosion, high rural population density and population growth are serious threats. Legal and illegal exploitation of the remaining natural forest for fuel, timber, forage and cork, produces some loss of forest but land clearance for extensions of the cultivated area, and other changes in the agricultural system such as the use of herbicides and fertilizers, and increased mechanization, are also resulting in loss of natural vegetation cover. Since 1989 cultivation of cannabis has increased in area from 25 000 ha to approximately 75 000 ha and this has greatly exacerbated the threat of degradation. A number of studies and initiatives are currently under way to address the challenges to the region and in particular the cannabis problem. It is suggested that an integrated approach using GIS methodology and carried out within the management framework of the Man and Biosphere Programme could provide a solution to the environmental threats facing the Rif mountains today.

Efforts to protect vulnerable environmental resources have focused largely on legal prohibitions and sanctions or on economic rewards or penalties. The role and importance of social and cultural factors have been much less considered. While theoretical arguments have addressed whether state institutions must be involved in resource protection, or whether private incentives can be manipulated to achieve desired outcomes, this preoccupation with either public sector or private sector solutions to the problems of environmental conservation has caused a neglect of social values and community consensus. The analysis offered here seeks to enlarge the debate from being two-sided to three-cornered.

By bringing in a third set of considerations, the socio-cultural, the analysis underscores that individual decisions are embedded in community and local contexts. All three kinds of incentives are considered to be potentially of equal importance for resource-conserving behaviour (RCB) vis-à-vis resource-degrading behaviour (RDB). The analysis is concerned first with the strength of different incentives in favour of RCB compared to RDB, comparing legal and economic with socio-cultural considerations affecting RCB and RDB. Efforts to protect vulnerable resources can seek to alter in an RCB direction the attitudes and incentives of people along any or all of these three dimensions of motivation, or they can seek to make a particular domain of motivation more salient if it is supportive of environmental conservation.

This analysis is proposed in part to get the socio-cultural domain taken more seriously alongside the legal and economic domains, as well as to prompt more systematic consideration of different kinds of policies, investments, actions or pronouncements that could shift the net balance of incentives in favour of RCB. While the analysis is admittedly simplified, there is utility in encouraging focused comparisons and evaluations of conservation alternatives. Examples of efforts to promote RCB in Madagascar and Costa Rica are given to illustrate this.

Definition of appropriate tropical forest policies must be supported by better information about forest distribution. New information technologies make possible the development of advanced systems which can accurately report on tropical forest area issues. The European Commission TREES (Tropical Ecosystem Environment observation by Satellite) project has produced a consistent map of the humid tropical forest cover based on 1 km resolution satellite data. This base-line reference information can be further calibrated using a sample of high-resolution data, in order to produce accurate forest area estimates. There is good general agreement with other pantropical inventories (Food & Agriculture Organization of the United Nations Forest Resources Assessment 90, World Conservation Union Conservation Atlas of Tropical Forests, National Aeronautics & Space Administration [USA] Landsat Pathfinder) using different approaches (compilation of existing data, statistical sampling, exhaustive survey with satellite data). However, for some countries, large differences appear among the assessments. Discrepancies arising from this comparison are here analysed in terms of limitations associated with each approach and they are generally associated with differences in forest definition, data source and processing methodology. According to the different inventories, the total area of closed tropical forest is estimated at 1090–1220 million hectares with the following continental distribution: 185–215 million hectares in Africa, 235–275 million hectares in Asia, and 670–730 million hectares in Latin America. A proposal for improving the current state of forest statistics by combining the contribution of the various methods under review is made.

Tropical moist forests are declining rapidly world-wide. Reforestation efforts in Trinidad have generally been insufficient and focused on non-native species. Some of these species (e.g. Pinus caribaea), however, appear ecologically inappropriate but have been used extensively on sandy soils after fires or where harvesting has degraded the original vegetation. Little research attention has been given to natural regeneration as a potential for future timber production. The purpose of this study was to determine whether or not post-fire regeneration provided sufficient species of commercial importance that could influence forest management planning. The field research was conducted at the Melajo Nature Reserve in north-east Trinidad, where there has been a particular focus on non-native species plantation in adjacent areas. A fire in 1987 devastated much of the remaining mature mora (Mora excelsa Benth.) forest at the Melajo Nature Reserve. The successional species were identified and recorded four years after the fire, and the abundances of commercially-important regenerating species were determined. The total number of species recorded was 201, representing 60 families with 153 genera. There were 14 species of timber value, with Mora excelsa, Terminalia amazonia, Byrsonima spicata and Sterculia caribaea being the most abundant. The abundance of commercially-important timber species in the most fire-damaged plot was 93% less than that for the least fire-damaged plot. The density of these species at the post-fire site in Melajo was on average higher than that of the same species in the mature mora forest. In 1991, the post-fire site at Melajo contained about 54% of the species recorded for a mature mora forest at Matura, north of Melajo (over 50 years ago).

Medicinal plants are a valuable resource for regional economic development in the tropics, and the Eastern Himalaya in particular harbours many such species. Extensive deforestation and over-exploitation in this region have brought several species to the brink of extinction, and Coptis teeta is such an endangered species; yet scientific information for its conservation is lacking. Investigations on the distribution range, demography, ecology, cytology, reproductive biology and population genetic structure of C. teeta were carried out; it was found to be endemic to a small area, to occupy a very narrow habitat and to be highly dispersed with very small population sizes. Edaphic factors were found to have played a vital role in ecological preference, natural distribution and evolutionary divergence of the species. The species exhibits a ‘K’ strategy, high male sterility, low reproductive success and efficiency, inadequate seed dispersal, and little genetic variability. A combination of these genetic hurdles and external threats in the form of habitat disturbance and over-exploitation for commercial purposes could result in its extinction. The species was found to have highly specific microsite requirements that cannot be met in other habitats. It is argued that in situ conservation measures would be the best strategy for the continued survival of this species. For effective management of the species it is recommended that its habitat be declared a protected area with the active cooperation of local inhabitants including the sharing of benefits of conservation.