Showing papers in "Environmental Conservation in 2000"

Trophic cascades in benthic marine ecosystems: Lessons for fisheries and protected-area management

Abstract: An important principle of environmental science is that changes in single components of systems are likely to have consequences elsewhere in the same systems. In the sea, food web data are one of the few foundations for predicting such indirect effects, whether of fishery exploitation or following recovery in marine protected areas (MPAs). We review the available literature on one type of indirect interaction in benthic marine ecosystems, namely trophic cascades, which involve three or more trophic levels connected by predation. Because many indirect effects have been revealed through fishery exploitation, in some cases we include humans as trophic levels. Our purpose is to establish how widespread cascades might be, and infer how likely they are to affect the properties of communities following the implementation of MPAs or intensive resource exploitation. We review 39 documented cascades (eight of which include humans as a trophic level) from 21 locations around the world; all but two of the cascades are from shallow systems underlain by hard substrata (kelp forests, rocky subtidal, coral reefs and rocky intertidal). We argue that these systems are well represented because they are accessible and also amenable to the type of work that is necessary. Nineteen examples come from the central-eastern and north-eastern Pacific, while no well-substantiated benthic cascades have been reported from the NE, CE or SW Atlantic, the Southern Oceans, E Indian Ocean or NW Pacific. The absence of examples from those zones is probably due to lack of study. Sea urchins are very prominent in the subtidal examples, and gastropods, especially limpets, in the intertidal examples; we suggest that this may reflect their predation by fewer specialist predators than is the case with fishes, but also their conspicuousness to investigators. The variation in ecological resolution amongst studies, and in intensity of study amongst systems and regions, indicates that more cascades will likely be identified in due course. Broadening the concept of cascades to include pathogenic interactions would immediately increase the number of examples. The existing evidence is that cascade effects are to be expected when hard-substratum systems are subject to artisanal resource exploitation, but that the particular problems of macroalgal overgrowth on Caribbean reefs and the expansion of coralline barrens in the Mediterranean rocky-sublittoral will not be readily reversed in MPAs, probably because factors other than predation-based cascades have contributed to them in the first place. More cascade effects are likely to be found in the soft-substratum systems that are crucial to so many large-scale fisheries, when opportunities such as those of MPAs and fishing gradients become available for study of such systems, and the search is widened to less conspicuous focal organisms such as polychaetes and crustaceans.

Cultural and socio-economic impacts of Mediterranean marine protected areas

Abstract: Summary Marine protected areas (MPAs) may be important for protecting the marine environment, but they may also have substantial socio-cultural impacts about which very little is currently known, or acknowledged. In the Mediterranean, few data are available on the socioeconomic consequences of MPAs. The present study reviews the existing data on MPAs in Spain, France, Italy and Greece. A general increase in tourist activities in Mediterranean MPAs is evident, as are increases in the abundances of larger fish species, although there are no data indicating yields for fisheries increase adjacent to MPAs. A large increase in the number of divers and vessels using MPAs has already had impacts on natural benthic communities as a result of diver damage, mooring and the feeding of large fish by divers. Emphasis has been given in only a few MPAs to promoting public awareness of these impacts. Although the conservation of nature should be considered the fundamental objective of MPAs, neglecting their social, cultural and economic impacts has at times led to poor local consensus, if not hostility. We believe that planning and managing MPAs should be conducted on a multidisciplinary basis. Nonetheless, no single model can be considered valid for the whole Mediterranean. The very variable characteristics of coastal areas, from those of small uninhabited islands to those of cities, require different weightings to be assigned for each factor in order to achieve a durable equilibrium and realize the original objectives of each MPA. Only with such flexibility of management will it be possible to reach a greater understanding of the MPA system and create a lasting consensus in favour of conservation, a consensus which would mean an overwhelming majority of people actively avoiding damaging nature and preventing others from doing so.

Reservoir effects on downstream river channel migration

Abstract: Summary Human occupation and development of alluvial river floodplains are adversely affected by river channel lateral migration, which may range as high as several hundred metres per year. Reservoirs that reduce the frequency and duration of high flows typically reduce lateral migration rates by factors of 3 to 6. The ecology of riverine corridors is dependent upon the processes of erosion and sedimentation, which lead to lateral migration. Multiple-objective use of floodplains adjacent to active rivers therefore requires tools for assessing the probability and magnitude of channel movements. Existing approaches for predicting river channel movement may be classified as empirical or mechanistic, and are inadequate for widespread application. The Missouri River downstream from Fort Peck Dam in Montana, a major alluvial river with flow highly perturbed by regulation, was selected for case study. Maps and aerial photographs were available before and after dam construction. This imagery was analysed by digitizing channel centrelines at successive coverages under pre-dam and post-dam conditions, and mean migration rates were computed by bend and by reach. The mean rate of channel centreline migration fell from 6.6 m yr -1 to 1.8 m yr -1 after impoundment. Bend-mean channel activity rates were only weakly correlated with variables describing channel form and geometry. Results indicate that flow regulation for flood control and hydropower production typical of the study reach had profound effects on river corridor dynamism, with implications for habitat type distribution and ecosystem integrity.

Density dependence in marine protected populations: a review

Abstract: Summary The cessation or reduction of fishing in marine protected areas (MPAs) should promote an increase in abundance and mean size and age of previously exploited populations. Thus density-dependent changes in life-history characteristics should occur when populations are allowed to recover in MPAs. In this review, we synthesize the existing information on resource limitation in marine ecosystems, densitydependent changes in life-history traits of exploited populations and evidence for biomass export from MPAs. Most evidence for compensatory changes in biological variables has been derived from observations on populations depleted by high fishing mortality or on strong year classes, but these changes are more evident in juveniles than in adults and in freshwater rather than in marine systems. It is unclear if adults of exploited marine populations are resource limited. This may suggest that exploited populations are controlled mainly by density-independent processes, which could be a consequence of the depleted state of most exploited populations. MPAs could be a useful tool for testing these hypotheses. If we assume that resources become limiting inside MPAs, it is plausible that, if suitable habitats exist, mobile species will search for resources outside of the MPAs, leading to export of biomass to areas which are fished. However, it is not possible to establish from the available data whether this export will be a response to resource limitation inside the MPAs, the result of random movements across MPA boundaries or both. We discuss the implications of this process for the use of MPAs as fisheries management tools.

Forest products and household economy: a case study from Mudumalai Wildlife Sanctuary, Southern India

Abstract: Traditional communities living at forest margins use forest resources in various ways. Understanding the resource-use patterns of such communities provides a basis for seeking the participation of such communities in forest conservation. The present study undertaken in the Mudumalai Wildlife Sanctuary and the adjoining Sigur Plateau in the state of Tamil Nadu, India, addressed the importance of forests in the household economy of indigenous communities. Its main objective was to quantify the forest dependence of local people, and assess to what extent restrictive biodiversity conservation strategies would affect their livelihoods. These questions help in understanding the stake of the people in forest conservation strategies. Economic activities of the households were investigated in eight selected villages, four of which (proximal villages) had access to reserve forest areas where collection of forest products was allowed and were also located close to markets that provided opportunities to sell forest products. The remaining four villages (distal villages) were close to the Wildlife Sanctuary where the collection of forest products was not allowed and there was no access to organized markets. A total of 132 households were surveyed. The households both in proximal and distal villages were classified into three distinct income groups namely ‘low’, ‘medium’ and ‘high’, based on their gross annual income. Use of forest resources in Mudumalai was found to be influenced by multiple factors. In terms of livelihood of the traditional communities, livestock rearing and collection of non-wood forest products (NWFPs) were very important, the latter both for cash income and subsistence use. Peripheral communities used the forest resources in a varied fashion, with NWFPs contributing differently to different income groups. Where there was no restriction on forest use, higher income groups used the resources more heavily than lower income groups, and hence would suffer most from any restriction on forest use. People's reliance on forests evidently declined with increased level both of education and of opportunities in non-forestry vocations. Forests were still very important to the household economy of the local people both in terms of food security and cash income.

Evaluating the ecological effects of Mediterranean marine protected areas: habitat, scale and the natural variability of ecosystems

Abstract: Summary The capability to detect and predict the responses of marine populations and communities to the establishment of marine protected areas (MPAs) depends on the ability to distinguish between the influences of management and natural variability due to the effects of factors other than protection. Thus, it is important to understand and quantify the magnitude and range of this natural variability at each scale of observation. Here we review the scale of responses of target populations and communities to protection within Mediterranean MPAs, against their ‘normal’ spatio-temporal heterogeneity, and compare those with documented cases from other temperate and tropical marine ecosystems. Additionally, we approach the problem of the relative importance of habitat structure, considered as a set of biological and physical elements of the seascape hierarchically arranged in space at multiple scales, to drive natural variability. We conclude that much more effort has to be made to characterize heterogeneity in relation to Mediterranean MPAs, and to quantify and explain relationships between target species and their habitats as sources of such variability. These studies should be based on sound sampling designs, which (1) generate long-term data sets, and would ideally (2) be based on a Mediterranean-wide comparison of a number of protected and unprotected localities, (3) be designed from a multi-scaled perspective, and (4) control for factors other than protection, in order to avoid their confounding effects. The need for appropriate spatial and temporal replication, nested designs and power analysis is advocated.

Analysis and resolution of protected area-people conflicts in Nanda Devi Biosphere Reserve, India.

Abstract: Conflicts between local people and protected area managers are a common problem in developing countries, but in many cases there has been little attempt to comprehensively characterize the underlying problems. Resource uses, management practices, economy and people's perceptions of problems and likely solutions were analysed in two villages near and two villages away from the core zone of Nanda Devi Biosphere Reserve in the Indian Himalaya. Agriculture, although practised on less than 1% of the area, was the primary occupation of local people. Six annual crops of a total of 22 and all four horticultural crops on private farms were damaged by wildlife, but Reserve management provided compensation only for livestock killing by wildlife and compensation amounted to only 4–10% of the total assessed monetary value of killed livestock. A variety of wild plant products were used locally but 27 were marketed by more than 50% of surveyed families; income from wild products was substantially lower than that from crops and livestock. A sociocultural change from a subsistence to a market economy, together with changes in traditional land/resource rights and institutions, has led to a number of changes in land-use and management practices. The livestock population has declined, agricultural area has remained the same and people have started cultivating medicinal species in the last 20 years. These changes seem complementary to the goal of conservation. However, changes such as abandonment of some traditional food crops and stress on cash crops lacking fodder value, requiring substantial manure inputs derived from forest litter and livestock excreta, and causing severe soil erosion, seem to counter the goal of environmental conservation. Some government-managed Reserve Forest sites were similar to the Community Forests in terms of species richness, basal area and soil physico-chemical properties. Two Reserve Forest sites showed basal areas of 160.5–191.5 m2/ha, exceeding the highest values reported so far from the region. The formal institutional framework of resource management seems to be not as effective as the traditional informal system. The Reserve Management Plan lays more emphasis on legal protection than on the sustainable livelihood of local communities and has led to conflicts between local people and reserve managers. Plantation of fodder and medicinal species in degraded forest lands, suppression of economic exploitation of local people in the market, enhancement of local knowledge of the economic potential of biodiversity, incentives for cultivation of crops with comparative advantages and lesser risks of damage by wildlife, and rejuvenation of the traditional involvement of the whole village community in decison-making, could be the options for resolving conflicts between people and protected areas in this case.

Resident attitudes towards conservation and black howler monkeys in Belize: the Community Baboon Sanctuary.

Abstract: The Community Baboon Sanctuary is held by the Belizean government to be a model for participatory ecotourism development. Membership in the Sanctuary is voluntary and involves a commitment to protect riverine resources as habitat for black howler monkeys (Alouatta nigra). While most local residents understand the intrinsic, aesthetic and material values of this important resource and recognize that protection of it can provide opportunities for promoting ecotourism activities in their communities, some members are dissatisfied with the project and threaten to withdraw their membership. This study aimed to define residents’ feelings about resource protection in their communities and their attitudes toward management of the sanctuary. Member and non-member households were surveyed, representing three of the eight villages located within the sanctuary boundaries; 74% of the sample were member households and 26% were non-member. Although the howlers had increased in number since the Sanctuary's establishment, many residents felt that neither their households nor themselves were benefiting. Some Sanctuary members argued that management was not well organized and that benefits to communities and individuals were not evenly distributed. Key issues included the extent and nature of benefits to local residents, perceptions regarding management capabilities, and how management is responding to these issues. While these problems existed, the majority of residents did not want the Sanctuary abolished and strongly supported maintaining Sanctuary status. They might not be reaping benefits directly, but they admitted their lives were no worse off than before and they recognized that some members were benefiting. They had hope that they, too, would be able to eventually take part in some type of tourism business. For long-term local support to be assured, management must orient its work to more directly address those factors that influence residents’ attitudes about the project, namely, the extent of local participation, representative organization, sound management structure, effective management capabilities, fair employment allocation, and education opportunities for community residents regarding the howlers, protection of their habitat, and the value of resource conservation.

Development of a coastal vulnerability index: a geomorphological perspective

Abstract: Sustainable coastal resource management requires the safeguarding and transmission to future generations of a level and quality of natural resources that will provide an ongoing yield of economic and environmental services. All maritime nations are approaching this goal with different issues in mind. The UK, which has a long history of development and flood protection in coastal areas, has chosen to adopt shoreline management, rather than coastal management, so placing coastal defence above all else as its primary and statutory objective. This paper aims to provide a geomorphological perspective of long-term coastal evolution and seeks to compare the UK approach with wider interpretations of coastal management. Based on a literature review, it is argued that coastal management (CM) and shoreline management, as a subset of CM, should share the same ultimate objectives, which are defined by many authorities as sustainable use. The objectives, both strategic and pragmatic, which follow from such an aim may appear to conflict with a reading of many of the texts for international and national CM or designated area management which emphasizes stability rather than sustainability. The result is that coastal defence is seen not merely as a means to an end but as an end in itself. It is argued within this paper that sustainable use of the coast, however, demands both spatial and temporal flexibility of its component systems, and management for change must therefore be the primary objective. Response of the natural system to independent forcing factors must be encouraged under this objective, whether such forces are natural or anthropogenic. In achieving such an objective the concept of shoreline vulnerability may prove useful. A simple and preliminary Vulnerability Index is proposed, relating disturbance event frequency to relaxation time (the time taken for the coastal feature to recover its form). This index provides a first order approximation of the temporal variability that may be expected in landform components of the shoreline system, so allowing management to provide more realistic objectives for long-term sustainability in response to both natural and artificial forces.

Differences between protected and unprotected reefs of the western Caribbean in attributes preferred by dive tourists

Abstract: Summary Tropical marine protected areas (MPAs) may promote conditions that are attractive to dive tourists, but a systematic basis for assessing their effectiveness in this regard is currently lacking. We therefore interviewed 195 dive tourists in Jamaica to determine which reef attributes they most preferred to see on dives. Attributes relating to fishes and other large animals (‘big fishes’, ‘other large animals’, ‘variety of fishes’, ‘abundance of fishes’, and ‘unusual fishes’) were more appreciated than those relating to reef structure and benthos (‘reef structure e.g., drop-offs’, ‘variety of corals’, ‘large corals’, ‘coral cover’, ‘unusual corals’, ‘sponges’, ‘unusual algae’, ‘lobsters, crabs etc.’). We then surveyed reef condition with regard to those aspects (abundance and variety of fishes, number of ‘unusual’, and number of ‘large’ fish) at four Caribbean MPAs and reference areas. In two cases, Hol Chan Marine Reserve in Belize and Parque Nacional Punta Frances in Cuba, these fish attributes were more pronounced in the MPAs than in the reference areas. Differences between the Montego Bay Marine Park in Jamaica (MBMP) and adjacent reference areas were mainly restricted to shallow sites (� 6m), while at Grand Cayman no differences between fully protected and partially protected areas were detected. Management had not been fully effective in the MBMP in the preceding months, while fishing pressure in the partially protected areas on Grand Cayman was very light. We conclude that, if fishing restrictions are well enforced, western Caribbean MPAs can be expected to be effective in ways appreciated by dive tourists.

Effects of marine protected areas on recruitment processes with special reference to Mediterranean littoral ecosystems

Abstract: Although site-attached fish can be expected to increase in abundance in marine protected areas (MPAs), there is little known about recruitment effects. The present work reviews concepts and field evidence for enhancement of recruitment of species in MPAs, focusing geographically on the Mediterranean littoral because of its long history of intensive fishery exploitation, but drawing on evidence from studies on recruitment processes in general on MPAs both in the Mediterranean and elsewhere. We considered recruitment as the process of a fish being added to the local population. The general questions of interest are whether the increase in biomass of species protected in MPAs has an effect on recruitment in the MPAs or in neighbouring areas, and, on competition and predation effects on new recruits. A flow diagram of the effects of MPA status on recruitment is developed and employed to identify the relevant processes. The diagram incorporates three levels of factors: (1) characteristics of MPAs (location, size, habitat type, oceanography and level of protection); (2) life stages of species protected in MPAs relevant to recruitment (eggs, larvae, settlers and juveniles); and (3) fundamental processes of dispersal/movement, predation and competition. From this conceptual diagram, the following main components of the recruitment process were identified and used to structure the review: (1) relationship between the ecology of pelagic stages and the design, location and oceanographic regime of MPAs; (2) effects of protection in MPAs from fishery exploitation of nursery habitats on settlement success; and (3) effects of protection on survival of settlers and juveniles from competition and predation. We found an exceptionally low number of studies specifically addressing recruitment processes in MPAs. This was particularly the case in what concerns the relationship between larval ecology and the characteristics and oceanographic regime of MPAs. The effectiveness of MPAs in promoting recruitment mainly depends on the locations and on sizes of the MPAs in relation to the reproductive biology and larval ecology of the species concerned. The locations and sizes of MPAs in turn depend on MPA objectives, whether the purpose is to protect entire life cycles, the juveniles, or to increase egg production and larval export. The assessment of the relationship between the protection of nursery habitats and settlement success indicates that the magnitude of the effects of protection depends on whether the recruitment of the species involved is restricted to a narrowly-defined set of environmental conditions or, on the contrary, can occur in diverse environments, including areas beyond the influence of the MPAs. Thus, the locations of MPAs determine the habitats which are protected and, consequently, the species, the settlement of which will be favoured. For Mediterranean shallow-water species, the near-shore zone encompasses most of the essential nursery habitats for protection. Recruitment studies conducted in MPAs in the north-western Mediterranean have showed no differences in survival of newly-settled littoral fish between MPAs and the areas outside of them. Conversely, for older recruits, mortality was found to be higher inside MPAs, probably due to the increased abundance and size of large predators. This study highlights the almost total absence of studies addressing even the most elementary questions of recruitment in the specific context of MPAs.

Economic crisis, small-scale agriculture, and forest cover change in Southern Cameroon

Abstract: The rate of forest cover loss in the humid tropics of Cameroon is one of the highest in Central Africa. The aim of the large-scale, two-year research project described here was to understand the effect of the country's economic crisis and policy change on small-scale agricultural systems and land-clearing practices. Hypotheses were tested through surveys of more than 5000 households in 125 villages, and through time-series remote sensing analysis at two sites. The principal findings are that: (1) the rate of deforestation increased significantly in the decade after the 1986 onset of the crisis, as compared to the decade prior to the crisis; (2) the main proximate causes of this change were sudden rural population growth and a shift from production of cocoa and coffee to plantain and other food crops; and (3) the main underlying causes were macroeconomic shocks and structural adjustment policies that led to rural population growth and farming system changes. The implication of this study is that it is necessary to understand and anticipate the undesirable consequences of macroeconomic shocks and adjustment policies for forest cover. Such policies, even though they are often not formulated with natural resource consequences in mind, are often of greater relevance to the fate of forests than forest policy.

Biodiversity in fresh waters – an issue of species preservation or system functioning?

Abstract: Fresh waters offer intricate diversity, from small hot springs to huge floodplain systems, from temporary pools to big lakes, each containing significant proportions of the world's stock of inland water. In this collection is a great diversity of organisms, and of interesting relationships amongst them and with traditional peoples. There is thus every reason to value the diversity of freshwater systems and reasons for conserving them, from the ethical to the economic, can be listed no less than for terrestrial systems.The approaches currently used to conserve the diversity of terrestrial systems, however, may be counter-productive for the conservation of freshwater systems. These approaches include emphasis on individual, often charismatic species, or on areas of high quality that can be boundaried and protected (fortress conservation) and rest on arguments that all species must be maintained for the system to function. The current decline in world biodiversity under our increasing impact suggests that these are failing approaches even for terrestrial systems. They may be disastrous for freshwater ones.

Park-people conflict resolution in Royal Chitwan National Park, Nepal: buying time at high cost?

Abstract: The grass cutting programme (GCP) of Royal Chitwan National Park (RCNP) has been very successful in gaining local people's acceptance of RCNP. The GCP is recognized internationally as a model for park-people conflict resolution, but has seemingly become a spent force. The aim of the present study was to assess the extent to which the GCP is a form of ‘community-based conservation’ on the one hand, or ‘nature-based development’ on the other. During the ten days of open access in 1999, almost 50 000 tonnes of biomass were removed from the Park; the total gross economic value of the GCP in 1999 was more than US$ 1 million. Illegal fuelwood was the single most important product extracted from RCNP and accounted for half of the total quantity and economic value of all resources collected. It is argued that the GCP does not, in its present form, comply with the concept of community-based conservation, but is rather an example of nature-based development, where important natural core areas are exploited in the name of development. This study suggests a two-fold approach to reappraise the importance of the GCP in solving park-people conflicts without ignoring nature conservation. Firstly, access should be provided in different areas at different times instead of opening the whole Park at the same time. Secondly, since for the last 10–15 years buffer-zone community forestry has not been able to substitute fuelwood from RCNP, other ways to address local people's energy demand should be considered. It is argued that park-people conflicts in RCNP have not been solved, but only postponed, especially by compromising forest conservation and the possibility of the GCP to supply villagers with essential products in the future.

Adaptive management in transboundary protected areas: The Bialowieza National Park and Biosphere Reserve as a case study

Abstract: Summary Transboundary protected areas (PAs) currently represent nearly 10% of the world’s network of PAs. The protection of their biological wealth poses special challenges because of the need for cooperation among sovereign states. Adaptive management strategies offer hope for a more accurate assessment of ecological conditions within PAs, and have the potential for furthering one of the major objectives of these PAs, namely enhancing environmental cooperation between countries across whose boundaries the protected area complex is situated. This paper examines the implications of adaptive management for transboundary PAs by using the Polish/Belarusian Bialowieza PAs as a case study. Managers of PAs have conventionally aimed at accurate predictions and short-term system equilibrium through ‘top-down’ policies of control and exclusion. In the case of PAs, these objectives have meant limiting use and employing models of linear growth. Adaptive management strategies rely instead on long-term experience, assessment of experimental interventions, and collection of greater amounts of information to assess future outcomes. They aim at the satisfaction of objectives that may include equilibrium changes. These features of adaptive management imply attention over time to the interactions between different key species, greater involvement of local populations in the collection of information about the resources, and experimenting with different levels of use to infer the most suitable protection strategies.

Effect of experimental trampling and off-road motorcycle traffic on soil and vegetation of stabilized coastal dunes, Israel.

Abstract: Coastal sand dunes are considered to be amongst the most fragile natural systems, however they may be subject to high-intensity recreational stresses. The aim of this study was to assess the response of soil and annual plants of stabilized Mediterranean coastal dunes in Israel to various short-duration pedestrian and motorcycle traffic intensities. A standard experimental procedure was used comprising of 0, 50, 100, 300 and 500 pedestrian passes, and 0, 20, 50, 100, 200 straight and 150 turn motorcycle passes. The response of annual plants was assessed by determining ground cover, height, species richness and diversity, and soil penetrable depth, organic matter and moisture content. The pedestrian traffic did not affect the cover of annual plants, however; mean annual height, species richness and species diversity were significantly but temporarily affected by 500 passes. Conversely, motorcycle passage had an immediate significant impact on annual plants at all traffic intensities. The maximum effect on plants was observed in the wheel tracks and in the turn lanes. The mean annual ground cover and height were less sensitive measures than species richness and diversity for determining the overall impact of motorcycles on the area. Impact of pedestrian and motorcycle traffic on soil was detected only as an increase in penetrable depth, which was significant at 300 and 500 pedestrian passes, and at 100, 200 straight and 150 turn motorcycle passes. The soil and herbaceous vegetation of Mediterranean stabilized coastal dunes is relatively resistant and shows recovery potential to recreational impacts.

Crisis and conservation at the end of the world: sheep ranching in Argentine Patagonia

Abstract: Patagonia was one of the last regions in the Americas to be settled by Europeans. It was not until the mid-1880s that the Argentine government secured effective control over the region, after which settlement and economic development were based on sheep ranching. Virtually free of domesticated animals in 1885, by 1910 Patagonian rangelands supported some 12 million sheep. This growth was sustained until 1952, when the sheep population of the region peaked at approximately 22 million, but the number of sheep in Patagonia has since declined to about 13 million. Numerous factors have been implicated in the collapse of sheep ranching, one of great significance being the very poor state of Patagonian rangelands. Soil erosion is widespread, and the flora has been so heavily modified that it is extremely difficult, if not impossible, to determine what the composition and characteristics of Patagonia's pre-European vegetation were. This paper reviews the evolution of Patagonia's sheep industry and the nature and extent of environmental degradation caused by livestock. Although researchers have long called for a response to the environmental and socio-economic dimensions of the crisis, only in the past decade have initiatives to assess, monitor, and reverse degradation in Patagonia been launched. These initiatives often promote the diversification of land-use and alternative production strategies. Case study evidence from the upper Percey River watershed in western Chubut province indicates that ranchers may view alternative livelihoods with suspicion. It is suggested that measures to restore and protect Patagonian ecosystems would gain greater acceptance if local producers were seen as equals in the conservation and development process. This could be achieved by replacing more-traditional top-down models of policy design and implementation with measures based on genuine consultation and participatory, community-based approaches to natural resource management.

Assessment of fuel resource diversity and utilization patterns in Askot Wildlife Sanctuary in Kumaun Himalaya, India, for conservation and management

Abstract: A general decrease in abundance of wild plant species used as sources of fuel suggests that more detailed information is urgently needed on species-level trends and their conservation. Such studies have not been carried out so far in India and elsewhere; we therefore quantified the species-wise extraction of fuel from a site (Gori Ganga Valley) in Askot Wildlife Sanctuary in the Kumaun Himalaya. In all, 31 species (26 trees and 5 shrubs) were used as fuel, of which 14 were native to the Himalaya. Utilization patterns, distributions, probabilities of use (PU), resource use indices (RUI), preferences and availabilities in forest communities of these species were determined. Use pattern did not vary much amongst low altitude villages (Similarity: 52–74%), whereas along the vertical (elevational) gradient it varied considerably (Similarity: 15–31%). Woodfordia fruticosa (L.) Kurz, Pinus roxburghii Sarg., Quercus leucotrichophora A.Camus, Macaranga pustulata King ex Hk. f., Quercus lanuginosa Don, Engelhardtia spicata Bl. and Mallotus philippensis (Lamk.) Muell. contributed most to collections, while Pyracantha crenulata (Don) Roem., Syzygium cuminii (L.) Skeels, Alnus nepalensis Don and Bauhinia vahlii Wt. & Arn. were in lesser demand. W. fruticosa, P. roxburghii, M. pustulata, Casearia elliptica Willd., E. spicata, M. philippensis, Q. leucotrichophora and Phoebe lanceolata (Nees) Nees showed high values of PU and RUI, indicating high pressure. High density of P. roxburghii, Rhododendron arboreum Sm., Q. lanuginosa, Q. leucotrichophora, Lyonia ovalifolia (Wall.) Drude, C. elliptica and M. pustulata amongst trees and Maesa indica A.DC., P. crenulata and W. fruticosa amongst shrubs exhibited high density but the remaining species showed low density indicating their possible depletion. Intensive management of natural habitats of species highly-preferred for fuel, diversification of choice of species from natives to non-natives, large scale propagation of highly preferred taxa and plantation of seedlings in the degraded, uncultivated and marginal lands through peoples’ participation should promote conservation and management of fuel resources.

The relevance of systematics in choosing priority areas for global conservation

Abstract: While some researchers suggest that higher taxon richness be used for setting conservation priorities, others claim that even data on ‘accepted species’ are inadequate, and that documentation of the finest patterns of differentiation is needed. The significance of taxonomic resolution was assessed using distributional data for 798 Andean bird species, which were recorded in 15′ × 15′ grid cells. This dataset was used because of the fine spatial resolution and the complex biogeographic patterns in this region. The primary database served as a template for creating three new databases, namely for genera, broadly defined biospecies and phylogenetic species. With this spatial resolution, the taxic richness ‘hotspots’ were roughly the same on all taxonomic levels, but the ratio between generic and species richness increased towards the biologically-poor high plateaus. Richness ‘hotspots’ covered only a small fraction of the endangered species. ‘Hotspots of endemism’ provided better guidance, and complementarity was decidedly best, but with generic data neither of these approaches were effective. On the other hand, the recognition of phylogenetic species revealed few new areas of endemism which were not also apparent using ‘accepted’ species. The analyses drew attention to aggregates of endemic species which are often sited in areas immediately adjacent to areas with dense human populations, possibly because traditional human settlements relied on ecoclimatic conditions which also determined the peaks of endemism. Since data are available for some taxonomic groups for detailed analysis of species data, there is little reason to base the conservation planning on coarser surrogates.

Harnessing carbon markets for tropical forest conservation: towards a more realistic assessment.

Abstract: The proposed Clean Development Mechanism (CDM) of the Kyoto Protocol paves the way for financial and technological transfers to support forestry projects that sequester carbon or protect carbon stocks. This paper examines the implications of CDM for forest conservation and sustainable use by drawing on recent literature and results of a Policy Dialogue with CDM stakeholders. Initial estimates of the contribution tropical forestry could make to climate change mitigation and forest conservation need to be scaled down and CDM payments are likely to be far more limited. The cost-effectiveness of forestry projects relative to projects in the energy sector may have been overestimated. Few estimates acknowledge that forests are unlikely to be conserved as long as the residency time of carbon in the atmosphere. Also political realities and investor priorities may not have been sufficiently understood. CDM funding for forestry may also decline as economically viable clean technologies are developed in the energy sector. Tropical forests provide an intermediate strategy to buy time until more permanent options are available. The most important justification for including forests in CDM may lie in its potential contribution to forest conservation and sustainable use. It is important to involve forest stakeholders more closely in the CDM debate. CDM projects may need to be limited to niches meeting certain political and institutional preconditions and where sufficient understanding of local decision-making and the broader context is available. There are pitfalls in using CDM to subsidise unprofitable forestry activities. The dangers of misusing CDM in relation to plantations, natural forest management and non-timber forest products are illustrated and examples given examples of how CDM could be harnessed for better use of forests. CDM is not a solution to the tropical forestry problem, but is a tool for enhancing forest conservation and sustainable use.

Comparative assessment of stakeholder management in traditional Fijian fishing-grounds.

Abstract: The customary tenure of reef areas in many parts of the South Pacific offers an obvious context within which fishery resources might be managed cooperatively between customary-rights owners and fisheries personnel in government, yet the local foundations for such co-management have received little critical attention. Seven customary fishing rights areas (CFRAs) in Fiji were the focus of the present study, the objective being to compare management of CFRAs subject to differing levels of fishing access and ascertain those factors most influential to local management practices. The intensity of access (‘access pressure’) was measured as the number of licences issued per CFRA and per unit area, while management was assessed as an index, based on evidence of five aspects of management (management structure, marshalling of information for management, approach to goodwill payments, management measures and patrolling and enforcement) derived from questionnaires. Management varied amongst the CFRAs, one of the seven being essentially unmanaged because of a breakdown in succession between chiefs. There was little evidence for management responding uniformly to access pressure; rather, two CFRAs evinced a certain management aptitude regardless of this pressure, and two other CFRAs evinced relatively little management although pressure was high. A simple survey technique can indicate useful contrasts amongst CFRAs in functional local management, and thus be useful for guiding decisions about where to make investments in local management or co-management.

Valuing ecotourism in a sacred lake of the Sikkim Himalaya, India

Abstract: Although monetary valuation of natural ecosystems is difficult, such valuation helps to draw attention to their importance, and highlight conservation needs, especially in developing countries. The recreational value of Khecheopalri, a lake situated in the West District of Sikkim State, India, which has recreational, biodiversity and sacredness values, was assessed. The demand curve function for recreation increased with decreases in travel cost and distance for Sikkimese visitors. The recreational value of the lake was similar to other protected sites in India; however, all these sites had very low values compared to sites elsewhere in the world. Willingness to pay for maintenance and preservation of the lake by all types of visitors ranged from US 7.19 for international tourists. The lake showed high recreational/sacredness values that were attributed to conservation of the site for biodiversity and pilgrimage. A large number of lakes in the Hindu-Kush Himalayan region, if properly managed and marketed for ecotourism, can bring economic development that can be linked with conservation.

Evaluating riparian vegetation in semi-arid Mediterranean watercourses in the south-eastern Iberian Peninsula

Abstract: Summary Riparian vegetation is vulnerable to human impact worldwide, and this is especially so in arid areas, yet there have been few quantitative studies and this is especially so in Spain. The state of the riparian vegetation along three major rivers and seasonal watercourses of south-eastern Spain was evaluated during 1992‐93, using the species composition and community structure in watercourses of different sizes under different management. Reaches of the watercourses were classified using five vegetation indices, namely percentage cover, species richness, degree of connectivity between patches of the plant communities, number of exotic species, and evidence of natural regeneration. With the integration of these into one index, the degradation state of the riparian vegetation in each reach was quantified. In addition, types of human activities exerting the greatest impact were noted, and a scale to evaluate the intensity of each impact was established. The indications are that agriculture has very substantially altered the natural vegetation, and this index has served to highlight the most altered zones, and thus those in most urgent need of restoration. Less-degraded zones could serve as models and sources of plant species for future restoration. The degradation index made it possible to establish quickly, easily, and with a high degree of accuracy, the state of conservation of the riparian vegetation in the study area.

Marine protected areas: challenges and opportunities for understanding and conserving coastal marine ecosystems

Abstract: The term ‘marine protected area’ (MPA) refers to areas in which human activities that cause reductions in populations either directly through exploitation or indirectly through habitat alteration are eliminated or greatly reduced. This spatially explicit approach to managing human impacts has many potential ecological and socio-economic benefits that can alleviate some of the problems fundamental to conventional management practices and can therefore complement, but is unlikely to supplant, the conventional practices (Allison et al. 1998; Bohnsack 1998, Lauck et al. 1998; Hastings & Botsford 1999; Murray et al. 1999). Five reviews in this number of Environmental Conservation summarize the main issues relevant to MPAs in the Western Mediterranean, our understanding of their ecological and management consequences, and our knowledge of the ecological and socio-economic processes that determine their effectiveness for fisheries management and conservation (Badalamenti et al. 2000; Garcia Charton et al. 2000; Pinnegar et al. 2000; Planes et al. 2000; Sanchez Lizaso et al. 2000). The reviews identify three issues of key importance to the development and success of MPAs for conservation and management. First, MPAs hold strong promise for management and conservation objectives, but the historical pattern of haphazard design, implementation, enforcement and evaluation has often produced equivocal and sometimes contradicting evidence for both their ecological effects and their effectiveness at achieving their intended objectives. Second, our understanding of many of the critical population and community processes that bear greatly on the consequences of this approach (e.g. dispersal, recruitment, direct and indirect effects of competition and predation) suffers from a lack of strong empirical studies and a comprehensive theoretical framework. Third, the global growth of interest in MPAs and concern for rapid development of organized systems of MPAs is great. Taken together, these three issues identify an urgent need for a well-developed theoretical framework, more rigorous empirical studies motivated and directed by theory, and actual implementation of systems of MPAs that will allow for proper evaluation and an evolution toward optimal design.

Urbanization in the Pacific: Environmental Change, Vulnerability and Human Security

Abstract: The world is in the midst of a substantial urban transition, but the impacts of this on the environment and human societies are not fully understood. Very little attention has been paid to urbanization processes in developing countries with smaller populations, despite the evident problems associated with urbanization. There are both biophysical and social vulnerabilities associated with urbanization in the South Pacific and these vulnerabilities affect human security. The biophysical vulnerabilities include the fragile environments of the island nations, limited land resources, shortages of basic resources, and the risks associated with global warming. The ability to respond to these problems is constrained by social vulnerabilities, notably weak economies, difficulties associated with land ownership, and institutional limitations. There is a need for institutional reform, improved planning, better urban resource management, and greater regional cooperation, if Pacific island nations are to respond effectively to rapid urbanization and global change.

Tourism – sustainable development option?

Abstract: In the 1990s, tourism received increasing attention as a low-impact, non-consumptive development option, in particular for developing countries. It is argued that tourism allows for the use of areas which are otherwise of low value, such as remote beaches, but perfectly meet the demands of the growing travel industry (e.g. WWF [World Wide Fund for Nature ] 1995; World Bank 1998). In line with the concept of sustainable tourism, it is believed that negative social and environmental impacts can be avoided or minimized if tourism development is thoroughly well planned and controlled. This view can be contrasted with the fact that what may be considered sustainable forms of tourism still represent an extremely small share of all tourism, presumably less than 5%, and that some impacts like the use of energy and its global consequences have virtually been excluded from the discussion on sustainability.

Phytogenic hillocks and blow-outs as 'safe sites' for plants in an oil-contaminated area of northern Kuwait.

Abstract: Towards the end of the Gulf War in 1991, the retreating Iraqi forces destroyed numerous oil installations in Kuwait, causing widespread oil pollution to extended areas of the desert ecosystem. Vegetation development in an oil-contaminated area of northern Kuwait, where the natural vegetation is dominated by the dwarf shrub Haloxylon salicornicum, was studied seven years after the release of the oil. Some sites of the study area were largely unaffected, whereas others were contaminated to varying degrees by oil. Tar-like oil tracks accounted for the largest proportion of contaminated ground, and these remained largely unvegetated. However, a number of Haloxylon shrubs survived the oil contamination mainly due to the presence of phytogenic hillocks around their bases. These phytogenic hillocks provided ‘safe sites’ for a number of plant species. This also applied to blow-outs, former phytogenic hillocks on the oil tracks that had been subject to severe sand deflation in recent years. Species composition on both the phytogenic hillocks and in the blow-outs was very similar to that of the control area. Laboratory studies showed that the seed bank under the oil tracks had been annihilated. The number of seedlings emerging from soil samples was lower on the phytogenic hillocks and blow-outs than in the control areas. We conclude that recolonization of oil tracks will gradually take place as the hard surface of the tracks begins to disintegrate, or in part becomes covered by sand. The break-up of the track surface has already begun to a limited extent, mainly due to factors such as off-road driving, large herds of grazing animals, burrowing animals (lizards, rodents) and colonies of ants. It is suggested that a specific programme aimed at breaking up the hard surface and allowing it to become mixed with uncontaminated sand would probably greatly enhance recolonization.

Is the alien tree species Maesopsis eminii engl. (Rhamnaceae) a threat to tropical forest conservation in the East Usambaras, Tanzania?

Abstract: The East Usambara mountains are globally important for biodiversity conservation. The work reported here aimed to clarify whether plantations of Maesopsis eminii, an introduced pioneer tree, are a source of alien tree invasion or a temporary element in a protected conservation forest ecosystem in these mountains. The natural regeneration dynamics of M. eminii and indigenous primary tree species were assessed in M. eminii plantations which were up to 35 years old, using clustered systematic sampling. A total of 103 and 95 woody species were observed in the sapling and lower canopy layers, respectively. Both layers showed an abundance of Cephalosphaera usambarensis, a local species also used in plantations. M. eminii was virtually absent in the sapling layer, and its frequency decreased in the lower canopy with time. Abundant spontaneous regeneration of native primary forest species occurred under M. eminii. The sapling density of Allanblackia stuhlmannii, Beilschmiedia kweo and Greenwayodendron suaveolens increased, and that of Newtonia buchananii decreased, with time. In the lower canopy, the density of G. suaveolens, Parinari excelsa and Strombosia scheffleri increased in relation to plantation age. Therefore, no active, risky eradication of Maesopsis is needed in the conservation area, but a priority management task should be to avoid canopy gaps.

First-year impacts of shelterwood logging on understory vegetation in an old-growth pine stand in central Ontario, Canada

Abstract: There is evidence in the literature that a variety of logging practices may result in significant short and long-term changes to vegetation in the forest understory, however, these changes are still largely unknown for many forest types. The objective of this study was to determine the short-term effects of shelterwood logging on tree and non-arboreal plant species composition and diversity in both the understory and sapling strata within the Owain Lake Stand of old-growth red and eastern white pine located in Temagami, Ontario. The most significant changes were increases of white birch (800%), red maple (363%) and bracken fern (110%) in the understory. The most significant decreases within the understory occurred in mosses and liverworts (110%), Canada mayflower (49%) and starflower (28%). Bracken fern, red maple, and bush honeysuckle were the three most abundant species in the post-harvest understory plant community and will probably increase in their abundance under the present disturbed condition. A second shelterwood cut in 20 to 40 years may further facilitate an increase in these three species primarily by increasing light levels at the forest floor. All three species are very vigorous and are likely to dominate the forest understory until the upper canopy closes resulting in decreased light intensity at the forest floor.

Incommensurable preferences in contingent valuation : the case of Natura 2000 Network in Finland

Abstract: Incommensurable preferences in contingent valuation: the case of Natura 2000 Network in Finland