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1.
Agroecology and conservation must overlap to protect biodiversity and farmer livelihoods. Coffee agroecosystems with complex shade canopies protect biodiversity. Yet, few have examined biodiversity in coffee agroecosystems in Asia relative to the Americas and many question whether coffee agroecosystems can play a similar role for conservation. We examined vegetation, ant and bird diversity, coffee yields and revenues, and harvest of alternative products in coffee farms and forests in SW Sumatra, Indonesia near Bukit Barisan Selatan National Park (BBS). BBS is among the last habitats for large mammals in Sumatra and >15,000 families illegally cultivate coffee inside of BBS. As a basis for informing management recommendations, we compared the conservation potential and economic outputs from farms inside and outside of BBS. Forests had higher canopy cover, canopy depth, tree height, epiphyte loads, and more emergent trees than coffee farms. Coffee farms inside BBS had more epiphytes and trees and fewer coffee plants than farms outside BBS. Tree, ant, and bird richness was significantly greater in forests than in coffee farms, and richness did not differ in coffee farms inside and outside of BBS. Species similarity of forest and coffee trees, ants, and birds was generally low (<50%). Surprisingly, farms inside the park were significantly older, but farm size, coffee yields, and revenues from coffee did not depend on farm location. Farmers outside BBS received higher prices for their coffee and also more often produced other crops in their coffee fields such that incentives could be created to draw illegal farmers out of the park. We also discuss these results with reference to similar work in Chiapas, Mexico to compare the relative contribution of coffee fields to conservation in the two continents, and discuss implications for working with farmers in Sumatra towards conservation plans incorporating sustainable coffee production.  相似文献   

2.
Relationships between spatial patterns of bird and mammal species richness in north‐eastern Mexico were analysed in relation to the location of three biosphere reserves (El Abra‐Tanchipa, El Cielo, and Sierra Gorda) and 13 priority areas recently identified for conservation. Ecological niches were modelled and potential distributions delimited for 285 bird and 114 mammal species using a genetic algorithm based on locality information from museum specimens and 15 selected environmental attributes. Potential distributions were transformed into hypothesized current distributions based on species–habitat associations as reflected in a recent land‐use map. Although species richness was lower when distributions were reduced from potential to current, spatial patterns of potential and current richness were similar. Heuristic, complementarity‐based prioritization procedures were used to identify combinations of areas and sites with maximal species representation: the biosphere reserves included 79% of birds and 74% of mammal species; eight priority areas provided an additional 11% of birds and 13% of mammals; the remaining 10% of birds and 13% of mammals were concentrated in new sites across the study area.  相似文献   

3.
Indicators of biodiversity change are of growing political relevance. To be effective, they need to meet a number of scientific requirements, some of which are not easy to fulfil. Here we use a simple typology of biodiversity indicators according to the following two requirements: (1) indicators should reflect changes in biodiversity in general rather than the ups and downs of particular species and species groups, and (2) indicators should be linked to environmental drivers. We apply this typology to existing indicators developed for the Dutch Environmental Data Compendium and describe how the typology may guide the development of indicators of biodiversity change. We conclude that more conceptual and statistical work is needed to make better biodiversity indicators.  相似文献   

4.
Identification of valid indicators of biodiversity is a critical need for sustainable forest management. We developed compositional, structural and functional indicators of biodiversity for five taxonomic groups—bryophytes, vascular plants, spiders, hoverflies and birds—using data from 44 Sitka spruce (Picea sitchensis) and ash (Fraxinus excelsior) plantation forests in Ireland. The best structural biodiversity indicator was stand stage, defined using a multivariate classification of forest structure variables. However, biodiversity trends over the forest cycle and between tree species differ among the taxonomic groups studied. Canopy cover was the main structural indicator and affected other structural variables such as cover of lower vegetation layers. Other structural indicators included deadwood and distances to forest edge and to broadleaved woodland. Functional indicators included stand age, site environmental characteristics and management practices. Compositional indicators were limited to more easily identifiable plant and bird species. Our results suggest that the biodiversity of any one of the species groups we surveyed cannot act as a surrogate for all of the other species groups. However, certain subgroups, such as forest bryophytes and saproxylic hoverflies, may be able to act as surrogates for each other. The indicators we have identified should be used together to identify stands of potentially high biodiversity or to evaluate the biodiversity effects of silvicultural management practices. They are readily assessed by non-specialists, ecologically meaningful and applicable over a broad area with similar climate conditions and silvicultural systems. The approach we have used to develop biodiversity indicators, including stand structural types, is widely relevant and can enhance sustainable forest management of plantations.  相似文献   

5.
Very few coral reefs are located close enough to metropolitan cities to study the influence of large urban populations on reef communities. Here, we compare the impact of a large-scale disturbance gradient with local-scale disturbance on coral richness, cover, and composition in the Jakarta Bay and Pulau Seribu reef complex off Jakarta, Indonesia. We found no effect of local land-use type of coral reef islands on richness, composition or cover, nor did taxon richness differ among zones at the large-scale. There was, however, a pronounced difference in composition and coral cover among zones. Cover was very low and composition differed markedly in the near-shore zone 1 (Jakarta Bay) where human-induced disturbance is most intense. Cover was highest in the outlying reefs of zone 3. The highly perturbed zone 1 reefs were, furthermore, distinguished by the virtual absence of otherwise abundant coral taxa such as Acropora hyacinthus and Porites rus and the prevalence of taxa such as Oulastrea crispata and Favia maxima. Almost 60% of the spatial variation in composition was related to variation in shelf depth and island size. The importance of shelf depth was related to the prevalence of a strong environmental gradient in reef depth, pollution, and mechanical reef disturbance and salinity from Jakarta Bay to the outlying reefs. Although there was a significant univariate relationship between spatial variation in composition and distance, this did not enter into the multivariate model, except when presence–absence data was used, indicating that environmental processes are the primary structuring forces in determining local coral assemblage composition across the Pulau Seribu complex.  相似文献   

6.
The degree to which different taxonomic groups show congruence in diversity patterns has attracted increased attention, yet such studies on stream biota are lacking. We examined environmental correlates of and congruence in the species richness patterns of bryophytes, macroinvertebrates, and fish in 101 boreal streams in Finland. Congruence in species richness among the taxonomic groups was generally low, mainly because of their differing responses to major environmental gradients. Bryophytes and macroinvertebrates showed the strongest degree of congruence, but even this relationship had a relatively weak predictive power. Bryophyte diversity showed the strongest relationship with water colour, followed by habitat stability, and stream size. Macroinvertebrate diversity increased with stream size, and further variation was accounted for by water colour and acidity. Fish species richness showed a weak and complex relationship with geographical location, stream size, and in-stream habitat characteristics. The regression models explained 23, 45, and 26% of the variation in species richness of bryophytes, macroinvertebrates, and fish, respectively. Our results suggest that indicator taxa may be of limited value in stream biodiversity inventories. Habitat-based approaches are suggested as an alternative surrogate measure in the conservation evaluation of lotic biodiversity.  相似文献   

7.
Patterns of biodiversity, environment and human impact were studied in 57 sample plots in an 1,178 ha forest area in a rural mountain area of Nepal that is administrated by the Annapurna Conservation Area Project. Alpha-, beta- and gamma-diversity was measured or estimated for six groups of organisms: trees, shrubs, climbers, herbs, polypores and mycorrhizal fungi, and the recorded patterns were correlated with a set of environmental variables. Human impact in terms of fuelwood collection, selective cutting and grazing was found to influence species diversity patterns in all organism groups. Species richness of trees, climbers and polypores at plot level (alpha-diversity) generally responded negatively to human impact, whereas species richness of herbs and shrubs showed a positive relation. Species turnover (beta-diversity), measured as length of the DCA first axis, was significantly correlated to distance to village for all species groups. This indicates that the human impact is very important for the biodiversity patterns in the study area, and that biodiversity connected to undisturbed forest habitats are potentially threatened in the area. The results are discussed in the context of practical conservation. A proposal for future management zones addressing protection of biodiversity without limiting the local use of the forest resource is put forward.  相似文献   

8.
Biodiversity is a multifaceted concept but most studies examining the association between the biodiversity of a community and its productivity focus only on species richness. Consequently, studies are needed to examine how other facets of biodiversity vary with productivity if we want to have a better understanding of the distribution of biodiversity across our planet. We evaluated how a number of biodiversity measures (species richness, evenness, dominance, rarity, Simpson’s diversity, and Shannon–Weiner diversity) varied across natural productivity gradients at 6 grassland sites in the continental US. Variation in productivity did not account for a substantial amount of variation in any measure of biodiversity at small spatial scales (≈1 m2) at most sites. When productivity accounted for substantial variation in biodiversity, different measures of biodiversity responded to productivity in different ways. For example, dominance changed in a U-shaped fashion along a productivity gradient whereas richness increased in an asymptotic fashion. Consequently, diversity indices, which account for both species richness and evenness, varied in a hump-shaped fashion along the productivity gradient. Our results highlight that an exclusive focus on the association between species richness and productivity provides an incomplete picture of how a community’s biodiversity is related to its functioning.  相似文献   

9.
10.

Aim

To test a method for rapidly and reliably collecting species distribution and abundance data over large tropical areas [known as Neotropical Biodiversity Mapping Initiative (NeoMaps)], explicitly seeking to improve cost‐ and time‐efficiencies over existing methods (i.e. museum collections, literature), while strengthening local capacity for data collection.

Location

Venezuela.

Methods

We placed a grid over Venezuela (0.5 × 0.5 degree cells) and applied a stratified sampling design to select a minimum set of 25 cells spanning environmental and biogeographical variation. We implemented standardized field sampling protocols for birds, butterflies and dung beetles, along transects on environmental gradients (‘gradsects’). We compared species richness estimates from our field surveys at national, bioregional and cell scales to those calculated from data compiled from museum collections and the literature. We estimated the variance in richness, composition, relative abundance and diversity between gradsects that could be explained by environmental and biogeographical variables. We also estimated total survey effort and cost.

Results

In one field season, we covered 8% of the country and recorded 66% of all known Venezuelan dung beetles, 52% of Pierid butterflies and 37% of birds. Environmental variables explained 27–60% of variation in richness for all groups and 13–43% of variation in abundance and diversity in dung beetles and birds. Bioregional and environmental variables explained 43–58% of the variation in the dissimilarity matrix between transects for all groups.

Main conclusions

NeoMaps provides reliable estimates of richness, composition and relative abundance, required for rigorous monitoring and spatial prediction. NeoMaps requires a substantial investment, but is highly efficient, achieving survey goals for each group with 1‐month fieldwork and about US$ 1–8 per km2. Future work should focus on other advantages of this type of survey, including the ability to monitor the changes in relative abundance and turnover in species composition, and thus overall diversity patterns.
  相似文献   

11.
In order to evaluate the usefulness of rapid surveys of indigenous knowledge for assessing trends in biodiversity, a case study was undertaken in two rural communities, Juznajab and Muquenal, in Chiapas, Mexico. This involved the use of a variety of rapid rural appraisal (RRA) and participatory rural appraisal (PRA) techniques, including semi-structured interviews, transect walks and participatory mapping. These approaches were used in conjunction with analysis of land use maps and aerial photographs to evaluate recent changes in vegetation cover and abundance of utilised species. In both communities, the extent of forest cover was considered by local people to have declined substantially in recent decades, with an annual decline in forest cover of 0.3% and 0.6% estimated by local people in Juznajab and Muquenal, respectively. Results from RRA indicated that this has been accompanied by significant declines in the abundance of useful species. In Juznajab 60% and 79%, and in Muquenal 96% and 85% of plants and animal species, respectively, were considered to have declined within living memory. These declines appear to result from over-utilization as well as habitat changes. For example, most of the tree species used for timber and the animal species used for meat were considered to have declined substantially in both communities. These results indicate that indigenous knowledge is potentially a valuable source of information about biodiversity trends, which could be assessed during Rapid Biodiversity Assessments and incorporated into the process of resource management by local communities. However, the contradictions recorded between assessments of vegetation change by local people and data obtained from other sources indicates the need for caution in the use of indigenous knowledge for this purpose.  相似文献   

12.
The aquatic birds of Mexico include both a rich fauna of residents and a significant proportion of migratory species that breed in Canada and the United States, yet their distribution and richness patterns remain poorly known. We developed a detailed database of occurrences, and estimated distributions using niche modeling interpolations for 134 species associated with wetlands. Validations of the resulting maps indicated that the niche-modeling approach yields a useful picture of aquatic bird species distributions in the country. Richness patterns among aquatic birds differ from those for landbirds: species richness is concentrated in coastal areas, but endemism is focused in the Transvolcanic Belt and the Altiplano. Place prioritization exercises identified sets of areas that would maximize the protection of this diversity.  相似文献   

13.
Expansion of coffee cultivation is one of the causes of deforestation and biodiversity loss. However, shade grown coffee has been promoted as a means for preserving biodiversity in the tropics. In this study we compared tree diversity in two types of coffee management regimes with the sacred groves in the Western Ghats of India. We computed species accumulation curves, species diversity indices and evenness indices to compare the different management regimes. Results of diversity indices showed that shade coffee had less diversity compared to sacred groves. Exotic species dominated the tree diversity in lands where the tree harvesting rights are with the growers. Native trees dominated the tree diversity when growers had no ownership rights on trees. A species accumulation curve suggested that the sacred grove had higher species richness compared to other two habitats. Lack of incentive to preserve endemic species as shade trees is forcing growers to plant more exotic species in shade grown coffee plots. If encouraged, shade grown coffee can preserve some biodiversity, but cannot provide all ecological benefits of a natural forest.  相似文献   

14.
Documenting financial resources in biodiversity conservation is a key aspect worldwide in order to set priorities and use effectively the limited resources available. In Mexico, a megadiverse country, studies on financial resources invested in biodiversity conservation are scarce and do not address funding for conservation comprehensively. Using recent data from several sources and applying criteria based on the national priorities for conservation, we compiled, systematized and analyzed data at a national scale on financing sources, financial resources and conservation organizations and their projects. The information obtained is presented in various ways and part of it (case study) is already an information system that can be continuously up-dated. Some of the results show the following: a steady diversification of mechanisms and methods for raising funds for conservation; an increase in governmental budgets; the acknowledgment by the private sector of the importance of biodiversity conservation; a greater technical capacity in people and organizations working in conservation; a greater accessibility of financial resources to support and maintain conservation projects; yet a short term vision in conservation projects; among other. Although the results obtained through this study are a first approach, they can now be used as a baseline to continue gathering and analyzing information on conservation financing in Mexico.  相似文献   

15.
We characterize the bird assemblage of an isolated relict temperaterainforest (Santa Inés) in terms of its structure, composition anddynamics. The relict character and long-term isolation of this forest remnant,immersed in a matrix of semiarid scrub, provide a natural experiment to assessthe consequences of long-term isolation and forest area reduction for temperatebird species. Bird surveys were conducted in a forest fragment and thesurrounding scrub matrix between April 1999 (austral autumn) and October 2000(austral spring) on a seasonal basis. Within the forest fragment wedistinguished two microhabitat types: creeks and areas far from creeks (i.e.slopes). A total of 36 species were recorded in the study site, of which 21were inside the relict forest. Highest bird abundance and richness wererecorded during winter and spring, and these were always higher in creek plotsrather than slope plots. Comparisons between this assemblage and thosedistributed in the continuous temperate forest (located more than 900km southwards) indicate that this bird assemblage shares moresimilarities, with regard to bird species composition, to southern temperateforest localities and to other relict forests, than to nearer scrub habitats.However, there are eight species, endemic to temperate forests in southern SouthAmerica, missing from our system. In this regard, our analyses indicate thatthese eight endemic species should be of great conservation concern and willlikely be the ones that will go extinct first if the fragmentation of thetemperate forest continues.  相似文献   

16.
Summary Foraging efficiency was studied by measuring the rate of tuna fish bait discovery by ants in unshaded and two types of shaded coffee systems. We also investigated the effect of weed biomass upon ant foraging efficiency. We found that the rate of discovery was faster in the coffee system with no shade than in systems with shade trees. The rate of discovery in the two types of shade systems (monospecific and polyspecific shade) was similar. Differences in the foraging rate between systems seem to be related to the composition of the ground ant community in each of the systems, and to cumulative factors such as plant diversity, microclimate and interspecific competition. No correlation was found between weed biomass and ant foraging efficiency. The results of this study support the idea of manipulating agroecosystem plant and structural diversity in order to enhance pest regulation by ants.  相似文献   

17.
Aquatic macrophytes provide essential spawning and nursery habitat for fish, valuable food source for waterfowl, migratory birds and mammals, and contribute greatly to overall biodiversity of coastal marshes of the Laurentian Great Lakes. Two approaches have been used to survey the plant community in coastal wetlands, and these include the grid (GR) and transect (TR) methods. These methods have been used to identify the average species richness at different sites, but their suitability for determining total species richness of a site has not been tested. In this paper, we compare the performance of these two established methods with that of the Stratified method (ST), which uses the sampler’s judgment to guide them to different habitat zones within the wetland. We used the three protocols to compare species richness of six coastal wetlands of the Great Lakes, three pristine marshes in eastern Georgian Bay (Lake Huron) and three degraded wetlands in Lake Ontario, Canada. The greatest species richness was associated with the ST method, irrespective of wetland quality. The ST method was also more efficient (fewer quadrats sampled), and revealed the most number of unique (those found with only one method) and uncommon species (those found in <5% of the quadrats). Despite these statistical differences, we found that sampling method did not significantly affect the performance of a recently developed index of wetland quality, the Wetland Macrophyte Index. These results have important implications for designing macrophyte surveys to track changes in biodiversity and wetland quality.  相似文献   

18.
The latitudinal gradient of biodiversity hypothesis was tested utilising the geographical distribution of species taxa belonging to the family Sabellidae (Annelida: Polychaeta), one of the polychaete families studied by only a few specialists around the world. An increase in species richness towards the Tropical region was revealed, with an asymmetric distribution between the two hemispheres. Data show that most of the species were found in Northern latitudes, producing a Northern area much richer than the Southern one. The Atlantic-Mediterranean Region was particularly rich, with the number of species close to those from the Indo-Pacific Region. Mediterranean species richness is discussed in the light of the particular history of the basin, also emphasising the importance of naturalistic studies that have made the Mediterranean marine flora and fauna one of the best known in the world. The existence of extrinsic factors that obscure the real pattern of distributions is hypothesised. Differences found between the two hemispheres could be attributed primarily to the higher number of specialists working in the Boreal Domains, including the Mediterranean area. Global trends produced by some representative genera are also discussed with respect to the distribution of the taxonomic specialists.  相似文献   

19.
We evaluate the empirical and theoretical support for the hypothesis that a large proportion of native species richness is required to maximize ecosystem stability and sustain function. This assessment is important for conservation strategies because sustenance of ecosystem functions has been used as an argument for the conservation of species. If ecosystem functions are sustained at relatively low species richness, then arguing for the conservation of ecosystem function, no matter how important in its own right, does not strongly argue for the conservation of species. Additionally, for this to be a strong conservation argument the link between species diversity and ecosystem functions of value to the human community must be clear. We review the empirical literature to quantify the support for two hypotheses: (1) species richness is positively correlated with ecosystem function, and (2) ecosystem functions do not saturate at low species richness relative to the observed or experimental diversity. Few empirical studies demonstrate improved function at high levels of species richness. Second, we analyze recent theoretical models in order to estimate the level of species richness required to maintain ecosystem function. Again we find that, within a single trophic level, most mathematical models predict saturation of ecosystem function at a low proportion of local species richness. We also analyze a theoretical model linking species number to ecosystem stability. This model predicts that species richness beyond the first few species does not typically increase ecosystem stability. One reason that high species richness may not contribute significantly to function or stability is that most communities are characterized by strong dominance such that a few species provide the vast majority of the community biomass. Rapid turnover of species may rescue the concept that diversity leads to maximum function and stability. The role of turnover in ecosystem function and stability has not been investigated. Despite the recent rush to embrace the linkage between biodiversity and ecosystem function, we find little support for the hypothesis that there is a strong dependence of ecosystem function on the full complement of diversity within sites. Given this observation, the conservation community should take a cautious view of endorsing this linkage as a model to promote conservation goals. Received: 2 September 1999 / Accepted: 26 October 1999  相似文献   

20.
The aims of this study were (1) to examine the geographic distribution of red-listed species of agricultural environments and identify their national threat spots (areas with high diversity of threatened species) in Finland and (2) to determine the main environmental variables related to the richness and occurrence patterns of red-listed species. Atlas data of 21 plant, 17 butterfly and 11 bird species recorded using 10 km grid squares were employed in the study. Generalized additive models (GAMs) were constructed separately for species richness and occurrence of individual species of the three species groups using climate and land cover predictor variables. The predictive accuracy of models, as measured using correlation between the observed and predicted values and AUC statistics, was generally good. Temperature-related variables were the most important determinants of species richness and occurrence of all three taxa. In addition, land cover variables had a strong effect on the distribution of species. Plants and butterflies were positively related to the cover of grasslands and birds to small-scale agricultural mosaic as well as to arable land. Spatial coincidence of threat spots of plants, butterflies and birds was limited, which emphasizes the importance of considering the potentially contrasting environmental requirements of different taxa in conservation planning. Further, it is obvious that the maintenance of various non-crop habitats and heterogeneous agricultural landscapes has an essential role in the preservation of red-listed species of boreal rural environments.  相似文献   

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