Assessment of the aquatic biodiversity of a threatened coastal lagoon at Bimini, Bahamas

Coastal biodiversity is threatened worldwide by both direct and indirect anthropogenic activities. To more effectively manage and protect coastal biodiversity, accurate assessments of genetic, species, and ecosystem level diversity are required. We present the results from an assessment of the aquatic species diversity of a small (3?km²), shallow, mangrove-fringed Bahamian lagoon (the North Sound) subject to ongoing anthropogenic development. The assessment was conducted through a collation of field observations and data in published literature. We found that eight angiosperm species, 30 macroalgal species, and 370 animal species (including 95 fishes, 69 arthropods, 56 birds, and 45 mollusks) were documented within the lagoon. At least 11 of these species are of conservation concern, such as the critically endangered smalltooth sawfish (Pristis pectinata) and hawksbill turtle (Eretmochelys imbricata). Comparisons of community similarity indicated that the North Sound has a relatively distinct fauna and flora, but available data suggest that the species found there are most similar to those found in nearby habitats in Cuba. The lagoon forms a key nursery habitat for many species, including lemon sharks (Negaprion brevirostris), Caribbean spiny lobsters (Panulirus argus), and queen conch (Strombas gigas). Recently, the lagoon was included as part of a new marine protected area (MPA), but much of the habitat has already experienced considerable anthropogenic disturbance and the MPA boundaries have yet to be established. We have therefore analyzed the lagoon biodiversity and expect the data presented here to serve as a baseline for future comparisons.     

Quantifying Rarity, Losses, and Risks for Native Fishes of the Lower Colorado River Basin: Implications for Conservation Listing

Abstract:  We examined spatial distributions of fishes native to the lower basin of the Colorado River (25 species) at three scales to determine percent decline from historical distributions based on a regional biodiversity database. We cumulated records from 1843 to 1980 to develop a "historical distribution" for each species and used those occurrences recorded from 1981 to 1998 as "modern" records. We then contrasted historical and modern distributions to (1) quantify losses in spatial distribution; (2) determine how strongly these losses and fragmentation patterns corresponded to the perceived risk of extinction of each species, as represented by its status under the IUCN Red List of Endangered Species; and (3) update extinction risk rankings for 15 fishes endemic to the lower Colorado Basin according to the IUCN criteria. Based on presence and absence data, fish fauna of the lower Colorado Basin have suffered massive distributional losses. On average, ranges of extant species have diminished more than 45% relative to their historical distribution, and 35% of species have lost 50% or more of their occurrences. We provide nine new IUCN rankings and six updates to reflect more accurately the heightened imperilment of these species. Based on our new rankings, 7 of the 15 lower Colorado Basin endemics are critically endangered, 1 is endangered, 2 are vulnerable, and 1 is already extinct. We categorize the remaining 2 endemics as lower risk. This work demonstrates the utility of matching quantitative spatial metrics such as the scale-area slope statistic to extinction risk criteria for species whose persistence is strongly influenced by spatial distribution.     

Challenges and Opportunities for Biodiversity Conservation in the Brazilian Atlantic Forest

Abstract:  With endangered status and more than 8,000 endemic species, the Atlantic Forest is one of the world's 25 biodiversity hotspots. Less than 100,000 km² (about 7%) of the forest remains. In some areas of endemism, all that is left are immense archipelagos of tiny and widely separated forest fragments. In addition to habitat loss, other threats contributing to forest degradation include the harvesting of firewood, illegal logging, hunting, plant collecting, and invasion by alien species—all despite the legislation that exists for the forest's protection. More than 530 plants and animals occurring in the forest are now officially threatened, some at the biome level, some throughout Brazil, and some globally. Many species have not been recorded in any protected areas, indicating the need to rationalize and expand the parks system. Although conservation initiatives have increased in number and scale during the last two decades, they are still insufficient to guarantee the conservation of Atlantic Forest biodiversity. To avoid further deforestation and massive species loss in the Brazilian Atlantic Forest, the challenge is to integrate the diverse regulations, public policies, new opportunities, and incentive mechanisms for forest protection and restoration and the various independent projects and programs carried out by governments and nongovernmental organizations into a single and comprehensive strategy for establishing networks of sustainable landscapes throughout the region.     

Use of surrogate species to cost-effectively prioritize conservation actions

Conservation efforts often focus on umbrella species whose distributions overlap with many other flora and fauna. However, because biodiversity is affected by different threats that are spatially variable, focusing only on the geographic range overlap of species may not be sufficient in allocating the necessary actions needed to efficiently abate threats. We developed a problem-based method for prioritizing conservation actions for umbrella species that maximizes the total number of flora and fauna benefiting from management while considering threats, actions, and costs. We tested our new method by assessing the performance of the Australian federal government's umbrella prioritization list, which identifies 73 umbrella species as priorities for conservation attention. Our results show that the federal government priority list benefits only 6% of all Australia's threatened terrestrial species. This could be increased to benefit nearly half (or 46%) of all threatened terrestrial species for the same budget of AU$550 million/year if more suitable umbrella species were chosen. This results in a 7-fold increase in management efficiency. We believe nations around the world can markedly improve the selection of prioritized umbrella species for conservation action with this transparent, quantitative, and objective prioritization approach.     

Orchid conservation in the biodiversity hotspot of southwestern China

Xishuangbanna is on the northern margins of tropical Asia in southwestern China and has the largest area of tropical forest remaining in the country. It is in the Indo‐Burma hotspot and contains 16% of China's vascular flora in <0.2% of the country's total area (19,690 km²). Rapid expansion of monoculture crops in the last 20 years, particularly rubber, threatens this region's exceptional biodiversity. To understand the effects of land‐use change and collection on orchid species diversity and determine protection priorities, we conducted systematic field surveys, observed markets, interviewed orchid collectors, and then determined the conservation status of all orchids. We identified 426 orchid species in 115 genera in Xishuangbanna: 31% of all orchid species that occur in China. Species richness was highest at 1000–1200 m elevation. Three orchid species were assessed as possibly extinct in the wild, 15 as critically endangered, 82 as endangered, 124 as vulnerable, 186 as least concern, and 16 as data deficient. Declines over 20 years in harvested species suggested over‐collection was the major threat, and utility value (i.e., medicinal or ornamental value) was significantly related to endangerment. Expansion of rubber tree plantations was less of a threat to orchids than to other taxa because only 75 orchid species (17.6%) occurred below the 1000‐m‐elevation ceiling for rubber cultivation, and most of these (46) occurred in nature reserves. However, climate change is projected to lift this ceiling to around 1300 m by 2050, and the limited area at higher elevations reduces the potential for upslope range expansion. The Xishuangbanna Tropical Botanical Garden is committed to achieving zero plant extinctions in Xishuangbanna, and orchids are a high priority. Appropriate in and ex situ conservation strategies, including new protected areas and seed banking, have been developed for every threatened orchid species and are being implemented.     

Mammal Diversity and Conservation in the Selva Lacandona, Chiapas, Mexico

The Selva Lacandona region of Chiapas, Mexico, has high biodiversity, represents the last large portion of tropical rainforest in México, and faces imminent destruction. Through fieldwork and literature searches I found a total of 112 mammal species (including 17 Middle-American endemics) on the Lacandona's 331,200 ha Montes Azules Biosphere Reserve. This inventory plus those from eight additional Neotropical localities show local mammal species richness in the Neotropics to be in the range of 70–116 species. Richness is primarily correlated with the amount of annual rainfall, but within rainforest areas species richness is probably not correlated with rainfall, latitude, altitude, or area size. Rather, above a certain limit of rainfall and below a critical level of latitude and altitude, mammal species richness seem to reach an asymptotic maximum. Areas covered with tropical rainforest and with a well-known, relatively intact fauna have about 112–116 mammal species. In the Montes Azules Reserve most mammals (57%) are bats. The most heavily occupied feeding guilds are frugivores/herbivores and insectivores/omnivores. Large species and carnivores appear most vulnerable to local extinction. Montes Azules (and thus the Selva Lacandona) is especially noteworthy because (1) it contains a greater proportion of species facing conservation problems than expected from a random draw of Mexican mammals; (2) it is probably the most diverse ecosystem in Mexico; (3) many species sustain their only Mexican populations in this area; and (4) it is the largest remnant of tropical rainforest in Mexico and is part of the largest expanse of that vegetation type in Central America.     

Conservation of the Biodiversity of Brazil's Inland Waters

Abstract:  In terms of biodiversity, Brazilian inland waters are of enormous global significance for Algae (25% of the world's species), Porifera (Demospongiae, 33%), Rotifera (25%), Cladocera (Branchiopoda, 20%), and fishes (21%). Threatened freshwater species include 44 species of invertebrates (mostly Porifera) and 134 fishes (mostly Cyprinodontiformes, Rivulidae), primarily distributed in south and southeastern Brazil. Reasons for the declines in biodiversity in Brazilian inland waters include pollution and eutrophication, siltation, impoundments and flood control, fisheries, and species introductions. These problems are more conspicuous in the more-developed regions. The majority of protected areas in Brazil have been created for terrestrial fauna and flora, but they also protect significant water bodies and wetlands. As a result, although very poorly documented, these areas are of great importance for aquatic species. A major and pressing challenge is the assessment of the freshwater biodiversity in protected areas and surveys to better understand the diversity and geography of freshwater species in Brazil. The concept of umbrella species (e.g., certain migratory fishes) would be beneficial for the protection of aquatic biodiversity and habitats. The conservation and improved management of river corridors and associated floodplains and the maintenance of their hydrological integrity is fundamental to preserving Brazil's freshwater biodiversity and the health of its aquatic resources.     

Ecology, management and monitoring of grey dunes in Flanders

Grey dunes are a priority habitat type of the European Union Habitats Directive and demand special attention for conservation and management. Knowledge of the ecology of coastal grey dunes can contribute to this policy. Dune grassland succession is initiated by fixation and driven by the complex of soil formation (humus accumulation) and vegetation development. Leaching and mobilization of CaCO₃. which are important in nutrient dynamics, complicate the picture. At present, grass- and scrub encroachment greatly overrules these fine scaled soil processes and causes substantial loss of regional biodiversity. Belgium has an international responsibility in grey dune conservation because of the limited range of its characteristic vegetation, flora and fauna. As biomass removal seems essential in grassland preservation, grazing is an important management tool. Evaluation of management measures focuses on biodiversity measurements on the levels of landscape, community and species.     

A Study of Plant Species Extinction in Singapore: Lessons for the Conservation of Tropical Biodiversity

The native vascular plant flora of the Republic of Singapore has suffered the extinction of 594 out of a total 2277 species. These represent local, not global, species extinctions. Coastal habitats, including mangroves, have lost 39% of their species, while inland forests have last 29%. Epiphytic species (62% loss) appear particularly prone to extinction, which is reflected in a similar disposition exhibited by the Orchidaceae. Deforestation and disturbance have been the main cause of plant species extinction in Singapore. The rich mangrove epiphyte flora has been totally exterminated, and a number of tree species are reduced to populations of a few mature individuals. Many more species continue to survive than the species-area relationship would predict given the 99.8% loss of primary forest. This is interpreted as a result of the failure of equilibrium to be achieved yet in the remnant forest fragments, even after more than a century of isolation. Singapore's secondary forests appear to accrete plant diversity very slowly, even if contiguous with primary forest areas. We conclude that remnant fragments of primary tropical forest, even of very small size, can play a major role in the conservation of tropical biodiversity. The patterns of extinction observed in Singapore indicate that coastal and estuarine sites are in greatest demand for development and therefore must be given high priority for conservation despite their somewhat lower biodiversity. Epiphyte and orchid diversity appear to be very good indicators of the degree of disturbance suffered by a habitat in the humid tropics.     

Red-list status and extinction risk of the world's whales,dolphins, and porpoises

To understand the scope and scale of the loss of biodiversity, tools are required that can be applied in a standardized manner to all species globally, spanning realms from land to the open ocean. We used data from the International Union for the Conservation of Nature Red List to provide a synthesis of the conservation status and extinction risk of cetaceans. One in 4 cetacean species (26% of 92 species) was threatened with extinction (i.e., critically endangered, endangered, or vulnerable) and 11% were near threatened. Ten percent of cetacean species were data deficient, and we predicted that 2–3 of these species may also be threatened. The proportion of threatened cetaceans has increased: 15% in 1991, 19% in 2008, and 26% in 2021. The assessed conservation status of 20% of species has worsened from 2008 to 2021, and only 3 moved into categories of lesser threat. Cetacean species with small geographic ranges were more likely to be listed as threatened than those with large ranges, and those that occur in freshwater (100% of species) and coastal (60% of species) habitats were under the greatest threat. Analysis of odontocete species distributions revealed a global hotspot of threatened small cetaceans in Southeast Asia, in an area encompassing the Coral Triangle and extending through nearshore waters of the Bay of Bengal, northern Australia, and Papua New Guinea and into the coastal waters of China. Improved management of fisheries to limit overfishing and reduce bycatch is urgently needed to avoid extinctions or further declines, especially in coastal areas of Asia, Africa, and South America.     

A Century of Plant Species Loss from an Isolated Fragment of Lowland Tropical Rain Forest

An isolated 4-ha fragment of lowland tropical rain forest has been preserved in the Singapore Botanic Gardens since their founding in 1859. The Botanic Gardens'Jungle has recently had enumerated all woody stems 5 cm diameter at breast height (dbh) and larger and the complete vascular plant flora inventoried. This inventory can be compared with the historic record of the flora of the Gardens'Jungle obtained from the extensive collection of herbarium specimens dating back to the 1890s. Of the 448 historically recorded native species, 220 are still present. Ninety-four native species for which there were no historic records and 80 introduced species were also recorded in the recent inventory. The 50.9% loss of plant species richness over approximately the last century has not been distributed uniformly across plant life-form groups. Tree species have been less likely to go extinct than shrubs, climbers, or epiphytes. But half of the tree species present in 1994 were represented by only one or two individuals ≥ 5 cm dbh and larger. Individual longevity may be the major correlate with persistence of plant species in isolated forest fragments. Shade-tolerant understory shrubs (mostly Rubiaceae ) and rattans ( Palmae ) have been particularly prone to extinction. Some species have probably proliferated during the period of isolation. The tree Calophyllum ferrugineum currently constitutes one quarter of all woody stems. A group of climbers has become very common and covers large areas, probably inhibiting tree regeneration. We conclude that tiny fragments will act as refuges for tropical rain-forest plant species for decades, possibly even centuries after isolation but on their own they will not provide a permanent guarantee of the conservation of tropical biodiversity.     

Afghanistan: Environmental degradation in a fragile ecological setting

SUMMARY

Currently, only 6% of the 15% of land in Afghanistan is usable and, if all the refugees were to return, problems of land ownership and adequacy of available land are inevitable. Natural forests have been severely degraded. Due to the nature of the topography and the arid climate, vast areas are subject to soil erosion. Loss of vegetation and soil humus have created ever more arid conditions. Abandoning the lands, poor reclamation schemes, overgrazing and destruction of vegetation for fuelwood have all caused desertifkation. The biological productivity of pastures has also deteriorated. This reduced productivity has affected livestock and has caused dramatic changes to the patterns of wildlife populations. Soil salinization and waterlogged lands are common. Farmland and pastures have been contaminated by landmines. Heavy concentrations of air-borne particulates and considerable amounts of transboundary pollutants from the Aral Sea have been found. Use of chemicals and the machinery of war have damaged the ecosystems.

Collection of plants and animals is unregulated and has resulted in excessive removal or extermination of some species endemic to the Hindu Kush. Uprooting of some plants and dynamite fishing are increasing and a disturbing number of fauna and flora are endangered. Agriculture is traditional, and natural resources are not being used in a sustainable way. A sound environmental strategy needs to be formulated and adopted.     

Offsets and Conservation of the Species of the EU Habitats and Birds Directives

Biodiversity offsets are intended to achieve no net loss of biodiversity due to economic and human development. A variety of biodiversity components are addressed by offset policies. It is required that loss of protected species due to development be offset under the EU Habitats and Birds Directives in Europe. We call this type of offset a species‐equality offset because the offset pertains to the same species affected by the development project. Whether species equality can be achieved by offset design is unknown. We addressed this gap by reviewing derogation files (i.e., specific files that describe mitigation measures to ensure no net loss under the EU Habitats and Birds Directives) from 85 development projects in France (2009–2010). We collected information on type of effect (reversible vs. irreversible) and characteristics of affected and offset sites (i.e., types of species, total area). We analyzed how the type of effect and the affected‐site characteristics influenced the occurrence of offset measures. The proportion of species targeted by offset measures (i.e., offset species) increased with the irreversibility of the effect of development and the conservation status of the species affected by development (i.e., affected species). Not all effects on endangered species (International Union for Conservation of Nature Red List) were offset; on average, 82% of affected species would be offset. Twenty‐six percent of species of least concern were offset species. Thirty‐five percent of development projects considered all affected species in their offset measures. Species richness was much lower in offset sites than in developed sites even after offset proposals. For developed areas where species richness was relatively high before development, species richness at offset sites was 5–10 times lower. The species‐equality principle appears to have been applied only partially in offset policies, as in the EU directives. We suggest the application of this principle through offsets is highly important for the long‐term conservation of biodiversity in Europe. Compensaciones y Conservación de las Especies de las Directivas de Hábitats y Aves de la UE     

四川喇叭河自然保护区的两栖爬行动物垂直分布及保护区型式

四川省喇叭河自然保护区已知分布有39种两栖爬行动物，本文对在该地区海拔700-2600m的地段划分为19个小带，并对其物种多样性的分布特点和分布规律进行了研究．结果表明：两栖爬行动物在保护区内具有明显的垂直分布现象，海拔900-1099m过渡带和2100-2299m过渡带是该地物种保护的关键地区，该区域具有物种丰富、区系复杂和生态脆弱等特点；因此，在规划建设和旅游开发过程中应避免对该区域的影响，同时保护区的规划应遵循物种多样性的分布规律，合理设计保护区的空间格局，初步提出了多核心、多层次的保护区新型式．图5表2参16     

Conservation of Deep Pelagic Biodiversity

Abstract:  The deep ocean is home to the largest ecosystems on our planet. This vast realm contains what may be the greatest number of animal species, the greatest biomass, and the greatest number of individual organisms in the living world. Humans have explored the deep ocean for about 150 years, and most of what is known is based on studies of the deep seafloor. In contrast, the water column above the deep seabed comprises more than 90% of the living space, yet less than 1% of this biome has been explored. The deep pelagic biota is the largest and least-known major faunal group on Earth despite its obvious importance at the global scale. Pelagic species represent an incomparable reservoir of biodiversity. Although we have yet to discover and describe the majority of these species, the threats to their continued existence are numerous and growing. Conserving deep pelagic biodiversity is a problem of global proportions that has never been addressed comprehensively. The potential effects of these threats include the extensive restructuring of entire ecosystems, changes in the geographical ranges of many species, large-scale elimination of taxa, and a decline in biodiversity at all scales. This review provides an initial framework of threat assessment for confronting the challenge of conserving deep pelagic biodiversity; and it outlines the need for baseline surveys and protected areas as preliminary policy goals.     

Selection of Islands for Conservation in the Urban Archipelago of Helsinki, Finland

Abstract: The occurrence of vascular plants was surveyed on 207 islands (size range 0.01–390.2 ha, number of plant species 1–449) offshore from the city of Helsinki in the Baltic Sea to examine the conservation value of these islands. We calculated a rarity score for each species (1/number of islands occupied by the species) and a biodiversity score for each island (sum of the rarity scores of each species present on the island). Positive correlations between species number and biodiversity score (r _s = 0.97, p < 0.001) and between biodiversity score and island area (r _s = 0.87, p < 0.001) indicated that these parameters are heavily dependent on island size. With the goal of including at least one occurrence (island) of all plant species, an iterative selection algorithm chose a set of 41 islands whose average size (29.3 ha) was four times the average size of all existing islands (7.0 ha). Strong nestedness ( N < 54) explains the concentration of plant species diversity on large islands. An operational strategy for selection of sites for protection is to complement the set produced by a selection algorithm with target species not yet included (e.g., endangered species with several occurrences). Comprehensive mapping and analysis of a taxonomic group will help integrate conservation biology into land-use planning and increase the quality of the networks of protected areas.     

Discrepancies in Reported Levels of International Wildlife Trade

Abstract:  The international wildlife trade is a principal cause of biodiversity loss, involving hundreds of millions of plants and animals each year, yet wildlife trade records are notoriously unreliable. We assessed the precision of wildlife trade reports for the United States, the world's largest consumer of endangered wildlife, by comparing data from the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) with U.S. Customs data. For both U.S. imports and exports, CITES and Customs reported substantially different trade volumes for all taxa in all years. Discrepancies ranged from a CITES-reported volume 376% greater than that reported by Customs (live coral imports, 2000) to a Customs' report 5202% greater than CITES (conch exports, 2000). These widely divergent data suggest widespread inaccuracies that may distort the perceived risk of targeted wildlife exploitation, leading to misallocation of management resources and less effective conservation strategies. Conservation scientists and practitioners should reexamine assumptions regarding the significance of the international wildlife trade.     

Threatened Status, Rarity, and Diversity as Alternative Selection Measures for Protected Areas: A Test Using Afrotropical Antelopes

A major aim of conservation today is the maintenance of biodiversity. Practically, this pursuit might involve protecting a representative sample of the current biotic diversity (where diversity can have a variety of different meanings as in Vane-Wright et al. 1991), safeguarding species with traits that may be correlated with susceptibility to extinction (see International Council for Bird Preservation 1992), or protecting those species that are currently categorized as under short-term threat of extinction. Priority areas for conservation may vary, however, depending on which of these three approaches is taken. We investigated the designation of priority areas using these different approaches for Afrotropical antelope. Sites were selected on the basis of (1) biotic diversity—simple species richness and taxonomic diversity; (2) uniqueness of the fauna relative to other sites—how geographically restricted the component species were; and (3) degree of endangerment of the fauna. When insufficient sites to represent all the species could be selected, there was little agreement between the priority sites selected using the different methods. Sites selected by each approach were also generally poor at representing the diversity components ranked highly by other approaches. Also, many of the species were represented in only one site in the selected network, which on its own probably does not represent a viable population for the species. Therefore, it is important that the precise aims and consequences of any selection procedure be understood. A combination of different approaches, emphasizing different aspects of biodiversity and implemented sequentially, may be the best compromise for preserving a full range of biotic diversity.     

Soil Collembola Diversity, Endemism, and Reforestation: A Case Study in the Pyrenees (France)

The diversity of soil Collembola was studied in two sites of the central Pyrenees (France). In each site a seminatural beech forest was compared to a conifer plantation. At the Rille site planted spruce and naturally regenerated beech forest were established on ancient meadows, and at the Carmil site a fir plantation had locally replaced the natural beech forest. Thirty-two soil cores of 250 cm³ were collected in each forest type at each site, and core fauna were extracted with a Berlese-Tullgren funnel. Differences in structure and composition of collembolan communities were observed from original to planted forest, and these changes followed different patterns at the two sites. In both cases, however, the diversity of the fauna was impoverished in the plantation. The endemic component suffered a particularly severe loss in species richness and abundance, whereas non-endemic species were more weakly affected. Endemic biota, which from a conservation perspective represent the most valuable element of the fauna, were its most vulnerable component. Endemic species and endemic areas therefore deserve particular attention when biodiversity fluctuations caused by reforestation are studied. This could lead to reassessment of the potential effects of artificial reforestation on the biodiversity of temperate forests. There is a general need for a systematic inventory and protection of forests with endemic soil biota.     

Environmental Synergisms and Extinctions of Tropical Species

Abstract: Environmental synergisms may pose the greatest threat to tropical biodiversity. Using recently updated data sets from the International Union for Conservation of Nature (IUCN) Red List, we evaluated the incidence of perceived threats to all known mammal, bird, and amphibian species in tropical forests. Vulnerable, endangered, and extinct species were collectively far more likely to be imperiled by combinations of threats than expected by chance. Among 45 possible pairwise combinations of 10 different threats, 69%, 93%, and 71% were significantly more frequent than expected for threatened mammals, birds, and amphibians, respectively, even with a stringent Bonferroni‐corrected probability value (p= 0.003). Based on this analysis, we identified five key environmental synergisms in the tropics and speculate on the existence of others. The most important involve interactions between habitat loss or alteration (from agriculture, urban sprawl, infrastructure, or logging) and other anthropogenic disturbances such as hunting, fire, exotic‐species invasions, or pollution. Climatic change and emerging pathogens also can interact with other threats. We assert that environmental synergisms are more likely the norm than the exception for threatened species and ecosystems, can vary markedly in nature among geographic regions and taxa, and may be exceedingly difficult to predict in terms of their ultimate impacts. The perils posed by environmental synergisms highlight the need for a precautionary approach to tropical biodiversity conservation.