Cryptic genetic diversity in “widespread” Southeast Asian bird species suggests that Philippine avian endemism is gravely underestimated

Mistakenly classifying morphologically cryptic endemic species as populations of widespread species potentially interferes with the conservation of biodiversity because undetected endemics that are imperilled may lack appropriate protection. It also impedes the reconstruction of the evolutionary history of a taxon by obscuring the number and distributional limits of species. Here, we present genetic and phylogenetic evidence corroborated by morphology that Philippine populations of seven widespread, non-migratory passerine birds might represent unrecognized, distinct species. An extrapolation based on this finding suggests that the proportion of endemic bird species in the Philippines could be much higher than currently estimated. This high degree of cryptic diversity in a well-studied, volant taxon implies that large numbers of unrecognized species can be expected in less thoroughly studied groups. We predict that genetic investigations of insular populations of widespread species will frequently reveal unrecognized island endemics, and because of the vulnerability of island habitats and their biota, these taxa may be particularly susceptible to extinction.     

Using ecological niche modelling to identify diversity hotspots for the herpetofauna of Pacific lowlands and adjacent interior valleys of Mexico

This article documents the conservation status of the herpetofauna in the Pacific lowlands and adjacent Balsas Basin and Chiapas Depression regions and the presents the results of modelling species spatial distributional patterns through GARP analysis, to identify hotspots of species richness, endemic and geographically restricted species in the study area. It also compares the distribution of these hotspots with the distribution of protected areas and intact seasonally tropical dry tropical forests, the dominant vegetation type in the study area and experiencing high deforestation rates. A total of 301 reptiles and amphibian species occur in the study area accounting for a third of the Mexican herpetofauna, and recording high levels of endemism and endangerment. Hotspots of species richness and endemism were located in coastal Jalisco, a considerable portion of the Colima state, as well as scattered areas in Michoacán, Guerrero, and Oaxaca. These areas should receive highest priority for protection. Unfortunately, there was a minimum correspondence when comparing the distribution of actually and proposed protected areas with hotspots identified. Fortunately, areas of high species richness, endemism and restricted species coincided with those where intact seasonally tropical dry tropical forests still exists. These areas should receive high priority in future plans for seasonally tropical dry tropical forests protected areas. It is hoped that this paper will call attention to the need for establishing a network of protected areas in the study area, as has been proposed by previous studies.     

Global warming, elevational ranges and the vulnerability of tropical biota

Tropical species with narrow elevational ranges may be thermally specialized and vulnerable to global warming. Local studies of distributions along elevational gradients reveal small-scale patterns but do not allow generalizations among geographic regions or taxa. We critically assessed data from 249 studies of species elevational distributions in the American, African, and Asia-Pacific tropics. Of these, 150 had sufficient data quality, sampling intensity, elevational range, and freedom from serious habitat disturbance to permit robust across-study comparisons. We found four main patterns: (1) species classified as elevational specialists (upper- or lower-zone specialists) are relatively more frequent in the American than Asia-Pacific tropics, with African tropics being intermediate; (2) elevational specialists are rare on islands, especially oceanic and smaller continental islands, largely due to a paucity of upper-zone specialists; (3) a relatively high proportion of plants and ectothermic vertebrates (amphibians and reptiles) are upper-zone specialists; and (4) relatively few endothermic vertebrates (birds and mammals) are upper-zone specialists. Understanding these broad-scale trends will help identify taxa and geographic regions vulnerable to global warming and highlight future research priorities.     

Nematode diversity and distribution in the southern maritime Antarctic—clues to history?

Nematode worms are one of the most important soil faunal groups in Antarctica. However, relatively little is known about their wider distribution, biogeography and history in the region, and taxonomic information remains confused or incomplete. Here, we hypothesise that the Alexander Island (southern maritime Antarctic) fauna includes elements that have survived (at least) the period of Pleistocene glaciation in situ, forming a regional centre of endemism and biodiversity hotspot. We describe nematological surveys carried out across a latitudinal gradient between 68 and 77°S along the southern Antarctic Peninsula, comparing the data obtained with the maritime Antarctic fauna described in the few previous studies between northern Marguerite Bay and the South Orkney Islands (60-68°S). In general, our survey supports previous findings of a lack of overlap at species level between the maritime and continental Antarctic biogeographical zones, with the large majority of specimens obtained from all survey sites being attributable to known maritime or new and currently endemic taxa. However, collections from Alexander Island, Alamode Island and the most westerly site sampled, Charcot Island, include specimens morphologically very close to two known continental Antarctic species, which may indicate a link between the two regions. The fauna obtained at the northern study sites (ca. 68°S, Adelaide Island, Marguerite Bay) closely matches that described previously. However, in contrast with widely described patterns of decreasing diversity in other Antarctic biota, species richness increased markedly at locations on Alexander Island (ca. 72°S), including a substantial element of undescribed species (50% of taxa across all locations, 40% of taxa found on Alexander Island). Finally, the most southerly samples obtained, from inland nunataks in Ellsworth Land (75-77°S), indicate a fauna that does not include nematodes, which is exceptional not only in an Antarctic context but also for soils worldwide.     

How long does the Atlantic Rain Forest take to recover after a disturbance? Changes in species composition and ecological features during secondary succession

We evaluated floristic and ecological changes in plant communities after disturbance in Southern Atlantic Rain Forests, in the Brazilian states of Rio de Janeiro, São Paulo, Paraná and Santa Catarina. We compiled data for 410 tree species from 18 forests ranging from 4 to 120 years after disturbance, and classified them by dispersal mode (animal vs. non-animal), successional group (pioneer vs. non-pioneer), vertical position (understorey vs. non-understorey) and geographic distribution (Atlantic Forest vs. widespread). We found that both geographical location and time since disturbance affect species distribution and β-diversity. Regression analyses showed significant, positive and strong relations (0.26 ? r² ? 0.63; P < 0.05) between fragment age and species richness, proportion of animal dispersed species, of non-pioneer species, of understorey species and with restricted distribution. Applying our data to values found in literature we predict that a forest needs about one to three hundred years to reach the proportion of animal-dispersed species (80% of the species), the proportion of non-pioneer species (90%) and of understorey species (50%) found in mature forests. On the other hand much more time is necessary (between one and four thousand years) to reach the endemism levels (40% of the species) that exist in mature forests. Our findings indicate that disturbance results in significant changes in species composition (decrease in endemic species) and ecological guilds (decrease in zoochory and in non-pioneer and understorey species), but forests can gradually recover over time spans of hundreds of years.     

Has survey effort of Australia's islands reflected conservation and biogeographical significance? An assessment using Collembola

Surveys of collembolan faunas of 10 of Australia's off-shore islands are recorded. The island's abiotic attributes are ranked according to their influence on species richness and endemism. The ranks are compared with rankings of the thoroughness of the survey and species richness of Collembola. The data suggest that, apart from Lord Howe Island, survey effort has been influenced to a greater extent by strategic, political and commercial interests and only rarely by any predicted conservation significance.     

Reserve selection using Red Listed taxa in three global biodiversity hotspots: Dragonflies in South Africa

The Red List can be used a gauging tool by conservationists to assess which species require focused conservation attention. Mapping the relative distributions of species, and identification of centers of richness, endemism and threat are a first step towards site-oriented conservation action. We use here a specially developed biodiversity index, based on three weighted sub-components assigned to each species: geographical distribution, Red List status, and sensitivity to habitat change. We test this approach using what is called here the Dragonfly Biotic Index (DBI) to prioritize sites for conservation action, with special emphasis on species occurrence in three global hotspots in southern Africa. Using a selected set of the 23 top prioritized sites, we compare the DBI’s performance to that of a rarity-complementarity algorithm. As with several other taxa, local endemism levels are highest in the Cape Floristic Region (CFR), while richness is highest in the north east, particularly in the stream systems of the Maputaland-Pondoland-Albany (MPA) hotspot. Red Listed Odonata species are also concentrated in the CFR, while richness is highest in the MPA hotspot. Site prioritization using the DBI reveals that CFR sites protect Red Listed taxa rather well, despite the fact that catchments are only partially protected. The DBI demonstrates high levels of redundancy in representing Red Listed species, in other words, the same species are represented in several catchments. The value in the DBI thus lies in maximizing redundancy (i.e. representation) of globally Red Listed species. The rarity-complementarity algorithm represents all species, but without greater emphasis on the rare and threatened (i.e. Red Listed) species. We conclude that the DBI is of great value in selecting biodiversity hotspots, while the algorithm is useful for selecting complementarity hotspots. We identify protection gaps and thus recommend continued searches in centers of endemism and existing reserves, as well as gap areas. These searches will hone Red List assessments and identify priority sites, as well as monitor already-identified sites for changes in quality of habitat.     

Biodiversity and its fragility in Yunnan,China

In Yunnan, 8 major aspects of biodiversity and fragility in landforms, ecosystems, distribution populations, alien invasion, segregation, pollution and maladministration with various menace factors causing biodiversity loss have been described. It is revealed that the facts that the biodiversity and fragility coexists in this paper. Accordingly, 6 major countermeasures for effective conservation and rational utilization of the provincial biodiversity were suggested on the basis of the scientific development concepts, principles of nature protection, conservation biology, resource management and ethnobotany and present status in Yunnan with rich intangible resources such as climatic, ethnical and cultural diversity, etc.     

Winners and losers among stream fishes in relation to land use legacies and urban development in the southeastern US

The southeastern United States is a center of aquatic species diversity and endemism in North America, but many taxa are imperiled or in decline. Proactive conservation strategies depend on developing sensitive measures of ecological response to environmental degradation early in the process. In the southern Appalachian highlands, much of the region has reforested following extensive logging and agriculture in the last century, but recently exurban development has surged. Patterns of aquatic ecosystem response to these changes were examined in 36 watersheds along a gradient of forest cover from moderately to heavily forested. A linear combination of watershed-scale measures reflecting the extent contemporary forest cover, the trajectory of forest cover change over time, and building and road density were stronger predictors of fish assemblage composition than topographic features. A measure of biotic homogenization relating the abundance of endemic highland fishes to abundance of broad-ranged fishes was sensitive to the gradient of anthropogenic disturbance. Across the watershed disturbance gradient, cosmopolitan species were clear winners as forms unique to the Appalachian highlands were lost. Similar measures of homogenization may be suitable elsewhere for tracking early warning signs of ecosystem stress, particularly in regions with significant endemism. Quantification of the homogenization process in response to urban development and other stressors is a promising avenue for proactive conservation, land use planning, and sustainable development efforts.     

Priority areas for conservation of Western Australian coastal fishes: A comparison of hotspot, biogeographical and complementarity approaches

Western Australia has an extensive coastline ranging from the tropical north to the temperate south, with a high diversity of neritic marine fishes. Distribution data of 1855 neritic fish species were used to compare a range of methods for identifying priority areas for their conservation. Species richness and endemism richness hotspots, biogeographic zoning and complementarity analysis were tested for their efficiency at representing the total suite of species. The hotspot approaches demonstrated low efficiency, as the sections of coastline selected were grouped together in isolated geographic locations and relatively few of the total suite of neritic fish species were represented. Biogeographic zoning divided the coast of Western Australia into six regions, and as such, priority areas were selected around the entire coastline, which resulted in fairly high levels of efficiency. However, the complementarity analysis proved to be the most efficient method, as >95% of all neritic fish species could be represented in six, appropriately located, 100 km long sections of coastline. Complementarity analysis indicated a total of 26 priority areas for neritic fish conservation, which were spread around the entire coast of Western Australia. However, as current marine conservation measures in Western Australia are focused on the west and northwest coasts, this study highlighted the need for marine conservation efforts to be extended to cover the north and south coasts.