Reef Fishes in Biodiversity Hotspots Are at Greatest Risk from Loss of Coral Species

Coral reef ecosystems are under a variety of threats from global change and anthropogenic disturbances that are reducing the number and type of coral species on reefs. Coral reefs support upwards of one third of all marine species of fish, so the loss of coral habitat may have substantial consequences to local fish diversity. We posit that the effects of habitat degradation will be most severe in coral regions with highest biodiversity of fishes due to greater specialization by fishes for particular coral habitats. Our novel approach to this important but untested hypothesis was to conduct the same field experiment at three geographic locations across the Indo-Pacific biodiversity gradient (Papua New Guinea; Great Barrier Reef, Australia; French Polynesia). Specifically, we experimentally explored whether the response of local fish communities to identical changes in diversity of habitat-providing corals was independent of the size of the regional species pool of fishes. We found that the proportional reduction (sensitivity) in fish biodiversity to loss of coral diversity was greater for regions with larger background species pools, reflecting variation in the degree of habitat specialization of fishes across the Indo-Pacific diversity gradient. This result implies that habitat-associated fish in diversity hotspots are at greater risk of local extinction to a given loss of habitat diversity compared to regions with lower species richness. This mechanism, related to the positive relationship between habitat specialization and regional biodiversity, and the elevated extinction risk this poses for biodiversity hotspots, may apply to species in other types of ecosystems.     

The Overlooked Biodiversity of Flower-Visiting Invertebrates

Estimates suggest that perhaps 40% of all invertebrate species are found in tropical rainforest canopies. Extrapolations of total diversity and food web analyses have been based almost exclusively on species inhabiting the foliage, under the assumption that foliage samples are representative of the entire canopy. We examined the validity of this assumption by comparing the density of invertebrates and the species richness of beetles across three canopy microhabitats (mature leaves, new leaves and flowers) on a one hectare plot in an Australian tropical rainforest. Specifically, we tested two hypotheses: 1) canopy invertebrate density and species richness are directly proportional to the amount of resource available; and 2) canopy microhabitats represent discrete resources that are utilised by their own specialised invertebrate communities. We show that flowers in the canopy support invertebrate densities that are ten to ten thousand times greater than on the nearby foliage when expressed on a per-unit resource biomass basis. Furthermore, species-level analyses of the beetle fauna revealed that flowers support a unique and remarkably rich fauna compared to foliage, with very little species overlap between microhabitats. We reject the hypothesis that the insect fauna on mature foliage is representative of the greater canopy community even though mature foliage comprises a very large proportion of canopy plant biomass. Although the significance of the evolutionary relationship between flowers and insects is well known with respect to plant reproduction, less is known about the importance of flowers as resources for tropical insects. Consequently, we suggest that this constitutes a more important piece of the ‘diversity jigsaw puzzle’ than has been previously recognised and could alter our understanding of the evolution of plant-herbivore interactions and food web dynamics, and provide a better foundation for accurately estimating global species richness.     

Future of Endemic Flora of Biodiversity Hotspots in India

India is one of the 12 mega biodiversity countries of the world, which represents 11% of world''s flora in about 2.4% of global land mass. Approximately 28% of the total Indian flora and 33% of angiosperms occurring in India are endemic. Higher human population density in biodiversity hotspots in India puts undue pressure on these sensitive eco-regions. In the present study, we predict the future distribution of 637 endemic plant species from three biodiversity hotspots in India; Himalaya, Western Ghats, Indo-Burma, based on A1B scenario for year 2050 and 2080. We develop individual variable based models as well as mixed models in MaxEnt by combining ten least co-related bioclimatic variables, two disturbance variables and one physiography variable as predictor variables. The projected changes suggest that the endemic flora will be adversely impacted, even under such a moderate climate scenario. The future distribution is predicted to shift in northern and north-eastern direction in Himalaya and Indo-Burma, while in southern and south-western direction in Western Ghats, due to cooler climatic conditions in these regions. In the future distribution of endemic plants, we observe a significant shift and reduction in the distribution range compared to the present distribution. The model predicts a 23.99% range reduction and a 7.70% range expansion in future distribution by 2050, while a 41.34% range reduction and a 24.10% range expansion by 2080. Integration of disturbance and physiography variables along with bioclimatic variables in the models improved the prediction accuracy. Mixed models provide most accurate results for most of the combinations of climatic and non-climatic variables as compared to individual variable based models. We conclude that a) regions with cooler climates and higher moisture availability could serve as refugia for endemic plants in future climatic conditions; b) mixed models provide more accurate results, compared to single variable based models.     

Honing Red List Assessments of Lesser-Known Taxa in Biodiversity Hotspots

Red Listing organisms is an iterative process involving two variables. First, the conservation status of a taxon becomes clearer as more information becomes available, and secondly, the actual status changes as the taxon becomes more threatened or less threatened. Using a 20-year database of South African dragonflies has enabled us to hone conservation assessments and to arrive at a realistic appraisal of their true conservation status. Changes in the evaluation of taxa came about through improved knowledge of habitat and particularly from information on the exact flight period. This background improved the apparency of the taxa so enabling accurate conservation assessments. The temporal shortcoming was addressed in detail by focusing on the core of the Cape Floristic Region global biodiversity hotspot, and recording the phenology of species. We found that there were large differences in emergence times. While flight times may not be a source of error in the temperate northern hemisphere, they can be a major issue in low and southern latitudes. Indeed, the error can be so great that species thought to be extinct were effectively resurrected. Temporal shortcomings can only be overcome by first undertaking a presence/absence survey over time to determine the appropriate time of year for making rigorous Red List assessments. This is not a criticism of the Red Listing process per se, which, for this taxon, we found to be largely sound. However, the results do emphasize that a critical approach to methodology is a necessary foundation when searching for trend indicators from the Red List with regards to lesser-known taxa.     

Climate Change Implications for River Restoration in Global Biodiversity Hotspots

Global biodiversity hotspots contain exceptional concentrations of endemic species in areas of escalating habitat loss. However, most hotspots are geographically constrained and consequently vulnerable to climate change as there is limited ability for the movement of species to less hostile conditions. Predicted changes to rainfall and temperature will undoubtedly further impact on freshwater ecosystems in these hotspots. Southwestern Australia is a biodiversity hotspot and, as one of the first to experience significant climate change, is an example and potentially a global bellwether for issues associated with river restoration. In this hotspot, current and predicted water temperatures may exceed thermal tolerances of aquatic fauna. Gondwanic aquatic fauna, characteristic of southwestern Australia, are typically cold stenotherms and consequently intolerant of elevated temperatures. The hotspot in southwestern Australia is geographically restricted being surrounded by ocean and desert, and many important national parks are located on the extreme south coast, where the landscape is relatively flat. Consequently, fauna cannot change their distribution southwards or with altitude as a response to increasing temperatures. Therefore, any mitigation responses need to be in situ to produce a suitable biophysical envelope to enhance species' resilience. This could be through “over restoration” by increased riparian replanting at a catchment scale. A rule‐of‐thumb of a 10% increase in riparian cover would be required to reduce water temperatures by 1°C. These restoration techniques are considered applicable to other global biodiversity hotspots where geography constrains species' movement and the present condition is the desired restoration endpoint.     

Amphibian Diversity in East African Biodiversity Hotspots: Altitudinal and latitudinal Patterns

The Eastern Arc mountain chain and adjoining coastal forests of Tanzania and Kenya have been listed as world biodiversity hotspots. We report on an ongoing attempt to estimate amphibian diversity on the three best studied mountains of the Eastern Arc, the East Usambara, Uluguru and Udzungwa mountains of Tanzania, complemented by an estimate of diversity on the adjoining coastal lowland. This proves to be a complex task, which introduces a note of caution into evaluating global biodiversity estimates. Most amphibian species in eastern Tanzania occur on the coastal lowlands and are widely distributed, extending at least north or south of Tanzania and, to a variable extent, westwards to the elevated interior. Diversity patterns along the length of the lowlands are complex, with the presence of a Sahelian element in the extreme north. On the three Eastern Arc mountains studied, species turnover associated with rising altitude is greater than turnover associated with latitudinal distance between the mountain blocks, leading to greater altitudinal than latitudinal diversity in this equatorial region. A long-standing divergence is indicated between montane and lowland endemics. Although forest-associated species are not the largest contributor to the eastern Tanzanian total species diversity (some 48%), the uniqueness of these species both in lowland and montane forests, combined with their evident vulnerability to disturbance, makes them a subject for particular conservation concern, and justifies hotspot status for both montane and lowland forests.     

Biogeochemical Hotspots in Forested Landscapes: The Role of Vernal Pools in Denitrification and Organic Matter Processing

Quantifying spatial and temporal heterogeneity in ecosystem processes presents a challenge for conserving ecosystem function across landscapes. In particular, many ecosystems contain small features that play larger roles in ecosystem processes than their size would indicate; thus, they may represent “hotspots” of activity relative to their surroundings. Biogeochemical hotspots are characterized as small features within a landscape that show comparatively high chemical reaction rates. In northeastern forests in North America, vernal pools are abundant, small features that typically fill in spring with snow melt and precipitation and dry by the end of summer. Ephemeral flooding alters soil moisture and the depth of the soil’s oxic/anoxic boundary, which may affect biogeochemical processes. We studied the effects of vernal pools on leaf-litter decomposition rates, soil enzyme activity, and denitrification in vernal pools to assess whether they function as biogeochemical hotspots. Our results indicate that seasonal inundation enhanced leaf-litter decomposition, denitrification, and enzyme activity in vernal pools relative to adjacent forest sites. Leaves in seasonally flooded areas decomposed faster than leaves in terra firme forest sites. Flooding also influenced the C, N, and P stoichiometry of decomposing leaf litter and explained the variance in microbial extracellular enzyme activity for phosphatase, β-d-glucosidase, and β-N-acetylglucosaminidase. Additionally, denitrification rates were enhanced by seasonal flooding across all of the study pools. Collectively, these data suggest that vernal pool ecosystems may function as hotspots of leaf-litter decomposition and denitrification and play a significant role in decomposition and nutrient dynamics relative to their size.     

Biodiversity of Jinggangshan Mountain: The Importance of Topography and Geographical Location in Supporting Higher Biodiversity

Diversity is mainly determined by climate and environment. In addition, topography is a complex factor, and the relationship between topography and biodiversity is still poorly understood. To understand the role of topography, i.e., altitude and slope, in biodiversity, we selected Jinggangshan Mountain (JGM), an area with unique topography, as the study area. We surveyed plant and animal species richness of JGM and compared the biodiversity and the main geographic characteristics of JGM with the adjacent 4 mountains. Gleason’s richness index was calculated to assess the diversity of species. In total, 2958 spermatophyte species, 418 bryophyte species, 355 pteridophyte species and 493 species of vertebrate animals were recorded in this survey. In general, the JGM biodiversity was higher than that of the adjacent mountains. Regarding topographic characteristics, 77% of JGM’s area was in the mid-altitude region and approximately 40% of JGM’s area was in the 10°–20° slope range, which may support more vegetation types in JGM area and make it a biodiversity hotspot. It should be noted that although the impact of topography on biodiversity was substantial, climate is still a more general factor driving the formation and maintenance of higher biodiversity. Topographic conditions can create microclimates, and both climatic and topographic conditions contribute to the formation of high biodiversity in JGM.     

Local Scale Effects of Disease on Biodiversity

To date, ecologists and conservation biologists have focused much of their attention on the population and ecosystem effects of disease at regional scales and the role that diseases play in global species extinction. Far less research has been dedicated to identifying the effects that diseases can have on local scale species assemblages. We examined the role of infectious disease in structuring local biodiversity. Our intention was to illustrate how variable outcomes can occur by focusing on three case studies: the influence of chestnut blight on forest communities dominated by chestnut trees, the influence of red-spot disease on urchin barrens and kelp forests, and the influence of sylvatic plague on grassland communities inhabited by prairie dogs. Our findings reveal that at local scales infectious disease seems to play an important, though unpredictable, role in structuring species diversity. Through our case studies, we have shown that diseases can cause drastic population declines or local extirpations in keystone species, ecosystem engineers, and otherwise abundant species. These changes in local diversity may be very important, particularly when considered alongside potentially corresponding changes in community structure and function, and we believe that future efforts to understand the importance of disease to species diversity should have an increased focus on these local scales.     

Biodiversity Hotspots from a Multigroup Perspective: Mosses and Senecios in the Transmexican Volcanic Belt

Geographical information for 703 mosses and Senecios (species of the tribe Senecioneae, Asteraceae) has been analyzed to identify patterns of species richness in the Transmexican Volcanic Belt (TMVB) of Mexico. Because the TMVB holds a high proportion of these taxa (596 mosses out of 980, and 107 Senecios out of 228) in the country, it is considered a high diversity area. However, the biodiversity is not uniform, as shown by the number of species in each of seventy nine 0.5° latitude and 0.5° longitude cells covering the surface area of the mountain range. Nineteen cells were identified as hotspots and further analysis showed that 11 of such hotspots were common to both groups. The application of a heuristic iterative method and a complementarity criterion indicated that the selection of 18 cells would conserve the total diversity of mosses and Senecios found in such hotspots.     

岷山山系大熊猫自然保护区2003年生物多样性监测

岷山山系是全球生物多样性保护的热点地区之一,有着全世界最大的大熊猫种群和面积最大的大熊猫栖息地。到2003年底,在该地区已建立了20个以保护大熊猫为主的自然保护区。从2003年开始,岷山17个大熊猫自然保护区实施了野外大熊猫及其栖息地监测。通过监测,了解了岷山自然保护区野生动物分布状况、人为活动对自然保护区的干扰情况,以及自然保护区周边社区经济情况,为自然保护区管理决策提供了依据。同时,通过监测活动还提高了自然保护区工作人员的业务水平。建议今后将自然保护区监测工作纳入自然保护区日常工作中。     

Factors Influencing the Seasonal Phenology and Composition of Zooplankton Communities in Mountain Temporary Pools

In 2001 nine temporary pools of the northern Apennines (Italy) were visited on 13 occasions during the ice‐free season (May to October). The aims of this research were to define the relationships between hydroperiod and other environmental variables and the zooplankton. In total, 49 zooplankton taxa were identified: 36 rotifers, 5 cladocerans, 6 copepods and 2 anostracans. Our results indicate that hydroperiod is a major determinant affecting zooplankton species richness. The highest number of taxa was found in the pond having the longest duration. Distinctive species assemblages were observed in different habitat types: pools with the shortest hydroperiod were characterised by organisms with brief life cycles (e.g. rotifers) and/or typical of temporary habitat (e.g. anostracans). Of the physical and chemical characteristics, pH and chlorophyll‐a appeared to have the largest influence on zooplankton distribution in the studied pools. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

A Critical Assessment of Marine Aquarist Biodiversity Data and Commercial Aquaculture: Identifying Gaps in Culture Initiatives to Inform Local Fisheries Managers

It is widely accepted that if well managed, the marine aquarium trade could provide socio-economic stability to local communities while incentivising the maintenance of coral reefs. However, the trade has also been implicated as having potentially widespread environmental impacts that has in part driven developments in aquaculture to relieve wild collection pressures. This study investigates the biodiversity in hobbyist aquaria (using an online survey) and those species currently available from an aquaculture source (commercial data and hobbyist initiatives) in the context of a traffic light system to highlight gaps in aquaculture effort and identify groups that require fisheries assessments. Two hundred and sixty nine species including clown fish, damsels, dotty backs, angelfish, gobies, sea horses and blennies, have reported breeding successes by hobbyists, a pattern mirrored by the European and US commercial organisations. However, there is a mismatch (high demand and low/non-existent aquaculture) for a number of groups including tangs, starfish, anemones and hermit crabs, which we recommend are priority candidates for local stock assessments. Hobbyist perception towards the concept of a sustainable aquarium trade is also explored with results demonstrating that only 40% of respondents were in agreement with industry and scientists who believe the trade could be an exemplar of a sustainable use of coral reefs. We believe that a more transparent evidence base, including the publication of the species collected and cultured, will go some way to align the concept of a sustainable trade across industry stakeholders and better inform the hobbyist when purchasing their aquaria stock. We conclude by proposing that a certification scheme established with government support is the most effective way to move towards a self-regulating industry. It would prevent industry “greenwashing” from multiple certification schemes, alleviate conservation concerns, and, ultimately, support aquaculture initiatives alongside well managed ornamental fisheries.     

芦芽山荷叶坪亚高山草甸生物多样性

以芦芽山荷叶坪亚高山草甸为研究对象,共设置150个5 m×5 m草本样方,进行群落生物学调查,对研究区36种草本植物重要值、α多样性指数、谱系多样性指数及其相关性进行研究.结果表明: 荷叶坪亚高山草甸物种多样性总体分布较均匀,边缘地区物种更丰富,呈现“边缘效应”;4个样地的群落谱系结构呈聚集模式,12个样地的群落谱系结构呈分散模式;谱系多样性指数(PD)与Petrick指数、Simpson指数和Shannon指数呈正相关,净亲缘关系指数(NRI)和最近种间亲缘关系指数(NTI)与α物种多样性指数无明显相关性.     

Are Replanted Floodplain Forests in Southeastern Australia Providing Bird Biodiversity Benefits?

Revegetation of massively altered landscapes for multiple benefits (including biodiversity and ecological function) has accelerated over the past two decades in southern Australia. However, much of the action has been conducted piecemeal, with little apparent strategy. We consider here replanted woodlands on the floodplain of the Murray River, northern Victoria, Australia. All are small in area (<18 ha) and recent (<30 years) and have been planted with appropriate trees and shrubs. We employed a scoring system devised to rapidly measure bird breeding success and linked these results to in-site and landscape variables. Most bird species using the replantings were those that are tolerant of much disturbed landscapes and of open country. Factors related to breeding success were different for each of the six species for which inferences could be made, indicating that it would be difficult to simultaneously plan for all species. Birds characteristic of the major forest floodplain remnants were poorly represented and there was little evidence of their breeding in the replantings. The value of the replanted sites for birds is marginal at present, although it may be that the sites are still too young to have realized their usefulness for species of conservation concern. We believe that most production landscapes in this region have far too little native vegetation to support the many species that are declining, and more strategic planning is necessary to overcome these deficiencies.     

海南岛吊罗山蕨类植物的多样性及其保育

对海南岛吊罗山的蕨类植物进行了专题研究。吊罗山有蕨类植物 4 3科 10 0属 2 13种及 4变种 ,其中 5种为海南新记录。蕨类物种密度高达 5 5 .8种 / 10 0km2 ,为海南蕨类多样性中心之一。该地蕨类植物区系以水龙骨科和膜蕨科为优势科 ,表现出明显的热带性质 ,热带分布的科、属、种分别达到 10 0 %、93.2 %和 95 .3%。在垂直分布上 ,蕨类植物的生态特点与植被类型相关 ,随着海拔升高 ,阳生性蕨类减少 ,阴生性蕨类、附生与石生蕨类增多 ,蕨类物种多样性在海拔 6 0 0～ 10 0 0m地段最为丰富。按照 2 0 0 1年IUCN红色名录等级及标准评估 ,在海南岛范围内 ,吊罗山有 36种受威胁蕨类植物 ,其中 6种为极危物种 ,13种为濒危物种 ,17种为渐危物种 ,这 36种受威胁蕨类中有 8种属于国家II级保护植物。导致这 36种蕨类植物受威胁的原因主要有 :人为直接破坏、生境旱化和分布区限制