An easy-to-use index of ecological integrity for prioritizing freshwater sites and for assessing habitat quality

Prioritizing and assessing the condition of sites for conservation action requires robust and ergonomic methodological tools. We focus here on prioritizing freshwater sites using two promising biodiversity indices, the Dragonfly Biotic Index (DBI) and Average Taxonomic Distinctness (AvTD). The AvTD had no significant association with either species richness or endemism. In contrast, the DBI was highly significantly associated with species richness and endemism, although the strengths of the associations were weak. These associations are related to how the sub-indices in the DBI are weighted, and how species are distributed geographically. Additionally, the DBI was found to be very useful for site selection based on its ability to measure ecological integrity, combined with level of threat, at multiple spatial scales. The AvTD was found to be useful principally for regional use. As the DBI is a low-cost, easy-to-use method, it has the additional use as a method for assessing habitat quality and recovery in restoration programs. The DBI operates at the species level, and is therefore highly sensitive to habitat condition and has great potential for environmental assessment and monitoring freshwater biodiversity and quality. Practical, worked examples of river restoration are given here. In view of the ease and versatility by which the DBI can be employed, we recommend its testing and possible integration into freshwater management and conservation schemes elsewhere in the world.     

Plant diversity and priority conservation areas of Northwestern Yunnan,China

The Global Plant Conservation Strategy of the Convention on Biological Diversity calls for “protection of 50% of the most important areas for plant diversity.” All global biodiversity analyses have identified the mountains of northwestern Yunnan as a conservation priority for plant diversity. The challenge we were presented with was how to transform this sweeping global recognition into regional geographic priorities and measurable conservation action. This challenge is especially acute in Yunnan where there are no readily accessible data on the distribution and status of plant diversity, yet great conservation urgency due to the rapid pace of economic development. We used endangered and endemic species to represent plant diversity as a whole due to time and financial constraints. To identify conservation priorities, we relied on experts’ knowledge, supplemented with a rapidly assembled plant diversity data base, rapid field assessments to fill knowledge gaps, and analyses of the spatial patterns of richness and habitat relationships. Ninety-eight endangered species and 703 endemic species occur in the project area. Experts identified nine Plant Diversity Conservation Areas for northwestern Yunnan, including eight specific geographies and one priority habitat. We found that the current nature reserve system is serving an important role in plant diversity protection, even though many of the reserves were not specifically designated for plant diversity considerations. This project provided a means for scientific experts to directly contribute to conservation decision-making by government and Non-Government Organizations, and essential information for the plant conservation in Northwestern Yunnan.     

Consequences of changes in thermal regime for plankton diversity and trait composition in a polymictic lake: a matter of temporal scale

1. Changes in plankton species diversity and community structure as a result of global warming are of growing concern in ecological studies, as these properties contribute substantially to key ecosystem processes. 2. We analysed the effect of short‐term temperature rise and changes in the thermal regime during summer on plankton diversity of the eutrophic and polymictic Müggelsee in Germany, from 26 years of summer records (1982–2007). We tested for changes in community properties, such as species richness, evenness and population size of phyto‐ and zooplankton, during alternating periods of thermal stratification and mixing, which were between 2 and 8 weeks long. Moreover, we tested for overall long‐term temporal trends in annual averages of the community properties during stratified and mixed events. 3. We found that the overall number of stratification events increased significantly across the study period. When the lake was stratified, consistently higher surface water temperatures and lower epilimnetic nutrient concentrations were found. As the length of thermal stratification increased, the phytoplankton shifted towards a higher proportion of buoyant cyanobacteria capable of N‐fixation (Aphanizomenon, Anabaena). Diatoms were at a disadvantage because of high temperature, exceeding their upper lethal limit and sedimentation losses. Zooplankton species with high thermal tolerances (i.e. Thermocyclops oithonoides, Thermocyclops crassus) and/or those that grow quickly at high temperatures (i.e. rotifers) became more common. 4. During periods of continuous mixing, the community remained largely unchanged, except for some minor increase in the biomass of diatoms. 5. While a noticeable shift towards N‐fixing cyanobacteria was observed with increasing length of stratified events, and rotifers and copepods became the main predators, there were minimal changes in diversity, except for an increase in cyclopoid copepods and a decrease in diatom diversity. As for cyanobacteria, the net short‐term effect on their diversity was neutral as a result of species replacements. In the long term, however, the diversity of cyanobacteria and cladocerans declined while that of rotifers increased. 6. Overall, our study presents a cautionary example of how we might fail to foresee the impact of climate‐induced changes on ecosystem processes if we restrict our studies to seasonal or yearly temporal scales, thus neglecting the impact of substantial changes operating at smaller temporal scales.     

Genetic diversity of Chinese alligator (Alligator sinensis) revealed by AFLP analysis: an implication on the management of captive conservation

Chinese alligator (Alligator sinensis) is one of the most critically endangered species among 23 extant crocodiles in the world. To prevent the extinction of the species, a captive propagation started at early 1980s, and the total number of alligator was brought up to 10 thousands from dozens of founder in 2000. But several genetic investigations showed those alligators were under an extremely low genetic diversity status with few detectible polymorphic loci. To get more insight into its genetic diversity for the management of captive Chinese alligator, AFLP was adopted to characterize variations in the population. Total of 347 bands were generated from 47 individuals using 3 primer combinations, of which 203 (58.50%) were polymorphic, and 35 AFLP phenotypes were revealed from those individuals. Comparing the results between RAPD and AFLP analysis on almost same sample set clearly indicated that AFLP is more efficient in revealing polymorphic loci, especially in those populations with extremely low genetic diversity. In present three assays, electrophoresis profile also displayed 3 individuals possessing very highly polymorphic AFLP phenotypes that were never been found by RAPD and mtDNA D-loop sequencing, implicating that we should offer these individuals more breeding opportunities to maintain the genetic diversity in the population and restrict those carrying few polymorphic loci from reproduction.     

Biotechnological approaches for conservation and improvement of rare and endangered plants of Saudi Arabia

Genetic variation is believed to be a prerequisite for the short-and long-term survival of the plant species in their natural habitat. It depends on many environmental factors which determine the number of alleles on various loci in the genome. Therefore, it is important to understand the genetic composition and structure of the rare and endangered plant species from their natural habitat to develop successful management strategies for their conservation. However, rare and endangered plant species have low genetic diversity due to which their survival rate is decreasing in the wilds. The evaluation of genetic diversity of such species is very important for their conservation and gene manipulation. However, plant species can be conserved by in situ and in vitro methods and each has advantages and disadvantages. DNA banking can be considered as a means of complimentary method for the conservation of plant species by preserving their genomic DNA at low temperatures. Such approach of preservation of biological information provides opportunity for researchers to search novel genes and its products. Therefore, in this review we are describing some potential biotechnological approaches for the conservation and further manipulation of these rare and endangered plant species to enhance their yield and quality traits.     

Using species distributions models for designing conservation strategies of Tropical Andean biodiversity under climate change

Biodiversity in the Tropical Andes is under continuous threat from anthropogenic activities. Projected changes in climate will likely exacerbate this situation. Using species distribution models, we assess possible future changes in the diversity and climatic niche size of an unprecedented number of species for the region. We modeled a broad range of taxa (11,012 species of birds and vascular plants), including both endemic and widespread species and provide a comprehensive estimation of climate change impacts on the Andes. We find that if no dispersal is assumed, by 2050s, more than 50% of the species studied are projected to undergo reductions of at least 45% in their climatic niche, whilst 10% of species could be extinct. Even assuming unlimited dispersal, most of the Andean endemics (comprising ∼5% of our dataset) would become severely threatened (>50% climatic niche loss). While some areas appear to be climatically stable (e.g. Pichincha and Imbabura in Ecuador; and Nariño, Cauca, Valle del Cauca and Putumayo in Colombia) and hence depict little diversity loss and/or potential species gains, major negative impacts were also observed. Tropical high Andean grasslands (páramos and punas) and evergreen montane forests, two key ecosystems for the provision of environmental services in the region, are projected to experience negative changes in species richness and high rates of species turnover. Adapting to these impacts would require a landscape-network based approach to conservation, including protected areas, their buffer zones and corridors. A central aspect of such network is the implementation of an integrated landscape management approach based on sustainable management and restoration practices covering wider areas than currently contemplated.     

Genetic diversity of Dinaric brown bears (Ursus arctos) in Croatia with implications for bear conservation in Europe

Brown bears have lost most of their range on the European continent. The remaining western populations are small, isolated and highly endangered. The Dinaric-Pindos brown bear population is the western-most stable population and the fourth largest in Europe. It has been recognized as a potential source for recolonization of populations whose survival is at risk. Indeed, several translocations of Dinaric bears to Italy, Austria and France have recently been made. Despite the importance of the Dinaric bear population, its genetic status remains poorly understood. Using tissue samples from 156 hunted or accidentally killed Dinaric bears in Croatia, this study analysed genetic diversity at 12 microsatellite loci, as well as population structure and past reductions in size. In addition, a subset of 59 samples was used to assess diversity of the mitochondrial DNA control region. The results indicate that Dinaric bears have high nuclear genetic diversity, as compared to other extant brown bear populations, despite genetic evidence of a bottleneck caused by past persecutions. However, haplotype diversity was low, probably as a result of male-biased dispersal and female philopatry. Not surprisingly, no evidence of population sub-structure was found using nuclear markers, as the bear habitat has remained continuous and the highway network has been built only recently. Management should focus on maintaining habitat connectivity and keeping the effective population size as large as possible. In addition, when removing individuals, care should be taken not to further deplete the population of rare haplotypes. A coordinated transboundary management of the entire Dinaric-Pindos brown bear population should be a priority for its long-term conservation.     

Evidence for rapid faunal changes on islands in a man-made lake

Summary Few studies of island biogeography have been made on islands in which the time of insularization is precisely known. We tested the effects of island formation on ant species diversity in a man-made lake in South Africa, to determine whether island effects are detectable after only 16 years of insularization. The number of ant species observed at trap-line censuses on islands was significantly correlated with island size (r=0.608; P<0.05) and ant species diversity was generally low compared with similar mainland habitats. Mean species number for all islands, including landbridge islands, was 5.5±3.3 species, and on mainland sites was 7.9±2.85 species. Island effects were more marked on islands <20 ha, which had a mean of 3.3±2.5 species per island. Species number on islands was inversely related to densities of the aggressive Anoplolepis custodiens and A. steingroeveri. These two species were only patchily distributed on mainlands, but these ants were nearly ubiquitous on small islands. Several lines of evidence suggest that this single species domination may be responsible for island effects. Island sites also differed in the number of ant species in different trophic groupings, tending to have fewer granivorous species than the mainland sites, but species in other diet groups were similar in both island and mainland habitats. We conclude that there have been marked changes in the ant faunas on islands smaller than 20 ha apparently due to changes in abundance of the dominant ant species. However, the causes of these changes are unknown.     

An examination of the diversity of a novel Campylobacter reservoir

The diversity of eukaryotic populations, in particular protozoa, in the water supplies of intensively reared broilers has not been previously studied. This important food-rearing environment was screened for the molecular diversity of eukaryotes by the analysis of PCR-amplified 18S rRNA. DNA was extracted from filtered water samples that were collected from the poultry drinking water systems of five farms. The total genomic DNA was used to produce rRNA-PCR amplicons, which, with the application of TTGE, provided an overview of the eukaryotic population diversity. The rRNA-PCR amplicons were then used to generate 34 random clones that were subject to comparative sequence analysis. Twenty-five of the clones (73.5%) showed high similarity with yeasts and fungi (>92%) and 9 clones demonstrated similarity (>86%) with certain protozoan groups, including flagellates and alveolates. Further studies of the microbial diversity in the previously ignored niche of intensively reared poultry drinking water systems are required, along with subsequent in vitro co-culture assays of the detected protozoa and bacterial strains.     

Food resource and temporal partitioning amongst a guild of predatory agroecosystem-inhabiting ant species

Prey diversity and temporal foraging patterns of six abundant,predatory ant species were investigated seasonally in an agroecosystem with two main vegetable crops.Pheidole sp.demonstrated the highest predation success and therefore appears to be the dominant species while Tapinoma melanocephalum showed the lowest success under the natural field conditions.Investigation of prey diversity and temporal activity patterns with the null model tests of niche overlap revealed a significant overlap indicating that t...     

Patterns of macroalgal diversity, community composition and long-term changes along the Swedish west coast

This study analyses the complicated patterns of vertical distribution of the macroalgal vegetation in an area where brackish and marine waters meet and mix. Variables used to record vegetation characteristics are algal cover, species composition and diversity. The data set includes 64 diving profiles, all from sites exposed to wave action, along a ca. 260 km long coastline. The profiles belong to four categories: coastal sites in the Skagerrak (more marine), coastal sites in the Kattegat (more brackish), coastal sites in the Kattegat after a toxic phytoplankton bloom, and submerged offshore stone reefs in the Kattegat. The highest species diversity was found at the reefs, which are not affected directly by land runoff. At the reefs the 18 most common perennial species penetrate 2–11 m (on average 5.5 m) deeper than at the coastal sites. The virtual absence of sedimentation, and thus the availability of substratum, at the reefs may explain the differences so that the lower limit for the algae is determined by light penetration or by recruitment problems caused by strong currents at the reefs, whereas sedimentation limits the settlement of algae in coastal sites. Ordination analysis based on species composition reveals that the major environmental gradients structuring the algal vegetation in the Kattegat and the Skagerrak are salinity and water depth. The large data set of this study made it possible to quantify the downward dislocation of Atlantic intertidal species to the sublittoral along the Swedish west coast. For example, the mean upper limit of Corallina officinalis is 2 m in the Skagerrak but 12.5 m in the Kattegat and the mean occurrence interval of Fucus serratus is 0.9–2.7 m in the Skagerrak, but 1.1–6.3 m in the Kattegat. This downward dislocation is suggested to be the result of decreased competition when species successively disappear with lower salinity. Comparisons of the present study's results with those of previous investigations show that eight common red algal species have moved upwards compared to the situation before the large-scale eutrophication started in the 1960s, e.g. Cystoclonium purpureum and Polysiphonia elongata by ca. 8 m, Phycodrys rubens and Delesseria sanguinea by ca. 5 m. A toxic phytoplankton bloom affected macroalgal community composition on the whole only slightly, but it had a negative effect on algal cover and species richness below a water depth of ca. 5 m, the algae were visibly damaged and the lower vegetation limit temporarily moved upwards.     

Genetic diversity of Allium munzii (Amaryllidaceae), a rare southern California species and implication for its conservation

An understanding of genetic diversity within and among populations of rare plant species is a prerequisite to develop effective conservation management strategies and reintroduction programs. Allium munzii is a narrow endemic species distributed in western Riverside County, California, USA and known from 18 extant element occurrences. We sampled 119 individuals from 11 element occurrences and investigated within and among population genetic diversity using two variable chloroplast markers (rpL32–trnL intergenic spacer and rpoC1 intron). Of the total genetic variation detected in A. munzii, 87.65% was due to differences among occurrences. Furthermore, our results revealed that most of the element occurrences are strongly genetically differentiated. There are low levels of gene flow between occurrences, not due to isolation by distance but possibly resulting from habitat fragmentation. Non-significant values of Tajima's D and Fu's Fs were found in all occurrences suggesting no demographic expansion in A. munzii. Ex situ seed and bulb conservation is recommended to enable introduction of individuals to occurrences with low abundance and genetic diversity.     

Assessing the conservation value of a human-dominated island landscape: Plant diversity in Hawaii

The conversion of native habitats to pasture and other working lands, unbuilt lands modified by humans for production, is one of the greatest threats to biodiversity. While some human-dominated landscapes on continents support relatively high native biodiversity, this capacity is little studied in oceanic island systems characterized by high endemism and vulnerability to invasion. Using Hawaii as a case study, we assessed the conservation value of working landscapes on an oceanic island by surveying native and non-native plant diversity in mature native forest and in the three dominant land covers/uses to which it has been converted: native, Acacia koa timber plantations, wooded pasture, and open pasture. As expected, native plant diversity (richness and abundance) was significantly higher and non-native abundance significantly lower in mature native forests than any other site type. A. koa plantations and wooded pasture supported four and three times greater, respectively, species richness of native understory plants than open pasture. Also, A. koa plantations and wooded pasture supported similar species communities with about 75% species in common. Conservation and restoration of mature native forest in Hawaii is essential for the protection of native, rare species and limiting the spread of non-native species. A. koa plantations and wooded pasture, however, may help harmonize production and conservation by supporting livelihoods, more biodiversity than open pasture, and some connectivity between native forest remnants important for sustaining landscape-level conservation value into the future.     

Microbial diversity in production waters of a low-temperature biodegraded oil reservoir

Microbial communities in two production waters of a low-temperature and low-salinity petroleum reservoir in Canada were examined using cultural and molecular approaches. The predominant cultivated microorganisms were homoacetogens but sulfate-reducers, acetoclastic methanogens and denitrifiers also gave significant counts. The dominant members of the culturable population were affiliated with the Firmicutes, the "Deltaproteobacteria", the "Epsilonproteobacteria", the Spirochaetes and the Euryarchaeota. 16S rRNA gene clone libraries were also constructed from the total DNA collected from production waters. The bacterial library was entirely composed by a single phylotype related to Arcobacter. The archaeal phylotypes were generally very closely related to members of the orders Methanosarcinales and Methanomicrobiales. Consistent with earlier observations, our data suggest that methanogenesis is a dominant terminal process in the reservoir. Moreover, the cross-evaluation of culture-dependent and -independent techniques also indicates that, contrary to most studies, both acetoclastic and lithotrophic methanogens may be involved in this process. This first investigation of the microbial diversity in a non water-flooded low-temperature and low-salinity petroleum reservoir expands substantially our knowledge of the extent of microbial diversity and highlights the complexity of microbial communities involved in the oil field food chain.     

Genetic diversity analysis and conservation of the endangered Chinese endemic herb Dendrobium officinale Kimura et Migo (Orchidaceae) based on AFLP

Dendrobium officinale is a critically endangered perennial herb endemic to China. Determining the levels of genetic diversity and patterns of population genetic structure of this species would assist in its conservation and management. Data of 12 populations were used to assess its genetic diversity and population structure, employing the method of amplified fragment length polymorphism (AFLP). A high level of genetic diversity was detected (H (E) = 0.269) with POPGENE. As revealed by AMOVA analysis, there was moderate variation between pairs of populations with Phi(ST) values ranging from 0.047 to 0.578 and on average 26.97% of the genetic variation occurred among populations. Three main clusters were shown in UPGMA dendrogram using TFPGA, which is consistent with the result of principal coordinate ananlysis (PCO) using NTSYS. Keeping a stable environment is critical for the in situ conservation and management of this rare and endangered plant, and for ex situ conservation it is important to design an integrated germplasm bank.     

Phylogenetic diversity of Sri Lankan freshwater crabs and its implications for conservation

As part of a Global Biodiversity Hotspot, the conservation of Sri Lanka's endemic biodiversity warrants special attention. With 51 species (50 of them endemic) occurring in the island, the biodiversity of freshwater crabs is unusually high for such a small area (65 600 km²). Freshwater crabs have successfully colonized most moist habitats and all climatic and elevational zones in Sri Lanka. We assessed the biodiversity of these crabs in relation to the different elevational zones (lowland, upland and highland) based on both species richness and phylogenetic diversity. Three different lineages appear to have radiated simultaneously, each within a specific elevational zone, with little interchange thereafter. The lowland and upland zones show a higher species richness than the highland zone while – unexpectedly – phylogenetic diversity is highest in the lowland zone, illustrating the importance of considering both these measures in conservation planning. The diversity indices for the species in the various IUCN Red List categories in each of the three zones suggest that risk of extinction may be related to elevational zone. Our results also show that overall more than 50% of Sri Lanka's freshwater crab species (including several as yet undescribed ones), or approximately 72 million years of evolutionary history, are threatened with extinction.     

Microsatellite analysis of the genetic structure of captive forest musk deer populations and its implication for conservation

Forest musk deer (Moschus berezovskii) are rare as a result of poaching for musk and habitat loss. Some captive populations of forest musk deer have been established for decades in China. However, little genetic information is available for conservation management. In this paper, genetic variations, population structures, and the genetic bottleneck hypothesis were examined using 11 microsatellite loci from captive populations in Miyalo, Jinfeng and Maerkang in Sichuan Province, China. Estimates of genetic variability revealed substantial genetic variation in the three populations. A total of 142 different alleles were observed in 121 forest musk deer and the effective number of alleles per locus varied from 6.76 to 12.95. The average values of observed heterozygosity, expected heterozygosity, and Nei's expected heterozygosity were 0.552, 0.899 and 0.894 respectively. The overall significant (P < 0.001) deficit of heterozygotes because of inbreeding within breeds amounted to 34.5%. The mean F_ST (P < 0.001) showed that approximately 90.2% of the genetic variation was within populations and 9.8% was across populations. The UPGMA diagram, based on Nei's unbiased genetic distance, indicated that the three populations were differentiated into two different groups and it agreed with their origin and history. Bottleneck tests indicated that all three populations have undergone a population bottleneck, suggesting a small effective population size. Acknowledging that the genetic structure of populations has crucial conservation implications, the present genetic information should be taken into account in management plans for the conservation of captive forest musk deer.     

Landscape heterogeneity in relation to variations in epigaeic beetle diversity of a Mediterranean ecosystem. Implications for conservation

Habitat heterogeneity is a determinant cause of biological diversity in natural ecosystems, and therefore its preservation should be a priority when planning conservation strategies. Sierra de Baza, in southern Spain, is a protected natural area in which biotopes of particular interest still remain, but extensive afforestation with pine species has been widespread in recent decades and, in some cases, continues. The aim of this paper is to test the role of habitat heterogeneity at the landscape scale in generating epigaeic beetle diversity in Sierra de Baza. After two-year-long cycles of sampling epigaeic beetles, differences in local diversity at nine sites, and differences in the pattern of species turnover between sites, have been measured. Local communities differed among sites, 74% of the species being scarce (less than 0.41% of total beetle abundance), and thus species replacement differed markedly between sites. Comparisons between habitat types showed that the planted pine forests support less diverse fauna. Our results identify habitat heterogeneity at the landscape scale as the main source of epigaeic beetle diversity at the landscape scale, practices such as extensive afforestation diminishing landscape heterogeneity and consequently local beetle diversity. Preservation of landscape heterogeneity should be encouraged for an adequate beetle biodiversity conservation.     

Freshwater rock pools: a review of habitat characteristics,faunal diversity and conservation value

1. In the light of the recent surge of interest in small and often temporary wetlands as model systems for ecological and evolutionary research, this article reviews current knowledge on freshwater rock pools and their fauna. 2. Freshwater rock pools occur all over the globe in all major biomes and depend mainly on precipitation for filling. Rock pool clusters are some of the more persistent and oldest freshwater habitats worldwide. Interactions between climate and geology (e.g. limestone, sandstone, granite) generally determine the morphology and hydrology of rock pool habitats, with hydroperiods ranging from several days up to the whole year. Pool volume is usually small, resulting in strongly fluctuating environmental conditions, low conductivity and wide variations in pH (from 4.0 to 11.0) and temperature (from freezing point to 40 °C) often with well‐marked diel cycles. The highly variable environmental conditions, combined with the unpredictability of the flooding regime, require high stress tolerance of the inhabitants, with adaptations for surviving the dry phase such as the production of resistant stages and active emigration followed by recolonisation. 3. About 460 aquatic animal species have been recorded from freshwater rock pools around the world. Approximately 170 of these are passive dispersers, which mainly disperse as resting stages via wind and overflow of water between pools. Successful long distance dispersal seems limited. This group is composed mainly of rock pool specialists with a high degree of endemicity. The remaining taxa can be considered active dispersers, with migration usually restricted to the adult stage. Often these taxa are broadly distributed and occur in a wide range of temporary habitats in addition to rock pools. 4. The inherent characteristics of freshwater rock pools, such as their simple structure and occurrence on similar substrata all over the world, facilitate comparison of research results and promote rock pools as model systems for ecological and evolutionary research. Nevertheless, despite their potential as model systems, the unique fauna and their importance as sources of freshwater in dry countries, the ecology of freshwater rock pools remain virtually unexplored in large parts of the world.