Freshwater ecosystems provide goods and services of critical importance to human societies, yet they are among the most heavily altered ecosystems with an overproportional loss of biodiversity. Major threats to freshwater biodiversity include overexploitation, water pollution, fragmentation, destruction or degradation of habitat, and invasions by non-native species. Alterations of natural flow regimes by man-made dams, land-use changes, river impoundments, and water abstraction often have profound impacts on lotic communities. An understanding of the functional interactions and processes in freshwater ecosystems presents a major challenge for scientists, but is crucial for effective and sustainable restoration. Most conservation approaches to date have considered single species or single level strategies. In contrast, the concept of ‘Integrative Freshwater Ecology and Biodiversity Conservation’ (IFEBC) proposed herein addresses the interactions between abiotic and biotic factors on different levels of organization qualitatively and quantitatively. It consequently results in a more holistic understanding of biodiversity functioning and management. Core questions include modeling of the processes in aquatic key habitats and their functionality based on the identification and quantification of factors which control the spatial and temporal distribution of biodiversity and productivity in aquatic ecosystems. The context and importance of research into IFEBC is illustrated using case studies from three major areas of research: (i) aquatic habitat quality and restoration ecology, (ii) the genetic and evolutionary potential of aquatic species, and (iii) the detection of stress and toxic effects in aquatic ecosystems using biomarkers. In conclusion, our understanding of the functioning of aquatic ecosystems and conservation management can greatly benefit from the methodological combination of molecular and ecological tools. 相似文献
This paper appraises the role of prehistoric human societies in modifying the natural woodland biodiversity of several regions throughout Scotland. It draws attention to the likelihood that, contrary to popular belief, biodiversity was enhanced by interactions between agricultural communities and woodlands. The possible purposefulness of such interactions is discussed. Mindful of the present concern to re-establish ‘native’ woodlands in many parts of northern Britain, we then review three approaches to the identification of native tree types in Scotland, and conclude that insufficient attention in reafforestation schemes is being paid to (a) the palaeoecological record as a record of native woodland or (b) the likely former high taxonomic diversity of woodlands. Both these failings will lead to the creation of new woodlands lacking in species diversity. 相似文献
We evaluate the empirical and theoretical support for the hypothesis that a large proportion of native species richness is
required to maximize ecosystem stability and sustain function. This assessment is important for conservation strategies because
sustenance of ecosystem functions has been used as an argument for the conservation of species. If ecosystem functions are
sustained at relatively low species richness, then arguing for the conservation of ecosystem function, no matter how important
in its own right, does not strongly argue for the conservation of species. Additionally, for this to be a strong conservation
argument the link between species diversity and ecosystem functions of value to the human community must be clear. We review
the empirical literature to quantify the support for two hypotheses: (1) species richness is positively correlated with ecosystem
function, and (2) ecosystem functions do not saturate at low species richness relative to the observed or experimental diversity.
Few empirical studies demonstrate improved function at high levels of species richness. Second, we analyze recent theoretical
models in order to estimate the level of species richness required to maintain ecosystem function. Again we find that, within
a single trophic level, most mathematical models predict saturation of ecosystem function at a low proportion of local species
richness. We also analyze a theoretical model linking species number to ecosystem stability. This model predicts that species
richness beyond the first few species does not typically increase ecosystem stability. One reason that high species richness
may not contribute significantly to function or stability is that most communities are characterized by strong dominance such
that a few species provide the vast majority of the community biomass. Rapid turnover of species may rescue the concept that
diversity leads to maximum function and stability. The role of turnover in ecosystem function and stability has not been investigated.
Despite the recent rush to embrace the linkage between biodiversity and ecosystem function, we find little support for the
hypothesis that there is a strong dependence of ecosystem function on the full complement of diversity within sites. Given
this observation, the conservation community should take a cautious view of endorsing this linkage as a model to promote conservation
goals.
Received: 2 September 1999 / Accepted: 26 October 1999 相似文献
Founder populations in reintroduction programmes can experience a genetic bottleneck simply because of their small size. The influence of reproductive skew brought on by polygynous or polyandrous mating systems in these populations can exacerbate already difficult conservation genetic problems, such as inbreeding depression and loss of adaptive potential. Without an understanding of reproductive skew in a target species, and the effect it can have on genetic diversity retained over generations, long‐term conservation goals will be compromised. In this issue of Molecular Ecology, Miller et al. (2009a) test how founder group size and variance in male reproductive success influence the maintenance of genetic diversity following reintroduction on a long‐term scale. They evaluated genetic diversity in two wild populations of the iconic New Zealand tuatara ( Fig. 1 ), which differ greatly in population size and genetic diversity, and compared this to genetic diversity in multiple founder populations sourced from both populations. Population viability analysis on the maintenance of genetic diversity over 400 years (10 generations) demonstrated that while the loss of heterozygosity was low when compared with both source populations (1–14%), the greater the male reproductive skew, the greater the predicted losses of genetic diversity. Importantly however, the loss of genetic diversity was ameliorated after population size exceeded 250 animals, regardless of the level of reproductive skew. This study demonstrates that highly informed conservation decisions could be made when you build on a solid foundation of demographic, natural history and behavioural ecology data. These data, when informed by modern population and genetic analysis, mean that fundamental applied conservation questions (how many animals should make up a founder population?) can be answered accurately and with an eye to the long‐term consequences of management decisions. Figure 1 Open in figure viewer PowerPoint Large adult male tuatara attacking a smaller male. Photo by Jeanine Refsnider. 相似文献
Reviews and notices are provided on 15 books, published over the years 2016–2018. These are concerned with diverse aspects of biodiversity and conservation, including biogeography, marine ecology and fisheries, legislation and regulation, mammals, sustainable development, and woodland ecology. This is the seventh of a series of cumulative reviews and book notices, which generally appear annually in the journal. 相似文献
Reviews and notices are provided on 62 books published over the years 2004–2012 which have been received by Biodiversity and Conservation. These are in the general areas of biodiversity, conservation, ecology, ethics, extinction, invasive species, methodology, and urban ecology. This is the third of a series of cumulative reviews and book notices, one or more instalments of which is included in the journal each year. 相似文献
Reviews and notices are provided on eight books published over the years 2012–2013. These are concerned with diverse aspects of biodiversity and conservation, including ecology, ethics, invasive species, mangroves, philosophy, primates, and trans-frontier reserves. This is the four of a series of cumulative reviews and book notices, one or more instalments of which is included appear in the journal each year. 相似文献
Reviews are provided for 22 books published over the years 2002–2011 which have been received by Biodiversity and Conservation. These are in the general areas of biodiversity, conservation, environmental crime, evolution, forestry, invasive species, legislation, methodology, and public perception. This is the second of a series of synoptic reviews, several instalments of which will now appear in the journal each year. 相似文献
Reviews are provided for 24 books published over the years 2006–2011 which have been received by Biodiversity and Conservation. These are in the general areas of ecology and the environment, mammals, birds, plants, evolution, and the human dimension of biodiversity, plus a miscellaneous work. Such batches of synoptic reviews are a new feature for Biodiversity and Conservation, and it is envisaged that 3–4 such groups of reviews will now be issued each year. 相似文献
Reviews and notices are provided on 21 books, all but two published in 2015 or 2016. These are concerned with diverse aspects of biodiversity and conservation, including phylogenetic diversity, conservation law, habitat management, soils, and regional works. This is the sixth of a series of cumulative reviews and book notices, which generally appear annually in the journal. 相似文献
The study and practice of conservation biology is inherently interdisciplinary, addresses short and long time-scales and occurs within complex human–natural interfaces. Zoos and aquaria, in partnership with researchers, other non-government organizations, government, industry and educators, are combining knowledge of species and ecosystems with economics, psychology and law to create solutions for conserving biodiversity. From 22 to 25 May, the Conservation Forum of the European Association of Zoos and Aquaria was a venue for discussing conservation research, education and interventions, from the scale of villages to global policy. 相似文献
Permafrost represents 26% of terrestrial soil ecosystems; yet its biology, essentially microbiology, remains relatively unexplored. The permafrost environment is considered extreme because indigenous microorganisms must survive prolonged exposure to subzero temperatures and background radiation for geological time scales in a habitat with low water activity and extremely low rates of nutrient and metabolite transfer. Yet considerable numbers and biodiversity of bacteria exist in permafrost, some of which may be among the most ancient viable life on Earth. This review describes the permafrost environment as a microbial habitat and reviews recent studies examining microbial biodiversity found in permafrost as well as microbial growth and activity at ambient in situ subzero temperatures. These investigations suggest that functional microbial ecosystems exist within the permafrost environment and may have important implications on global biogeochemical processes as well as the search for past or extant life in permafrost presumably present on Mars and other bodies in our solar system. 相似文献