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951.
Luke T. Kelly Andrew F. Bennett Michael F. Clarke Michael A. McCarthy 《Conservation biology》2015,29(2):473-481
Fire is used as a management tool for biodiversity conservation worldwide. A common objective is to avoid population extinctions due to inappropriate fire regimes. However, in many ecosystems, it is unclear what mix of fire histories will achieve this goal. We determined the optimal fire history of a given area for biological conservation with a method that links tools from 3 fields of research: species distribution modeling, composite indices of biodiversity, and decision science. We based our case study on extensive field surveys of birds, reptiles, and mammals in fire‐prone semi‐arid Australia. First, we developed statistical models of species’ responses to fire history. Second, we determined the optimal allocation of successional states in a given area, based on the geometric mean of species relative abundance. Finally, we showed how conservation targets based on this index can be incorporated into a decision‐making framework for fire management. Pyrodiversity per se did not necessarily promote vertebrate biodiversity. Maximizing pyrodiversity by having an even allocation of successional states did not maximize the geometric mean abundance of bird species. Older vegetation was disproportionately important for the conservation of birds, reptiles, and small mammals. Because our method defines fire management objectives based on the habitat requirements of multiple species in the community, it could be used widely to maximize biodiversity in fire‐prone ecosystems. Historiales de Incendios Óptimos para la Conservación de la Biodiversidad 相似文献
952.
Oswald Marinoni Sonja Heyenga Amanda Brigden Ainsley Archer Andrew Higgins 《Environmental Modeling and Assessment》2012,17(3):315-324
Growing urbanisation causes pressures on many environmental assets such as groundwater systems, waterways, atmosphere, ecosystems
and others. To manage and mitigate the negative effects of these pressures, environmental programs are typically launched,
which comprise of eligible projects in different affected locations. The implementation of individual projects has a cost.
However, due to budget constraints, most frequently not all suggested projects can be implemented which makes necessary to
choose a subset. In this paper, we use a cost utility approach and a subsequent combinatorial optimisation based on metaheuristics
to determine a project portfolio which returns a maximum aggregated utility while keeping the budget constraint. To ensure
that the mutual exclusiveness of projects at one particular site is guaranteed, we further developed the employed metaheuristics.
We apply this approach within a waterway health program in a river catchment in Brisbane, Australia, and compare its results
to a commonly used selection process that does not involve combinatorial optimisation. We find that the use of combinatorial
optimisation leads to a considerable improvement of the selection process and can help to more effectively allocate environmental
expenditure. 相似文献
953.
James J. Bell Emily McGrath Andrew Biggerstaff Tracey Bates César A. Cárdenas Holly Bennett 《Conservation biology》2015,29(1):42-53
Sponges are important for maintaining ecosystem function and integrity of marine and freshwater benthic communities worldwide. Despite this, there has been no assessment of their current global conservation status. We assessed their status, accounting for the distribution of research effort; patterns of temporal variation in sponge populations and assemblages; the number of sponges on threatened species lists; and the impact of environmental pressures. Sponge research effort has been variable; marine sponges in the northeastern Atlantic and Mediterranean and freshwater sponges in Europe and North America have received the most attention. Although sponge abundance has increased in some locations since 1990, these were typically on coral reefs, in response to declines in other benthic organisms, and restricted to a few species. Few data were available on temporal trends in freshwater sponge abundance. Despite over 8500 described sponge species, only 20 are on threatened species lists, and all are marine species from the northeastern Atlantic and Mediterranean. Of the 202 studies identified, the effects of temperature, suspended sediment, substratum loss, and microbial pathogens have been studied the most intensively for marine sponges, although responses appear to be variable. There were 20 studies examining environmental impacts on freshwater sponges, and most of these were on temperature and heavy metal contamination. We found that most sponges do not appear to be threatened globally. However, little information is available for most species and more data are needed on the impacts of anthropogenic‐related pressures. This is a critical information gap in understanding sponge conservation status. Estado Global de la Conservación de Esponjas 相似文献
954.
Human pressure on the environment is expanding and intensifying, especially in coastal and offshore areas. Major contributors to this are the current push for offshore renewable energy sources, which are thought of as environmentally friendly sources of power, as well as the continued demand for petroleum. Human disturbances, including the noise almost ubiquitously associated with human activity, are likely to increase the incidence, magnitude, and duration of adverse effects on marine life, including stress responses. Stress responses have the potential to induce fitness consequences for individuals, which add to more obvious directed takes (e.g., hunting or fishing) to increase the overall population‐level impact. To meet the requirements of marine spatial planning and ecosystem‐based management, many efforts are ongoing to quantify the cumulative impacts of all human actions on marine species or populations. Meanwhile, regulators face the challenge of managing these accumulating and interacting impacts with limited scientific guidance. We believe there is scientific support for capping the level of impact for (at a minimum) populations in decline or with unknown statuses. This cap on impact can be facilitated through implementation of regular application cycles for project authorization or improved programmatic and aggregated impact assessments that simultaneously consider multiple projects. Cross‐company collaborations and a better incorporation of uncertainty into decision making could also help limit, if not reduce, cumulative impacts of multiple human activities. These simple management steps may also form the basis of a rudimentary form of marine spatial planning and could be used in support of future ecosystem‐based management efforts. 相似文献
955.
Boyero L Pearson RG Dudgeon D Graça MA Gessner MO Albariño RJ Ferreira V Yule CM Boulton AJ Arunachalam M Callisto M Chauvet E Ramírez A Chará J Moretti MS Gonçalves JF Helson JE Chará-Serna AM Encalada AC Davies JN Lamothe S Cornejo A Li AO Buria LM Villanueva VD Zúñiga MC Pringle CM 《Ecology》2011,92(9):1839-1848
Most hypotheses explaining the general gradient of higher diversity toward the equator are implicit or explicit about greater species packing in the tropics. However, global patterns of diversity within guilds, including trophic guilds (i.e., groups of organisms that use similar food resources), are poorly known. We explored global diversity patterns of a key trophic guild in stream ecosystems, the detritivore shredders. This was motivated by the fundamental ecological role of shredders as decomposers of leaf litter and by some records pointing to low shredder diversity and abundance in the tropics, which contrasts with diversity patterns of most major taxa for which broad-scale latitudinal patterns haven been examined. Given this evidence, we hypothesized that shredders are more abundant and diverse in temperate than in tropical streams, and that this pattern is related to the higher temperatures and lower availability of high-quality leaf litter in the tropics. Our comprehensive global survey (129 stream sites from 14 regions on six continents) corroborated the expected latitudinal pattern and showed that shredder distribution (abundance, diversity and assemblage composition) was explained by a combination of factors, including water temperature (some taxa were restricted to cool waters) and biogeography (some taxa were more diverse in particular biogeographic realms). In contrast to our hypothesis, shredder diversity was unrelated to leaf toughness, but it was inversely related to litter diversity. Our findings markedly contrast with global trends of diversity for most taxa, and with the general rule of higher consumer diversity at higher levels of resource diversity. Moreover, they highlight the emerging role of temperature in understanding global patterns of diversity, which is of great relevance in the face of projected global warming. 相似文献
956.
Influence of corallivory, competition, and habitat structure on coral community shifts 总被引:1,自引:0,他引:1
The species composition of coral communities has shifted in many areas worldwide through the relative loss of important ecosystem engineers such as highly branched corals, which are integral in maintaining reef biodiversity. We assessed the degree to which the performance of recently recruited branching corals was influenced by corallivory, competition, sedimentation, and the interactions between these factors. We also explored whether the species-specific influence of these biotic and abiotic constraints helps to explain recent shifts in the coral community in lagoons of Moorea, French Polynesia. Population surveys revealed evidence of a community shift away from a historically acroporid-dominated community to a pocilloporid- and poritid-dominated community, but also showed that the distribution and abundance of coral taxa varied predictably with location in the lagoon. At the microhabitat scale, branching corals grew mainly on dead or partially dead massive Porites ("bommies"), promontories with enhanced current velocities and reduced sedimentation. A demographic study revealed that growth and survival of juvenile Pocillopora verrucosa and Acropora retusa, the two most common branching species of each taxon, were affected by predation and competition with vermetid gastropods. By 24 months of age, 20-60% of juvenile corals suffered partial predation by corallivorous fishes, and injured corals experienced reduced growth and survival. A field experiment confirmed that partial predation by corallivorous fishes is an important, but habitat-modulated, constraint for branching corals. Competition with vermetid gastropods reduced growth of both branching species but unexpectedly also provided an associational defense against corallivory. Overall, the impact of abiotic constraints was habitat-specific and similar for Acropora and Pocillopora, but biotic interactions, especially corallivory, had a greater negative effect on Acropora than Pocillopora, which may explain the local shift in coral community composition. 相似文献
957.
Broad-scale clearing of native vegetation for agriculture in southwestern Australia has resulted in severe ecosystem degradation,
which has been compounded by the subsequent development of large areas of dryland salinity; decreased transevaporation allows
the water table to rise, dissolving ancient aeolian salt deposits and creating saline surface pools. The mosquito-borne disease
Ross River virus has been noted as a potential adverse human health outcome in salinity-affected regions because the principal
vector, Aedes camptorhynchus, is salt tolerant and thrives preferentially in such systems. To understand the geology and ecology underlying the relationship
between land clearing and disease emergence, we examine the relationship between dryland salinity processes that determine
the dissolved solids profile of saline pools in affected areas, the mosquito vectors and interactions with the human population
within the disease cycle. Aedes camptorhynchus is able to survive in a wide range of salinities in pools created by dryland salinity processes. The link with disease emergence
is achieved where population distribution and activity overlaps with the convergence of environmental and ecological conditions
that enhance disease transmission. 相似文献
958.
959.
Entropy maximization (EM) is a method that can link functional traits and community composition by predicting relative abundances of each species in a community using limited trait information. We developed a complementary suite of tests to examine the strengths and limitations of EM and the community-aggregated traits (CATs; i.e., weighted averages) on which it depends that can be applied to virtually any plant community data set. We show that suites of CATs can be used to differentiate communities and that EM can address the classic problem of characterizing ecological niches by quantifying constraints (CATs) on complex trait relationships in local communities. EM outperformed null models and comparable regression models in communities with different levels of dominance, diversity, and trait similarity. EM predicted well the abundance of the dominant species that drive community-level traits; it typically identified rarer species as such, although it struggled to predict the abundances of the rarest species in some cases. Predictions were sensitive to choice of traits, were substantially improved by using informative priors based on null models, and were robust to variation in trait measurement due to intraspecific variability or measurement error. We demonstrate how similarity in species' traits confounds predictions and provide guidelines for applying EM. 相似文献
960.
The architectural complexity of ecosystems can greatly influence their capacity to support biodiversity and deliver ecosystem services. Understanding the components underlying this complexity can aid the development of effective strategies for ecosystem conservation. Caribbean coral reefs support and protect millions of livelihoods, but recent anthropogenic change is shifting communities toward reefs dominated by stress-resistant coral species, which are often less architecturally complex. With the regionwide decline in reef fish abundance, it is becoming increasingly important to understand changes in coral reef community structure and function. We quantify the influence of coral composition, diversity, and morpho-functional traits on the architectural complexity of reefs across 91 sites at Cozumel, Mexico. Although reef architectural complexity increases with coral cover and species richness, it is highest on sites that are low in taxonomic evenness and dominated by morpho-functionally important, reef-building coral genera, particularly Montastraea. Sites with similar coral community composition also tend to occur on reefs with very similar architectural complexity, suggesting that reef structure tends to be determined by the same key species across sites. Our findings provide support for prioritizing and protecting particular reef types, especially those dominated by key reef-building corals, in order to enhance reef complexity. 相似文献