Environmental Synergisms and Extinctions of Tropical Species

Abstract: Environmental synergisms may pose the greatest threat to tropical biodiversity. Using recently updated data sets from the International Union for Conservation of Nature (IUCN) Red List, we evaluated the incidence of perceived threats to all known mammal, bird, and amphibian species in tropical forests. Vulnerable, endangered, and extinct species were collectively far more likely to be imperiled by combinations of threats than expected by chance. Among 45 possible pairwise combinations of 10 different threats, 69%, 93%, and 71% were significantly more frequent than expected for threatened mammals, birds, and amphibians, respectively, even with a stringent Bonferroni‐corrected probability value (p= 0.003). Based on this analysis, we identified five key environmental synergisms in the tropics and speculate on the existence of others. The most important involve interactions between habitat loss or alteration (from agriculture, urban sprawl, infrastructure, or logging) and other anthropogenic disturbances such as hunting, fire, exotic‐species invasions, or pollution. Climatic change and emerging pathogens also can interact with other threats. We assert that environmental synergisms are more likely the norm than the exception for threatened species and ecosystems, can vary markedly in nature among geographic regions and taxa, and may be exceedingly difficult to predict in terms of their ultimate impacts. The perils posed by environmental synergisms highlight the need for a precautionary approach to tropical biodiversity conservation.     

长江上游陡坡耕地退耕的难点与对策

长江上游属于 2 5°以上的陡坡退耕还林地面积达 170万hm2 ,是长江上游水土流失的重要策源地 ,严重制约了该区域社会经济的可持续发展。因此 ,实行陡坡耕地退耕还林是建设长江上游生态屏障的重要组成部分 ,也是生态建设的主要内容之一。本文较为系统地论述了陡坡耕地的形成原因与危害 ,以及退耕的难点与有利时机 ,并探讨了详细分析了主要对策     

Incorporating effectiveness of community-based management in a national marine gap analysis for Fiji

Every action in a conservation plan has a different level of effect and consequently contributes differentially to conservation. We examined how several community-based, marine, management actions differed in their contribution to national-level conservation goals in Fiji. We held a workshop with experts on local fauna and flora and local marine management actions to translate conservation goals developed by the national government into ecosystem-specific quantitative objectives and to estimate the relative effectiveness of Fiji's community-based management actions in achieving these objectives. The national conservation objectives were to effectively manage 30% of the nation's fringing reefs, nonfringing reefs, mangroves, and intertidal ecosystems (30% objective) and 10% of other benthic ecosystems (10% objective). The experts evaluated the contribution of the various management actions toward national objectives. Scores ranged from 0 (ineffective) to 1 (maximum effectiveness) and included the following management actions: permanent closures (i.e., all extractive use of resources prohibited indefinitely) (score of 1); conditional closures harvested once per year or less as dictated by a management plan (0.50-0.95); conditional closures harvested without predetermined frequency or duration (0.10-0.85); other management actions, such as regulations on gear and species harvested (0.15-0.50). Through 3 gap analyses, we assessed whether the conservation objectives in Fiji had been achieved. Each analysis was based on a different assumption: (1) all parts of locally managed marine areas (including closures and other management) conserve species and ecosystems effectively; (2) closures conserve species and ecosystems, whereas areas outside closures, open to varying levels of resource extraction, do not; and (3) actions that allow different levels of resource extraction vary in their ability to conserve species and ecosystems. Under assumption 1, Fiji's national conservation objectives were exceeded in all marine ecosystems; under assumption 2, none of Fiji's conservation objectives were met; and under assumption 3, on the basis of the scores assigned by experts, Fiji achieved the 10% but not the 30% objectives for ecosystems. Understanding the relative contribution of management actions to achieving conservation objectives is critical in the assessment of conservation achievements at the national level, where multiple management actions will be needed to achieve national conservation objectives.     

Academic Research Training for a Nonacademic Workplace: a Case Study of Graduate Student Alumni Who Work in Conservation

Abstract: Graduate education in conservation biology has been assailed as ineffective and inadequate to train the professionals needed to solve conservation problems. To identify how graduate education might better fit the needs of the conservation workplace, we surveyed practitioners and academics about the importance of particular skills on the job and the perceived importance of teaching those same skills in graduate school. All survey participants (n = 189) were alumni from the University of California Davis Graduate Group in Ecology and received thesis‐based degrees from 1973 to 2008. Academic and practitioner respondents clearly differed in workplace skills, although there was considerably more agreement in training recommendations. On the basis of participant responses, skill sets particularly at risk of underemphasis in graduate programs are decision making and implementation of policy, whereas research skills may be overemphasized. Practitioners in different job positions, however, require a variety of skill sets, and we suggest that ever‐increasing calls to broaden training to fit this multitude of jobs will lead to a trade‐off in the teaching of other skills. Some skills, such as program management, may be best developed in on‐the‐job training or collaborative projects. We argue that the problem of graduate education in conservation will not be solved by restructuring academia alone. Conservation employers need to communicate their specific needs to educators, universities need to be more flexible with their opportunities, and students need to be better consumers of the skills offered by universities and other institutions.     

Channel Roughness in North Carolina Mountain Streams

Channel roughness, often described by Manning's n, is used to represent the amount of resistance that flow encounters, and has direct implications on velocity and discharge. Ideally, n is calculated from a long‐term record of channel discharge and hydraulic geometry. In the absence of these data, a combination of photo references and a validated qualitative method is preferable to simply choosing n arbitrarily or from a table. The purpose of this study was to use United States Geological Survey (USGS) streamflow data to calculate roughness coefficients for streams in the mountains of North Carolina. Five USGS gage stations were selected for this study, representing drainage areas between 71.5 and 337 km². Photo references of the study sites are presented. Measured discharges were combined with hydraulic geometry at a cross‐section to calculate roughness coefficients for flows of interest. At bankfull flow, n ranged between 0.039 and 0.064 for the five study sites. Roughness coefficients were not constant for all flows in a channel, and fluctuated over a large range. At all sites, roughness was highest during low‐flow conditions, then quickly decreased as flow increased, up to the bankfull elevation.     

Effect of hybridization with genome exclusion on extinction risk

Human‐induced habitat changes may lead to the breakdown of reproductive barriers between distantly related species. This phenomenon may result in fertile first‐generation hybrids (F₁) that exclude the genome of one parental species during gametogenesis, thus disabling introgression. The species extinction risk associated with hybridization with genome exclusion is largely underappreciated because the phenomenon produces only F₁ hybrid phenotype, leading to the misconception that hybrids are sterile and potentially of minor conservation concern. We used a simulation model that integrates the main genetic, demographic, and ecological processes to examine the dynamics of hybridization with genome exclusion. We showed that this mode of hybridization may lead to extremely rapid extinction when the process of genome exclusion is unbalanced between the interbreeding species and when the hybridization rate is not negligible. The coexistence of parental species was possible in some cases of asymmetrical genome exclusion, but show this equilibrium was highly vulnerable to environmental variation. Expanding the exclusive habitat of the species at risk allowed its persistence. Our results highlight the extent of possible extinction risk due to hybridization with genome exclusion and suggest habitat management as a promising conservation strategy. In anticipation of serious threats to biodiversity due to hybridization with genome exclusion, we recommend a detailed assessment of the reproductive status of hybrids in conservation programs. We suggest such assessments include the inspection of genetic content in hybrid gametes.     

Wrestling with the complexity of evaluation for organizations at the boundary of science,policy, and practice

Boundary organizations are situated between science, policy, and practice and have a goal of supporting communication and collaboration among these sectors. They have been promoted as a way to improve the effectiveness of conservation efforts by building stronger relationships between scientists, policy makers, industry, and practitioners (Cook et al. 2013). Although their promise has been discussed in theory, the work of and expectations for boundary organizations are less defined in practice. Biodiversity conservation is characterized by complexity, uncertainty, dissent, and tight budgets, so boundary organizations face the challenging task of demonstrating their value to diverse stakeholders. We examined the challenges boundary organizations face when seeking to evaluate their work and thus aimed to encourage more productive conversations about evaluation of boundary organizations and their projects. Although no off‐the‐shelf solution is available for a given boundary organization, we identified 4 principles that will support effective evaluation for boundary organizations: engage diverse stakeholders, support learning and reflection, assess contribution to change, and align evaluation with assumption and values.     

A landscape of conservation philanthropy for U.S. land trusts

Finding ways to increase financial support is critical to conservation efforts. We used conservation fundraising data, unprecedented in their resolution, to reveal spatial patterns in philanthropic giving to a major land protection organization in the United States. We also quantified the relationship between the amount of effort devoted to fundraising and donations received. Around 40% of the variation in the propensity to give and overall value of gifts was explained by sociodemographic and other predictors. For example, education level had greater predictive capacity than income, political views, and other factors often considered important. Fundraising effort was strongly predictive of the amount donated in an area. Our model estimated a doubling of funds raised with a 5-fold increase of effort. Conservation organizations could use our statistical framework to inform efforts aimed at increasing philanthropic giving by identifying locations with large model residuals. An example application of our framework showed an almost 40% increase (US$200 million) in fundraising revenue for the case-study conservation organization.     

Frog occupancy of polluted wetlands in urban landscapes

Urban sprawl and the rising popularity of water-sensitive urban design of urban landscapes has led to a global surge in the number of wetlands constructed to collect and treat stormwater runoff in cities. However, contaminants, such as heavy metals and pesticides, in stormwater adversely affect the survival, growth, and reproduction of animals inhabiting these wetlands. A key question is whether wildlife can identify and avoid highly polluted wetlands. We investigated whether pond-breeding frogs are attempting to breed in wetlands that affect the fitness of their offspring across 67 urban wetlands in Melbourne, Australia. Frog species richness and the concentration of contaminants (heavy metals and pesticides) were not significantly related, even in the most polluted wetlands. The proportion of fringing vegetation at a wetland had the greatest positive influence on the number of frog species present and the probability of occurrence of individual species, indicating that frogs inhabited wetlands with abundant vegetation, regardless of their pollution status. These wetlands contained contaminant levels similar to urban wetlands around the world at levels that reduce larval amphibian survival. These results are, thus, likely generalizable to other areas, suggesting that urban managers could inadvertently be creating ecological traps in countless cities. Wetlands are important tools for the management of urban stormwater runoff, but their construction should not facilitate declines in wetland-dependent urban wildlife.