Advantages of Volunteer-Based Biodiversity Monitoring in Europe

Abstract:  Without robust and unbiased systems for monitoring, changes in natural systems will remain enigmatic for policy makers, leaving them without a clear idea of the consequences of any environmental policies they might adopt. Generally, biodiversity-monitoring activities are not integrated or evaluated across any large geographic region. The EuMon project conducted the first large-scale evaluation of monitoring practices in Europe through an on-line questionnaire and is reporting on the results of this survey. In September 2007 the EuMon project had documented 395 monitoring schemes for species, which represents a total annual cost of about €4 million, involving more than 46,000 persons devoting over 148,000 person-days/year to biodiversity-monitoring activities. Here we focused on the analysis of variations of monitoring practices across a set of taxonomic groups (birds, amphibians and reptiles, mammals, butterflies, plants, and other insects) and across 5 European countries (France, Germany, Hungary, Lithuania, and Poland). Our results suggest that the overall sampling effort of a scheme is linked with the proportion of volunteers involved in that scheme. Because precision is a function of the number of monitored sites and the number of sites is maximized by volunteer involvement, our results do not support the common belief that volunteer-based schemes are too noisy to be informative. Just the opposite, we believe volunteer-based schemes provide relatively reliable data, with state-of-the-art survey designs or data-analysis methods, and consequently can yield unbiased results. Quality of data collected by volunteers is more likely determined by survey design, analytical methodology, and communication skills within the schemes rather than by volunteer involvement per se.     

用快速溶剂萃取仪测定土壤中的二噁英和呋喃

快速溶剂萃取PSE(Pressurized solvent extraction)是在高温和高压条件下,可在很短时间内非常高效地完成溶剂萃取.介绍了用快速溶剂萃取仪PSE对土壤样品中的二噁英和呋喃进行提取,再用平行浓缩仪Syncore进行浓缩,最后用GC-HRMS进行测定的过程.其结果与ASE进行比较,具有可比性,说明该测定结果准确可靠.     

National Responsibilities in European Species Conservation: a Methodological Review

Abstract: One particular challenge in reducing the loss of biodiversity by 2010, as agreed on at the Earth Summit in 2002, is to assign conservation tasks to geographic or administrative entities (e.g., countries or regions) on different geographical scales. To identify conservation tasks, it is imperative to determine the importance of a specific area for the global survival of a species. So far, these national or subnational responsibilities for the conservation of species have been included differently in methods prioritizing conservation. We reviewed how 12 European and 3 non‐European methods determined national conservation responsibilities and evaluated the international importance of a biological population. Different countries used different methodologies, which made a direct comparison of assessments of national responsibilities among countries extremely difficult. Differences existed in the importance criteria used. Criteria included population decline, range reduction, rarity status, degree of isolation of a population, endemism, proportional distribution, and geographic location. To increase comparability, it is imperative to develop criteria for which data are generally available and to standardize the methodology among countries. A standardized method would allow conservation decisions to be based on the conservation status of a species and on the responsibility of a geographic or administrative entity for the survival of a species. We suggest that such a method should use a scalable index of proportional distribution, taxonomic status, and the distribution pattern of a taxon or species as key elements. Such a method would allow for the creation of hierarchical lists and would be highly relevant for parts of the world with multiple political jurisdictions or state unions and for nations with regional governmental structures. Conservation priorities could then be reasonably set by combining national responsibility assessments with the international conservation status of a species.     

Declines in Woodland Salamander Abundance Associated with Non-Native Earthworm and Plant Invasions

Abstract:  Factors that negatively affect the quality of wildlife habitat are a major concern for conservation. Non-native species invasions, in particular, are perceived as a global threat to the quality of wildlife habitat. Recent evidence indicates that some changes to understory plant communities in northern temperate forests of North America, including invasions by 3 non-native plant species, are facilitated by non-native earthworm invasion. Furthermore, non-native earthworm invasions cause a reduction in leaf litter on the forest floor, and the loss of forest leaf litter is commonly associated with declines in forest fauna, including amphibians. We conducted a mark-recapture study of woodland salamander abundance across plant invasion fronts at 10 sites to determine whether earthworm or plant invasions were associated with reduced salamander abundance. Salamander abundance declined exponentially with decreasing leaf litter volume. There was no significant relationship between invasive plant cover and salamander abundance, independent of the effects of leaf litter loss due to earthworm invasion. An analysis of selected salamander prey abundance (excluding earthworms) at 4 sites showed that prey abundance declined with declining leaf litter. The loss of leaf litter layers due to non-native earthworm invasions appears to be negatively affecting woodland salamander abundance, in part, because of declines in the abundance of small arthropods that are a stable resource for salamanders. Our results demonstrate that earthworm invasions pose a significant threat to woodland amphibian fauna in the northeastern United States, and that plant invasions are symptomatic of degraded amphibian habitat but are not necessarily drivers of habitat degradation.     

Earthworm Invasion as the Driving Force Behind Plant Invasion and Community Change in Northeastern North American Forests

Abstract:  Identification of factors that drive changes in plant community structure and contribute to decline and endangerment of native plant species is essential to the development of appropriate management strategies. Introduced species are assumed to be driving causes of shifts in native plant communities, but unequivocal evidence supporting this view is frequently lacking. We measured native vegetation, non-native earthworm biomass, and leaf-litter volume in 15 forests in the presence and absence of 3 non-native plant species ( Microstegium vimineum, Alliaria petiolata, Berberis thunbergii ) to assess the general impact of non-native plant and earthworm invasions on native plant communities in northeastern United States. Non-native plant cover was positively correlated with total native plant cover and non-native earthworm biomass. Earthworm biomass was negatively associated with cover of native woody and most herbaceous plants and with litter volume. Graminoid cover was positively associated with non-native earthworm biomass and non-native plant cover. These earthworm-associated responses were detected at all sites despite differences in earthworm species and abundance, composition of the native plant community, identity of invasive plant species, and geographic region. These patterns suggest earthworm invasion, rather than non-native plant invasion, is the driving force behind changes in forest plant communities in northeastern North America, including declines in native plant species, and earthworm invasions appear to facilitate plant invasions in these forests. Thus, a focus on management of invasive plant species may be insufficient to protect northeastern forest understory species.