A spatial explicit agent based model approach to evaluate the performance of different monitoring options for mortality estimates in the scope of onshore windfarm impact assessments

Despite the environmental benefits associated with wind energy, studies have confirmed the occurrence of significant levels of bat and bird fatalities at windfarms, which raise concerns about the long-term effects of these infra-structures on these populations. Reliable estimates of windfarm fatalities are fundamental for accurate environmental assessment studies and supporting management actions. A spatially explicit agent-based model (ABM) was developed to investigate how searcher “controlled” variables, i.e., different field monitoring protocols, monitoring periods and periodicities influence the success of carcasses detection in field trials and estimator accuracy. Different rates of bat mortality due to collision, scavenger pressures and habitat complexity were simulated in order to reproduce variable conditions that might take place at onshore wind facilities. Based on our findings we propose a reduction in the monitoring periods and a shortening in the periodicity of searches in order to reduce bias in the estimations and increase the confidence limits of impact assessments associated with mortality estimates at onshore windfarms.     

Landscape structure and management regime as indicators of calcareous grassland habitat condition and species diversity

This study investigates the importance of spatial landscape characteristics and habitat management on the condition of calcareous grassland in the North Down Natural Area, Kent UK. We used a digitised map of the study area containing shapefiles of all the habitats including 82 patches of calcareous grassland together with management information for each patch and data on the presence and abundance of a range of calcareous grassland indicator plant species. We defined habitat condition by presence of indicator species and used classification trees to generate models with rules for predicting habitat condition from the landscape spatial characteristics and management information. We also applied the same method to investigate the factors affecting presence or diversity of three ecological groups of positive indicator species and dominance of a negative indicator species. All the models except one showed good classification accuracy and high kappa statistic. Favourable habitat condition was predicted by presence of different types of grazing management, presence of woodland around patches of calcareous grassland and shape complexity. These results indicate that calcareous grassland in favourable condition is management-dependent but also located in less intensively managed landscapes. Unfavourable habitat condition was predicted by threat factors such as lack of management and high incidence of arable or improved grassland around patches of calcareous grassland, indicating nutrient enrichment and habitat degradation. Some of these factors also predicted high diversity of the different ecological species groups. The value of this method for predicting habitat condition and species diversity from baseline ecological data for conservation monitoring at the landscape level is emphasised.     

Wind power plants and the conservation of birds and bats in Spain: a geographical assessment

The number of wind power plants installed in Spain has increased dramatically, and many are located in important wildlife areas. This paper explores the geographical overlap of wind power plants with the ranges of flying vertebrate species. The list of animals studied includes bats, soaring birds, and other birds that may be killed by turbines. Results show that the 10 × 10 km UTM squares occupied by wind power plants fell within the range of more bat and bird species than squares free of these infrastructures. For species included in the Spanish Red List, there were more wind power plants than expected inside the range of two raptors (Neophron percnopterus and Circus pygargus) and less than expected in six species (Ciconia nigra, Aquila adalberti, Hieraetus fasciatus Myotis capaccinii, Rhinolophus mehelyi and Myotis myotis). The rest of endangered species (15) had a range occupation similar to that predicted by random sampling, a result that reflects a poor strategy to prevent the overlap. These patterns may be explained by the small amount of overlap of the range of many of these animals with the windiest areas in Spain, where wind power plants are concentrated today. However, this situation is changing rapidly with the densification and expansion of wind power plants promoted under the Spanish Plan of Renewable Energies. This may produce the occupation of many areas important to bird and bat conservation, and therefore preventive measures should be implemented to protect these species and their habitats.     

OECD pressure–state–response indicators for managing biodiversity: a realistic perspective for a French biosphere reserve

Sustainability is said to be the science of integration, be it integration of scale, discipline or of stakeholders’ interests. One way to integrate such diverse elements is to develop sustainable development indicators. Numerous national and international organizations have attempted to develop such indicators, among which interaction indicators are of critical importance because they enable us to link up human activities, ecological dynamics, and social goals. Among the various ways to develop such indicators, the most common ones are the pressure–state–response (PSR) indicators, as well as others coming from this framework. With realistic methodology one shall observe how PSR indicators might appear as an operational tool to face rapid social and ecological changes within a French biosphere reserve in Brittany. Results suggest that such a framework is insufficient to describe, understand and manage social and ecological interactions.

Microclimate of tree cavities during winter nights—implications for roost site selection in birds

We examined the relationships between cavity temperature, ambient temperature outside the cavity and structural characteristics of 70 cavities measured for 1 night to determine if cavity roosting birds may potentially select warmer tree cavities for wintertime roosting. The mean temperature increment of the cavity (=cavity-ambient temperature) varied from −2.4 to 4.9°C and increased with higher day-to-night fluctuations in the ambient temperature, smaller cavity entrance and better health status of the cavity tree. Cavities in healthy trees were warmer than those in dead trees, but this difference disappeared with rising mean ambient temperatures. This interaction between the effects of tree health status and mean ambient temperature, as well as the effect of day-to-night fluctuations in the ambient temperature, were supported by the analysis of repeated measurements of temperature taken on 12 consecutive nights in five cavities. The variability in cavity microclimates makes the selection of warmer roost sites possible, and the predictors of microclimate may provide indirect cues to prospecting birds.     

Relative influence of habitat heterogeneity, climate, human disturbance, and spatial structure on vertebrate species richness in Spain

Many factors affect the distribution of species richness. This study examines the relative influence of habitat heterogeneity, climate, human disturbance, and spatial structure on the species-richness distribution of terrestrial vertebrates (amphibians, reptiles, birds and mammals) in mainland Spain. The results indicate that spatial structure and environment exert similar influences on species richness. For all four taxa, species richness increases southward and northward, being lower in the center of the country, when controlled for other variables. This may be the result of a peninsular effect, as found in other studies, and reflect the importance of historical events on species richness in the Iberian Peninsula. Climate is more important than habitat heterogeneity in determining species richness. Temperature is positively correlated with amphibian, reptile, and bird species richness, while mammalian species richness is highest at intermediate temperatures. This effect is stronger in ectotherms than among endotherms, perhaps reflecting physiological differences. Precipitation positively correlates with bird and mammalian species richness, but has no effect on ectotherm species richness. Amphibian species richness increases with altitudinal range, and bird species richness with habitat diversity. Human population density is positively correlated with bird and mammalian species richness, but does not affect ectotherm species richness, while amphibian and bird species richness is highest at moderate levels of human land alteration (farmland). However, unexplained variance remains, and we discuss that the effects of environmental variables on species richness may vary geographically, causing different effects to be obscured on a national scale, diminishing the explanatory power of environmental variables.     

闽江河口湿地生物多样性及其保护

根据闽江河口湿地比较系统的调查资料,分析了生物多样性的状况及其受人为活动影响的原因,提出了湿地生物多样性保护的对策。研究表明,闽江河口区西自闽侯竹岐,东至连江川石岛,共划分10个湿地类型,总面积约459.2km2。闽江河口众多的湿地串珠状排列,有6块面积较大的湿地,是鸟类的主要栖息、繁殖和迁徙地。闽江河口湿地的维管束植物107科337属465种,被子植物89科317属438种,大型水生无脊椎动物61种,鸟类29科118种,植被类型4种类型、18个群系和22个群丛。文中分析了环境污染、不合理开发利用、盲目围垦等人为活动对闽江口湿地生物多样性的影响,最后提出了湿地生物多样性的保护对策。     

Patterns of frugivore species richness and abundance in forest islands and in agricultural habitats at Los Tuxtlas,Mexico

Destruction and fragmentation of tropical rain forest result in a loss of species and of generating capacity of the ecosystem via animal vectors such as seed dispersal agents. To gather quantitative data regarding this ecological problem, birds and mammals were censused in 30 forest fragments, 15 agricultural islands representing five types of vegetation (coffee, cacao, citrus, pepper and mixed-crops) and in three pastures in Los Tuxtlas, southern Veracruz, Mexico. More than 6000 animals of 257 species were detected thus suggesting the existence of a rich species pool in the fragmented landscape. Frugivores accounted for 60% of species, for 72% of individuals censured and for 85% of the total animal biomass recorded. Clusters of small forest fragments (<100 ha) were richer in species and individuals than clusters of large area (>100 ha) forest islands. Pastures were especially poor in forest birds and mammals. While the agricultural islands studied contributed to only 1% of the total area of vegetation sampled, they contained 58% of all species detected and 34% of all individual birds and mammals censured. Recaptures indicated inter-island movements of forest birds and mammals. Forty percent of the species were detected in forest habitats only, the rest were detected in forest and in agricultural habitats. Seeds of forest interior plants dispersed by birds and bats were detected in the agricultural habitats. The value of agricultural islands as landscape features providing some degree of biotic connectivity among fragmented animal populations is discussed.     

Making the matrix matter: challenges in Australian grazing landscapes

Many ecological theories are based on the concept of patches. Patches are a useful starting point for conservation efforts, but a focus on patches alone will not always achieve desired conservation outcomes. Conservation strategies in the grazing landscapes of southeastern Australia suggest that large patches of trees are widely regarded as habitat while other forms of habitat are largely ignored. We provide data on birds and reptiles from the Nanangroe grazing landscape that illustrate the potential habitat value of areas located between large patches of trees – that is, the matrix. Despite evidence on its potential value, present conservation strategies rarely consider the matrix. Possible reasons for this bias relate to the economics of farming and the history of land use, the current environmental law framework, and also the reluctance of ecologists to study the matrix. More scientific evidence on the role of the matrix will be crucial if conservation strategies are to consider not only patches, but entire landscapes. However, for science to be relevant to land management, there is a need for new research approaches. First, an increased consideration of environmental policy and law will increase the likelihood of scientific findings being adopted by policy makers. Second, at an applied level, more practical on-ground research into farming practices and clearer communication are necessary to achieve more sustainable matrix management in Australian grazing landscapes.     

浙江天童国家森林公园鸟类区系和群落特征

2006～2009年对浙江天童国家森林公园地区的7个样点、6条样线的3种生境鸟类资源状况进行调查。共发现鸟类16目45科142种,其中东洋界75种、古北界59种、广布型8种;留鸟59种、旅鸟30种、冬候鸟30种、夏候鸟23种。国家Ⅱ级保护鸟类23种,中日候鸟保护协议鸟种49种,中澳候鸟保护协议鸟种9种,CITES附录Ⅰ物种1种,CITES附录Ⅱ物种23种。于2009年1月23日发现浙江新纪录1种——日本歌鸲(Erithacus akahige)。调查地区鸟类区系上偏重于东洋界,居留型上以留鸟为主;生境丰富,无绝对优势种,森林和农田鸟类多样性及均匀度均较湿地生境高。     

Age distribution of trees in stationary forest system

A statistical theory for the age distribution of spatially dominant trees in a stationary forest system is developed. The result depends whether or not mortality is spatially correlated, as well as whether or not the stand boundaries are pre-determined. In the case of spatially non-correlated mortality, the tree age distribution is an exponential with survival rate as the base. In the case of spatially correlated mortality within a stand with pre-determined boundaries, the age distribution within the stand is an exponential with natural base. For a small stand, the median life span of the stand is inversely proportional to the number of trees (n); the median life span in relation to stand closure time is inversely proportional to n ln(n). For a large stand, the stand life does not extend to the closure time.The behaviour of a forest system without fixed stand boundaries depends on the dimensionality of the system. In the case of a one-dimensional system, the longevity distribution is exponential, most of the trees however having the same longevity. Consequently, the probability density of tree age is constant. However, the probability mass of size of catastrophe destroying a particular tree is evenly distributed. This is due to trees being rapidly born on empty areas in the beginning of the life cycle, and clusters rapidly growing into larger ones close to the end of tree life.