Responses of plant, insect and spider biodiversity to local and landscape scale management intensity in cereal crops and grasslands

The aim of this study was to determine the relative effects of landscape scale management intensity, agroecosystem type, local management intensity and edges on diversity patterns of functional groups of plants, carabid beetles, spiders and grasshoppers. Nine landscapes were selected differing in percent intensively used agricultural area (IAA), each with a pair of organic and conventional winter wheat fields and a pair of organic and conventional mown meadows. Within fields, plants were surveyed in the edge and in the interior. Carabid beetles and spiders were captured by funnel traps, while grasshoppers were sweep-netted in the meadows. Diversity patterns of study organisms were affected both by local variables (local management, agroecosystem type and within-field position) and by landscape scale management intensity. Species richness of grasses, presumably because of sowing low-diversity mixtures, and hunting spiders decreased with percent cover of IAA. Meadows differed from wheat fields in that they had higher species richness of forbs and grasses, as well as higher densities of hunting spiders. In contrast, more carabid individuals, especially of non-carnivore species, were captured in wheat fields. In field edges with their reduced management intensity and increased immigration, species richness of plants, carabids and spiders was higher than in the interiors regardless of agroecosystem type and management. Organic management enhanced forb richness and cover in both agroecosystem types. Organic management also increased grass cover in wheat fields, but not in meadows, and promoted species richness of non-carnivore carabids and hunting spiders, but not grasshoppers. The results show that agri-environmental management needs to be targeted to the agroecosystem's field size, because higher edge area led to higher species richness. Organic management affected several functional groups positively (forbs, non-carnivore carabids, hunting spiders), while lower landscape scale management intensity only increased species richness of grasses and spiders. The great differences in responses of functional groups to local cereal and grassland as well as landscape management suggest implementing more scale and group specific targets for agri-environmental schemes to improve their efficiency.     

Organic versus conventional arable farming systems: Functional grouping helps understand staphylinid response

The response of different feeding groups of staphylinid beetles to organic management, distance to perennial boundary and landscape context was studied in 42 paired organic and conventional winter wheat fields. Management effects were found to strongly depend on feeding group. While the activity-density of predators was higher in the conventional fields, both activity-density and species richness of detritivores were higher in the organic fields. Activity-density and species richness of detritivores were positively correlated to crop yield in the conventional but not in the organic fields. Unexpectedly, species richness as high as in the less productive organic fields was thus found in intensified conventional systems. No significant effects of landscape context could be found on activity-density or species richness of the different feeding groups. More species were caught near the field edge than in the middle, showing the importance of spill-over from field boundaries into arable crops for diversity. In conclusion, separation of species into feeding groups revealed patterns that have not been shown before. Decomposer diversity (but not that of predators and fungivores) was higher in organic fields, but reached similar levels in high-yielding conventional fields. Thus resource quality (purely organic or organic/synthetic fertiliser) and quantity appear to play a major role for this functional group.     

Delayed colonisation of arable fields by spring breeding ground beetles (Coleoptera: Carabidae) in landscapes with a high availability of hibernation sites

The colonisation of winter barley fields by spring breeding carabids and its temporal modulation by the amount of potential hibernation sites was studied. Species richness of carabids was lower in landscapes with high length of boundaries and a high amount of non-cropped open habitats during early stages of the beetles’ colonisation of arable fields. Species number of beetles with high dispersal potential responded to this landscape features at coarse spatial scales whereas beetles with low dispersal potential responded to intermediate scales. However, the negative impact of potential hibernation sites on colonisation diminished in later sampling phases. The patterns observed may be explained by both overwintering in arable soils in less complex landscapes and delayed colonisation in more complex landscapes. The seasonal patterns of landscape control suggest a need to account for temporal dynamics in interactions between species or functional groups and landscape properties. A high temporal resolution is needed in studies that focus on ecosystem function and services in agricultural landscapes, as direction of effect (positive/negative) of management on animal communities may change across spatial scales and within short time periods.     

Fragmented habitats of traditional fruit orchards are important for dead wood-dependent beetles associated with open canopy deciduous woodlands

The conservation of traditional fruit orchards might be considered to be a fashion, and many people might find it difficult to accept that these artificial habitats can be significant for overall biodiversity. The main aim of this study was to identify possible roles of traditional fruit orchards for dead wood-dependent (saproxylic) beetles. The study was performed in the Central European landscape in the Czech Republic, which was historically covered by lowland sparse deciduous woodlands. Window traps were used to catch saproxylic beetles in 25 traditional fruit orchards. The species richness, as one of the best indicators of biodiversity, was positively driven by very high canopy openness and the rising proportion of deciduous woodlands in the matrix of the surrounding landscape. Due to the disappearance of natural and semi-natural habitats (i.e., sparse deciduous woodlands) of saproxylic beetles, orchards might complement the functions of suitable habitat fragments as the last biotic islands in the matrix of the cultural Central European landscape.     

人工替代栖息地对长江口湿地的补充作用研究

利用恢复生态学和景观生态学原理构建人工替代栖息地是恢复和重建生物栖息地环境的重要手段之一,是用于滨海河口区修复或重建滩涂湿地等栖息地的一种替代方法。人工替代栖息地构建出了接近自然原貌的人工系统,创造一种湿地植被和湿地动物可以协调共存的生境,不仅可以为鸟类资源和渔业资源提供良好的栖息环境,其中多样化组合的植被群落在滨水景观、水质净化等方面也起到了重要的作用,对长江口自然湿地的恢复和自然保护区的动态管理具有不可忽视的补充作用。在迁徙鸟类重要中转驿站,珍稀或者经济鱼类的洄游通道,特殊价值的重要湿地景观格局以及水资源战略储备区域中布局人工替代栖息地,可以发挥其对长江口湿地的补充作用,使高度开放而又极为敏感的长江河口地区循着生态健康道路发展。     

Overstorey tree density and understorey regrowth effects on plant composition,stand structure and floristic richness in grazed temperate woodlands in eastern Australia

As natural woodlands decline in both extent and quality worldwide, there is an increasing recognition of the biodiversity conservation value of production landscapes. In low-input, low-productivity grazing systems in Australia, the modification of natural woodlands through overstorey tree and woody regrowth removal are vegetation management options used by landholders to increase native grass production for livestock grazing; however, there is little empirical evidence to indicate at what tree densities biodiversity attributes are compromised. We examined the effects of overstorey tree density and understorey regowth on the floristic composition, stand structure and species richness of eucalypt woodlands in a grazing landscape in the Traprock region of southern Queensland, Australia. We sampled 47 sites stratified according to vegetation type (Eucalyptus crebra/Eucalyptus dealbata woodland; Eucalyptus melliodora/Eucalyptus microcarpa grassy woodland), density of mature trees (<6 trees/ha; 6–20 trees/ha; >20 trees/ha), and presence/absence of regrowth. Distinct patterns in composition were detected using indicator species analysis and non-metric multidimensional scaling, with low density areas compositionally indistinguishable, although distinct from other land management units. Within vegetation type, medium tree density woodlands were compositionally similar to high density and reference woodlands. Species richness ranged from 18 to 67 species per 500 m² across all sites. No differences in total or native species richness were detected across management units; however, some differences in exotic species richness were detected. Differences in grass cover existed between low and high density management units, yet no difference in grass cover was evident between low and medium density management units. Our results suggest that medium tree densities may provide biodiversity benefits concordant with more natural areas, yet not adversely impact on pasture production. Retaining trees in grazing landscapes provides significant landscape heterogeneity and important refuges for species that may be largely excluded from open grassland habitats. Maintaining a medium density of overstorey trees in grazed paddocks can provide both production and biodiversity benefits.     

Pesticide exposure in honey bees results in increased levels of the gut pathogen <Emphasis Type="Italic">Nosema</Emphasis>

Global pollinator declines have been attributed to habitat destruction, pesticide use, and climate change or some combination of these factors, and managed honey bees, Apis mellifera, are part of worldwide pollinator declines. Here we exposed honey bee colonies during three brood generations to sub-lethal doses of a widely used pesticide, imidacloprid, and then subsequently challenged newly emerged bees with the gut parasite, Nosema spp. The pesticide dosages used were below levels demonstrated to cause effects on longevity or foraging in adult honey bees. Nosema infections increased significantly in the bees from pesticide-treated hives when compared to bees from control hives demonstrating an indirect effect of pesticides on pathogen growth in honey bees. We clearly demonstrate an increase in pathogen growth within individual bees reared in colonies exposed to one of the most widely used pesticides worldwide, imidacloprid, at below levels considered harmful to bees. The finding that individual bees with undetectable levels of the target pesticide, after being reared in a sub-lethal pesticide environment within the colony, had higher Nosema is significant. Interactions between pesticides and pathogens could be a major contributor to increased mortality of honey bee colonies, including colony collapse disorder, and other pollinator declines worldwide.     

Mollusc communities in Bulgarian fens: predictive power of the environment,vegetation, and spatial structure in an isolated habitat

Mollusc communities of previously unexplored Bulgarian fens were studied in order to determine and generalise the patterns of species richness and composition along the mineral richness gradient. The aim was also to compare predictive values of the environment, vegetation and spatial structure. Altogether, 44 mollusc species were recorded at 40 treeless fen sites. Species richness varied from 0 to 18 species per site, and it was positively associated with the mineral gradient and negatively with altitude. However, the best predictor was obtained using plant species composition. All explanatory variables had higher effect on land snails than on the entire mollusc assemblage (including aquatic species). Species richness and abundance were significantly and positively correlated with the species composition turnover; the communities were highly nested, with poor sites having subsets of the fauna found in the richest. The main direction of mollusc species turnover was highly associated with that observed for vegetation, and the main gradient of plant species composition was able to explain nearly 20% of total variation in mollusc data. We found that spatial structure explained by far the highest proportion of independent variation, which reflected the high level of geographical isolation of Bulgarian fens and regional differences independent of any environmental variation. Our results demonstrate (1) the general role of mineral richness gradient for structuring mollusc communities in fens, (2) the pivotal indicator role of plant species composition in predicting species composition of mollusc communities, despite being trophically independent and (3) the effect of isolation and origins of the habitat on species composition: most species have wide geographical distributions within the habitat type, and geographical patterns within Bulgaria may have a stochastic element.     

Community richness and stability in agricultural landscapes: The importance of surrounding habitats

In this paper, the role played by habitat diversity in the landscape on species richness and on the stability of farmland bird communities was investigated. Species richness was estimated on 374 samples monitored in farmland by the French breeding bird survey during the 2001–2005 period. A capture–recapture approach was used to estimate species richness accounting for the variation in detection probability among species of the 100 most common species detected in farmland. Landscape structure and composition were measured both in farmland and in adjacent habitats. The independent effect of each variable on community richness and stability was further assessed using hierarchical variance partitioning and taking spatial autocorrelation into account. A strong matrix effect was detected: non-cropped land deeply influenced richness and stability of bird assemblages.     

北盘江梯级水电开发对陆生生态的影响研究

水电开发工程在当今社会发展中发挥着重要作用,尤其是梯级水电开发,但是其发展对环境的影响更是备受关注。本文以北盘江梯级水电开发项目为研究对象,主要采用3S技术研究方法,针对流域梯级水电开发对陆生生态系统的影响进行分析,确定陆生生态环境影响评价识别因子,做出针对植物、植被,陆生动物,黑叶猴自然保护区和自然景观生态体系影响的具体分析。经研究结果表明：梯级电站建设主要不利影响是改变了河流自然生态系统,对适应原生境的动物造成不利影响,使其栖息地缩小或丧失,水库淹没和施工占地及移民安置活动对区域土地资源、自然保护区的影响,对自然景观生态体系的影响。     

随机森林算法在新疆物种丰富度影响因素研究中的应用

基于多源遥感数据及其产品,以2010年新疆地区鸟类与哺乳动物物种丰富度空间分布数据为基础,结合土地利用、植被、气候、地形等遥感数据产品,探讨了影响新疆地区鸟类和哺乳动物物种丰富度的各环境因子空间分布及其差异.通过随机森林算法对影响鸟类和哺乳动物种数的环境解释变量进行了重要性评估,同时采用探索性回归分析对物种丰富度与环境因子的关系进行建模,比较了鸟类和哺乳动物在草地、林地和耕地三种生境中的主要环境影响因子及其差异.结果显示：影响物种丰富度的环境因子中,植被生长状态与能量转换能力对鸟类丰富度十分重要,且草地的海拔高度重要性最高,为38.38%;耕地所处的气候类型对鸟类丰富度有明显影响,其中年均温重要性达到32.98%;哺乳动物的三种生境选择中气候和海拔条件十分重要,共占重要性的60%以上,最高达76.85%,在耕地中哺乳动物更看重气候而非植被生长情况;三种生境中鸟类和哺乳动物的最优模型及其影响因子均不同,耕地对于鸟类、林地对于哺乳动物的模型解释力最高,分别为69.9%和68.9%,随机森林和探索性回归分析均显示年均温、年降水量和海拔高度是哺乳动物丰富度差异的重要解释因子.     

Influence of habitat type and surrounding landscape on spider diversity in Swedish agroecosystems

Lycosid and linyphiid spiders were collected over a full cropping season around Uppsala, Sweden, in eight organic spring sown cereal fields in three different habitat types: field margin, field, and the edge between the two. The sites were located in landscapes with different proportions of non-crops, forest, perennial crops, annual crops, and number and sizes of arable fields. The field margin, compared with the field habitat, was found to be important for the activity density of lycosids, and for the species richness and composition of linyphiids. Landscape parameters were central for the activity density of linyphiids and for the species richness and composition of Lycosidae. A diverse landscape with easy access to perennial crops and forest in addition to field margins will augment both the number of species and individuals of the two spider families.     

Estimating the magnitude of morphoscapes: how to measure the morphological component of biodiversity in relation to habitats using geometric morphometrics

Ecological indicators are currently developed to account for the different facets of loss of biological diversity due to direct or indirect effects of human activities. Most ecological indicators include species richness as a metric. Others, such as functional traits and phylogenetic diversity, account for differences in species, even when species richness is the same. Here, we describe and apply a different indicator, called morphoscape dimension, accounting for morphological variability across habitats in a geographical region. We use the case of ground beetles (Coleoptera: Carabidae) in four different habitats in the Po Plain in Northern Italy to exemplify how to quantify the magnitude of the morphological space (i.e. the dimension of the morphoscape) occupied by the species in each habitat using geometric morphometrics. To this aim, we employed a variety of metrics of morphological disparity related to univariate size, and more complex multivariate shape and form. Our ‘proof of concept’ suggests that metrics assessing size and form might largely tend to simply mirror the information provided by species richness, whereas shape morphoscape disparity may be able to account for non-trivial differences in species traits amongst habitats. This is indicated by the woodland morphoscape being on average bigger than that of crops, the most species-rich habitat, despite having almost 20% less species. We conclude suggesting that the analysis of morphoscape dimension has the potential to become a new additional and complimentary tool in the hands of conservation biologists and ecologists to explore and quantify habitat complexity and inform decisions on management and conservation based on a wide set of ecological indicators.     

The influence of grassland management on ground beetles (Carabidae, Coleoptera) in Swiss montane meadows

Effects of grassland management type and intensity on carabid species richness, number of individuals and species composition were studied in the Swiss Prealps. Carabids were censused in 2001 and 2002 in 21 mown and 20 grazed meadows by means of pitfall traps.Mean species richness was significantly higher in mown plots than in grazed plots and species composition was significantly different between these two management types. Additionally, different species characteristic for mown and grazed plots were found. These results suggest that mown meadows and grazed meadows represent two habitat types for carabid beetles.Within both habitats, management intensity was quantified by fertilizing intensity, the number of cuts, cattle density and/or grazing intensity. The relationship between management intensity and the number of individuals and species was positive. Higher fertilizing intensity was the most important factor for higher species richness and had a significant influence on species composition in both habitats. Other variables positively related to the number of individuals, were the number of cuts in mown meadows and grazing intensity and altitude in grazed meadows. Additionally to fertilizing intensity, cattle density was positively related to the number of species in grazed meadows. These results illustrate that in the extensive management systems found in the Swiss Alps and Prealps, even intensively managed meadows can sustain high carabid diversity and abundance.     

Climate change is predicted to negatively influence Moroccan endemic reptile richness. Implications for conservation in protected areas

The identification of species-rich areas and their prognosticated turnover under climate change are crucial for the conservation of endemic taxa. This study aims to identify areas of reptile endemicity richness in a global biodiversity hot spot (Morocco) under current and future climatic conditions and to investigate the role of protected areas in biodiversity conservation under climate change. Species distribution models (SDM) were performed over the distribution of 21 endemic reptiles, combined to estimate current species richness at 1?×?1 km resolution and projected to years 2050 and 2080 according to distinct story lines and ensemble global circulation models, assuming unlimited and null dispersion ability. Generalized additive models were performed between species richness and geographic characteristics of 43 protected areas. SDM found precipitation as the most important factor related to current species distributions. Important reductions in future suitable areas were predicted for 50 % of species, and four species were identified as highly vulnerable to extinction. Drastic reductions in species-rich areas were predicted for the future, with considerable variability between years and dispersal scenarios. High turnover rates of species composition were predicted for eastern Morocco, whereas low values were forecasted for the Northern Atlantic coast and mountains. Species richness for current and future conditions was significantly related to the altitude and latitude of protected areas. Protected areas located in mountains and/or in the Northern Atlantic coast were identified as refugia, where population monitoring and conservation management is needed.

     

Landscape pattern and its effect on ecosystem functions in Seoul Metropolitan area: urban ecology on distribution of the naturalized plant species

During land transformation process in the human history,naturalized plants were introduced to several land use patterns by the different ways of plant itself .Including some naturalized plants that had been contribute to land restoration,many naturalized plants have been invaded to original habitat or landscape for native plants.Once the plants were colonized,they extend their area and population size.Urban developed areas often give an impotant role of source habitat for naturalized plants and expanding their popuation size.In recent,this tituation is appearing as one of environmental problems about the urban landscape management controlling the naturalized plants that invaded in the developed area and conserving the native vegetation.This paper is focusing on relationships between distribution of habitat of naturalized plants and landscape patch in urban area in Seoul.Gengdong-Gu ,one of the administrative areas in Seoul was selected for this study.We examined the recent land use change using LANDSAT TM data and spreading of the representative naturalized plants(Robinia pseudoacacia and Eupatorium rugosum)by Seoul Biotope Mapping Project and field survey in 1999.As a result,these two species were often occurred in the same habitat and distributed in forest edge disturbed by man.Their distribution patterns were related to landscape indices (patch size and shape)in the forest edge.     

Strategy for conservation of wild bees in an agricultural landscape

Investigations carried out by the author for 15 years on the Wielkopolsko-Kujawska Lowland (Western Poland) showed that wild bees (Apoidea) are today under strong human pressure. About 260 bee species were found in the area of 20 000 km². A similar number of species was recorded in this area by investigators half a century ago, which indicates that the survival of the fauna seems to be the result of some compensating factors reducing the effects of intensive agricultural management. The main factor among these is the mosaic structure of the landscape, consisting of meadows and residues of natural and semi-natural plant communities as a fauna refuge system and crop fields as an additional nutritive system. It was found that in a normally functioning agricultural landscape, the share of farmland should not exceed three-quarters of the total surface. The remaining part of the landscape should be made up of refuge habitats for Apoidea. Within such a system, qualitative and quantitative changes of the bee fauna can occur on a microregional scale and are usually of temporary character. On a regional scale they are not perceivable and probably not so important. Hence, instead of changes in fauna, one should rather speak about quantitative oscillations inside a given region. The second factor decreasing the negative effects of management is the introduction of extensive areas of some nutritive plants, e.g. rape.     

Pollinator diversity increases fruit production in Mexican coffee plantations: The importance of rustic management systems

Pollination is an ecological process that provides important services to humans. Pollination service in agroecosystems depends on several factors, including the land management systems used by farmers. Here we focused on the effects of insect pollinator diversity on coffee fruit production along a gradient of management systems in central Veracruz, Mexico. The gradient ranged from low environmental impact management systems (the native forest is not completely removed) to high environmental impact management systems (the native forest is completely removed). We hypothesized that pollinator diversity should be higher in low-impact systems. Then, if fruit production is positively related to pollinator diversity, plantations with low-impact management systems should display higher fruit production than plantations with high-impact management systems. We used observational and experimental data to test this hypothesis. Our results indicated that low-impact management systems have higher species richness and relative diversity (measured with the Shannon-Wiener diversity index) of pollinators than high-impact management systems. In all cases, fruit production was positively related with species richness and diversity of pollinators. Moreover, fruit production was higher in low-impact than in high-impact management systems. These results suggest that the diversity of insect pollinators can be influenced by the management system applied by farmers, and that such effects may have strong consequences on coffee fruit production.