北京城市及近郊区环境结构对鸟类的影响

本文研究了北京市区及近郊环境结构与四季鸟类群落的关系,用相对数量路线调查法估计了鸟类的实际分布。环境结构分为面积和空间异质性两个主要因素,后者又包括自然度和环境多样性两个方面。结果表明,空间异质性对鸟类物种数及多样性有显著的影响,其中自然度的作用较环境多样性的作用更为显著。“边缘效应”是由于环境多样造成的。当空间异质性较高时,面积对鸟类物种数的影响是明显的。由于城市环境的空间异质性较低,由少数优势种决定了鸟类群落特征。为改善城市环境结构,建议增加绿化面积,丰富植被层次及物种组成,同时在北京城市环境中适当增加各种形式的水体。     

Heterogeneous Landscapes on Steep Slopes at Low Altitudes as Hotspots of Bird Diversity in a Hilly Region of Nepal in the Central Himalayas

Understanding factors determining the distribution of species is a key requirement for protecting diversity in a specific area. The aim of this study was to explore the factors affecting diversity and distribution of species of birds on different forested hills in central Nepal. The area is rich in species of birds. Because the area is characterized by steep gradients, we were also interested in the importance of altitude in determining the diversity and species composition of the bird communities. We assessed bird diversity and species composition based on point observations along a gradient of increasing altitude in two valleys (Kathmandu and Palung) in central Nepal. Data on environmental variables were also collected in order to identify the main determinants of bird diversity and species composition of the bird communities. We recorded 6522 individual birds belonging to 146 species, 77 genera and 23 families. Resident birds made up 80% (117 species) of the total dataset. The study supported the original expectation that altitude is a major determinant of species richness and composition of bird communities in the area. More diverse bird communities were found also in areas with steeper slopes. This together with the positive effect of greater heterogeneity suggests that forests on steep slopes intermixed with patches of open habitats on shallow soil at large spatial scales are more important for diverse bird communities than more disturbed habitats on shallow slopes. In addition, we demonstrated that while different habitat characteristics such as presence of forests edges and shrubs play an important role in driving species composition, but they do not affect species richness. This indicates that while habitat conditions are important determinants of the distribution of specific species, the number of niches is determined by large scale characteristics, such as landscape level habitat heterogeneity and altitude. Thus, to protect bird diversity in the mid-hills of central Nepal, we should maintain diverse local habitats (viz. forest, shrubs, open land, etc.) but also make sure the natural habitats on steeper slopes with large scale heterogeneity are maintained.     

Faunal diversity and vegetation structure of some deciduous forests in South Sweden

The relationships of faunal diversity and vegetation structure were studied in twenty deciduous forest plots in South Sweden, all of them managed. Following animal groups were censused: shrews (Soricidae), bats (Chiroptera), voles (Cricetidae), fieldmice (Muridae), birds (Aves), groundliving beetles (Coleoptera), spiders (Araneida), and harvestmen (Opilionidae). The analysis of the 22 vegetation variables was made by means of repeated and rotated PCA. Rarefaction was used to ordinate the bird species richness of the different forest plots.
The multivariate vegetational analysis resulted in three distinct and readily interpretable components: horizontal and vertical spatial heterogeneity, and mean basal area. The number of small mammal species (except bats) was greatest in forests with great amount of understory while the number of bat species increased with increasing mean basal area. The number of bird species in a fixed number of territories was also highly correlated with the mean basal area. Hence, maximum bird species richness was obtained in mature forests but not in those with greatest vertical heterogeneity. The invertebrate communities showed very few distinct relationships to the vegetation structure.
Dominance decreased as vegetation complexity increased. Dominance also decreased with increasing species richness in all faunal communities studied.     

Bird community patterns in response to the island features of urban woodlots in eastern China

Many studies have demonstrated the changes in the spatial patterns of plant and animal communities with respect to habitat fragmentation.Insular communities tend to exhibit some special patterns in connection with the characteristics of island habitats.In this paper,the relationships between richness,assemblage,and abundance of bird communities with respect to island features were analyzed in 20 urban woodlots in Hangzhou,China.Field investigations of bird communities,using the line transect method,were conducted from January to December,1997.Each woodlot was surveyed 16 times during the year.Results indicated that bird richness was higher,per unit area,in the smaller woodlots than the larger ones,and overall bird density decreased with the increase in the size of woodlot.However,the evenness of species abundance increased with the area,and small woodlots were usually dominated by higher density species and large woodlots by medium density species.Most species occurring in the small woodlots also occurred in larger woodlots.Also,bird communities among urban woodlots showed a nestedness pattern in assemblage.These patterns implied that the main impacts of woodland habitat fragmentation are:(1) species are constricted and thus species number will increase at a given sample size;(2) as surface area decreases,the proportion of forest edge species as to interior species will increase;(3)community abundance will therefore increase per unit area but most individuals will be from a few dominant species;and (4) overall species diversity will decrease at a habitat level as well as at a region level.These patterns of community in response to the island features were therefore summarized as "island effects in community".The underlying processes of such observations were also examined in this paper.Woodlot area,edge ratio,isolation,and habitat nestedness were considered as the important factors forming the island effects in community.High heterogeneity between habitats usually contributed most to the maintenance of regional biodiversity,especially in urban woodlots.     

晋北大型露天矿区景观生态风险时空异质性

矿产资源开采对生态环境产生了剧烈扰动,加剧了矿区生态环境的风险性,严重威胁区域的可持续发展。从景观生态学角度将景观格局与生态风险相结合对矿区生态环境进行评估,从而揭示矿区景观生态风险的时空异质性,促进土地资源的可持续利用。以1990-2018年7期Landsat TM影像解译后的土地利用现状数据为数据源,构建景观生态风险指数,结合空间统计学及地统计学理论,探究1990-2018年平朔矿区景观生态风险的时空异质性。结果表明:1990-2018年平朔矿区景观生态风险的空间分布呈集聚分布模式,Moran’s I指数处于0.53~0.68,Z得分远高于检验阈值1.96,风险的空间集聚效应明显。1990-2018年平朔矿区的景观生态风险等级以中低、中、中高水平为主,占全区总面积的70%~90%,低风险区域主要分布于井坪镇以及白堂乡与向阳堡乡的大片林地,耕地是中等风险的主要分布区域,高风险区域逐渐向矿界内的矿业核心区收缩。1990-2018年平朔矿区景观生态风险空间异质性中的随机变异均小于空间自相关变异,由空间自相关部分引起的空间异质性占据主导地位。研究表明,在0.50 km×0.50 km的研究尺度下,1990—2018年平朔矿区景观生态风险具有很强的时空异质性,时间上呈现先增加后降低的趋势,空间相关性显著,空间分异特征明显。     

Some problems of studying spatial heterogeneity of animal communities

The efficiency of different techniques of data collection and processing was considered by the example of bird communities. Accounted variance of the coefficients of bird complex similarity was used as the measure. Annual censuses in different sites proved more expedient than a long-term census in a single key site to study medium-and small-scale spatial heterogeneity of bird communities. Averaging and generalization of data collected in different years and sites yielded satisfactory results. Estimated informativeness in this case proved closer to the real one compared to averaged long-term data since the included representation errors in space and time.     

洞庭湖生态经济区生态系统服务价值的时空演绎及其驱动因素

伴随城镇化的快速推进,生态系统服务价值(ESV)的时空评估及驱动因子探测对区域社会-经济-生态协调可持续发展具有重要意义。借助洞庭湖生态经济区2005、2010、2015、2018年的遥感解译数据,从3 km×3 km的格网尺度出发,在ArcGIS和GeoDa的技术支撑下,结合当量因子法、空间自相关分析、热点分析等方法来研究洞庭湖生态经济区ESV的时空格局演变,进一步运用地理探测器工具探究ESV空间分异的主导驱动因子及各驱动因子的交互作用机制。结果表明: 2005—2018年,研究区建设用地有最明显的增长态势,增幅高达49.2%,草地和水域呈较大规模减小,其他土地资源变化不显著。研究期间,生态系统服务价值总体逐渐递减,仅未利用地的ESV呈大幅增长态势,其他地类的ESV均呈不同规模的减少态势。研究区ESV总体呈“中间高四周低”的空间分布格局,且ESV空间分布存在显著的集聚效应,但ESV的高值和低值集聚效应均有逐渐弱化的倾向,表明生态价值空间集聚效应逐渐递减。研究区ESV空间分异受自然环境和社会经济因子耦合协调的作用,其中,人为影响指数的贡献最大。     

Direct and indirect effects of area,energy and habitat heterogeneity on breeding bird communities

Aim To compare the ability of island biogeography theory, niche theory and species–energy theory to explain patterns of species richness and density for breeding bird communities across islands with contrasting characteristics. Location Thirty forested islands in two freshwater lakes in the boreal forest zone of northern Sweden (65°55′ N to 66°09′ N; 17°43′ E to 17°55′ E). Methods We performed bird censuses on 30 lake islands that have each previously been well characterized in terms of size, isolation, habitat heterogeneity (plant diversity and forest age), net primary productivity (NPP), and invertebrate prey abundance. To test the relative abilities of island biogeography theory, niche theory and species–energy theory to describe bird community patterns, we used both traditional statistical approaches (linear and multiple regressions) and structural equation modelling (SEM; in which both direct and indirect influences can be quantified). Results Using regression‐based approaches, area and bird abundance were the two most important predictors of bird species richness. However, when the data were analysed by SEM, area was not found to exert a direct effect on bird species richness. Instead, terrestrial prey abundance was the strongest predictor of bird abundance, and bird abundance in combination with NPP was the best predictor of bird species richness. Area was only of indirect importance through its positive effect on terrestrial prey abundance, but habitat heterogeneity and spatial subsidies (emerging aquatic insects) also showed important indirect influences. Thus, our results provided the strongest support for species–energy theory. Main conclusions Our results suggest that, by using statistical approaches that allow for analyses of both direct and indirect influences, a seemingly direct influence of area on species richness can be explained by greater energy availability on larger islands. As such, animal community patterns that seem to be in line with island biogeography theory may be primarily driven by energy availability. Our results also point to the need to consider several aspects of habitat quality (e.g. heterogeneity, NPP, prey availability and spatial subsidies) for successful management of breeding bird diversity at local spatial scales and in fragmented or insular habitats.     

Spatial similarity of urban bird communities: a multiscale approach

Aim Human land use, especially urbanization, might homogenize the world's biota. The objective of this study is to find out if urbanization homogenizes wintering bird communities, and if habitat type affects the spatial variation of urban bird communities across spatial scales. Location We compared the quantitative similarity of winter bird communities between town centres, apartment block areas and single‐family house areas across regional and local scales in five towns in northern Finland. Methods The wintering birds were surveyed using a single‐visit study plot (30 ha) method in January and February 2001. The validity of single‐visit and single‐year data was confirmed by using data from several‐visit surveys and multi‐year data set. The level of urbanization was measured according to the number of inhabitants and general structure of the habitat. Results Temporal variability in species richness and total number of individuals was low, both between winters and within winter. Bird community similarity between different habitat types within a single town was about the same as that in similar habitats in different towns. At the regional scale, bird community similarity between town centres (30%) was lower than between areas of apartment blocks (54%) or between areas of single‐family houses (54%). We detected a threshold point between towns of 35,000 and 105,000 inhabitants and between town sizes of 5.0–8.5 km in diameter where human impact causes marked changes in bird community structure. At the local scale, bird community similarity level between apartment block areas (49%) and single‐family house areas (62%) were about the same. Passer domesticus, Parus major and Pica pica dominated the bird communities in residential areas. Different habitat factors affected bird species abundances on the local and regional scales. Conclusions Urbanization cannot be seen as a process that monotonically increases the similarity of bird communities. Our results indicate that the similarity between urban bird communities is dependent on the size of the town, location of the study site within the town and especially the local habitat structure. Because different habitat factors affected bird species abundances, it is difficult to extrapolate bird–habitat relationships derived from one scale to other scales. In wintertime, single‐family house areas are important biodiversity hotspots in cities. Therefore, it is especially important to understand the factors affecting the occurrence of birds in the single‐family house area in order to maintain or even increase diversity on winter birds in other urban habitats.     

Species richness of migratory birds is influenced by global climate change

Aim  Global climate change is increasingly influencing ecosystems. Long-term effects on the species richness and composition of ecological communities have been predicted using modelling approaches but, so far, hardly demonstrated in the field. Here, we test whether changes in the composition of bird communities have been influenced by recent climate change.
Location  Europe.
Methods  We focus on the proportion of migratory and resident bird species because these groups are expected to respond differently to climatic change. We used the spatial relationship between climatic factors and bird communities in Europe to predict changes in 21 European bird communities under recent climate change.
Results  Observed changes corresponded significantly to predicted changes and could not be explained by the effects of spatial autocorrelation. Alternative factors such as changes in land use were tested in a first approximation as well but no effects were found.
Main conclusions  This study demonstrates that global climate change has already influenced the species richness and composition of European bird communities.     

Bird community patterns in response to the island features of urban woodlots in eastern China

Many studies have demonstrated the changes in the spatial patterns of plant and animal communities with respect to habitat fragmentation. Insular communities tend to exhibit some special patterns in connection with the characteristics of island habitats. In this paper, the relationships between richness, assemblage, and abundance of bird communities with respect to island features were analyzed in 20 urban woodlots in Hangzhou, China. Field investigations of bird communities, using the line transect method, were conducted from January to December, 1997. Each woodlot was surveyed 16 times during the year. Results indicated that bird richness was higher, per unit area, in the smaller woodlots than the larger ones, and overall bird density decreased with the increase in the size of woodlot. However, the evenness of species abundance increased with the area, and small woodlots were usually dominated by higher density species and large woodlots by medium density species. Most species occurring in the small woodlots also occurred in larger woodlots. Also, bird communities among urban woodlots showed a nestedness pattern in assemblage. These patterns implied that the main impacts of woodland habitat fragmentation are: (1) species are constricted and thus species number will increase at a given sample size; (2) as surface area decreases, the proportion of forest edge species as to interior species will increase; (3) community abundance will therefore increase per unit area but most individuals will be from a few dominant species; and (4) overall species diversity will decrease at a habitat level as well as at a region level. These patterns of community in response to the island features were therefore summarized as “island effects in community”. The underlying processes of such observations were also examined in this paper. Woodlot area, edge ratio, isolation, and habitat nestedness were considered as the important factors forming the island effects in community. High heterogeneity between habitats usually contributed most to the maintenance of regional biodiversity, especially in urban woodlots. __________ Translated from Acta Ecologica Sinica, 2005, 25(4): 657–663 [译自: 生态学报, 2005, 25(4): 657–663]     

Landscape-ecological assessment of bird communities in the middle Aldan valley

Studies on the bird fauna of the middle Aldan River valley, a poorly explored area of Russia, have been performed to reveal trends of spatial changes in the group of dominants, faunistic composition, density, species richness, and distribution of bird assemblages by vegetation layers and to identify environmental factors accounting for these trends. The roles of zonal and local landscape-ecological conditions in the formation of bird communities have been compared. The status of rare and endangered species in the study region has been determined. The results are compared with similar data on the lower Maya River valley.     

Relationship between the presence of House Sparrows (<Emphasis Type="Italic">Passer domesticus</Emphasis>) and Neotropical bird community structure and diversity

Invasive exotic species pose an important threat to biodiversity worldwide. However, there is little information on the effects that specific exotic bird species have on native biota. The House Sparrow is an excellent ecological model to evaluate the effect that an invasive exotic species has on native bird communities. Our study describes the relationship of the presence and abundance of House Sparrows with the structure, diversity, and composition of native bird communities in West Mexico. We used two approaches to compare House Sparrow invaded and non-invaded bird communities: (1) at a small geographic-scale that allowed us to evaluate shifts in avian communities with presence of the House Sparrow under similar environmental conditions; and (2) at the landscape-level to evaluate the effect of this species under a scenario of greater environmental heterogeneity. Results from both approaches show that areas invaded by House Sparrows have heavily-dominated avian communities with low species richness, while non-invaded areas exhibit highly-even and species-rich bird communities. Species turnover analysis indicates that the decrease in the number of bird species in House Sparrow invaded areas is caused by species loss, rather than a shift in species composition. Our results indicate that the invasion of an area by the House Sparrow, through synergistic interactions with human activities, determines the composition, structure, and diversity of native bird communities.     

Spatial pattern of grazing affects influence of herbivores on spatial heterogeneity of plants and soils

With our enhanced understanding of the factors that determine biodiversity and assemblage structure has come increasing acknowledgment that the use of an appropriate disturbance regime to maintain spatial heterogeneity is an effective conservation technique. A herbivore’s behavior affects its disturbance regime (size and intensity); this, in turn, may modify the associated spatial heterogeneity of plants and soil properties. We examined whether the pattern of spatial disturbance created by the Siberian marmot (Marmota sibirica) affects the spatial heterogeneity of vegetation and soils at a colony scale on the Mongolian steppe. We expected that the difference in management between two types of area (protection against hunting marmots vs. hunting allowed) would result in different behavioral patterns; therefore, we estimated the patterns of spatial disturbance separately in protected and unprotected areas. We then surveyed plant communities and soil nutrients in these areas to assess their spatial heterogeneity. We found that disturbance of both vegetation and soil was more concentrated near marmot burrows in the unprotected area than in the protected area. In addition, the degrees of spatial heterogeneity of vegetation and soil NO₃-N were greater in the unprotected area than in the protected area, where disturbance was more widely distributed. These results indicate that the spatial pattern of disturbance by herbivores affects the spatial heterogeneity of vegetation and soil properties through changes in the disturbance regime. Our findings also suggest that the intensity of disturbance is more important than its size in determining community structure in Mongolian grasslands.     

The effects of individual interactions and habitat preferences on spatial structure in a grassland bird community

Spatial structure and the distribution of individuals within a community might be influenced by several factors such as habitat heterogeneity and local interactions among individuals of the same and different species. We investigated the spatial distributions of eight bird species in a grassland community during the breeding season and examined whether the spatial distributions of individuals were influenced by interactions among neighboring individuals or different habitat preferences of different bird species.
In order to identify the effects of the interactions among neighboring individuals and habitat preference, we developed a randomization test in which species identifications were randomly allocated to the observed individual positions within areas with the same vegetation structure. The randomization test indicated that individuals tend to have territories near the territories of individuals of the same species or of a particular species more frequently (or less frequently) than those expected from random distributions of individuals.
Among these associations, only one case was explained by individual interactions, and 19 cases were explained by habitat preference.
The results suggest that both individual interactions and habitat preference affected the spatial distributions of individuals and possibly influence the species compositions and diversity in grassland bird communities.     

Pasture area and landscape heterogeneity are key determinants of bird diversity in intensively managed farmland

Agriculture intensification has drastically altered farmland mosaics, while semi-natural grasslands have been considerably reduced and fragmented. Bird declines in northern temperate latitudes are attributed to habitat loss and degradation in farmed landscapes. Conversely, landscape-modification effects on grassland/farmland bird communities are less studied in the South American temperate grasslands. We investigated how bird communities were influenced by landscape characteristics in the Rolling Pampa (Argentina). We sampled bird communities in 356 landscapes of 1-km radius that varied in cover and configuration of pastureland, flooding grassland and cropland. Using generalized linear models, we explored the relationship between both bird species richness and abundance, and landscape structure. Analyses were carried out for all species, and open-habitat, grassland and aquatic species. Pasture area was far the most important factor, followed by landscape composition, in predicting species richness and abundance, irrespective of specific habitat preferences, followed by partially-flooded grassland cover and its mean shape index. Grassland fragmentation did not affect species richness or abundance. When comparing the effects of landscape variables on bird richness and abundance (using mean model coefficients), pasture and grassland area effects were on average more than four times greater than those of compositional heterogeneity, and about ten times greater than shape effects. To conserve species-rich bird communities persisting in Rolling Pampa farmland, we recommend the preservation of pasture and grassland habitats, irrespective of their fragmentation level, in intensively managed farmland mosaics.     

合肥市小微湿地鸟类多样性的时空格局及其影响因素

小微湿地是城市生态系统的重要组成部分, 也是生物多样性的重要庇护场所。鸟类作为城市小微湿地生态系统的指示类群, 其多样性时空格局受多种环境因子影响。本研究于2020年8月至2021年7月采用样点法对合肥市45个小微湿地鸟类的种类、数量分布和生境因子进行了调查, 并获取湿地面积、湿地形状、建筑面积比例、植被面积比例、环境噪声、人为干扰和城市化指数等生境变量。通过α多样性和β多样性分析, 研究城市小微湿地鸟类多样性的时空特征及其决定因素。采用信息论模型选择和模型平均法以及基于距离矩阵的多重回归模型进行计算, 确定影响鸟类群落α多样性和β多样性及其组分的主要环境因子。结果显示, 研究区域共有鸟类13目39科102种, 其中水鸟31种, 国家二级重点保护鸟类2种, 安徽省重点保护鸟类17种, IUCN濒危物种红色名录中的易危(VU)物种1种。湿地面积和城市化指数对小微湿地陆地鸟类和水鸟的α多样性、β多样性及其组分均具有显著影响, 其中陆地鸟类物种丰富度在中度和低度城市化之间的小微湿地中达到最高值, 面积超过4 ha的小微湿地能维持较多的水鸟物种。植被面积比例对陆地鸟类多样性具有重要的影响, 而建筑面积比例对水鸟多样性具有显著影响。此外, 总体β多样性及其组分计算结果显示物种周转组分占明显优势, 表明城市小微湿地群作为城市复合生态系统的重要组成部分, 加强整体保护更为必要。研究结果对于加强城市鸟类保护和提高城市生态环境质量具有指导意义。     

Spatial-typological heterogeneity and environmental organization of the summer population of birds in the Middle Region of Northern Eurasia

The area under study covered the West Siberian Plain from the Urals to the Yenisei River and the same band to the southern borders of the former Soviet Union in 1991, including a part of the Altai-Sayan mountain country, Kazakhstan, Uzbekistan, Turkmenistan, and the whole of Kyrgyzstan and Tajikistan. The results of ornithogeographic surveys carried out on routes with a length of 63000 km in 3140 habitats from May 16 to July 31 in the period from 1936 to 2013 were analyzed for this territory. More than 110 specialists took part in the study. The collected data were averaged according to the contours of natural-geographical maps. The subsequent cluster analysis revealed the presence of three systems (series) of bird communities in undeveloped and developed lands, as well as in water and riparian areas. Eight types of communities were distinguished within the first system: 1—tundra type; 2—forest-tundra type; 3—forest type; 4 and 5—West Siberian meadow-steppe and semidesert-steppe types; 6 and 7—Middle Asian northern desert-steppe and southern desert types; 8—high-mountain type. The borders of their distribution do not coincide with the zonal borders. Seven and six types of communities were distinguished in the second and third systems, respectively. A part of them was divided into 29 subtypes in total. The revealed heterogeneity of bird communities is largely determined by 12 environmental factors. The greatest correlation was detected for forestation, buildup, and watering. The multiple correlation of the bird population variability with all the identified environmental factors amounted to about 54 ± 1% of variance in the similarity matrix, which approximately corresponds to the correlation coefficient of 0.74.