融入植被连续性因子的生态单元制图法在城市生物多样性维护中的应用

基于一个以植被结构为构建框架的生态单元分类系统,构建了融入了植被覆盖连续性因子的改良城市生态单元制图模型,并将其应用于瑞典赫尔辛堡市的绿色空间研究.使用原生林地指示种或林地连续性指示种（AWIS）鉴定长、短连续性林地的分布,对比其含有维管束植物的物种丰富度,对植被覆盖的连续性因子进行评估检验.结果表明： 长连续性林地中含有较多的AWIS;在建群种均龄大于30年的林地中,长连续性林地相对于结构相似的短连续性林地通常含有较高的生物多样性.融入植被连续性因子的生态单元制图模型是调查城市生物多样性的重要工具,通过图谱中各生态单元所含有的生物多样性信息,可对今后城市生物多样性的维护提出相应策略.     

Gill filaments of Liza ramada, a biotope for ectoparasites: surface area acquisition using image analysis and growth models

Ecology of plant or animal communities requires knowledge of the biotope structure of these organisms. In the case of parasitic communities, the organs of a host constitute heterogeneous biotopes. Fish gills are an example of this, but their heterogeneity is not often considered. The gills of the mullet Liza ramada are such a biotope for several ectoparasites. Parasite density is an important factor in the study of fish-parasite interactions, but cannot be determined if the colonized surface area of the gills is not known. The number of primary filaments, and therefore the surface area potentially colonized, is subject to variation with age. Assessment of the colonizable area raises specific problems of estimation. A new method taking into account surface areas of primary filaments and using image-processing techniques is proposed. Models related to the increase of filament number and colonizable gill area as functions of the fish fork length are proposed. The increase of primary lamellae number with fish length can be fitted by an exponential-type model and the accompanying increase in size of the colonizable gill area by A polynomial-type model.     

The influence of biotope availability on macroinvertebrate assemblages in South African rivers: implications for aquatic bioassessment

1. Macroinvertebrate biotope preferences and the influence of differences in the availability of biotopes on individual taxa, macroinvertebrate assemblages and a biotic index, the South African Scoring System (SASS), were investigated in two regions of South Africa. 2. Among biotope differences in individual taxa and macroinvertebrate assemblages resulted in differences in SASS scores, with differences in assemblages being greater among biotopes than between sites. 3. All three metrics studied (SASS score, number of taxa and average score per taxon, ASPT), differed significantly among biotopes, with highest scores consistently recorded in the stones biotope, while lowest SASS scores and fewest taxa were recorded in the sand biotope. 4. SASS score and number of taxa were positively, while ASPT was negatively correlated with number of biotopes sampled. 5. The observed biotope differences highlight the importance of sampling and comparing data from sites separately for each biotope.     

德国人文聚落区生态单元制图国家项目

联邦德国自然保护法、德国各州自然保护法要求在自然景观区和人文聚落区保护、管理和发展自然。实现这一法律要求 ,必须以现实的、全面的、高质量的、与自然保护原则相匹配的数据为基础。实践证明 ,城乡生态单元制图是获取和解释这些数据不可或缺的手段。德国人文聚落区生态单元制图始于 1 978年 ,同年组建成立了德国联邦与各州自然保护部门参加并联合协调的“人文聚落区生态单元制图工作组”。 1 986年工作组提出了德国人文聚落区生态单元制图基本方案 ,1 993年完成基本方案修订版。基本方案的目标是在全国范围建立标准制图方法 ,使获取的科学数据可以相互比较。至 2 0 0 0年 ,德国在人文聚落区生态单元制图项目上的投资约合 2亿马克 ;至 2 0 0 1年 3月 ,德国有 2 2 3个大中城市已经完成或正在实施生态单元制图 ,人文聚落区生态单元制图已经成为德国各级政府生态规划的基本工作内容。     

An Ecological Classification of British Butterflies: Ecological Attributes and Biotope Occupancy

We classify British butterflies using 136 non-biotope associated binary state ecological attributes describing all stages of butterfly life-cycles. Using cluster analysis we identify two groups of woodland species, a group occurring in tall open grassland, another group associated with short sward herb-rich grassland, and a ruderal group. Principal Component and Factor analyses (4 factor solution) are used to identify ecological attributes that determine species groupings. No single attribute or attribute type is responsible for the groupings, which are also insensitive to hostplant type. We use presence/absence data from Butterfly Monitoring Scheme transects in southern Britain to test our classification. On the basis of adult occurrences, similarities within two of the four groups identified from PCA are greater than between groups. Exclusivity between species pairs is also more frequent between groups than within groups. Species' ranges, distributions, biotope range, dispersal ability and recent decline in abundances differ between groups identified by their factor loadings. Ruderal species have large ranges, abundances, extensive mobilities and show little recent decline. The group associated with short sward grassland have the lowest mobilities, and the smallest distributions within their geographic ranges. True woodland species have the smallest biotope range, and the species associated with open areas have the second smallest decline in their distributions. Our ecological classification identifies characteristics of species that determine their habitat requirements and could serve to predict the response of species groups to environmental change on the basis of their ecological attributes. Our method may be of use in identifying the relative importance of ecological attributes of less-well studied taxa and be applicable in less well known geographic regions.     

A niche perspective on the range expansion of symbionts

Range expansion results from complex eco‐evolutionary processes where range dynamics and niche shifts interact in a novel physical space and/or environment, with scale playing a major role. Obligate symbionts (i.e. organisms permanently living on hosts) differ from free‐living organisms in that they depend on strong biotic interactions with their hosts which alter their niche and spatial dynamics. A symbiotic lifestyle modifies organism–environment relationships across levels of organisation, from individuals to geographical ranges. These changes influence how symbionts experience colonisation and, by extension, range expansion. Here, we investigate the potential implications of a symbiotic lifestyle on range expansion capacity. We present a unified conceptual overview on range expansion of symbionts that integrates concepts grounded in niche and metapopulation theories. Overall, we explain how niche‐driven and dispersal‐driven processes govern symbiont range dynamics through their interaction across scales, from host switching to geographical range shifts. First, we describe a background framework for range dynamics based on metapopulation concepts applied to symbiont organisation levels. Then, we integrate metapopulation processes operating in the physical space with niche dynamics grounded in the environmental arena. For this purpose, we provide a definition of the biotope (i.e. living place) specific to symbionts as a hinge concept to link the physical and environmental spaces, wherein the biotope unit is a metapopulation patch (either a host individual or a land fragment). Further, we highlight the dual nature of the symbionts' niche, which is characterised by both host traits and the external environment, and define proper conceptual variants to provide a meaningful unification of niche, biotope and symbiont organisation levels. We also explore variation across systems in the relative relevance of both external environment and host traits to the symbiont's niche and their potential implications on range expansion. We describe in detail the potential mechanisms by which hosts, through their function as biotopes, could influence how some symbionts expand their range – depending on the life history and traits of both associates. From the spatial point of view, hosts can extend symbiont dispersal range via host‐mediated dispersal, although the requirement for among‐host dispersal can challenge symbiont range expansion. From the niche point of view, homeostatic properties of host bodies may allow symbiont populations to become insensitive to off‐host environmental gradients during host‐mediated dispersal. These two potential benefits of the symbiont–host interaction can enhance symbiont range expansion capacity. On the other hand, the central role of hosts governing the symbiont niche makes symbionts strongly dependent on the availability of suitable hosts. Thus, environmental, dispersal and biotic barriers faced by suitable hosts apply also to the symbiont, unless eventual opportunities for host switching allow the symbiont to expand its repertoire of suitable hosts (thus expanding its fundamental niche). Finally, symbionts can also improve their range expansion capacity through their impacts on hosts, via protecting their affiliated hosts from environmental harshness through biotic facilitation.     

A provisional classification of algal-characterised rocky shore biotopes in the Azores

Recent studies of the rocky shores of the Azores archipelago have provided information on community structure allowing provisional identification of plant-characterised biotopes (habitats and their associated communities). Although the Azores share some littoral and sublittoral biotopes with the Atlantic coast of mainland Europe, shores in the archipelago mostly lack the functionally important leathery macrophyte communities of fucoids and laminarians widespread in the North Atlantic. Intertidal biotopes are mainly turfs typical of warm-temperate and tropical regions, and characterised by articulated Corallinaceae or by non-coralline algae such as Cladophora spp., Gelidium spp., Pterocladiella capillacea, Stypocaulon scoparia, and Valonia utricularis. Subtidal algal biotopes are characterised by Dictyota spp., Halopteris filicina, Sphaerococcus coronopifolius and, most commonly, Zonaria tournefortii.     

基于生态单元制图的宝鸡市城区生物多样性保护规划研究

为探寻适合我国城乡生物多样性保护的有效措施和方法,以宝鸡城区为研究对象,通过实地调研和室内制图相结合的研究方法,创建一套融入植被结构因子(植被水平结构因子、植被优势种的年龄因子、植被垂直结构因子、林木类型因子)的生态单元分类系统,将研究区域内的城市绿地现状以图谱形式表示。通过对不同植被结构的绿地中维管束植物物种丰富度的对比,以检验此分类系统在城乡生物多样性信息采集中的有效性。基于制图信息和检验结果,分析研究区域内绿地空间结构存在的问题并针对宝鸡市城乡生物多样性保护提出相应策略,以期为今后我国城乡生物多样性保护提供理论依据和实践方法。     

Natural distinction of carbon and nitrogen isotopic niches in common fish species across marine biotopes in the Yellow River estuary

Stable isotope analysis is a universally recognized and efficient method of indicating trophic relationships that is widely applied in research. However, variation in stable isotope ratios may lead to inaccuracies due to the effects of complex environmental conditions. This research compared the carbon and nitrogen isotopic niches of fish communities between diverse biotopes around the Yellow River estuary and adjacent sea areas, with the aim of revealing distinctions in stable isotopic niche metrics, trophic positions, and feeding preferences. Our analysis of the food source contribution indicated that allochthonous sources were considered major energy sources in estuarine areas directly affected by Yellow River‐diluted water, while autochthonous benthic and pelagic producers dominated carbon input into the food web in Laizhou Bay and the open water. A significant variation in the fish δ¹⁵N characteristic was found within estuarine adjacent regions, so, together with the results from previous studies, we deemed the local high concentration of dissolved inorganic nitrogen as the original trigger of the abnormal δ¹⁵N characteristic in fishes via a transport process along food chains. These results provide a new perspective on the natural distinction of carbon and nitrogen isotopic niches. The detailed data reported here enhance our understanding of variations in fish communities in estuarine ecosystems.