Oribatid mite (Acari) community structure in steppic habitats of Burgos Province,central northern Spain

This work is a study of the communities of oribatid mites in steppic areas of Burgos Province, central northern Spain, in relation to different habitat types belonging to natural or disturbed ecosystems. The primary objective was to find the relationship between anthropogenic use of land and several diversity indices. Parameters such as abundance, species richness, real diversity (H′) and equitability (J′) of the mite communities were calculated in 20 soil plots, sampled in spring and autumn 2000, belonging to the predominant habitat types of this area: (1) cultivated lands, (2) abandoned crop lands, (3) grasslands/pastures, and (4) natural oak forests or a pine plantation. The most widespread species in the area as well as the most abundant taxa overall are documented, together with the faunistic checklist of oribatid mites identified in the study. The results show a general decline in the composition of the oribatid community, in terms of species diversity and abundance, from non‐disturbed soils to cultivated lands. The number of species (richness) was usually higher in forest soils than in disturbed ecosystems, in which the most degraded soils showed the lowest number of species. The community analysis shows the differences due to habitat type and ubiquitous bioindicator species.     

稻纵卷叶螟幼虫寄生性天敌的种群特征与多样性分析(英文)

水稻卷叶螟的田间种群包括三个种,即稻纵卷叶螟(Cnaphalocrocis medinalis),和 MarasmiaPatnalis,M.exigua。1989年雨季在菲律宾吕宋岛上两个点进行的试验共分别记录了15(内湖省)和12(中吕宋)个种的幼虫寄生性天敌,它们分别攻击寄主卵～幼虫、幼虫和幼虫～蛹期,这些寄生性天敌分属于外寄生或内寄生,单寄生或多寄生,这种生物学特征上的差异为寄生性天敌提供了降低寄主种群的广大的机会。进一步的调查显示,那些攻击低龄寄主的种类具有高繁殖力的小个体的特征,而攻击高龄寄主的种类具有较宽的寄主范围且常常发育历期较短。多数天敌寄生于2或3龄幼虫,将寄主杀死于5龄之前,优势种及寄生率随寄主密度和水稻的生长期不同而变化。 根据Hill(1972)的多样性序列指数分析指出,当以N_2为标准时,在内湖省的整个水稻生育期内始终仅有2—3个种为极优势种,其数据适于用几何或对数序列进行描述。两个点的寄生性天敌种群多样性(N_2)接近于常数3—4,均匀度(E_5)与寄主幼虫密度呈负相关。因此,幼虫的寄生作用可被认为是一个抑制并稳定水稻卷叶螟田间种群的关键因子。     

缙云山常绿阔叶林次生演替序列群落物种多样性动态研究

采用物种丰富度Ｓ和物种多样性香农指数Ｈ、物种均匀度指数Ｊ以多样性－面积曲线研究缙云山常绿阔叶林次生演替序列物种多样性近十年的变化,结果表明,１０年后,群落各层物种多样性指数均有下降趋势,草本层下降最为明显;群落及乔、灌木层的多样性指数（Ｓ,Ｈ,Ｊ）在演替中后期阶段均呈下降趋势,而演替前期的马尾松和林龄较短的混交林Ⅰ却有上升趋势;群落各层多样性最小面积按马尾松林、混交林到常绿阔叶林顺序增长,两个混交     

How many insect species are in your country? The example of Trinidad and Tobago

Data from well-studied taxa are used together with explicit assumptions and estimates of the world fauna to estimate the number of insect species in Trinidad and Tobago. The median estimate of the world fauna is 4.8 million, while the median estimate of Trinidad and Tobago’s share in the world fauna is 4.8%. Accordingly, it is estimated within broad confidence limits that Trinidad and Tobago harbour 230,400 species. The approach used allows for a refinement of this estimate as new or better data become available.     

Multi-scale patterns in the host specificity of plant-dwelling arthropods: the influence of host plant and temporal variation on species richness and assemblage composition of true bugs (Hemiptera)

The influence of temporal variation in the host specificity of invertebrates to estimates of biodiversity is rarely considered. While patterns at large spatial scales have stimulated much attention, such comparisons are constrained for southern-hemisphere biomes because the patterning of invertebrates on plants is largely unknown. Here, we analyse variation of plant-dwelling Hemiptera from 15 understorey plant species over 18 months in the south-west Australian biodiversity hotspot. Analyses showed significant interactions in species composition between sampling period and plant species. Fauna that were “effectively specialized” (host-specificity index) to plants changed with season, although this was also related to the number of singletons and overall species richness. Sampling from a single season also overestimated the degree of host specificity by 52% and underestimated the perception of species richness when an outbreak of a particular herbivore occurred. High host-specificity values (12.7 hemipteran species per plant) support the case for high estimates of global arthropod richness.     

公平价值与和谐社会之构建

党的十六届四中全会提出了建设“和谐社会”的命题。和谐社会包括社会系统和自然生态系统之间以及社会系统内部的协调发展与和谐相处,即人类与自然的和谐及人与人之间的和谐。其中,社会是否公平是能否实现社会和谐的关键之一。针对我国目前日益扩大的贫富差距,公平价值对和谐社会的构建具有重大意义。     

小兴安岭小叶章湿地植物群落的物种丰富度研究

选取中国东北部高寒高纬度具有代表性的小兴安岭乌伊岭国家级湿地自然保护区为研究对象,采用样方调查法、α多样性指数分析法和多重比较分析法,研究不同恢复时间被垦小叶章湿地植物群落的物种组成结构以及α多样性的变化规律;并与天然小叶章湿地相比,综合定量评价湿地的自然恢复效果,以便为中国东小兴安岭北地区开垦湿地生态系统的恢复与重建提供依据。研究结果如下:被垦小叶章湿地的植物群落经过一段时间的自然恢复,是可以得到恢复的;而且植物群落发生了明显的群落演替,被垦小叶章湿地植被自然恢复的时间至少需要10年。不同恢复时间被垦小叶章湿地植物群落之间,及其与天然小叶章湿地植物群落α多样性指数之间的差异性较为复杂。恢复时间为5年的植物群落的α多样性与天然小叶章之间差异性明显;随着恢复时间的增加,差异性降低;恢复时间为12年的植物群落与天然小叶章之间的物种多样性已无明显差异。     

湘西汞矿带苔藓植物生态分布特征

湘西汞矿带是中国大型-特大型汞矿床的主要分布带之一。经野外调查和室内鉴定,发现湘西汞矿带不同矿区(新晃、茶田、东坪汞矿区)、不同污染源(废渣、废石、废洞、冶炼废址、废渣堆积处溪流瀑布)共分布苔藓植物17科41属106种,占优势的科是丛藓科(42.5%)和真藓科(19.8%)。苔藓植物生活型有3种:丛集型占81.13%、交织型占16.04%、平铺型占2.83%。该汞矿带上不同矿区苔藓植物物种丰富度差异明显,相似性较低。不同污染源苔藓植物物种丰富度变化较大,废渣上丰富度很低,污染最大。结果揭示了苔藓植物在湘西汞矿带不同污染源的分布规律。短叶小石藓Weisia semipallida C.Muell.、双色真藓Bryum dichotomum Hedw.、银叶真藓B.argenteum Hedw.、卵蒴真藓B.blindii B.S.G.和南亚小曲尾藓Dicranella coarctata(C.Muell)Boesch etLac.,在该汞矿带不同污染源上分布广泛,可作为进一步环境监测的良好材料。     

Spatial distribution of ichthyofauna in the northern Alboran Sea (western Mediterranean)

This study describes the four main demersal fish assemblages identified along the continental shelf and slope (30–800 m depth) of the northern Alboran Sea (western Mediterranean), based on the analysis of the MEDITS (International bottom trawl survey in the Mediterranean) 12-year data series. We collected 186 fish species belonging to three classes, 24 orders and 69 families. Taxonomically, the order Perciformes was the most diverse, represented by 18 families and 58 species. Each assemblage had particular characteristics of abundance, biomass, mean fish weight and species richness. The geographical differences associated with the distribution of some species occurred within shelf assemblages. The middle slope was characterised by the highest similarity between samples, probably due to its lower environmental variability compared to that of the other assemblages.