广东内伶仃岛夏季鸟类群落生物多样性的研究

于1997－1999年7月10－20日,对内伶仃岛夏季鸟类群落进行了调查和研究,结果表明,34种鸟类是该岛的优势种类,又次内伶仃岛划分为5个岛类群落,并对这5个夏季鸟类群落的组成,群落间的相似性和均匀度以及各群落生物多样性做了分析和讨论。     

Using resistance distance from circuit theory to model dispersal through habitat corridors

Aims Resistance distance (RD), based on circuit theory, is a promising metric for modelling effects of landscape configuration on dispersal of organisms and the resulting population and community patterns. The values of RD reflect the likelihood of a random walker to reach from a source to a certain destination in the landscape. Although it has successfully been used to model genetic structures of animal populations, where it most often outperforms other isolation metrics, there are hardly any applications to plants and, in particular, to plant community data. Our aims were to test if RD was a suitable metric for studying dispersal processes of plants in narrow habitat corridors (linear landscape elements [LLE]). This would be the case, if dispersal processes (seed dispersal and migration) resembled random walks. Further, we compared the model performance of RD against least-cost distance (LCD) and Euclidean distance (ED). Finally, we tested the suitability of different cost surfaces for calculations of LCD and RD.Methods We used data from 50 vegetation plots located on semi-natural LLE (field margins, ditches, road verges) in eight agricultural landscapes of Northwest Germany. We mapped LLE, including hedges and tree rows, from aerial images in a Geographic Information System, converted the maps into raster layers, and assigned resistance values to the raster cells, where all cells outside of LLE received infinite resistance and, thus, represented barriers to dispersal. For all pairs of plots within study areas, we calculated Jaccard similarity assuming that it was a proxy (or correlate) of dispersal events between plots. Further, we calculated RD and LCD of the network of LLE and ED between the plots. We modelled the effects of distance metrics on community similarity using binomial generalized linear mixed models.Important findings ED was clearly the least suitable isolation metrics. Further, we found that RD performed better than LCD at modelling Jaccard similarity. Predictions varied markedly between the two distance metrics suggesting that RD comprises additional information about the landscape beyond spatial distance, such as the possible presence of multiple pathways between plots. Cost surfaces with equal cell-level resistances for all types of LLE performed better than more complex ones with habitat-specific resistances. We conclude that RD is a highly suitable measure of isolation or, inversely, connectivity for studying dispersal processes of plants within habitat corridors. It is likely also suitable for assessing landscape permeability in other landscape types with areal habitats instead of narrow corridors. RD holds the potential to improve assessments of isolation (or connectivity) for models of regional population and meta-community dynamics.     

城市河流改造工程对河流生态系统野生维管植物的影响

随着城市化的发展,许多城市对流经市区的河流进行了大规模工程改造,在获得了多种效益的同时,也引起了诸如生物多样性破坏和物种组成改变等一系列生态问题,因此对城市河流改造工程的生态影响进行研究非常重要,将有助于在未来城市河流改造中更有效地保护河流生态系统。该文以汾河太原段的河道改造工程为研究对象,用Shannon-Weiner 多样性指数、Sørensen群落相似性指数和单因素方差分析方法,研究了河流改造工程对河流生态系统中的野生维管植物物种多样性、频度和群落物种组成相似性的影响。结果表明:太原汾河段改造后比改造前的野生维管植物物种数和Shannon-Weiner 多样性指数显著降低;低频度的物种数明显增加而高频度的物种数明显减少;河流改造前后的群落相似性明显降低。由此可见,城市河流改造工程对河流生态系统中的野生维管植物物种多样性、频度和群落相似性有明显影响。     

七种犁头尖属(Typhonium Schott)植物和两个近缘属等位酶的研究

用凝胶电泳法分析了七种犁头尖属植物和两个近缘属三个种的6种酶系统,检测了7个等位酶位点,利用软件BIOSIS-2进行遗传相似性的聚类分析,绘出树状分支图,将七种犁头尖属植物分为三个组,同时澄清了犁头尖属、斑龙芋属和半夏属之间的近缘性,即犁头尖属与斑龙芋属比与半夏属有较近的亲缘关系。     

Role of the bilayer in the shape of the isolated erythrocyte membrane

Summary The determinants of cell shape were explored in a study of the crenation (spiculation) of the isolated erythrocyte membrane. Standard ghosts prepared in 5mm NaP_i (pH 8) were plump, dimpled disks even when prepared from echinocytic (spiculated) red cells. These ghosts became crenated in the presence of isotonic saline, millimolar levels of divalent cations, 1mm 2,4-dinitrophenol or 0.1mm lysolecithin. Crenation was suppressed in ghosts generated under conditions of minimal osmotic stress, in ghosts from red cells partially depleted of cholesterol, and, paradoxically, in ghosts from red cells crenated by lysolecithin. The susceptibility of ghosts to crenation was lost with time; this process was potentiated by elevated temperature, low ionic strength, and traces of detergents or chlorpromazine.In that ghost shape was influenced by a variety of amphipaths, our results favor the premise that the bilayer and not the subjacent protein reticulum drives ghost crenation. The data also suggest that vigorous osmotic hemolysis induces a redistribution of lipids between the two leaflets of the bilayer which affects membrane contour through a bilayer couple mechanism. Subsequent relaxation of that metastable distribution could account for the observed loss of crenatability.     

京津冀太行山片区不同生境昆虫种类和群落多样性调查与分析

通过对京津冀太行山片区不同生境昆虫群落多样性调查,为京津冀太行山片区生物多样性的保育和决策提供科学依据。在2019年7月-2020年10月,在京津冀太行山片区的9个县(区)(包括北京市的昌平区和房山区,以及河北省的涿鹿县、蔚县、涞水县、涞源县、易县、唐县和阜平县)的6种生境(即森林、人造林、湿地、灌丛、草地和农田)共设置106个样点,具体采用“样线踏查法”和“马来氏网法”相结合共进行了6次昆虫调查。共采集昆虫62 450头,隶属于14目153科608种。不同生境间昆虫的Margalef丰富度指数(P<0.01)、多样性指数H(P<0.01)和均匀度指数E(P<0.05)存在显著或极显著差异。Margalef丰富度指数依次为森林>人造林>湿地>灌丛>农田>草地,且森林的Margalef丰富度指数最高为5.64、草地最低为2.70;多样性指数H依次为草地>灌丛>湿地>农田>森林=人造林;均匀度指数E依次为草地>森林>灌丛>湿地>农田>人造林。不同生境之间昆虫种群相似度分析表明,森林和人造林...     

Molecular and morphological analyses of EuropeanAconitum species (Ranunculaceae)

The systematics of the yellow-floweredAconitum lycoctonum species complex (Ranunculaceae) has long been considered difficult because of high morphological variability and hypothesized hybridization. To elucidate the systematic value of these taxa, and to study their phylogeny in a broader context, we studied all species of the subgenusLycoctonum from Europe and the Caucasus Mountains and the European species of the subgen.Aconitum. We sequenced the ITS region and the chloroplast intergenic spacerpsbA-trnH and conducted parsimony analyses. We also measured morphological characters from 19A. lycoctonum populations. The two subgenera in Europe are clearly separated but hybridization between subgenera might have taken place in the past. Sequence variation withinA. lycoctonum and among all taxa of subgenusLycoctonum was very low and probably the result of recent speciation, leading to one morphologically highly variable species in which color morphs could be seen as subspecies. There was high morphological variability within and among populations and the morphological characters have no value as systematic characters.     

植被格局的分形特征

目前植被格局研究存在一些问题,分形模型是解决这些问题的有力工具。选择从分枝到景观的各个等级层次上若干有代表性的研究实例进行介绍。给出了尺度,自相似性和分形维数在植被格局研究中的应用方法,说明了分形模型描述植被格局的实用性和优越性。在此基础上提出了植被格局的分形机制,认为植被格局是具有自组织特征的分形体。最后对植被格局的分形模型进行了评价,提出了研究中需要注意的若干问题以及未来的发展方向。     

Do plant communities exist? Evidence from scaling‐up local species‐area relations to the regional level

Abstract. One long tradition in ecology is that discrete communities exist, at least in the sense that there are areas of relatively uniform vegetation, with more rapid change in species composition between them. The alternative extreme view is the Self‐similarity concept – that similar community variation occurs at all spatial scales. We test between these two by calculating species‐area curves within areas of vegetation that are as uniform as can be found, and then extrapolating the within‐community variation to much larger areas, that will contain many ‘communities’. Using the Arrhenius species‐area model, the extrapolations are remarkably close to the observed number of species at the regional/country level. We conclude that the type of heterogeneity that occurs within ‘homogeneous’ communities is sufficient to explain species richness at much larger scales. Therefore, whilst we can speak of ‘communities’ for convenience, the variation that certainly exists at the ‘community’ level can be seen as only a larger‐scale manifestation of micro‐habitat variation.     

利用RAPD技术检测香菇双—单杂交后代

利用ＲＡＰＤ技术对香菇６个双单杂交菌株及其两个双核体基因组ＤＮＡ进行了检测,结果显示：１－３号杂交菌株之间的相似系数为０．８９３－０．９６２,它们与其亲本Ｓ之间的相似系数为０．８４２－０．８５９;４－６号杂交菌株之间的相似系数０．８５７－０．９２５,与其亲本ＳＳＯ１之间相似系数为０．７０８－０．９０２;表明杂交菌株与其双核体亲本基因组具有较大差异,杂交菌株之间存在着不同程度差异,６个杂交菌株是真正