共查询到20条相似文献,搜索用时 31 毫秒
1.
应用多样性指数、主成分分析及多元逐步回归等方法,对陕西吴起县生态恢复区直翅目昆虫的群落结构,植被因素与直翅目昆虫群落特征的相关性进行研究。共获得标本1 155号,隶属于10科17属,共计20种。黄胫小车蝗Oedaleus infernalis Saussure,宽翅曲背蝗Pararcyptera microptera meridionalis,短星翅蝗Calliptamus abbreviatusIkonn分别占总数量的17.58%,15.15%和14.89%,共同构成该地区直翅目昆虫的优势类群。多样性的变化趋势是县城>白豹>周湾>王洼。对各生境植被因素和直翅目昆虫群落所进行的主成分分析,两维主成分的累计方差贡献率分别达到了95.299%和86.304%。影响直翅目昆虫种类和数量变化的植被因素有草本植物高度多样性、草本植物种数、菊科优势度、禾本科优势度、其他科优势度。 相似文献
2.
Patterns of zonal changes in the spatial structure of Orthopteran communities in the European steppe
Patterns of zonal changes in the species composition, diversity, and community structure of Orthoptera were studied along
the latitudinal series of steppe types from meadow to desert steppe in European Russia. The maximum abundance of Orthoptera
was recorded in the typical steppe, while the maximum species richness shifted to the southern dry steppe. Changes in the
ecological preferences of orthopterans due to aridization are shown by the example of zonal communities. A gradual decline
of the forest-steppe orthopteran complex and an increase in the number of semidesert and desert species are demonstrated.
The changes in the species composition are accompanied by the intra-landscape shifts of areas with high species diversity.
Most species in the meadow steppe occupy mesophytic habitats in depressions. In the typical and dry steppe, the species richness
and abundance are restricted to habitats with zonal and xerophytic vegetation. In the desert steppe, the species diversity
is the highest in dry habitats, including halophytic ones, where xerophilic and desert species predominate. The diversity
and evenness indices increase in the northern and southern ecotones of the steppe zone. 相似文献
3.
《Acta Oecologica》2001,22(3):175-185
Microhabitat heterogeneity is considered to be one of the main factors affecting the structure and diversity of natural communities. This study evaluated: (i) whether it is possible to associate the distribution of four orthopteran species with small-scale spatial microhabitat heterogeneity based on floristic composition; and (ii) whether interspecific differences exist in microhabitat was among the different orthopteran species over a gradient of vegetation succession induced by abandonment of meadows. Orthoptera and plant species were sampled on 72 plots across an ecotonal area on Monte Bondone in the Southern Italian Alps. Microhabitats were identified based on grassland and undergrowth vegetation composition and by classifying sample plots using cluster analysis. Eight microhabitats were identified, each corresponding to a separate successional stage, and microhabitat use by each species was assessed. The distribution of orthopteran species revealed a different use of microhabitats. Species also had differing patterns of distribution, and a shift in distribution occurred following a change in microhabitat structure caused by mowing. The importance of the maintenance of a mosaic of microhabitats, with differently managed adjacent areas is discussed. 相似文献
4.
济南地区直翅目昆虫群落多样性 总被引:3,自引:0,他引:3
济南地区位于鲁中丘陵山区和黄河冲积平原交接地带 ,境内生境丰富多样。研究不同生境中直翅目昆虫群落的组成及多样性既有重要的理论意义又有现实的应用价值。近来对该地区直翅目昆虫的研究成果已有报道[2 ,3 ,6 ],但有关多样性的工作还少有研究。作者于 1 994年对本地区的直翅目昆虫做了较为全面的调查 ,应用生境型的概念[9,13],将直翅目昆虫分布的 1 3种生境划分为 5个生境型[2 ]。在此基础上本文着重研究了直翅目昆虫群落的多样性及环境等因素与群落多样性的关系。1 自然条件概况济南位于山东省中部 ,整个地势南高北低。南部为鲁中丘陵… 相似文献
5.
Michael G. Sergeev 《Journal of Insect Conservation》1998,2(3-4):247-252
This paper discusses orthopteran conservation in temperate and subtropical Eurasia. Distribution patterns of the orthopteran centres of diversity and endemism are described. Eleven main areas of diversity and endemism are identified. The majority of rare taxa are associated with these areas. The distribution of protected areas is discussed in relation to orthopteran conservation. Some proposals for inclusion or exclusion of certain orthopteran species on the IUCN and national Red Lists are debated. Emphasis is given to landscape heterogeneity and ecosystem mosaics for orthopteran biodiversity conservation. 相似文献
6.
英国英格兰西北部和威尔士北部岩溶地区钙华苔藓植物群落研究 总被引:10,自引:0,他引:10
报道了英国英格兰西北部和威尔士北部共 6个岩溶沉积地点苔藓植物群落的研究结果。记载典型钙华苔藓群落 1 0个 ,苔藓种类 9科 1 2属 1 4种 (含变种 ) ;区系地理成分含北温带分布 ( 6 4 .3% )、温带欧洲分布( 1 4 .3% )和世界广泛分布 ( 2 1 .4 % ) 3种类型 ;生活型含高丛集型 ( 7.1 % )、垫状矮丛集型 ( 4 2 .9% )、交织型( 35 .8% )和平埔型 ( 1 4 .2 % ) 4种。根据岩溶沉积环境特征 ,划分该地区苔藓群落为 :泉华苔藓群落、瀑华苔藓群落、洞穴钙华苔藓群落、峭壁钙华苔藓群落和溪流钙华苔藓群落等 5种生态类型。研究地点现代苔藓植物群落钙华沉积作用十分活跃 相似文献
7.
Sebastian Schuch Julian Bock Christoph Leuschner Matthias Schaefer Karsten Wesche 《Journal of Insect Conservation》2011,15(6):811-822
During the past 50 years development of farming practices caused tremendous changes in European agricultural landscapes and
many insect species became increasingly restricted to protected areas. Yet little is known about long-term trends of insect
diversity and community composition in these often small reserves. We performed a comparative study on changes in orthopteran
communities of protected dry grasslands in East Germany, which had been surveyed in the 1960s. Applying the same sampling
techniques, we revisited 26 of the original sites in 2008 and 2009. Nearly all sites are controlled by conservation policies
and changes in vegetation composition were relatively small, although some sites showed shrub encroachment. Changes in orthopteran
diversity were not significant. Community composition showed minor changes which were correlated with evidence of woody plant
encroachment as derived from historical and recent aerial imagery. The frequency of some Caelifera species decreased from
the 1960s to 2008/2009 with one species inhabiting bare soils (Myrmeleotettix maculatus) showing the strongest decline. Some Ensifera, especially two species inhabiting open woodland and scrub (Tettigonia viridissima, Phaneroptera falcata) showed positive trends. Nevertheless, three different regions (each belonging to a different German federal state) had shown
distinct orthopteran assemblages in the 1960s, and these were equally different 40 years later. We conclude that the orthopteran
fauna of Central European protected dry grasslands showed small changes in species composition, and overall diversity remained
rather constant during the past 40 years, which is in accordance with the minor changes in the surrounding landscape. Consequently,
the applied conservation management practises—mainly sheep grazing and trimming—are largely effective. 相似文献
8.
Rotifer communities of ponds supplied with post-waste water 总被引:1,自引:0,他引:1
The studies concern the changes in communities of rotifers in a model system of 4 through-flow ponds linked in a row and constantly supplied with waste-water after mechanical-biological treatment. Studies were carried out from the spring of 1977 to the spring of 1978 – i.e. during the first year the ponds were used.
Twenty-four species of rotifers, forming three cenotic communities differing in number of species, dominance structure and abundance, were found. Gradually increasing similarity of communities with the distance from the source of post-waste water reflects the increasing stability of physico-chemical and biological conditions in the examined model ecosystem.
Maximum biocenotic stability was observed in the last pond with the highest specific differentiation, and also considerable share of oligo- and β-mesosaprobionts, the highest frequency of species and slight differences in abundance between the dominant and accompanying species.
The role of trophic factor in formation of rotifer communities in the successive links of the presented model pond system is pointed out. 相似文献
Twenty-four species of rotifers, forming three cenotic communities differing in number of species, dominance structure and abundance, were found. Gradually increasing similarity of communities with the distance from the source of post-waste water reflects the increasing stability of physico-chemical and biological conditions in the examined model ecosystem.
Maximum biocenotic stability was observed in the last pond with the highest specific differentiation, and also considerable share of oligo- and β-mesosaprobionts, the highest frequency of species and slight differences in abundance between the dominant and accompanying species.
The role of trophic factor in formation of rotifer communities in the successive links of the presented model pond system is pointed out. 相似文献
9.
This work studies the diversity of cyanobacterial and algal-bacterial communities of saline water bodies in the Crimean Peninsula
and Altai Region. Plant-bacterial communities are described for the first time. The dependence of the production and destruction
on the season and salinity of the water body is shown. The development of planktonic cyanobacteria is related to the presence
of zooplankton, the development of which is controlled by hydrogen sulfide. The high hydrogen sulfide tolerance of benthic
cyanobacteria secures the integrity of cyanobacterial communities. Observations in nature and laboratory modeling show that
the formation of mineral layers is restricted to conditions of supersaturation with mineral components. Carbonate precipitation
can take place in cyanobacterial communities under conditions of mixing sea water enriched with Ca and Mg with continental
water enriched with sodium carbonate. Cyanobacteria are able to form and transform various Ca-Mg-carbonates. Dolomite formation
is a derived process that occurs in cyanobacterial mats in the presence of sulfate-reducing bacteria. Carbonatization of cyanobacterial
cells is considered using the example of the unicellular halophilic-alkaliphilic cyanobacterium Euhalothece sp. The accomplished study is of certain interest for interpretation of geological and paleontological data in the context
of the supposed analogy between cyanobacterial mats and ancient stromatolites. 相似文献
10.
Background
The effect of low nutrient availability on plant-consumer interactions during early succession is poorly understood. The low productivity and complexity of primary successional communities are expected to limit diversity and abundance of arthropods, but few studies have examined arthropod responses to enhanced nutrient supply in this context. We investigated the effects of nitrogen (N) and phosphorus (P) addition on plant productivity and arthropod abundance on 24-yr-old soils at Mount St. Helens volcano.Methodology/Principal Findings
We measured the relative abundance of eight arthropod orders and five families in plots that received N, P, or no nutrients for 3–5 years. We also measured plant % cover, leaf %N, and plant diversity. Vegetation responded rapidly to N addition but showed a lagged response to P that, combined with evidence of increased N fixation, suggested P-limitation to N availability. After 3 yrs of fertilization, orthopterans (primarily Anabrus simplex (Tettigoniidae) and Melanoplus spp (Acrididae)) showed a striking attraction to P addition plots, while no other taxa responded to fertilization. After 5 yrs of fertilization, orthopteran density in the same plots increased 80%–130% with P addition and 40% with N. Using structural equation modeling, we show that in year 3 orthopteran abundance was associated with a P-mediated increase in plant cover (or correlated increases in resource quality), whereas in year 5 orthopteran density was not related to cover, diversity or plant %N, but rather to unmeasured effects of P, such as its influence on other aspects of resource quality.Conclusions/Significance
The marked surprising response to P by orthopterans, combined with a previous observation of P-limitation in lepidopteran herbivores at these sites, suggests that P-mediated effects of food quantity or quality are critical to insect herbivores in this N-P co-limited primary successional system. Our results also support a previous suggestion that the availability of N in these soils is P-limited. 相似文献11.
V. V. Vinogradov 《Contemporary Problems of Ecology》2011,4(4):433-439
The composition and structure of mouse-like rodent communities in altitudinal belts of the Kuznetsk Alatau Mountains are studied,
and their comparative characterization is made. It is shown that the complex altitudinal-zonal differentiation of the mountain
range leads to the formation of several types of mouse-like rodent communities: forest-steppe, dark coniferous-taiga, chern
forests, and mountain tundra. The communities differ in species composition, structure, and total number. The main factors
influencing the spatial distribution of species and their number are hydrothermal conditions, vegetation type, and anthropogenic
transformation of the territory. 相似文献
12.
Understanding and predicting the composition and spatial structure of communities is a central challenge in ecology. An important structural property of animal communities is the distribution of individual home ranges. Home range formation is controlled by resource heterogeneity, the physiology and behaviour of individual animals, and their intra‐ and interspecific interactions. However, a quantitative mechanistic understanding of how home range formation influences community composition is still lacking. To explore the link between home range formation and community composition in heterogeneous landscapes we combine allometric relationships for physiological properties with an algorithm that selects optimal home ranges given locomotion costs, resource depletion and competition in a spatially‐explicit individual‐based modelling framework. From a spatial distribution of resources and an input distribution of animal body mass, our model predicts the size and location of individual home ranges as well as the individual size distribution (ISD) in an animal community. For a broad range of body mass input distributions, including empirical body mass distributions of North American and Australian mammals, our model predictions agree with independent data on the body mass scaling of home range size and individual abundance in terrestrial mammals. Model predictions are also robust against variation in habitat productivity and landscape heterogeneity. The combination of allometric relationships for locomotion costs and resource needs with resource competition in an optimal foraging framework enables us to scale from individual properties to the structure of animal communities in heterogeneous landscapes. The proposed spatially‐explicit modelling concept not only allows for detailed investigation of landscape effects on animal communities, but also provides novel insights into the mechanisms by which resource competition in space shapes animal communities. 相似文献
13.
O. A. Kalacheva 《Biology Bulletin》2005,32(5):503-507
Species composition and distribution of orthopterans in the foothills and mountains of Southern Russia were studied on the basis of original and published data. The list includes 175 orthopteran species in 86 genera. Their origin was considered and current range types of orthopteran genera were analyzed. Six ecological groups associated with different habitats were recognized. 相似文献
14.
The Species Abundance Distribution (SAD) is a fundamental property of ecological communities and the form and formation of SADs have been examined for a wide range of communities including those of microorganisms. Progress in understanding microbial SADs, however, has been limited by the remarkable diversity and vast size of microbial communities. As a result, few microbial systems have been sampled with sufficient depth to generate reliable estimates of the community SAD. We have used a novel approach to characterize the SAD of bacterial communities by coupling genomic DNA fractionation with analysis of terminal restriction fragment length polymorphisms (GC-TRFLP). Examination of a soil microbial community through GC-TRFLP revealed 731 bacterial operational taxonomic units (OTUs) that followed a lognormal distribution. To recover the same 731 OTUs through analysis of DNA sequence data is estimated to require analysis of 86,264 16S rRNA sequences. The approach is examined and validated through construction and analysis of simulated microbial communities in silico. Additional simulations performed to assess the potential effects of PCR bias show that biased amplification can cause a community whose distribution follows a power-law function to appear lognormally distributed. We also show that TRFLP analysis, in contrast to GC-TRFLP, is not able to effectively distinguish between competing SAD models. Our analysis supports use of the lognormal as the null distribution for studying the SAD of bacterial communities as for plant and animal communities. 相似文献
15.
Pugachev ON 《Parazitologiia》2002,36(1):3-10
High values of dominance index, low values of evenness and Shannon index are characteristic of component parasite communities of prespawning (Prosopium cylindraceum) and spawn migratory fishes (Coregonus autumnalis, Oncorhynchus nerka). Autogenic specialists are dominant in the component parasite communities of C. autumnalis. The component parasite communities of P. cylindraceum and O. nerka are dominant in a content of generalist species. The O. nerka parasite communities are communities "sentenced to death". Low values of dominance index, high values of evenness abd Shannon index are peculiar to component parasite communities of prespawning and spawning cyprinid fishes (Phoxinus phoxinus, Oreoleuciscus humilis). Autogenic specialists are dominant. Increase of dominance index and decrease of two other indexes characterize the postspawning period. The same tendency characterises infracommunities. Thus, the component parasite communities respond differently to the fish spawn of the cyprinid and coregonid/salmonid fishes. Similarity is in the dominance of autogenic specialists in one case only (C. autumnalis). These differences are defined by the mode of fish stock formation for spawn. The cyprinids congregate for spawning and move apart for foraging and vice versa is observed in the coregonids and salmonids. Autogenic specialists dominance seems to be the important adaptation to reduce a negative effect to host during spawning. Bush and Kennedy in 1994 established that "parasites live in patches (host individuals) and fragments (host populations)". They consider the host fragmentation as "hedging your bets against extinction" due to frequency and magnitude anthropogenic factors, which increase fragmenting of host populations. This conclusion was made for a species level. From the other hand the fragmentation is a natural feature for a single host population too. Such fragmentation is a host population structure. The role of fragmentation is obvious from the data on component parasite communities during fish spawn. The fragmentation decreases in the cyprinids and increases in the salmonids that leads to the growing of the cyprinid component parasite communities diversity and to declining the salmonid component parasite communities diversity. Nevertheless the role of host population structure in a component parsite community structure is not obvious, because parasites are able or not able to "recognise" different host subpopulation groups. It is well known from data on parasite species population biology. Such recognizable subpopulation groups or groups can be a "real fragment" for the parasite community. The question is what parameters could be used for this purpose on a component community level. Host population age structure can be used as an example, because the age groups are one of the invariable population characters. Value of Shannon index for component parasite communities of spawn migratory O. nerka (5+) is similar to that of fishes of 1+ age. Difference is statistically insignificant. It is insignificant between the parasite communities of 2+ and 3+ age groups too. Fishes of these two groups could be defined as a real united fragment. It spite of similarity between the fishes of 5+ age group and fish of 1+ age group they are not united fragment. The parasite community of 1+ age fishes is not stabilized yet and one of 5+ age is a community "sentenced to death". Thus the structuring of O. nerka freshwater parasite communities are defined by 3 real host age fragments: 1+ age group, 2 and 3+ age group, 4+ age group. It looks as that Shannon index is suitable parameter to study a parasite communities structure. 相似文献
16.
Sophie A. Howard Clodagh M. Carr Habteab Isaack Sbahtu Uchechukwu Onwukwe Maria J. López Alan D. W. Dobson Ronan R. McCarthy 《Environmental microbiology》2023,25(12):2698-2718
Plastic pollution is an increasing worldwide problem urgently requiring a solution. While recycling rates are increasing globally, only 9% of all plastic waste has been recycled, and with the cost and limited downstream uses of recycled plastic, an alternative is needed. Here, we found that expanded polystyrene (EPS) promoted high levels of bacterial biofilm formation and sought out environmental EPS waste to characterize these native communities. We demonstrated that the EPS attached communities had limited plastic degrading activity. We then performed a long-term enrichment experiment where we placed a robust selection pressure on these communities by limiting carbon availability such that the waste plastic was the only carbon source. Seven of the resulting enriched bacterial communities had increased plastic degrading activity compared to the starting bacterial communities. Pseudomonas stutzeri was predominantly identified in six of the seven enriched communities as the strongest polyester degrader. Sequencing of one isolate of P. stutzeri revealed two putative polyesterases and one putative MHETase. This indicates that waste plastic-associated biofilms are a source for bacteria that have plastic-degrading potential, and that this potential can be unlocked through selective pressure and further in vitro enrichment experiments, resulting in biodegradative communities that are better than nature. 相似文献
17.
Ying Zheng Lei Dong Zhiyong Li Jinghui Zhang Zijing Li Bailing Miao Chengzhen Jia Cunzhu Liang Lixin Wang Frank Yonghong Li 《Ecology and evolution》2019,9(23):13320-13331
The mechanisms of species coexistence within a community have always been the focus in ecological research. Community phylogenetic structure reflects the relationship of historical processes, regional environments, and interactions between species, and studying it is imperative to understand the formation and maintenance mechanisms of community composition and biodiversity. We studied the phylogenetic structure of the shrub communities in arid and semiarid areas of the Mongolian Plateau. First, the phylogenetic signals of four plant traits (height, canopy, leaf length, and leaf width) of shrubs and subshrubs were measured to determine the phylogenetic conservation of these traits. Then, the net relatedness index (NRI) of shrub communities was calculated to characterize their phylogenetic structure. Finally, the relationship between the NRI and current climate and paleoclimate (since the Last Glacial Maximum, LGM) factors was analyzed to understand the formation and maintenance mechanisms of these plant communities. We found that desert shrub communities showed a trend toward phylogenetic overdispersion; that is, limiting similarity was predominant in arid and semiarid areas of the Mongolian Plateau despite the phylogenetic structure and formation mechanisms differing across habitats. The typical desert and sandy shrub communities showed a significant phylogenetic overdispersion, while the steppified desert shrub communities showed a weak phylogenetic clustering. It was found that mean winter temperature (i.e., in the driest quarter) was the major factor limiting steppified desert shrub phylogeny distribution. Both cold and drought (despite having opposite consequences) differentiated the typical desert to steppified desert shrub communities. The increase in temperature since the LGM is conducive to the invasion of shrub plants into steppe grassland, and this process may be intensified by global warming. 相似文献
18.
O. A. Kalacheva 《Biology Bulletin》2005,32(6):604-608
Species composition and distribution of orthopterans in the deserts and semideserts of Southern Russia were studied on the basis of original and published data. The list includes 112 orthopteran species in 60 genera. Their origin was considered and current range types of orthopteran genera were analyzed. Five ecological groups associated with different habitats were recognized. 相似文献
19.
Torres J.A. Valle F. Pinto C. García-Fuentes A. Salazar C. Cano E. 《Plant Ecology》2002,160(2):207-223
Arbutus unedo L. communities in the southern part of the Iberian Peninsula (Spain and Portugal) were studied, highlighting the differences regarding their floristic composition, biological diversity and plant dynamics according to the dominant geological substratum. Firstly, this type of formation on the little-known decarbonated calcareous substrata was analysed using classification techniques. Later, they were compared to the remaining phytocoenoses in the southern part of the Iberian Peninsula using an ordination analysis. As a result, a new suballiance is proposed together with two plant associations, which will enable us to characterize the strawberry tree groves growing on carbonated substrata and those already proposed for siliceous substrata are confirmed. 相似文献
20.
Nitrogen gixation (acetylene reduction) associated with various communities in the intertidal sand and mud flat was measured in situ. Areas which were colonized by algae, plants, and animals generally had significantly higher activities than areas which were visibly uncolonized. The highest activities were measured at sites colonized by a mixed bloom of Oscillatoria-Euglena-photosynthetic bacteria. These areas occupied only about 1% of the surface of the sediments, yet contributed nearly 50% of the biologically fixed nitrogen. Enteromorpha communities also exhibited relatively high activities. Sites were grouped according to the statistical significance of the mean of their activities: group I: uncolonized sand, mud and gravel flats, Eelgrass (Zostera) communities, and snail (amphibola) beds, with an estimated contribution of 1 g N ha-1 day-1; group II: Cockel (Chione) beds, 3 g N ha-1 day-1; group III: Salicornia, Ulva, Juncus, and Enteromorpha, 10 g N ha-1 day-1; and group IV: Oscillatoria-Euglena-photosynthetic bacteria association, 200 g N ha-1 day-1. Enteromorpha and Oscillatoria-Euglena-photosynthetic bacteria communities showed significantly lower rates of nitrogen fixation in the dark than in the light. 相似文献