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2005年5月下旬在崇明东滩中潮区相同高程上的裸地(ld)、海三棱藨草(Scirpus×mariqueter)地(hs)、芦苇(Phragmites australis)地(lw)、互花米草(Spartinaalterniflora)地(hh)里取样研究了大型底栖动物群落。ld物种数、总个体数、Shannon-Wiener指数、Margalef物种丰富度指数、平均密度和平均生物量都是最低的;平均密度在裸地和3种盐沼植物地间都存在显著差异(P<0.05,LSD检验);平均生物量在海三棱藨草地与裸地间存在极显著的差异(P<0.01,LSD检验);等级聚类分析(Cluster)表明,裸地和盐沼植物地间大型底栖动物群落差异明显。hs、lw、hh中的优势种都是底上附着型的软体动物,而ld中则以穴居型的甲壳动物占优势;hs、lw、hh、ld的面上群与面下群的比值分别为0.56、0.63、0.63、0.75。3种盐沼植物地间大型底栖动物群落相似性程度较高,但非度量多维标度(MDS)排序仍然揭示出可以区分的差异。这些差异体现了盐沼植物对大型底栖动物群落的明显影响。盐沼植物是通过直接改变生境结构或间接影响水动力和沉积物扰动等作用进而明显地影响大型底栖动物群落,盐沼植物也是影响潮间带大型底栖动物群落的重要生态因子。 相似文献
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土地利用/覆被变化对溪流生态系统的影响是溪流生态学研究的热点.生物完整性是诊断溪流生物学状况和生态健康的重要指标.目的是研究西苕溪流域内土地利用类型对大型底栖无脊椎动物完整性(B-IBI)的影响.利用2003年西苕溪TM数据和DEM模型计算了62个样点上游3种空间尺度下(亚流域、沿岸和局部)的土地利用类型.结果表明,耕地,民居和竹园在流域中的百分比与B-IBI负相关,耕地百分比对B-IBI的影响在亚流域(r=-0.527,p<0.001),河岸(r=-0.665, p<0.001)和局部(r=-0.696, p<0.001)尺度上均显著.针叶林,阔叶林和混交林百分比与B-IBI正相关.阔叶林百分比在亚流域(r=0.333,p<0.001),河岸(r=0.589 ,p<0.001)和局部尺度(r=0.618,p<0.001)与B-IBI显著相关.而针叶林百分比仅在亚流域尺度(r=0.366,p<0.001)与B-IBI显著相关.在研究流域内耕地百分比小于50%的情况下,B-IBI并非随着耕地百分比的增长而线性下降,而是在达到一定阀值后(亚流域尺度,27%;河岸尺度,57%;局部尺度,59%)耕地的影响逐渐趋缓.在耕地百分比小于阀值前,B-IBI在局部尺度上与耕地百分比的增长的关系最强(r=-0.808, p<0.001, n=46).建议在沿岸区增加阔叶林,针叶林与混交林的占有率,或者建立耕地与溪流间的林地缓冲带,有助于保护和恢复西苕溪生态健康. 相似文献
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大型底栖无脊椎动物的生物扰动作用是维持淡水生态系统物质循环稳定的关键因素之一,当前对底栖动物群落与单一物种生物扰动作用异同的认识还十分有限。以微生境反应器培养五种典型底栖动物种群及其群落,通过测定底栖动物生物扰动作用引起的沉积物、上覆水中营养盐(NH3-N、NO2--N、NO3--N和DTP)及溶解有机碳(DOC)的含量变化,同时计算各组单位生物量引起的元素变化量,探究单物种和生物群落扰动作用的差异以及对沉积物-水界面生源要素的影响。结果表明:单物种扰动作用导致沉积物NH3-N含量降低(P < 0.05),并使整个体系中NO3--N含量增加(P < 0.05),但对DTP无显著影响(P > 0.05);而群落扰动作用则促进体系NH3-N的增加(P < 0.05),使上覆水中NO3--N向沉积物沉积,同时引起上覆水DTP含量显著上升(P < 0.05)。单物种的独立扰动皆促进上覆水DOC含量降低(P < 0.05),霍甫水丝蚓的生物扰动导致沉积物的DOC含量降低且为唯一产生影响的物种(P < 0.05),而群落中各物种相互作用导致体系DOC浓度无变化(P > 0.05)。单物种/群落单位生物量对各类物质分布存在明显差异,霍甫水丝蚓的生物扰动作用对于上覆水和沉积物中的单位生物量C、N、P变化影响最为显著,但其扰动作用在群落组合中受到抑制,表明单位生物量扰动强度较大的物种,其扰动强度在群落中更容易受到抑制。 相似文献
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Development of an Index of Trophic Completeness for benthic macroinvertebrate communities in flowing waters 总被引：3，自引：2，他引：3
The analysis of the trophic structure of benthic macroinvertebrate communities can be used in biological assessments of the condition of river ecosystems. Using the trophic, or functional approach, the Index of Trophic Completeness (ITC) was developed. The goal was to overcome the problems and drawbacks of using conventional diversity or biotic indices in biological assessments of rivers, such as limitation to distinct geographical regions or focus on species richness without regard for ecosystem functioning. Following an extensive review of the literature on the trophic characteristics of benthic macroinvertebrates, a large number of species (±300) were characterized according to a number of trophic criteria: plant:animal ratio in the diet, feeding mechanism, food size, food acquisition behaviour, and energy and substance transfers. On the basis of their trophic characteristics, the species could be divided into 12 trophic groups. After examination of data from geographically diverse rivers, it was concluded that any undisturbed riverine benthic macroinvertebrate community should be represented by members of each of these 12 trophic groups, with each group fulfilling a function in the benthic community. Being a community which plays a central role in the functioning of the aquatic ecosystem, the benthic invertebrates are expected to respond to disturbances to the hydrobiocoenose. The outcome of an ITC assessment is clearly presentable in the form of a pie graph with 12 wedges, each representing one of the 12 defined trophic groups. Functionally complete communities are represented by 12 wedges; a blank wedge indicates that a trophic group is not represented. This paper describes the preliminary developments in the ITC method, its potential as a biological assessment method in rivers in different geographical zones, and presents examples of trial mappings of Russian and European rivers. The application of the ITC to these rivers demonstrated the absence of ITC trophic groups at sites under the influence of anthropogenic activity. 相似文献
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太浦河连接东太湖和黄浦江,是东太湖向下游行洪的主河道,也是黄浦江上游重要的引水水源。分别于2017年10月、12月和2018年3月、6月在太浦河沿程设置的5个站点开展了大型底栖动物季节频次的取样调研,分析了太浦河大型底栖动物群落的结构特征及其主要影响因子。调查期间共采集到大型底栖动物25种,隶属于3门6纲14科,其中以河蚬（Corbicula fluminea）为代表的双壳类和以铜锈环棱螺（Bellamya aeruginosa）为代表的腹足类处优势地位。太浦河大型底栖动物群落的密度、生物量及多样性特征在不同站点间均存在显著差异（P<0.05）;而在不同季节间均不存在显著差异（P>0.05）。聚类排序分析表明,太浦河大型底栖动物群落在空间上的差异较季节间的变化更为明显。太浦河大型底栖动物群落的物种组成特征与太浦河、东太湖的水文连通格局密切相关;而沿程不同程度人为干扰下的水体营养水平以及底质类型与生境异质性等生境条件对太浦河大型底栖动物群落的分布特征具有重要影响,其综合作用机理有待进一步研究。 相似文献
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Reinhard Prestele Peter Alexander Mark D. A. Rounsevell Almut Arneth Katherine Calvin Jonathan Doelman David A. Eitelberg Kerstin Engström Shinichiro Fujimori Tomoko Hasegawa Petr Havlik Florian Humpenöder Atul K. Jain Tamás Krisztin Page Kyle Prasanth Meiyappan Alexander Popp Ronald D. Sands Rüdiger Schaldach Jan Schüngel Elke Stehfest Andrzej Tabeau Hans Van Meijl Jasper Van Vliet Peter H. Verburg 《Global Change Biology》2016,22(12):3967-3983
Model‐based global projections of future land‐use and land‐cover (LULC) change are frequently used in environmental assessments to study the impact of LULC change on environmental services and to provide decision support for policy. These projections are characterized by a high uncertainty in terms of quantity and allocation of projected changes, which can severely impact the results of environmental assessments. In this study, we identify hotspots of uncertainty, based on 43 simulations from 11 global‐scale LULC change models representing a wide range of assumptions of future biophysical and socioeconomic conditions. We attribute components of uncertainty to input data, model structure, scenario storyline and a residual term, based on a regression analysis and analysis of variance. From this diverse set of models and scenarios, we find that the uncertainty varies, depending on the region and the LULC type under consideration. Hotspots of uncertainty appear mainly at the edges of globally important biomes (e.g., boreal and tropical forests). Our results indicate that an important source of uncertainty in forest and pasture areas originates from different input data applied in the models. Cropland, in contrast, is more consistent among the starting conditions, while variation in the projections gradually increases over time due to diverse scenario assumptions and different modeling approaches. Comparisons at the grid cell level indicate that disagreement is mainly related to LULC type definitions and the individual model allocation schemes. We conclude that improving the quality and consistency of observational data utilized in the modeling process and improving the allocation mechanisms of LULC change models remain important challenges. Current LULC representation in environmental assessments might miss the uncertainty arising from the diversity of LULC change modeling approaches, and many studies ignore the uncertainty in LULC projections in assessments of LULC change impacts on climate, water resources or biodiversity. 相似文献
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Functional diversity research enhances our understanding of ecosystems and both their functioning and their responses to environmental variations. This study investigated the biological trait responses of benthic invertebrate communities to various environmental conditions in estuarine habitats. We analyzed benthic macroinvertebrate communities in freshwater and estuarine environments to compare their characteristics between estuary sites with and without artificial barriers. Moreover, we combined taxonomic analyses (species richness, abundance, and four community indices) with functional diversity indices and biological trait analyses. The major results are as follows: (i) the most important environmental factors shaping species distribution in estuarine habitats were salinity and electrical conductivity; (ii) comparing functional diversity indices, tidal estuaries revealed that seawater intrusion induced changes in species distribution and the dispersion of benthic macroinvertebrates; (iii) the presence or absence of artificial barriers in estuaries affected biological traits owing to the influence of specific functional strategies of certain species. Consequently, the presence or absence of artificial barriers in estuaries can lead to significant changes in habitat connectivity and functional diversity related to ecosystem functions. These findings indicate that the presence of artificial barriers can significantly influence the ecological dynamics of estuarine ecosystems, thereby affecting species distribution, functional diversity and habitat connectivity. Understanding these effects contributes to a more comprehensive understanding of ecosystem functionings, as it complements existing taxonomic findings and integrates information about the functional aspects of diverse ecosystems. 相似文献
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Species richness and composition of bird assemblages found in the understory of undisturbed Neotropical forests vary at local and regional scales but the extent of that variation has not been well documented. Yet, such variation can be important for understanding patterns of diversity and for conservation. Here, we use capture data from two ca 100-ha study plots (sampled from March 2001 through March 2005) to compare understory assemblages at a local scale; nets on the plots were separated by approximately 1.7 km at the closest point. A total of 157 species (133 per plot) was represented in 6023 captures of 4001 individuals. After eliminating species not likely to be well-sampled with nets, there were 122 species total with 110 and 113 on the two plots, respectively. Species-accumulation curves and abundance-rank relationships were almost identical on both plots. Capture rates were high (53 and 56 birds captured per 100 mist-net-hours, mnh) on both plots. Distributions of species and individuals among families and genera were similar on the two plots but numbers of captures of some common species differed between plots in response to small-scale variation in environmental features. Indicator-species analyses selected seven species as more characteristic of one plot and nine as more characteristic of the other. At the regional level, understory assemblages were most similar to a site in Peru but differed from sites in Brazil, Venezuela, and, especially, Costa Rica. Dissimilarity in species richness per family was related to geographic distance only when Costa Rica was included in the analysis. 相似文献
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Distribution of benthic algae in the upper Illinois River basin in relation to geology and land use 总被引：14，自引：0，他引：14
- 1 Benthic‐algal distributions in the upper Illinois River basin, IL, U.S.A., were examined in relation to geology, land use, water chemistry and stream habitat using (detrended) (canonical) correspondence analysis, autecological metrics and indicator‐species analysis in order to identify the major environmental gradients influencing community variation.
- 2 Ionic composition and major nutrient [i.e. nitrogen (N) and phosphorus (P)] concentration of surface waters, salinity (Na‐Cl type), substratum type and physiognomic form of dominant species were primary factors contributing to variation in benthic‐algal assemblages of the basin. Basin geology was a significant contributing factor, but the explained variance associated with this factor was less than that related to land use.
- 3 Proportions of algal biomass consisting of cyanophytes, filamentous chlorophytes, halophilic diatoms and diatoms which utilize nitrogen heterotrophically were greater in eutrophic river segments than in less nutrient‐enriched segments. Composition of the benthic flora indicated meso‐eutrophic or eutrophic conditions throughout the basin; there were few diatoms indicative of hypertrophic waters. Shifts in diatom‐assemblage structure in response to nutrient loading provided an incomplete representation of the community‐response curve.
- 4 A weighted‐averages regression model based on total P and benthic‐algal abundances (all divisions included) yielded a highly significant correlation (r2 = 0.83) between species‐inferred [WA(tol)] and observed total P, with systematic bias (increased deviation of residuals) occurring only at concentrations greater than ～ 1.0 mg L?1 total P. This result indicates that total P regression and calibration models can be predictable for a river basin receiving excessive loadings of phosphorus.
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Walsh Christopher J. Gooderham John P. R. Grace Michael R. Sdraulig Sandra Rosyidi M. Imron Lelono Asmoro 《Hydrobiologia》2002,487(1):183-192
The relative effects of a diffuse disturbance (alteration of land use from forest to plantation) and a point-source disturbance (a village and its associated coffee-processing plant, within the plantation) on longitudinal variation in water chemistry and macroinvertebrate community composition were assessed in Kali Dinoyo, a small upland stream in East Java, Indonesia. Four sites were sampled. The catchments of the two most-upstream sites were covered primarily by rainforest, while the two lower sites fell within a coffee plantation. The lowest site was downstream of a small village and its associated coffee-processing plant. Most of the variance in all water quality variables and in several community composition measures was explained by the difference between plantation and forest sites. Comparatively small differences in total suspended solids and macroinvertebrate community composition were observed downstream of the village. Diffuse disturbances associated with land clearance and plantation agriculture therefore appear to have a larger impact on the ecology of Kali Dinoyo than the point source impacts associated with the village. More robust and powerful study designs to formally test these findings are discussed. 相似文献
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为研究太子河大型底栖动物摄食功能群对河岸带土地利用类型的响应关系,于2012年5月对太子河流域底栖动物和水环境因子和土地利用类型进行野外调查及数据分析。结果表明：1）太子河流域底栖动物群落在4种不同土地利用类型内具有极显著差异,平均丰度、Shannon-Wiener多样性指数和Pielou均匀度指数在森林用地中最高,分别为8.86、0.73和0.94,平均密度在森林耕作用地中最高（782.75个/m2）,除食碎屑者功能群（S）,其他摄食功能群在不同土地利用类型内无差异（P > 0.05）。2）太子河土地利用类型与水环境因子之间的Pearson分析表明,森林用地与EC、TDS、TN、NH3-N、CODMn之间呈显著负相关性,与DO、IOS之间呈显著正相关性;耕地与DO和IOS之间呈显著负相关性;城镇用地与EC、TDS和TN之间呈正相关性。3）太子河土地利用类型与底栖动物功能群之间的Spearman分析表明森林用地与食碎屑者（S）、刮食者（SC）和收集者（GC）呈正相关性。耕地与食碎屑者（S）、滤食者（FC）之间呈负相关性,城镇用地与刮食者（SC）和收集者（GC）之间呈显著负相关性。4）底栖动物功能群和水环境因子之间的典范对应分析表明,食碎屑者（S）功能群主要受底质指数（IOS）驱动,其他功能群与环境因子之间无相关性。因此,水环境因子和底栖动物群落参数比摄食功能群更能反映人类活动对土地利用的改变,水环境和底栖动物群落研究可为河岸带土地利用保护提供理论依据。 相似文献
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Xue Du Dan Song Kun Ming Xing Jin Huibo Wang Le Wang Hui Liu Chen Zhao Tangbin Huo 《Ecology and evolution》2021,11(3):1368
Macroinvertebrate assemblages are structured by a number of abiotic and biotic factors interacting simultaneously. We investigated macroinvertebrate assemblages along gradients of human disturbance and morphometric characteristics in five lakes connected by the same stream. We aimed to assess the relative effects of environmental gradients on macroinvertebrate assemblages and to investigate whether water quality effects on the assemblages were correlated with buffer land use. There were significant differences in macroinvertebrate community compositions among lakes, and our results indicated that oligochaetes (mainly Limnodrilus) and insects (mainly Chironomus) contributed highly to the differences. We used redundancy analysis with variation partitioning to quantify the independent and combined anthropogenic effects of water quality and land use gradients on the macroinvertebrate community. The independent effect of water quality was responsible for 17% of the total variance in macroinvertebrate community composition, the independent effect of buffer land use accounted for 6% of variation, and the combined variation between land use change and water quality accounted for 12%. Our study indicated that both the independent effects of land use and within‐lake water quality can explain the influence in macroinvertebrate assemblages, with significant interactions between the two. This is rather important to notice that changes in buffer land use generally may alter nutrient inputs and thus severely affect abiotic conditions encountered by macroinvertebrate. Our study demonstrates that considering buffer zone effects explicitly may be significant in the selection and application of conservation and management strategies. 相似文献
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轻中度石漠化地区生态环境较为脆弱,昆虫是生态系统中的重要角色。以叶蝉作为指示生物,在轻中度石漠化地区选取刺梨林、核桃林、玫瑰园、桃林、李子林以及草地6种不同土地利用类型的样地进行叶蝉标本采集,分析6类样地中叶蝉群落的物种组成、相似性、多样性、均匀度和丰富度等特征及其与各地理要素之间的关系。同时还分析了不同月份叶蝉群落的物种组成、多样性、均匀度和丰富度等指数的变化趋势。结果如下：共鉴定叶蝉11亚科52属。拟竹叶蝉属Bambusananus Li&Xing、顶斑叶蝉属Empoascanara Distant和小绿叶蝉属Empoasca Walsh是各样地的优势类群,共占69.4%。尤其是小绿叶蝉属Empoasca,在不同样地中个体数都是最多,占总采集数量的44.6%。Shannon-Wiener多样性指数表现为：刺梨林 > 草地 > 核桃林 > 李子林 > 桃树林 > 玫瑰园;Pieluo均匀性指数则是：草地 > 刺梨林 > 李子林 > 桃树林 > 核桃林 > 玫瑰园,Simpson优势度指数为：玫瑰园 > 李子林 > 草地 > 刺梨林 > 桃树林 > 核桃林。温度是影响叶蝉群落个体数量的重要环境因子之一,气压和湿度等环境因子则与之无明显相关性。结果表明在生态环境脆弱的轻中度石漠化地区,草地和刺梨林两种土地利用类型的叶蝉个体数与类群数较为丰富,是较为合适的喀斯特生态环境修复的土地利用类型,研究结果将对石漠化治理和喀斯特轻-中度石漠化地区生态恢复技术集成与示范具有重要指导意义。 相似文献
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Vesna Gagic Sebastian Hnke Carsten Thies Teja Tscharntke 《Insect Conservation and Diversity》2014,7(2):103-112
- Agricultural intensification (AI) is a great threat to biodiversity and its negative effects on species richness of different communities have been repeatedly shown. The effects of AI on community composition and variability, however, are important for assessing the predictability of community responses, but have rarely been studied simultaneously and across different taxonomic groups.
- In this study, we focused on parasitoids (primary and secondary) and predators (hoverflies and carabid beetles) of aphids in winter wheat fields with contrasting AI regimes (low AI, i.e. organic fields in structurally complex landscapes vs. high AI, i.e. conventional fields in structurally simple landscapes).
- We found divergence in species composition of more specialised, low‐dispersing primary and secondary parasitoids within high AI fields, probably due to the disruption of the exchanges of species between local populations in structurally simple landscapes. In contrast, species composition of less specialised, highly dispersing carabid beetles and hoverflies converged in fields with high AI, where they were characterised by the dominance of a single, vagile species adapted to high land‐use conditions. Furthermore, temporal community shifts were only pronounced in primary parasitoids and hoverflies, with higher temporal changes in fields with high AI in primary parasitoids.
- Collectively, our results illustrate that environmental homogenisation due to AI does not necessarily induce spatio‐temporal homogenisation of communities, but rather can have contrasting effects on more specialised, low‐dispersive parasitoids versus more generalised, high‐dispersive predators, thereby demonstrating great differences in the predictability of responses to AI among aphid natural enemies.
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通过对黄土高原南北样带大面积(北纬34°05'—40°75'、东经107°14'—111°09')土壤含水量(0—500 cm剖面)测定和相应植被类型调查,研究了黄土高原农田、草地、灌木林地和乔木林地4种土地利用类型土壤含水量的空间变化及它们之间的差异性。结果表明:黄土高原4种土地利用类型的土壤含水量皆呈现南北向地带性变化,自南向北土壤含水量有明显递减趋势,与多年平均降雨量、潜在蒸散量、土壤质地等的分布具有一致性;同一地点不同土地利用类型下土壤水分含量具有显著差异(农地草地灌木和乔木林地),不同植被类型根系分布、蒸散耗水量的不同是造成含水量差异性的原因。植被建设应遵循土壤水分分布规律,研究结果对黄土高原植被恢复建设具有一定参考价值。 相似文献
19.
K. Holmgren 《Journal of fish biology》1999,55(3):535-552
The benthic fish communities of 26 Swedish lakes were monitored annually with multi-mesh gillnets in a standardized way in the years 1994–1997. No major environmental changes (e.g. in nutrient level or acidity) occurred within the lakes during the 4 years of study. In most of the lakes, the between-year variation of biomass (per unit of effort) was close to the sampling precision, and biomass was usually less variable than abundance. Median values of lakespecific indices of variance compensation indicated no general covariance of biomass between species, but a tendency for positive covariance between size classes. This indicates that the benthic fish communities of small to intermediate-sized Swedish lakes most often show low between-year variation in total biomass of fish older than 0+, and that their biomass–size distributions are not, in general, shaped by periodic strong year-classes of keystone species. In a few individual lakes, density compensation was indicated as complementary proportions of a pair of species or size classes that made major contributions to the total biomass. 相似文献
20.
Long-term studies of freshwater macroinvertebrates: a review of the frequency, duration and ecological significance 总被引：4，自引：0，他引：4
1. The importance of a long‐term ecological perspective is well documented, yet the availability of long‐term data remains limited. This paper highlights the value of long‐term ecological studies of freshwater macroinvertebrates by reviewing both the availability of long‐term data and recent ecological contributions based on them. 2. A survey of recent literature on stream macroinvertebrates identified 46 papers published between 1987 and 2004 that included long‐term (i.e. ≥5 years) data. Most recently published long‐term studies of stream macroinvertebrates began collecting data in the 1970s and 1980s and their duration (time between first and last year sampled) was relatively brief (median = 9 years, maximum = 96 years). Most studies did not expand their temporal perspective by incorporating older data collected by other researchers. 3. Recent long‐term studies of macroinvertebrates have made major contributions to our understanding of interannual variation and cycles, complex abiotic and biotic interactions, and natural and anthropogenic disturbance and recovery. Without these studies, we would know much less about the magnitude of natural temporal variation, the importance of physical and biological disturbance and interactions, the role of pathogens and introduced species, the overall impact of pollution and the effectiveness of protection and remediation efforts. 4. If we are to encourage long‐term perspectives in our science, we need to facilitate the transfer of individual studies, as well as knowledge and data, among scientists. This includes efforts to archive and annotate data more effectively, so that they can be more easily incorporated into future research. 相似文献