Effects of natural forest conversion and plantation tree species composition on soil macrofauna communities in Northeast China mountains

As primary and secondary forests are being replaced by plantations across the globe,the soil macrofauna community structure is also affected,but little is known about the impact of mixed culture plantations compared with monocultures on the soil macrofauna.To determine the impact of forest conversion on soil macrofauna,we surveyed the soil macrofauna in two broad-leaved and three coniferous monoculture stands and four coniferous-broadleaved mixed stands,and in adjacent reserved secondary stands as a reference.Soil macro fauna community composition was significant affected by forest type,season and their interaction(P<0.05).The abundance,taxa richness and diversity of soil macro fauna changed to different degrees depending on the plantation type.Broadleaved monoculture stands and secondary stands had similar macrofauna abundance and taxa richness,but values were lower in coniferous stands than in secondary stands.The Shannon index for macrofauna in coniferous stands was also the lowest,but the Pielou index did not differ between forest types.The negative effects of the conifer monoculture on soil macro fauna were not present in the mixed stands with broad-leaved trees.Forest conversion impacted soil properties;soil moisture,NO_(3)^(-),and pH were significant drivers of soil macrofauna community structure.The impact of forest conversion on soil macrofauna was closely dependent on tree species composition and diversity.The macro fauna community structure in the broadleaved and the mixed stands were relatively similar to that in the natural forest,and thus recommended for forest conversion in the study area.

Using benthic macrofauna to assess environmental quality of four intertidal mudflats in Hong Kong and Shenzhen Coast

Intertidal zone is a significant wetland between land and ocean. It plays an important rolein maintaining local ecological balance. Both Mai Po and Futian intertidal mudflats are located in Shenzhen Bay and are important 'refueling' point along the East Asian/Australian flyway of migratory birds. The environmental quality of Mai Po and Futian mudflats have aroused great concern due to rapid economic developments in Hong Kong and Shenzhen in recent decades. Macroinfauna of Mai Po and Futian mudflats was investigated in December 2000 and the faunal data were used to assess their environmental quality. Two other mudflats, namely Ma Wan Typhoon Shelter (a more disturbed area) and Luk Keng intertidal mudflat (a place with relatively less human disturbance), were also sampled for macroinfauna and used as reference mudflats. Shannon - Weaver species diversity index (Isd), biotic coefficient (Cb) and macrofaunal pollution index (Imp) of the macrofauna community on four intertidal mudflats were used to determine their environmental quality. The results showed that Luk Keng intertidal mudflat was unpolluted, Mai Po and Futian mudflats were slightly polluted, and Ma Wan was moderately polluted. The pollution in Ma Wan Typhoon Shelter mainly came from various types of rubbish and fishing boats that disturbed the sediment, while pollution sources in Mai Po and Futian mudflats were discharges of industrial water, municipal sewage and from nearby rivers.

Ecological influence of exotic plants of Sonneratia apetala on understory macrofauna

The study aims to compare the differences of macrofauna communities of wetlands at 3-year-forest- age, 5-year-forest-age Sonneratia apetala artificial mangroves, 5-year-forest-age Kandelia candel ar- tificial mangroves with the same restoration background, and the naked tidal flat in the Qi’ao Island Mangrove Nature Reserve of Zhuhai, Guangdong Province. The results show that there were signif- icant structural differences in macrofauna communities among four kinds of habitats. The increase of biomass and species diversity of macrofauna at 3-year-forest-age S. apetala artificial mangroves was obviously faster than that at 5-year-forest-age K. candel artificial mangroves whose average tree height was close to that of 3-year-forest-age S. apetala artificial mangroves. The BIOENV analysis shows that it was related to the rapid growth of S. apetala, which rapidly changed the light level and shading conditions in the forests. The 5-year-forest-age S. apetala artificial mangroves had lower macrofauna species diversity but higher density and biomass than K. candel artificial mangroves with the same forest age. This was due to the rapid changes of physical and chemical properties of habitat soil by the ecological restoration of S. apetala artificial mangroves as well as the changed food sources possibly caused by the leaf-litter of such non-indigenous mangrove species S. apetala. However, further survey should be conducted on whether there are any negative ecological impacts of large-scale cultivation of S. apetala on macrofauna communities, so as to evaluate correctly S. apetala’s role in the restoration of coastal mangrove ecosystems.

An ecological survey of the abundance and diversity of benthic macrofauna in Indonesian multispecific seagrass beds

Seagrasses are one of the most productive ecosystems in coastal areas and support a wide variety of associated fauna. The tropical Indo-Pacific region is considered to have the highest diversity of seagrass plant species and the largest distribution areas of seagrass, yet the seagrass macrofauna in this region are poorly understood. To help fill this gap in our knowledge, an ecological survey was conducted to describe the abundance and diversity of benthic macrofauna from tropical seagrass beds and to determine between-station variations within a transect and between-site variations in macrofaunal abundance, taxa richness and community structure. Benthic macrofaunal samples associated with seagrass beds were collected with a core sampler on the east coast of North Sulawesi in May 2014 and on the west coast in October 2015. A total of 149 species from 14 higher taxa was collected. The most species-rich groups were polychaetes（56 species, 26% of total individual numbers）, decapods（20 species, 9% of total numbers） and amphipods（18 species, 35% of total numbers）. Between-station variations within a transect displayed different patterns between the east coast and the west coast. On the east coast, there were marked variations in abundance between stations within a transect for the macrofauna and amphipod assemblages. Both taxa richness and abundance varied with station for the macrofauna and polychaete assemblages on the west coast, resulting from the heterogeneity of the substrate along a transect. One-way ANOSIM together with MDS ordination indicated that macrofaunal community structure in seagrasses differed significantly between the east coast and the west coast, corresponding with the division of seagrasses into two broad categories of habitats, i.e.,mangrove-seagrass-reef continuum and seagrass-reef continuum. Compared with other studies in tropical areas,the abundance and diversity of benthic macrofauna in the present study were moderate. The reason for the two markedly distinct macrofaunal communities might be attributed to multiple factors, including sediment pattern,seagrass structure and temporal changes.

Ecological indicators showing the succession of macrofauna communities in Sonneratia apetala artificial mangrove wetlands on Qi'ao Island at Zhuhai, South China

The Sonneratia apetala artificial mangroves in the intertidal zone of Da Wei Bay at Qi’ao Island of Zhu-hai, South China were chosen as the macrofauna succession plots while bare tidal flats of the same size were established as control plots in surrounding interference-free areas. Conventional change indicators of community structure, such as biomass and biodiversity, and indicators, such as exergy and specific exergy, which reflect the information change of overall communities, were used to analyze the succession of macro-fauna communities inS. apetala artificial mangroves. The similarities and differences in variation tendency of the different ecological indicators and their reflected ecological principles were compared. The results showed that from D-1 to D-1275 after plantingS. apetala, the biomass of the macrofauna communities first increased, which was then followed by an increase in the network relationship between the macrofauna communities （analysis of the Pielou evenness index and Shannon-Wiener diversity index）. The system in-formation （specific exergy） increased the slowest. Between D-1460 and D-2370 after plantingS. apetala, there was a decrease in biomass, network structure, and system information in the succession plots. After the decrease in the system information （the specific exergy）, there was a decline in the network relationships （Pielou evenness index and Shannon-Wiener diversity index）. Biomass was the last indicator to decrease. The similarities and differences among the different ecological indicators varied during the succession pro-cess, which reflected the relativity and differences among the indicators. This study suggested that, although the species diversity index can be an effective indicator of two types of changes （network structure and system information）, it was quite clear that species diversity measurement was not suitable for expressing the changes in biomass during the succession process. While exergy and specific exergy can provide useful information about the structural development of communities, they cannot identify the information state of the system. Therefore, when evaluating macrofaunal succession inS. apetala artificial mangrove wetlands, it would be better to apply a number of different ecological indicators, rather than just one single indicator.

Confounding response of macrofauna from a confluence of impacts: brine and sewage pollution

Throughout the shores of the world, a confluence of different sources of pollution is common, e.g., through outlets releasing brine, industrial, and domestic sewage. In this study, we assessed whether a combined disposal of domestic sewage and brine altered the patterns of abundance and assemblage structure of sub- tidal macrofauna inhabiting sandy seabeds on the south coast of Gran Canaria （Canary Islands, NE Atlantic Ocean）. Samples were collected in two surveys （May 2008 and January 2009） at three distances （0, 15, and 30 m） away from the discharge point. Macrofaunal abundances showed different patterns with varying proximity from the disposal point in the two surveys. In May 2008, lower abundances were observed at 0 m （53.89±46.82 ind.） than at 15 m （120±91.7 ind.） and 30 m （283.89±189.33 ind.） away from the dis- posal point. In January 2009, however, higher abundances were observed at 0 m （131.33±58.69 ind.） than at 30 m （100±24.44 ind.） and 15 m （84.78±58.39 ind.） away from the disposal point. Significant differ- ences in macrofaunal assemblage structure were found with varying proximity from the discharge point in both surveys. The effect of proximity from the disposal point was confounded by changes in sedimen- tary composition between surveys, which contributed to explain differences in macrofaunal abundances and assemblage structure with varying proximity from the discharge point. As a result, confounding driver- s of macrofaunal assemblage structure, here, changes in sediment composition, accounted for changes in macrofaunal abundances and assemblage structure with varying proximity from a combined disposal point of brine and sewage.

Macrofaunal communities of threatened subtidal maёrl seabeds on Tenerife (Canary Islands, north-east Atlantic Ocean) in summer

This study contributes with the first data on physical and taxonomical structure of macrofaunal assemblages of maerl beds from the Canary Islands. Maerl beds and Cymodocea nodosa meadows of the Canary Islands are considered biodiversity hot-spots in terms of taxonomic and functional biodiversity with a broad geographical and depth ranges. The authors have studied the structure of the macrofaunal assemblages on different habitat types （Cymodocea, Caulerpa, sabellid field, garden eel and maerl beds）. Samples were taken at a range of depths between 14 and 46 m. Correlations were performed among abiotic variables （granulometry, organic matter, nitrogen and phosphates） and the most abundant taxa. Similarity analysis was performed to explore the patchiness of seabeds at a local scale. Significant differences were found in macrofaunal assemblages among seabed types, with highest abundances and lowest biodiversity in sabellid fields, where the sabellid Bispira viola dominated. The polychaetes Aponuphis bilineata and Chone filicauda and the mollusc Turritella brochii were the most abundant taxa on maerl beds. The mosaic of granulometric conditions would explain the associated macroinfaunal community structure and contribute to the creation of diversity on these relatively well preserved seabeds at a local scale.

General Patterns of Spatial Distribution of the Integral Characteristics of Benthic Macrofauna of the Northwestern Pacific and Biological Structure of Ocean

Horizontal (geographic) and vertical (geonemic) spatial distribution of the integral properties of a large multispecies assemblage (1306 species of fish and invertebrate with body size ≥ 1 cm) from northwest Pacific sea bottom is investigated. There are total number and biomass, average animal size (mean individual weight), species diversity (Shannon’s index) and its components: species richness and evenness (Pielou’s index), i.e. generalized parameters describing benthic macrofauna as a whole. Correlations of these parameters with distance from shore and depth have been found as well as very weak latitudinal zonality display in the region. Even such well-known generalization as Humboldt-Wallace’s law and Bergman’s rule has no noticeable manifestations here. Earlier similar, but not identical, regularities were discovered in the northwest Pacific pelagic water layer. Collation of what there is in the two different sea zones results in new supplements to Zenkevich-Bogorov’s concept of biological structure of the ocean.

Soil Macrofauna Behaviour in the Presence of Pesticides and Organic Amendments

Insects attack vegetable crop, leading to an overuse of pesticides. Organic amendments are recommended to increase soil fertility. The impact of two insecticides, on soil macrofauna under rainfed cultivation of tomato (Lycopersicon esculentum L.) with or without organic amendments was evaluated. The insecticides were Lambda Super (lambda-cyhalothrin) and Dursban (chlorpyrifos ethyl) and organic amendments were compost, pig manure and cattle manure. An experimental device in split-plot with three replicate was installed. Pesticides were applied periodically each week during the experiment. The results have showed that with organic amendments, Lambda super increased the earthworm population compared to the control. Indeed, we found 42 individuals/m2 with compost;1 individuals/m2 with pig manure and 27 individuals/m2 with cattle manure but the control was 0 individuals/m2 in the presence of Lambda super without organic amendment. Similarly, Dursban increased the population of earthworms in the presence of organic amendment with 11, 37 and 91 individuals/m2 respectively for compost, pig manure and cattle manure. Lambda super with compost has led to a total elimination of termites. In the presence of Dursban, a decrease in the number of termites was observed when adding cattle manure (11 individuals/ m2) compared to the control containing only Dursban (21 individuals/m2). Better distribution of macrofauna was obtained with treatment with Dursban and compost (E = 0.99 for earthworms and E = 0.96 for termites). All organic amendments used in our study stimulated earthworm population, but more in the presence of Lambda super or Dursban.

Assessment of Sediment and Benthic Macrofauna Distribution at Dar es Salaam Harbour Channel

Sediment and macrobenthic fauna distribution at Dar es Salaam harbour channel were investigated to attest the influence of sediment grain size distribution and total organic carbon contents on benthic macrofauna dominance and diversity. Sampling campaign was conducted from January to April, 2019 in 25 sampling stations along the channel. Sediment grain sizes ranged between 0.7405 and 0.00273 mm with an average of 0.0804 mm classified as medium silt. Sediment distribution showed an onshore-offshore pattern consisting of fine dark clay-silt sediments in the southern part of the harbour close to Mwalimu Nyerere Bridge, medium (sandy) at the harbour and coarse sandy offshore. Five classes of macrofauna were identified with sedentary Polychaetes (Diopatra cuprea) found in tubes and free forms being dominant in most of the sediment types, however more abundant in clay-silt. High species diversity index values were encountered in sediments with medium total organic carbon (TOC) and sediment grain sizes (sand-silt). Apparently, low species similarity indices were observed in all sediment type indicating significant dissimilarities in species composition among sediment grain sizes. Thus, the distribution of benthic macrofauna species along Dar es Salaam harbour channel is strongly influenced by the sediment grain sizes and organic carbon contents in sediments.

Taxonomic Distinctness of Macrofauna as an Ecological Indicator in Laizhou Bay and Adjacent Waters

In this paper, we assessed the ecological and biodiversity status in the Bohai Sea through a quantitative survey on mac-rofaunal community at 25 stations in Laizhou Bay and adjacent waters in the autumn of 2006.We tested the robustness and effectiveness of taxonomic distinctness as an ecological indictor by analyzing its correlation with species richness and natural environmental variables and by analyzing other ecological indicators (Shannon-Wiener H' and W statistics from Abundance Biomass Comparison curve).Results so obtained indicated that the benthic environment of the study waters in general is not under major impact of anthropogenic disturbance, but some stations in Laizhou Bay and along the coast of the Shandong Peninsula and even in the central Bohai Sea might be moderately disturbed and showed signs of ecological degradation.The taxonomic distinctness measures △+ and Λ+ were independent of sampling effort and natural environment factors and were compliant to other ecological indicators.Further application of the taxonomic distinctness indicator to assess marine biodiversity and ecosystem health on a larger regional scale with historical data seems promising.

Benthic Macrofaunal Assemblage in the Arid Zone Mangroves of Gulf of Kachchh-Gujarat

The total benthic macrofauna consisting of 62 species in 5 groups,viz. crustaceans(18),gastropods(17),bivalves(16),polychaetes(9) and fishes(2),was recorded in western Kachchh mangroves near Gujarat. The population densities of benthic macro-fauna ranged from 424 to 2393 ind.m-2,the diversity ranged from 1.84 to 2.45 bits ind.-1,the richness varied between 0.82 and 0.98,and the evenness varied between 0.64 and 0.81. Two maximum diversity values were recorded during winter and summer. The salin-ity ranged from 34 to 44,temperature varied between 17 and 37 ℃,and the acidity ranged from 7 to 8.9.

玉米秸秆留高茬免耕对黑土农田大型土壤动物群落的影响

为阐明玉米秸秆留高茬免耕对黑土农田大型土壤动物群落的影响,在吉林省梨树县保护性耕作研发基地,对常规耕作(CT)、免耕(NT)和秸秆留高茬免耕(SS)处理样地分3个季节开展大型土壤动物群落调查。结果显示,获得的土壤动物隶属2门4纲14目。在各处理中,线蚓科(Enchytraeidae)为优势类群,鞘翅目(Coleoptera)、地蜈蚣目(Geophilomorpha)、双翅目幼虫(Diptera larvae)和蚁科(Formicidae)多为常见类群。春季,NT处理的土壤动物密度显著(P<0.05)高于CT,是CT的3.8倍;夏季,SS处理的土壤动物密度显著高于CT,是CT的2.8倍;秋季,NT与SS处理的土壤动物密度均显著高于CT,分别是CT的2.1倍与2.3倍。各处理的土壤动物密度均表现出春低秋高的特点。SS处理的大型土壤动物群落组成与CT差异明显,特别是在夏、秋季节,但与NT处理差异不明显。相较于CT,SS处理显著增加了夏、秋季线蚓科的密度。综上,秸秆留高茬免耕有助于增加农田大型土壤动物的密度。

Soil macrofaunal communities develop a habitat-specific trophic structure dependent on the degree of degradation of alpine wetlands

The alpine wetlands in the Qinghai-Tibetan Plateau have degraded in recent decades.However,the response of the soil food web to the degradation is still unclear.Four habitats including a wet meadow(WM),a grassland meadow(GM),a moderately degraded meadow(MDM)and a severely degraded meadow(SDM)(sandy meadows)were selected along the degrees of degradation.The soil macrofaunal biomass and the environmental factors of vegetation and soil were investigated.The soil macrofaunal community biomass increased significantly from WMto MDM and decreasedto a very small amount in SDM,with most taxa disappearing.The biomass of the trophic groups of detritivores,herbivores and predators exhibited similar responses to soil macrofaunal communities.The relative biomass of detritivores increased from WM to MDM,but herbivores responded in an opposite manner,resulting in the dominant trophic group and trophic structure varying progressively from WM to GM to MDM.Soil properties but not vegetation determined the changes in trophic groups and trophic structure.The results implied that the higher trophic levels(carnivores or omnivores)responded more sensitively than the lower trophic levels(herbivores)to alpine wetland degradation.Our results also suggested that soil macrofauna have a habitat-specific characteristic trophic structure and can be used as indicators of soil health conditions.

Seasonal implications for taxonomic sufficiency to simplify M-AMBI methodology in the coastal area adjacent to a eutrophic estuary

Taxonomic sufficiency(TS)refers to identifying taxa to a taxonomic level sufficient to detect community changes in stressed environments and may provide a cost-effective approach in routine monitoring programs.However,there is still limited information regarding the seasonal impact of applying TS and its implications for the ecological quality evaluation in the estuarine ecosystem.This study investigated the relationship between the multivariate-AZTI’s Marine Biotic Index(M-AMBI)and environmental variables in three seasons(i.e.,spring,summer,and autumn)in the Liaohe River Estuary.We tested the reliability of TS for simplifying the M-AMBI methodology.The results showed that family and genus level data could reproduce the spatial-temporal patterns of community structure at the species level.The M-AMBI values showed a consistent spatial distribution pattern in all sampling seasons,with a decreasing trend with the increasing distance from the estuary mouth.Both genus and family level data performed nearly as well as species level in detecting the seasonal variations of pollutants(i.e.,nutrients and total organic content).The family level M-AMBI was feasible to discern stress in the Liaohe River Estuary because of the high aggregation ratios at different taxonomic levels in all sampling seasons.These findings suggest that applying taxonomic sufficiency based on the M-AMBI provides an efficient approach for evaluating ecological quality in the Liaohe River Estuary.

湖南大通湖大型底栖动物群落结构特征与水质评价

大通湖是湖南省内最大的淡水养殖湖。为了解大通湖大型底栖动物的群落结构特征和环境质量状况,于2019年6月在大通湖水域设置15个站位进行现场调查,对底栖动物的种类组成、多样性以及群落结构进行分析,并利用Shannon-Wiener多样性指数(H')、生物指数(BI)和Goodnight-Whitley指数(IGW)对大通湖水质状况进行评价。本次调查共鉴定出大型底栖动物3门5纲32种,其中软体动物优势种为铜锈环棱螺(Bellamya aeruginosa),节肢动物优势种为孤雌拟长跗摇蚊(Paratanytarsus grimmii),环节动物优势种为瑞士水丝蚓(Limnodrilus helveticus)、克拉泊水丝蚓(Limnodrilus claparedianus)、霍甫水丝蚓(Limnodrilus hoffmeisteri)和前囊管水蚓(Aulodrilus prothecatus)。各调查站位Shannon-Wiener物种多样性指数(H')、Pielou均匀度指数(J')、丰富度指数(d)范围分别为1.51—3.62、0.58—0.94、0.63—2.30。与1997年及2008—2009年的历史数据相比,软体动物种类、丰度和生物量均有所下降,软体动物优势种群呈现由双壳类向腹足类演替的趋势。生物指数(BI)及IGW指数均显示大通湖大部分站位处于中污染—重污染状态,部分站位为轻污染,而Shannon-Wiener多样性指数(H')显示大部分站位为轻污染。

城市嵌草式铺装植被和大型土壤动物群落组成特征——以新泰市为例

嵌草式铺装近年来广泛应用于城市停车场及道路,研究其群落组成特征对城市生态的综合治理具有重要意义。以新泰市为例,通过现场采样调研分析探讨了嵌草式铺装对植被和土壤动物群落组成和多样性的影响。结果显示,植被调查中共记录草本植物14科22属22种。牛筋草(Eleusine indica)为新泰市嵌草式铺装中植被的优势种。植被的平均密度和生物量分别为(21.87±2.15)株/m^(2)和(4.15±0.45)g/m^(2)。不同站点间植株密度和高度有显著空间差异(P<0.05),生物量和盖度差异不显著。不同站点的植被物种多样性特征也有所差异。大型土壤动物调查共记录7目8科10种,其中蚁科为优势类群。嵌草式铺装中土壤动物的丰度、生物量均显著高于不透水路面(P<0.05)。逐步回归分析表明,嵌草式铺装中植被和土壤动物的丰度和生物量与土壤的容积密度和含水率等理化性质显著相关(P<0.05)。土壤动物丰度与植被盖度、土壤动物生物量与植被生物量间也具有显著相关关系(P<0.05)。结果表明,嵌草式铺装能够有效提高城市生态系统中植被和土壤动物群落的丰度、生物量和多样性,这种影响是直接和间接多种方式的协同作用。未来应结合多种环境因子的监测,在不同时空尺度上系统探究嵌草式铺装带来的生态效应及其高效合理利用途径。

基于大型土壤动物多样性视角的景观驳岸生态学特征研究

【目的】揭示大型土壤动物群落特征与不同类型景观驳岸生态因子间的联系,以期为未来城市景观驳岸的建造以及生态环境修复与保护提供一定理论参考。【方法】采用实地调查法和数据分析法,对成都市温江区江安河、杨柳河及金马河3条河流不同景观驳岸类型大型土壤动物群落特征进行了研究。【结果】共捕获大型土壤动物1252只,隶属于27目117科。不同类型景观驳岸大型土壤动物密度存在显著差异(P<0.05),类群数与个体密度均呈现混合型驳岸>自然型驳岸>硬质型驳岸;大型土壤动物季节动态存在显著差异(P<0.05);大型土壤动物类群数和个体密度总体呈现秋季显著高于其他季节的趋势(P<0.05),而其余季节之间无显著差异(P>0.05)。【结论】不同景观驳岸大型土壤动物群落多样性有显著差异。建议在建造园林景观驳岸时,应注重驳岸材料的选择,适当保留原有植被,充分发挥景观驳岸的生态、观赏等功能。

西藏年楚河流域沙棘林大型土壤动物群落特征及其影响因素

【目的】为了解西藏年楚河流域沙棘林大型土壤动物群落特征及其与环境因子的关系。【方法】于2020年5月、8月和10月,根据沙棘林的地理分布特征共设置5个样地25个采样点,采用手捡法对75个土壤样品的表面和样品内大型土壤动物进行了调查,同时测得相应的环境因子。【结果】经3次采样,共捕获大型土壤动物798头,隶属于3门5纲17目28科39类群。其中优势类群为蚁科(Formicidae)、狼蛛科(Lycosidae)和石蜈蚣科(Lithobiidae),占总捕获量的62.90%;常见类群10类,占28.32%;稀有类群共26类,占8.77%。单因素方差分析显示,大型土壤动物个体数、类群数、Shannon-wiener多样性指数(H)、Simpson优势度指数(C)和Pielou均匀度指数(E)3个季节间均无显著差异(P>0.05)。Jaccard相似性结果显示,5个样地的土壤动物分布具有一定差异,主坐标分析(PCOA)结果显示,土壤动物在季节间相似程度具有差异性。Pearson相关性分析结果显示,海拔、土壤含水量、土壤温度、pH、总氮和有效磷与土壤动物的群落特征具有显著相关性(P>0.05)。冗余分析(RDA)结果显示,排序轴1和2最能反映大型土壤动物群落类群组成变化的影响因子梯度,有效磷(AP)是显著解释变量。【结论】大型土壤动物各项生物指标3个季节间无显著差异(P>0.05),其群落特征时空分布具有一定差异性,海拔、土壤含水量、土壤温度、pH、总氮和有效磷是影响沙棘林大型土壤动物的重要因子。

海洋底栖动物多样性指数污染程度评价标准的分析

Shannon Weaver种类多样性指数在国内外普遍被用来描述生物群落的生态学特征 ,也常用来监测淡水、海水底栖生物群落结构的变化 ,被认为是个较好的评价污染程度的工具 .根据 1996年 1月至 2 0 0 2年 1月连续 6年在深圳湾福田潮间带泥滩获得的底栖动物数据 ,分析了不同对数底H′值的空间分布以及H′值时间变动与种数变动的关系 ,比较了不同参数计算的H′值以及其它指数值的评价效果 ,比较了不同断面实际计算H′值与平均H′值的差异 .结果表明 ,以密度计算的H′值比以生物量计算的H′值更能反映污染状况 ;Shannon Weaver种类多样性指数 (H′)比Margalef、Simpson和Pielou指数更能反映污染状况 ;Shannon Weaver种类多样性指数能反映季节变化 ,但敏感度不够 .根据深圳湾福田潮间带泥滩底栖动物多样性指数时空分布结合群落结构的变化以及有机质等参数的分析 ,建议将多样性指数污染评价范围分为 5级 ,即无底栖动物为严重污染 ;H′值小于 1,重度污染 ;H′值在 1～ 2之间 ,中度污染 ;H′值在 2～ 3之间 ,轻度污染 ;H′值大于 3。