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1.
This study investigated pollinator assemblage diversity and richness in four forested ecosystems of southern Punjab, Pakistan, with different landscape types. Pirowal is situated in the plains of irrigated Punjab, Lal Suhanra is part of a sandy desert ecosystem, Ghazi Ghat is part of the Indus River delta, and Fort Munro is located in dry hilly mountains. A yearlong survey of pollinator populations was carried out in these four forested ecosystems from January to December of 2010. Fortnightly hand netting was performed for collecting flower-visiting insects whereas, pan traps of three colors (white, blue, and yellow) were deployed for collecting the data. A total of 8,812 individuals from two orders (Lepidoptera and Diptera) were observed, including 22 families and 154 species. Bees were the most abundant, with 4,502 individuals, and the most species-rich taxa, with 70 species in five families, followed by flies having 2,509 individuals and 51species in 10 families. Wasps were the least abundant with 1,801 individuals and 33 species in seven families. The assemblage structure of pollinator communities as visualized through rank abundance curves showed that there were many species with low abundance and only a few species with a much higher abundance. The most abundant species among the bees, in order, were Nomia sp.3, Megachile bicolor, and Colletes sp.3; among flies, Syrphus sp.2, Calliphoridae sp.1, and Empididae sp.4; and among wasps, Tiphiidae sp.1, Myzininae sp.2, and Scelionidae sp.1.  相似文献   

2.
Vespidae is one of the major families of Hymenoptera with more than 115000 described species. In the present paper, Simpson and Shannon-Wiener diversity indices, Simpson,Camargo, Smith and Wilson, and modified Nee evenness indices, and richness index based on rarefaction method were adopted to study the biodiversity of vespid wasps in spatial and temporal dimensions in northern Zanjan Province of Iran. In spatial dimension, Zanjan and Gilvan showed the highest and the lowest species diversity, evenness, and richness, respectively; while in tem-poral dimension, 16 July-6 August showed the highest species diversity and richness, and 18 May -27 May and 23 August -2 September showed the highest and the lowest species evenness,respectively. Significant differences in species abundance between localities of study area were observed by Kruskal-Wallis nonparametric test.  相似文献   

3.
蝴蝶是地球生物多样性的重要指示物种之一, 其种群动态及群落结构变化能够揭示环境改变对生态系统的影响。六盘山国家级自然保护区生境优越, 植物区系多样, 孕育了丰富的蝶类资源。为了有效利用环境和保护蝶类资源, 2016-2018年, 作者采用样线调查法, 对宁夏六盘山国家级自然保护区人工植被、针阔混交林、阔叶林、灌木林4种生境中眼蝶亚科昆虫进行了调查, 分析了眼蝶在空间及时间上的动态变化。共记录眼蝶亚科13属19种4,363只, 其中阿芬眼蝶(Aphantopus hyperanthus, 961只)、亚洲白眼蝶(Melanargia asiatica, 637只)、爱珍眼蝶(Coenonympha oedippus, 594只)分别占总数的22%、15%和13%, 为保护区优势种; 蟾眼蝶(Triphysa phryne, 17只)仅占总数的0.39%, 为保护区的稀有种。在空间分布上, 4类生境中针阔混交林眼蝶物种丰富度和优势度低, 多样性指数最高, 不同生境眼蝶群落物种丰富度指数、多样性指数、均匀度指数存在明显差异(P < 0.05), 优势度指数差异不显著。在时间动态上, 2016-2018年眼蝶个体数量呈下降趋势, 物种个体数量高峰期主要发生在8月, 优势种变化明显。因此, 保护宁夏六盘山国家级自然保护区蝴蝶种类多样性刻不容缓。  相似文献   

4.
《植物生态学报》2016,40(9):861
Aims Spatial distribution patterns and formation mechanisms of species diversity are fundamental issues in community ecology. The objectives of this study are to assess the species diversity patterns at the different spatial scales in Jianfengling, Hainan Island, China.
Methods Based on the dataset from the 60 hm2 plot in the tropical montane rain forest in Jianfengling, Hainan Island, the spatial distribution patterns of species richness, species abundance, Shannon-Wiener, Simpson and Pielou’s evenness indices were analyzed at six spatial scales, including 5 m × 5 m, 10 m × 10 m, 20 m × 20 m, 40 m × 40 m, 100 m × 100 m, and 200 m × 200 m, respectively.Important findings
Results showed that spatial distribution patterns of species richness, species abundance and Shannon-Wiener index were much more obviously changed with the spatial scales than Simpson and Pielou’s evenness indices. Change of variance of the species richness with the increase of spatial scales was unimodal, which had the maximum value at the 20 m × 20 m scale. Variance of the species abundance showed a linear relationship with the increase of spatial scales. The positive relationship between species richness and abundance gradually decreased and even disappeared with the increase of sampling scales, which may be correlated with the increase of habitat heterogeneity. The effects of spatial scales on Shannon-Wiener, Simpson, and Pielou’s evenness indices may be also correlated with the composition of rare species in the plot.  相似文献   

5.
森林群落物种多样性格局和动态一直是生态学的研究热点,人工林弃管后演替进程中物种多样性变化也很值得研究。杉木(Cunninghamia lanceolata)作为我国南方林区人工栽培最广、经济价值最高的用材树种之一,其人工林分布面积很大,通常群落结构简单、物种多样性低,然而群落中杉木数量如何影响植物物种多样性,迄今缺乏研究。在浙江省自然保护区内,选择不同疏伐强度和弃管时间的杉木人工林,建立了6个1 hm~2长期动态监测样地,在10 m×10 m、20 m×20 m、50 m×50 m和100 m×100 m尺度下,探究群落物种多样性(物种丰富度、Simpson指数、Shannon-Wiener指数和Pielou均匀度指数)的变化规律,分析杉木数量(多度和相对多度)对物种多样性的影响。结果显示:弃管前对杉木林的疏伐强度越高,演替恢复后的群落物种多样性越高。相同疏伐程度下,物种多样性随演替时间的延长有先升高后降低的趋势。取样尺度小于100 m×100 m时,杉木数量与物种多样性呈极显著负相关;100 m×100 m尺度下仅杉木相对多度与3种多样性指数呈显著负相关,杉木多度与各物种多样性均无显...  相似文献   

6.
物种多样性的空间分布格局和维持机制是群落生态学的基本问题。为了探讨海南尖峰岭地区物种多样性空间分布格局的尺度效应, 以海南尖峰岭热带山地雨林60 hm2样地为研究对象, 分析了物种丰富度、物种多度、Shannon-Wiener指数、Simpson指数以及Pielou均匀度指数随6个空间取样尺度(5 m × 5 m、10 m × 10 m、20 m × 20 m、40 m × 40 m、100 m ×100 m、200 m × 200 m)的变化。结果表明: 相比Simpson指数和Pielou均匀度指数, 物种丰富度、多度以及Shannon-Wiener指数具有更为明显的空间尺度效应; 物种丰富度的方差随取样尺度增加呈现单峰分布特征, 并且在20 m × 20 m尺度上达到最大值, 而物种多度的方差随取样尺度的增加而增大; 物种丰富度和多度的正相关性随着取样尺度的增加逐渐减小甚至消失, 这可能与随取样尺度增加生境异质性增加有关; 取样尺度对3个物种多样性指数空间分布的影响可能与研究区域内稀有种的组成有关。  相似文献   

7.
Anthropogenic habitat disturbance can have profound effects on multiple components of forest biotas including pollinator assemblages. We assessed the effect of small-scale disturbance on local richness, abundance, diversity and evenness of insect pollinator fauna; and how habitat disturbance affected species turnover across the landscape and overall diversity along a precipitation gradient in NW Patagonia (Argentina). We evaluated the effect of disturbance on overall pollinator fauna and then separately for bees (i.e. Apoidea) and non-bee pollinators. Locally, disturbed habitats had significantly higher pollinator species richness and abundances than undisturbed habitats for the whole pollinator assemblage, but not for bees or non-bees separately. However, significant differences in species richness between habitats vanished after accounting for differences in abundance between habitat types. At a local scale Shannon–Weaver diversity and evenness did not vary with disturbance. A β diversity index indicated that, across forest types, species turnover was lower between disturbed habitats than between undisturbed habitats. In addition, rarefaction curves showed that disturbed habitats as a whole accumulated fewer species than undisturbed habitats at equivalent sample sizes. We concluded that small patches of disturbed habitat have a negligible effect on local pollinator diversity; however, habitat disturbance reduced β diversity through a homogenization of the pollinator fauna (in particular of bees) across the landscape.  相似文献   

8.
Effect of disturbance on root colonization and vertical distribution of arbuscular mycorrhizal fungi (AMF) and dark septate endophytes (DSE) was investigated at two adjacent sites of Lal Suhanra Biosphere Reserve, Pakistan. Disturbance clearly affected AMF and DSE colonization, vertical distribution of AMF and plant community structure. Mean colonization of AMF and DSE was slightly less at the disturbed site. Average spore densities, diversity and richness of AMF and DSE were higher at the undisturbed site. A study of the vertical distribution of AMF associated with the five plant species most common to each study site indicated that beside AMF and DSE colonization disturbance may affect AMF species composition. Correlation of AMF with DSE is also discussed.  相似文献   

9.
【目的】明确不同生育期调查方法对棉田物种结构和生物多样性的影响,以期选择合适的生育期调查方法开展转基因棉花的安全性研究。【方法】于2016和2017年,选择2个新型转基因棉花(GGK2,N15-5)及其亲本(K312,J14)为材料,使用3种调查方法对棉田节肢动物群落进行调查:(1)在整个生育期每7 d调查一次(5月上旬—9月中下旬);(2)主要生育期调查(5月中旬、6月中旬、7月中旬、8月中旬和9月中旬)和(3)6月中旬—8月下旬期间的3个棉铃虫发生高峰期调查。计算出不同调查方法下的棉田节肢动物群落个体总数、物种丰富度、多样性指数、均匀性指数和优势集中性指数。【结果】3种方法对物种个体总数和物种丰富度影响最大,第1种方法数值最大,第3种方法数值最小。2016年,转抗除草剂基因棉田(GGK2)与其亲本(K312)相比,3种调查方法得到的物种个体总数在节肢动物群落和害虫亚群落差异显著,其他指数无差异。此外,2016年与2017年相比,相同棉田中的多样性指数、均匀性指数和优势集中性指数均无明显差异。【结论】不同生育期调查方法仅对物种个体总数和物种丰富度有影响,而对多样性指数、均匀性指数和优势集中性指数无显著影响。因此,在转基因生物安全研究中可根据不同的研究目的选择合适的生育期开展调查。  相似文献   

10.
Preserving species diversity is critical to ensure ecosystem functioning; however, different components of diversity might respond to human disturbance in different ways. Similarly, trophic levels might have uncoupled responses to the same disturbance, thus ameliorating or aggravating the persistence of ecological communities. In this study, we analysed how the density, richness and evenness of flowers and pollinators respond to four levels of woodland thinning intensity (0, 30, 50 and 70% of woodland basal area removed) over 2 years in three contrasting sites. We found a mismatch in the response of flowers and pollinators to thinning. Flower density and richness had disparate responses, depending on the site and year, while evenness did not change with thinning. In contrast, pollinator density and richness, but not evenness, consistently increased with thinning among years and sites. These results suggest that thinning has a great influence on pollinators through changes in abiotic conditions and, perhaps, flower attractiveness rather than through small‐scale changes in flower density and richness. At the site where tree flowers were absent, bee pollinator community composition was impoverished, suggesting that trees provide important floral resources to pollinators. Our findings indicate that disturbance may diminish local plant abundance and richness, but pollinator abundance and richness are enhanced after intense thinning at small scales.  相似文献   

11.
Agricultural intensification and loss of semi-natural grassland have contributed to biodiversity decline, including pollinator species, in pastures around the world. To reverse the decline, agri-environmental schemes have been implemented, varying widely in effectiveness. In addition, many countries, including the Netherlands, have established nature reserves in which semi-natural grasslands are restored and are often managed for specific groups of species, e.g. meadow birds or plants. The effects of such measures on insect biodiversity are not well known but recent reports on the dramatic decline of insect biomass in nature reserves have put even more attention to the impact of land use and management on biodiversity. This study compares pollinator abundance and species richness in three common semi-natural grassland management types in the Netherlands: (1) hay meadows, (2) herb-rich grasslands and (3) meadow bird grasslands. Pollinator abundance and species richness were assessed in eleven study areas, each with all three management types present. Standardized transects, insect sampling within a standard 20 min time frame and plot-based flower surveys were used in spring and summer to assess the relationships between management regime, floral abundance and diversity and pollinator communities. The results show that meadow bird grasslands have lower pollinator abundance and diversity and a less unique pollinator assemblage than both other types. Moreover, flower abundance has a positive effect on pollinator abundance and flower diversity has a positive effect on pollinator species richness. These results indicate that meadow-bird grasslands are a comparatively unfavourable habitat for bees, hoverflies and butterflies, which may be explained by a lack of flowers as well as unsuitable mowing practices. Measures benefitting both insectivorous birds and flower-visiting insects, such as rotational mowing, could remediate this imbalance.  相似文献   

12.
王佳佳  贺涛  张沂  徐海量  李丙文 《生态学报》2022,42(23):9761-9768
以阿尔泰山天然林为研究对象,探究不同间伐强度(19%、33%、55%、62%)对林下植被的影响,为该区天然林的经营管理提供理论依据。运用样地调查法,对间伐30 a后的林木进行每木检尺,调查林下植被结构、物种多样性,对测定数据进行单因素方差分析和LSD多重比较检验。结果表明:(1)草本层物种丰富度随间伐强度的增大而增大,62%间伐强度显著大于其他处理;灌木层物种丰富度随间伐强度的增大呈先增后减的趋势,55%间伐强度最大(P>0.05);不同间伐强度处理之间,林下植被的Simpson指数、Shannon-Wiener指数和Pielou均匀度指数均无显著差异(P>0.05),草本植物优势种各间伐强度之间大致相同;(2)适当增加间伐强度可以明显提高灌木层和草本层密度,以55%间伐强度为优(P<0.05),林下植被的盖度随着间伐强度的增大先增后减,间伐显著影响灌木植物盖度,而对草本层盖度则影响不显著(P>0.05)。以上研究表明从恢复林地多样性的角度考虑,间伐强度选取55%更合理。  相似文献   

13.
幕阜山地处中亚热带-北亚热带过渡地带,物种资源丰富.通过对其典型样地的调查,分别采用Shannon-Wiener指数、Simpson指数和Pielou均匀度指数作为测度指标,研究了幕阜山地区森林群落结构及其物种多样性特征.结果表明,该地区主要有21个森林群落类型.其中常绿阔叶林中,物种丰富度指数与多样性指数在群落梯度上的总体趋势均为灌木层相对高于乔木层,乔木层相对高于草本层;在落叶阔叶林中,其丰富度指数的趋势为灌木层>草本层和乔木层,而在草本层与乔木层间是波动的,多样性指数的趋势为灌木层>草本层>乔木层;在针叶林中,物种丰富度、多样性指数表现的总趋势基本一致,即灌木层的丰富度相对较高,其次为草本层,乔木层的相对较小.在其他群落类型中,多样性指数、均匀度指数在乔木层、灌木层和草本层则表现出多样化的趋势;另外,从总体上看,各种指数在海拔梯度上并未表现出明显的规律性.  相似文献   

14.
山脉是生物多样性研究的热点地区,以往关于山脉的研究多集中于地上植物和脊椎动物,无脊椎动物相关的研究明显滞后。跳虫(Collembola)是土壤无脊椎动物的主要类群之一,在分解有机质、疏松和活化土壤过程中发挥着重要的作用。以跳虫为研究对象,采用梯度格局法,在长白山北坡自海拔800 m至1700 m,每隔150 m进行凋落物层和土壤层样品的采集,对比分析了土壤层和凋落物层的群落组成与群落结构,采用4个物种多样性指数(丰富度指数、Pielou均匀度指数、Shannon-Weiner多样性指数和Simpson多样性指数)和4个功能多样性指数(功能丰富度FRic指数、功能均匀度FEve指数、二次熵Rao''s Q指数和功能离散FEiv指数),探讨了多样性沿海拔梯度的分布格局。共获得跳虫5542头,隶属于12科42属83种,其中等节跳科为绝对优势类群(相对密度>50%)。非度量多维尺度分析结果表明,凋落物层和土壤层的跳虫群落结构差异显著,长角跳科、鳞跳科和疣跳科物种多分布于凋落物层,而棘跳科物种多分布于土壤层。线性或二次回归模型结果表明,在凋落物层跳虫的丰富度指数,Shannon-Weiner多样性指数和Simpson多样性指数沿海拔梯度的变化呈增加格局;但在土壤层跳虫物种多样性指数沿海拔梯度的变化无明显趋势。在凋落物层,跳虫的功能丰富度指数和功能离散度Rao''s Q指数随海拔梯度的变化呈现单峰分布格局;在土壤层,跳虫的功能丰富度指数随海拔梯度的变化也呈现单峰分布格局,但其他功能多样性指数沿海拔梯度的变化无明显趋势。研究表明凋落物层和土壤层跳虫的群落组成,群落结构及多样性存在显著差异,跳虫的物种多样性指数和功能多样性指数对海拔梯度变化的响应不同,未来在探讨土壤动物沿海拔梯度的分布格局及其物种共存机制时,应综合考量垂直分层(凋落物层和土壤层)和多个度量维度(物种多样性和功能多样性)。  相似文献   

15.
张敬怀 《生物多样性》2014,22(3):302-1263
利用2006年7-8月(夏季)、2007年4-5月(春季)和2007年10-12月(秋季)珠江丰水期、平水期和枯水期3个航次在南中国海北部珠江口附近海域4条由河口、近岸到深水区调查断面的数据, 研究大型底栖动物多样性由河口-近岸-深水的变化趋势及与环境因子的关系。春季、夏季和秋季分别获得大型底栖动物273、256和148种, 各季节均以环节动物种类最多, 节肢动物次之。大型底栖动物种类数、丰度、生物量和Shannon-Wiener多样性指数均由河口向近岸海域升高, 再由近岸向外海深水区降低。Pielou均匀度深水区最高, 其次为近岸。河口和深水区大型底栖动物k-优势度曲线位于近岸浅水域曲线之上, 表明生物多样性由河口向近岸升高, 而由近岸向深水则降低。大型底栖动物与环境因子Pearson相关性分析表明, 春、秋季大型底栖动物种类数、丰度和生物量与水深呈显著的负相关, 秋季种类多样性指数和均匀度也与水深呈显著的负相关性, 而夏季仅生物量与水深呈显著的负相关; 春、秋季大型底栖动物种类数、生物量、丰度、多样性指数和种类均匀度与盐度的相关性不显著, 但是夏季大型底栖动物种类数、丰度、多样性指数和种类均匀度与盐度呈显著正相关。单位面积(0.2 m2)内, 珠江口及邻近海域大型底栖动物在近岸浅水区较深水区和河口生物多样性高, 且生物量丰富。  相似文献   

16.
亚高山针叶林人工恢复过程中物种多样性变化   总被引:28,自引:0,他引:28  
吴彦  刘庆  何海  林波 《应用生态学报》2004,15(8):1301-1306
通过样方调查,以空间代替时间的方法,对亚高山人工针叶林恢复过程中,乔木、灌木和草本层物种多样性的变化进行了研究,探讨了不同恢复阶段各层物种的相关系数.结果表明,亚高山人工针叶林恢复过程中物种的丰富度、多样性和均匀性都在波动中逐渐增加,云杉人工林恢复过程中总体上是朝着有利于物种多样性恢复的方向发展.在人工林恢复序列中群落乔木物种的平均相关系数为41.88%。灌木为50.61%,草本为37.22%,说明在70年的人工林恢复过程中,灌木种类具有较高的连续性和稳定性;草本植物则随着人工林环境条件的改变而出现较大的消亡和更新,显示出较大的波动性.乔木层物种的稳定性和连续性介于灌木和草本植物之间.  相似文献   

17.
为进一步了解养分添加和水分添加对干旱区草地植物多样性的影响, 2009-2011年5月15日, 对准噶尔盆地荒漠草地进行养分和水分添加, 2009-2012年5月25日进行植被调查, 研究群落结构与植物多样性对养分N、P、K与水分(雨、雪)添加的响应, 得出以下结果: (1)添加肥、水后, 荒漠草地植物群落结构发生了变化, 物种数由肥、水添加前的17种减少到添加后的11种, 减少了35.3%, 禾草类植物数目增加, 十字花科植物数量下降; (2)通过裂区试验方差分析, 2009年和2010年, 养分主效应对物种丰富度、Simpson指数、Shannon-Wiener指数、Pielou均匀度指数的影响不显著, 水分主效应和肥水交互作用对以上4个植物多样性指数的影响也不显著; (3) 2012年, 养分主效应对物种丰富度影响显著(p < 0.05), 养分添加降低了荒漠草地物种丰富度, 而水分作用、肥水交互作用对物种丰富度的影响均不显著; 肥水交互作用对植物Simpson指数、Shannon-Wiener指数的影响显著(p < 0.05), 而养分添加、水分添加对其影响亦不显著; (4)荒漠草地植物的Simpson指数、Shannon-Wiener指数、Pielou均匀度指数在年际间呈上升趋势。  相似文献   

18.
1. The introduction of livestock in natural areas is a common disturbance that affects both plant and pollinator diversity and might affect their interaction. Understanding whether livestock affect a food resource for pollinators (i.e. flower abundance) and/or a pollinator assemblage (i.e. abundance and richness) has important implications for plant–pollinator interactions and still needs deeper investigation. 2. This study investigated how pollinator communities and flower abundance determined floral visitation frequency along a grazing gradient, using seven large paddocks in Patagonian Monte Desert that varied in livestock densities. Pollinator visitation frequency was measured in five of the most abundant native plant species of the region, present in all the paddocks, but that differed in reproductive strategy ranging from insect‐pollinated self‐compatible and self‐incompatible to wind‐pollinated. The influence of livestock density, insect, and flower abundance on visitation frequency was evaluated using D‐separation hierarchical path models. 3. Intermediate stocking densities showed the highest insect richness and abundance. Livestock density showed a negative quadratic relationship with insect richness; hymenopterans being the main insect group in the region. Flower density decreased with the increase in livestock density. The five plant species shared several pollinator species although each one supported a distinct assemblage. 4. The path model showed that livestock was not directly associated with pollinator visitation frequency; however, this apparent lack of association was as a result of opposite forces acting together. An increase in livestock density reduced visitation frequency through a decrease in insect abundance, yet, livestock simultaneously increased the pollinator visitation rate through decreased flower abundance. 5. This study describes how changes in the density of exotic mammals can affect pollinator and flower abundance, resulting in contrasting effects on flower visitation rates with, apparently, neutral net consequences. This illustrates the complexity of responses to plant–pollinator interactions to anthropogenic disturbances that alter the ecological context.  相似文献   

19.
Monthly samples of the macrobenthic fauna were collected during February 1983-February 1984, in a coastal lagoon of Evros Delta (North Aegean Sea), characterized by a very strong monthly fluctuation of temperature and salinity. 3 groups of samples were distinguished, the first including those taken during the spring months, the second, those taken during summer and autumn, and the third, the samples of winter months. All the above samples were homogeneous concerning number of species, species richness (Margálef index) and evenness, but not as far as species diversity (Shannon-Wiener index) is concerned. The monthly variation of the total number of individuals and total biomass was significant, with highest values in spring, beginning of summer and autumn. Most months, polychaetes dominating, having the highest relative abundance and wet biomass. The 8 dominating species, which had a cumulative dominance of about 93%, showed strong monthly variation of abundance and biomass.  相似文献   

20.
Wu G L  Huang M Y  Duan R Y  Zhao K 《农业工程》2006,26(12):3924-3930
The effects of different traveling disturbances on the different layers of the Pinus taiwanensis community in Tianzhu Mountain National Forest Park were studied using the diversity indices of species richness index (S), Simpson index (D), Shannon-Wiener index (H) and Pielou evenness index (J). The results showed that the diversity indices of the arbor layer in low disturbance were the highest. Whereas, the diversity indices of the other layers in intermediate disturbance were the highest. The values of S, D, H, and J in low disturbance were 38, 3.0976, 0.9326, and 0.7515. The values of the indices in intermediate disturbance were 44, 3.2519, 0.9421, and 0.8594, higher than those in low disturbed forest, especially in the shrub and herb layers. In the highly disturbed forest, the diversity indices were 34, 3.0095, 0.9289, and 0.7834, lower than those in the intermediately disturbed forest. By comparing the stability of differently disturbed forests with the community dominance index (C), it was clear that the C of the intermediately disturbed forests was the lowest among the three differently disturbed forests. It is proposed that the intermediately disturbed forests can improve the species diversity, but maybe decrease the community stability.  相似文献   

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