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1.
Camera traps serve as an important tool for monitoring species diversity. We used data from camera traps set for capturing snow leopards (Panthera uncia) in the Yanchiwan National Nature Reserve, Gansu Province, China, to assess species richness with respect to mammal and birds species. We also assessed survey efficiency for species detection, and conducted an initial analysis of species interactions. The survey effort of 10, 171 camera workdays yielded 2, 868 suitable animal image events involving 17 mammal and 20 bird species. Among these, the dhole (Cuon alpinus) is considered to be Endangered, the snow leopard and white-lipped deer (Cervus albirostris) Vulnerable, and the Pallas’s cat (Feli smanul), mountain weasel (Mustela altaica), Himalayan griffon (Gyps himalayensis) and cinereous vulture (Aegypius monachus) Near Threatened under the IUCN red list. Fourteen species were also listed as key protected wild animals according to China national standards. Both the rarefaction curves and richness estimators suggested our sampling for mammal and pheasant species is sufficient, while more survey efforts are still needed to detect other bird species. With a focus on the dominant species Eurasian lynx (Lynx lynx), occupancy models were used to estimate site use and detection probability for selected species, and to investigate predator-prey relationships between lynx on the one hand and woolly hare (Lepus oiostolus), pika (Ochotona spp.) and Tibetan partridge (Perdix hodgsoniae) on the other. We give recommendations on how to increase efficiency in camera-based species inventory and biodiversity monitoring.  相似文献   

2.
Remote-sensing models have become increasingly popular for identifying, characterizing, monitoring, and predicting avian habitat but have largely focused on single bird species. The Normalized Difference Vegetation Index (NDVI) has been shown to positively correlate with avian abundance and richness and has been successfully applied to southwestern riparian systems which are uniquely composed of narrow bands of vegetation in an otherwise dry landscape. Desert riparian ecosystems are important breeding and stopover sites for many bird species but have been degraded due to altered hydrology and land management practices. Here we investigated the use of NDVI, coupled with vegetation, to model the avian community structure along the San Pedro River, Arizona. We also investigated how vegetation and physical features measured locally compared to those data that can be gathered through remote-sensing. We found that NDVI has statistically significant relationships with both avian abundance and species richness, although is better applied at the individual species level. However, the amount of variation explained by even our best models was quite low, suggesting that NDVI habitat models may not presently be an accurate tool for extensive modeling of avian communities. We suggest additional studies in other watersheds to increase our understanding of these bird/NDVI relationships.  相似文献   

3.
研究呼伦贝尔沙地植物群落与土壤特征相互关系有助于促进中国北方的生态恢复与重建工作。分析了呼伦贝尔沙地北部沙带58个样地174个样方的植物和土壤的调查数据,调查到94种植物,分属于26科64属,其中菊科(Compositae)、禾本科(Gramineae)、豆科(Leguminosae)和蔷薇科(Rosaceae)为前四大科,占总物种数55.33%。采用Ward系统分类法,将所调查植被分为4类。寸草薹-二裂委陵菜群落(Carex duriuscula-Potentilla bifurca) Tsallis多样性最高,冰草-星毛委陵菜-糙隐子草群落(Agropyron cristatum-Potentilla acaulis-Cleistogenes squarrosa) Tsallis多样性最低。不同植物群落间土壤物理特性有显著差异,化学特征差异不显著。随着土层深度的增加,各群落土壤全氮、全磷、有机质含量逐渐降低,表聚现象明显,脚薹草-贝加尔针茅群落(Carex pediformis-Stipa baicalensis)和冰草-星毛委陵菜-糙隐子草群落养分层次特征显著,羊草群落(Leymus chinensis)和寸草薹-二裂委陵菜群落养分层次特征不明显。CCA排序结果表明影响植被群落物种分布的土壤因子有全氮、全磷、有机质、pH和土壤水分,其中深层土壤全氮、全磷、有机质(20~40 cm土层)的作用最显著。呼伦贝尔沙地北部沙带植物群落分布存在较显著差异,呈现出斑块状分布规律,而土壤养分对植被群落格局具有重要影响。  相似文献   

4.
Black-tailed prairie dogs (BTPD; Cynomys ludovicianus) have often been labeled as keystone species because of their ability to strongly influence grassland ecosystems. I used line-transect surveys and distance sampling to compare breeding bird and mammal communities on shortgrass prairie occupied by BTPD colonies versus similar uncolonized habitat in New Mexico, and to identify species that were either strongly associated with, or that avoided, BTPD colonies. Overall, I detected 32 bird and 8 mammal species during three years. Mountain plover (Charadrius montanus), ferruginous hawk (Buteo regalis), burrowing owl (Athene cunicularia), curve-billed thrasher (Toxostoma curvirostre), desert cottontail (Sylvilagus audubonii), and American badger (Taxidea taxus) were more abundant on, or at least strongly associated with, colonies, while long-billed curlew (Numenius americanus), horned lark (Eremophila alpestris), vesper sparrow (Poecetes gramineus), lark sparrow (Chondestes grammacus), Cassin's sparrow (Aimophila cassinii), and western meadowlark (Sturnella neglecta) were more abundant on, or strongly associated with, uncolonized prairie. Observed responses of several species differed from other studies suggesting that a species' response to BTPD activities may vary by location, grassland type, or season. Although BTPDs negatively impacted a suite of grassland bird species, biodiversity is maximized in this landscape by maintaining a mixture of colonized and uncolonized habitats.  相似文献   

5.
Knowledge of altitudinal covariation in interspecific competition and life history of birds inhabiting meadow-wastelands in the Tibetan plateau can contribute to our understanding for ecological adaptation of organisms to extreme environments and aid conservation for the unique ecosystem in the world. We reported reproductive ecology of two sympatric Montifringilla snowfinch species (Montifringilla taczanowskii and Montifringilla ruficollis) in a higher altitude wasteland, and compared the data with those of their lower altitude conspecifics. Both species nested in pika burrows and had similar breeding phenology. Nesting habitats of the two species tended to be separated in space as a result of asymmetrical competition, with large-sized M. taczanowskii occupying patches with better vegetation and small-sized M. ruficollis using poorly vegetated patches. In the less harsh lower altitude, however, their nest sites are randomly distributed. Relative to their lower altitude conspecifics, the higher altitude snowfinches had small body sizes but long wings, assuming an adaptation to increasing power demands for flying in thin air. There was a reduced fecundity with increasing altitudes, suggesting an adaptive response to the unpredictable conditions. We argue that the simplified bird community in stressful environments will be more vulnerable to perturbations. This highlights the importance to maintain ecological processes of the ecosystem.  相似文献   

6.
The island of Surtsey, Iceland, was formed in 1963 by a volcanic eruption. Since then, it has served as a unique natural laboratory for scientists interested in primary succession. In this study we investigated the state of the soil microfauna succession in 1995. We examined locations on the island with different vegetation types (unvegetated soil, soil with one or two plant species, and bird colony soil with a diverse vegetation). We recorded at least 16 nematode taxa and 13 flagellate taxa. Most of these were not reported in previous surveys from Surtsey. On the location with unvegetated soil, ciliates and nematodes were absent and only amoebae and heterotrophic flagellates were found. Most of the protozoan populations we examined were unable to survive salinity levels corresponding to seawater. We therefore conclude that many of soil protozoa populations on Surtsey arrived to the island as airborne cysts brought there from nearby land. However, in the bird colony soil with a high input of salts from the bird droppings, several flagellate species survived and multiplied at seawater salinity. This indicates that the bird colony soil harbours microhabitats where marine flagellate populations have been established.  相似文献   

7.
Plant communities in dryland riparian ecosystems are influenced by flood disturbance and water availability. As global climate change alters stream flow regimes, there is increasing need to understand which traits allow plant species to persist under increased stress and disturbance. Small seed mass is part of a strategy that adapts for disturbance, but the role of seed mass as an adaptation for drought is less well documented. For dryland riparian plant communities, we asked, does seed mass vary with water availability and flood frequency? We compared community seed mass between sites that vary in flow permanence (longitudinal water gradient) and between hydrogeomorphic surfaces within sites (lateral gradients of moisture and disturbance). Using data from four rivers in Arizona, we contrasted seed mass between plant groups. We found community seed mass to be greater at sites with ephemeral than perennial flow, and to increase laterally from wet, frequently-flooded channel edges to dry, less disturbed terraces. Seed mass varied by moisture group (smallest for hydroriparian species) and by disturbance group (smallest for disturbance species), and showed a trend for being greater in introduced species. We conclude that small seed mass is independently associated with wet and disturbed conditions in dryland riparian ecosystems.  相似文献   

8.
Fat sand rats (Psammomys obesus) are strictly herbivorous and live in densely complex burrows in the desert of North Africa and the Middle East. Little is known however about the effect of their foraging and burrowing activities on surface morphology and plant community attributes. This study evaluated such effects by comparing burrow and mound surface morphology, canopy of the main host chenopod shrub Anabasis articulata, vegetation cover, and plant abundance and species richness on and off both active and abandoned colonies in the semi-stabilized sand dunes of the Northern Sinai. In general, active burrow systems were characterized by reduced A. articulata canopy area, and more soil disturbance, with higher and larger burrow mounds dominated by bare ground, dung, and dead and fresh litter. The abandonment of mounds for five years has resulted in significant increases of plant cover, canopy height, abundance and species richness. Vegetation structure and plant species assemblages differed between mound and non-mound patches of both active and abandoned sites. The results suggest that fat sand rats can have significant direct and indirect, short-term and long-term effects on vegetation dynamics and structure through their mound building and foraging.  相似文献   

9.
Macroinvertebrate communities were studied in two saline tributaries of the Hopkins River, western Victoria. Monthly sampling from May to August, 1990, showed the mean salinity of Bushy Creek was 5 g L−1 while in Back Creek mean salinity varied from 9 to 20 g L−1 between sites. Macroinvertebrate species richness and relative abundance were measured on each sampling occasion. Cluster analysis showed that community composition varied between creeks and between sites within a creek. Bushy Creek sites were more similar to each other than to Back Creek sites. A negative relationship was found between site salinity and species richness over the range 4 to 26 g L−1, although there was a wide range of salinity (up to 12 g L−1) over which the relationship of species richness to salinity was not clear cut. The effects of salinity on species richness in stream communities appear to be similar to that described elsewhere in salt lakes.  相似文献   

10.
通过野外样方调查河西走廊西段荒漠戈壁典型灌木群落多样性状况,研究探讨了 8 种典型 灌木群落物种多样性的空间分布格局及其与地理因子的关系,对荒漠戈壁植物群落的多样性的保 护和可持续发展具有重要意义。结果表明:(1) 8 个典型灌木群落 Shannon-Wiener 指数、Simpson 指 数、Margalef 指数和 Pielou 指数从高到低为:盐爪爪群落>麻黄群落>合头草群落>红砂群落>梭梭群 落>泡泡刺群落>多枝柽柳群落>沙拐枣群落;波动范围分别为 0.314 ~ 1.355、0.179 ~ 0.666、0.334 ~ 1.222 和 0.051 ~ 0.218,说明荒漠戈壁灌木群落物种多样性指数偏低,群落结构简单,物种组成稀 少。(2) 不同灌木群落内物种数越多,群落间 Jaccard 相似性系数越大。大部分灌木群落类型间 Jac? card 相似性在 0.20 ~ 0.60 之间,群落间相似水平较低,群落相对稳定。(3) 随着海拔的升高,Margalef 指数、Pielou 指数和 Shannon-Wiener 指数均呈先增加后降低的单峰型分布格局,最大值出现在海拔 2 000 m,且与海拔显著相关(P<0.05);在经度梯度上,从东到西,Margalef 指数、Pielou 指数和 Shan? non-Wiener 指数呈递增格局,但与经度无显著相关性(P>0.05);在纬度梯度上,从南到北,Margalef 指数、Pielou 指数和 Shannon-Wiener 指数呈显著递增趋势(P<0.05)。总体上,荒漠戈壁灌木群落物 种多样性呈现出明显的垂直(海拔)和纬度地带性分布格局。  相似文献   

11.
本文分析了云南哀牢山中山湿性常绿阔叶林区次生环境中鸟类群落的年动态。各类次生环境中,鸟类群落多样性和稳定性之间并非成简单的正相关。比气候顶极群落结构简单的林缘、林窗次生植被中的鸟类群落具有较高的物种多样性,但其群落稳定性较差;在植被简单的沼泽化草甸环境鸟类群落物种的多样性低,却表现其群落结构的稳定性。鸟类群落的稳定性与其生境的稳定性相关。在林缘、林窗鸟种类和密度变化显著,鸟类传播植物种子促进林缘、林窗地带自然更新和植被复化,能加速次生植被恢复到顶极群落的进程。  相似文献   

12.
The objectives of this study were to determine if metrics for ant species assemblages can be used as indicators of rangeland condition, and to determine the influence of vegetation and ground cover variables, factors often influenced by livestock grazing, on ant communities. The study was conducted in two areas in the Great Basin: a sagebrush-steppe in southeastern Idaho (n=30 sites), and a salt-desert shrub in western Utah (n=27 sites). Sites were selected based on known rangeland condition (i.e. good, fair, poor) associated with livestock grazing. Ant communities differed considerably between the two study areas. Collectively, more ant species occurred at the Idaho sites (30) than at the Utah sites (21), relatively few species (eight) occurred in both areas, species richness was significantly greater at the Idaho sites (mean=12·0 species) than the Utah sites (mean=6·9 species), and Formica spp. were diverse (total of 15 species) at the Idaho sites but rare (one species) at the Utah sites. In Idaho, all species collectively, generalists, and Formica spp. were significantly less abundant on sites in poor condition than that on sites in good or fair condition, whereas in Utah, seed harvesters and Pheidole spp. were significantly more abundant on sites in poor condition than that on sites in good or fair condition. In Idaho, species richness was significantly lower on sites in poor condition. In Idaho, species richness and relative abundances of several ant groups were significantly related to bare patch size and parameters for cover or species richness of several vegetation groups. In contrast to the comparisons involving sites in poor condition, no differences in ant communities in either Idaho or Utah were evident between sites in good and fair condition. Thus, the ant communities responded only to large changes in rangeland condition and to large differences in climatic/edaphic conditions between the two areas. Hence, ant community metrics appear to have limited utility as indicators of rangeland condition in the Great Basin.  相似文献   

13.
In this article I attempt to shed light on the relationships between indigenous communities and bird populations through research on hunting in five neighboring villages in western Panama. Over eight months, 59 households captured 1,584 birds using rifles, sling‐shots, traps, and other methods, resulting in a total yield of 252 kilograms. Although hunters captured more than 125 avian species, just four species account for more than half of the total harvest. The most important game bird is the great curassow (Crax rubra), followed by the great tinamou (Tinamus major) and crested guan (Penelope purpurascens). The type and quantity of avifauna captured varies significantly according to habitat and hunting strategy. The spatial distribution of bird kill sites is highly concentrated, with 62 percent of the harvest by weight captured within just 1 kilometer of the participating households. Even the more vulnerable species are encountered close to home, suggesting that overhunting has not occurred.  相似文献   

14.
本文运用了群落相似系数、种间相遇机率指数、生态位分布型和食性研究,观测分析了同一山体两侧山坡八块样地冬季鸟类群落状况。在哀牢山西坡观测到鸟类44种,东坡观测到28种,其中13种为两坡共有。西坡除种多样性较高外,鸟类生态类型也与东坡有别。所有这些差别与哀牢山地理位置,西南季风影响所形成的东西坡植被和气候等环境因素有关。文章还分析了人类活动对森林演替和鸟类群落的影响。  相似文献   

15.
退化沙质草地土壤种子库和地上植被对封育的响应机理   总被引:3,自引:3,他引:0  
从植物种和植物功能类群两个水平系统探讨退化沙质草地土壤种子库和地上植被对短期封育管理响应机理的研究尚不多。以内蒙古东部的科尔沁沙地退化沙质草地为研究对象,采取随机样方法对禁牧6 a的封育区及与其相邻的自由放牧草地的土壤种子库和地上植物群落的物种密度进行了比较研究,草本植物群落被区分为一年生禾本科植物、非禾本科一年生植物和多年生植物3个主要功能类群。利用测定数据,分析研究了短期禁牧封育对土壤种子库和地上群落不同植物种和各植物功能类群的生态恢复作用机理。主要研究结果是:①短期封育显著促进了退化沙质草地植被的生态恢复,但发现土壤种子库和地上植被对禁牧的响应模式和机理存在明显差异,短期禁牧使土壤种子库中所有3个植物功能类群的密度均得到显著提高,而仅提高了地上植被一年生禾本科植物和多年生植物两个类群的密度;相反,禁牧显著提高了地上植被所有3个功能类群的物种丰富度和多样性,仅提高了土壤种子库中多年生植物类群的物种多样性。②短期禁牧显著增加了地上植物群落组成中可食和优良牧草的比例,提高了草地的经济利用价值。主要结论是:短期禁牧封育是一种经济有效的提高退化沙质草地植被多样性、生产力及对植物群落物种组成和草地品质进行优化调控和改良的重要草地管理手段。研究建议,今后应重点开展不同禁牧时间下对退化沙质草地土壤种子库和地上植被多样性、生产力及其物种组成变化影响的长期生态学控制实验研究。  相似文献   

16.
广东南岭国家级自然保护区森林鸟类多样性监测   总被引:1,自引:0,他引:1  
野生鸟类资源是自然保护区生物多样性的重要组成部分,为了解广东南岭国家级自然保护区鸟类种类和数量动态变化以及鸟类栖息地环境状况,2017年4月、7月和10月对区内11条鸟类监测样线进行了调查。调查结果显示:1)记录鸟种11目27科89种,其中雀形目15科61种;发现频次888次,记录数量3 367只,频次和数量均居前五的有栗背短脚鹎Hemixos castanonotus、灰眶雀鹛Alcippe morrisonia、灰树鹊Dendrocitta formosae、红嘴相思鸟Leiothrix lutea。2)居留型以留鸟为主,共61种,占68.5%;夏候鸟15种,占16.9%;旅鸟7种,占7.9%;冬侯鸟6种,占6.7%。鸟类区系组成以东洋界鸟种为主,共62种,占总数的69.7%;广布种19种,占21.3%;古北种8种,占9.0%。3)4月份是南岭鸟类繁殖活跃期,也是调查记录鸟种和数量最多的月份。11条样线中,相思坑、炉田、横水、南木、泽子坪、电视台、第一峰鸟类多样性(Shannon Wiener index)较高,怡坑、仙洞、担杆冲、竹坳多样性较低。4)根据海拔和植被类型,样线鸟类群落可分为4类:低海拔针阔混交林、常绿阔叶林、高海拔针阔混交林和山顶矮林。300~1 500 m的针阔混交林和常绿阔叶林生境鸟类群落并没有很大差异,优势种均为栗背短脚鹎、灰眶雀鹛、灰树鹊等;而高海拔山顶矮林(1 300~1 800 m)生境鸟种则明显不同,以画眉科(Timaliidae)的红嘴相思鸟、红头穗鹛、赤尾噪鹛、褐胸噪鹛、灰眶雀鹛及莺科(Sylviidae)的金头缝叶莺、比氏鹟莺、栗头鹟莺、冠纹柳莺为主。建议建立南岭鸟类多样性监测网络和评价体系,以鸟类长期监测数据,如种类变化、种群波动,作为评价保护区生态环境质量的指标。  相似文献   

17.
The effect of both a non-prescribed summer fire and grazing at high stocking rate following fire on plant community composition, the frequency of occurrence of bare soil, grasses and shrubs, species diversity and biomass of herbaceous forage were evaluated for three growing seasons after fire. Changes in community composition occurred as a consequence of both fire and grazing. Communities were dominated by unpalatable shrubs and grasses in unburned sites as a result of a long history of overgrazing. Fire contributed to a conversion of those shrublands to communities with a more favourable balance between woody and herbaceous species. The frequency of palatable grasses and herbaceous forage biomass increased by a factor ofc. 3 at the expense of woody vegetation. Grazing after fire had significant positive (i.e. decrease in undesirable grasses) and negative (i.e. increase in bare soil) effects.  相似文献   

18.
β-多样性反映群落之间的物种组成差异,群落β-多样性的形成和维持一直是生态学研究的核心问题.通过对库姆塔格沙漠南缘60个植物群落的调查,结合环境因素和空间距离,通过Mantel分析以及基于距离的多元回归(MRM),分析了环境过滤和扩散限制对研究区植物群落β-多样性及组分的影响.结果表明:库姆塔格沙漠南缘植物群落存在明显...  相似文献   

19.
调查了苏州8个湿地公园的鸟类资源,分析了湿地公园鸟类多样性与影响因子的相关性。结果表明:8个湿地公园样地共记录到鸟类10目33科114种,总数量11 200只,湿地水鸟种类占31.6%。种群以鹭科Ardeidae、麻雀科Passeridae、莺科Sylviidae和鸭科Anatidae为优势种群,白鹭Egretta garzetta为广布种,8个湿地公园的鸟类多样性差异较大。湿地公园可达面积与鸟类密度呈显著负相关;湿地公园水域面积与鸟类多样性呈显著正相关,与鸟类密度呈显著负相关;湿地公园日均游客密度与鸟类多样性呈显著负相关;保育区管理的局限性导致湿地公园保育区占比与鸟类多样性相关性不显著。  相似文献   

20.
太岳山森林群落物种多样性   总被引:14,自引:2,他引:14  
根据 8个样地的调查资料 ,用丰富度指数、多样性指数和均匀度指数对山西太岳山 10个森林群落多样性进行研究 ,结果表明 :1)同一群落不同层次的物种多样性指数存在一定的波动范围 ;不同群落间 ,物种多样性指数也存在差异 ,这种差异与群落所处的演替阶段相关 ;当群落处于演替的顶级阶段时乔、灌、草 3个层次的物种多样性和均匀度指数多为乔木层 <灌木层 <草本层 ;演替先锋阶段和进展阶段多为乔木层 <灌木层 >草本层或乔木层>灌木层 <草本层。 2 )分布在不同海拔高度的森林群落的物种多样性呈连续性波动的变化 ,表现为随海拔高度的增加 ,物种多样性指数呈上升趋势。 3)群落物种多样性在空间上的差异不仅决定于物种丰富度指数 ,更与各物种间的均匀度指数密切相关 ;进而影响不同层次的物种多样性对群落总体物种多样性的贡献  相似文献   

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