海口和三亚两城市破碎化林地中鸟类群落多样性与嵌套分布格局

城市化是生物多样性快速丧失的主要原因之一。鸟类作为城市生态系统的重要组成部分, 其生物多样性格局和物种保护已成为城市生态学研究的热点。为揭示城市化过程中城区和郊区破碎化林地中鸟类群落的多样性差异和嵌套格局, 本研究于2021年春、夏季鸟类繁殖期采用样线法对海口和三亚市的城区、郊区共13个林地斑块中的鸟类群落进行调查。使用NODF (nestedness metric based on overlap and decreasing fill)和WNODF (weighted nestedness metric based on overlap and decreasing fill)方法进行嵌套格局分析。研究发现: (1)共记录到林鸟100种, 隶属于11目39科, 其中三亚郊区的鸟类丰富度最高, 共8目29科68种。记录到国家重点保护鸟类共18种, 其中两城市郊区的国家重点保护鸟类物种数均多于城区, 海口郊区还记录到国家I级重点保护鸟类黄胸鹀(Emberiza aureola)。(2)鸟类群落多度、物种丰富度、Pielou均匀度指数和Shannon-Wiener多样性指数在不同区域中均存在差异。海口城区的鸟类群落多度显著高于海口郊区(P < 0.05), 三亚郊区的鸟类群落物种丰富度、Pielou均匀度指数和Shannon-Wiener多样性指数均显著高于三亚城区和海口郊区(P < 0.05)。(3)嵌套分析结果表明, 海口和三亚市的城区、郊区林地鸟类群落均呈现反嵌套分布格局。线性回归分析显示, 三亚市城区和郊区的斑块面积与鸟类物种丰富度呈显著正相关, 而物种丰富度与斑块距最近大面积林地的距离之间无显著相关性。研究表明, 两城市鸟类群落多样性都表现出郊区高于城区的特点, 少数优势种(如白头鹎 Pycnonotus sinensis)占据了城市中的主要生态位。受城市化的影响, 海口郊区与城区鸟类群落有同质化的趋势。鸟类在城区和郊区斑块间的高流动性、种间竞争和斑块中资源的可利用性等因素可能导致斑块间鸟类群落的反嵌套分布格局。我们建议应加强城区和郊区鸟类的保护, 减少对林地的破坏, 提高城市鸟类多样性。     

Effects of fire on bird diversity and abundance in an East African savanna

Fire is an important determinant of many aspects of savanna ecosystem structure and function. However, relatively little is known about the effects of fire on faunal biodiversity in savannas. We conducted a short‐term study to examine the effects of a replicated experimental burn on bird diversity and abundance in savanna habitat of central Kenya. Twenty‐two months after the burn, Shannon diversity of birds was 32% higher on plots that had been burned compared with paired control plots. We observed no significant effects of burning on total bird abundance or species richness. Several families of birds were found only on plots that had been burned; one species, the rattling cisticola (Cisticola chiniana), was found only on unburned plots. Shrub canopy area was negatively correlated with bird diversity on each plot, and highly correlated with grass height and the abundance of orthopterans. Our results suggest that the highest landscape‐level bird diversity might be obtained through a mosaic of burned and unburned patches. This is also most likely to approximate the historical state of bird diversity in this habitat, because patchy fires have been an important natural disturbance in tropical ecosystems for millennia.     

基于物种落差分析的公园鸟类多样性提升设计——以湖南常德螺湾湿地公园为例

随着城市化发展,许多公园鸟类栖息环境遭受破坏,导致当前的鸟类多样性与历史上的和周边的都存在较大差异,为此,我们从项目区域的当前-周边-历史三者间在鸟类物种及其栖息地上的落差分析入手,以此确定目标物种及其栖息地,并加以归类,从而有针对性地进行相关设计。2016年5月至2017年3月在湖南常德柳叶湖螺湾湿地公园开展的鸟类多样性提升设计中,通过实地调查并结合文献查阅,记录到项目区域16种,周边79种,历史上146种鸟类,运用三者间的物种落差分析法确定主要的21种可恢复目标物种和4种栖息地类型,结合项目区域及周边空间特点,将项目区域划分为4个区域,在各区域内设计并营建相应的栖息地,再配套采用多种鸟类招引措施。至2017年3月,项目区鸟类已可实地观察到39种,并于2017年12月吸引到超过2000只的野鸭群来此越冬。以上实际效果表明,设计有效地提升了湿地公园鸟类多样性且增加了景观要素,可充分发挥生物保护功能。     

The impact of shrub encroachment on savanna bird diversity from local to regional scale

Aim  Evidence is accumulating of a general increase in woody cover of many savanna regions of the world. Little is known about the consequences of this widespread and fundamental ecosystem structural shift on biodiversity.
Location  South Africa.
Methods  We assessed the potential response of bird species to shrub encroachment in a South African savanna by censusing bird species in five habitats along a gradient of increasing shrub cover, from grassland/open woodland to shrubland dominated by various shrub species. We also explored historical bird species population trends across southern Africa during the second half of the 20th century to determine if any quantifiable shifts had occurred that support an ongoing impact of shrub encroachment at the regional scale.
Results  At the local scale, species richness peaked at intermediate levels of shrub cover. Bird species composition showed high turnover along the gradient, suggesting that widespread shrub encroachment is likely to lead to the loss of certain species with a concomitant decline in bird species richness at the landscape scale. Finally, savanna bird species responded to changes in vegetation structure rather than vegetation species composition: bird assemblages were very similar in shrublands dominated by Acacia mellifera and those dominated by Tarchonanthus camphoratus .
Main conclusions  Shrub encroachment might have a bigger impact on bird diversity in grassland than in open woodland, regardless of the shrub species. Species recorded in our study area were associated with historical population changes at the scale of southern Africa suggesting that shrub encroachment could be one of the main drivers of bird population dynamics in southern African savannas. If current trends continue, the persistence of several southern African bird species associated with open savanna might be jeopardized regionally.     

A Large-scale, Multihabitat Inventory of the Phylum Tardigrada in the Great Smoky Mountains National Park, USA: A Preliminary Report

An All Taxa Biodiversity Inventory (ATBI) is underway in the Great Smoky Mountains National Park (GSMNP), with the goal of attempting to identify all species of life in the 2000 km² park. The GSMNP is a hotbed of biodiversity, a U.N. Biosphere Reserve, and one of the largest protected, deciduous forests in the temperate world. We have completed two field seasons of work on the tardigrades in the park (2001–2002). As of July 2003, we have collected 420 samples from soil/decomposed leaf litter, lichens and mosses on trees, and stream sediment and periphyton. A few samples from caves, bird nests, and lichens/mosses on rocks were also collected. Samples were taken from within permanent plots established for the ATBI, representing the major biological communities of the GSMNP. Tardigrades were extracted from samples using centrifugation with Ludox AM™, individually mounted on microscope slides in Hoyer’s medium, and studied with phase contrast and DIC microscopy. We have examined 1524 slides from 60 samples as of July 2003. Prior to our work, only three species of tardigrades had been previously reported from a few samples in the park. We have now recorded 42 species, 8 of which we believe may be new to science. Species richness estimates were calculated using EstimateS 6 software for each of the major tardigrade habitats. Overall, we predict that there are 47 to 76 species in the GSMNP, with generally similar species richness in soil, lichen, moss, and stream habitats. Species richness estimates were also used to determine that the number of tardigrade species was greater in mosses at breast height on trees than in mosses at the base of trees.     

Seed arrival, ecological filters, and plant species richness: a meta-analysis

Theoretical models predict that effects of dispersal on local biodiversity are influenced by the size and composition of the species pool, as well as ecological filters that limit local species membership. We tested these predictions by conducting a meta-analysis of 28 studies encompassing 62 experiments examining effects of propagule supply (seed arrival) on plant species richness under contrasting intensities of ecological filters (owing to disturbance and resource availability). Seed arrival increased local species richness in a wide range of communities (forest, grassland, montane, savanna, wetland), resulting in a positive mean effect size across experiments. Mean effect size was 70% higher in disturbed relative to undisturbed communities, suggesting that disturbance increases recruitment opportunities for immigrating species. In contrast, effect size was not significantly influenced by nutrient or water availability. Among seed-addition experiments, effect size was positively correlated with species and functional diversity within the pool of added seeds (species evenness and seed-size diversity), primarily in disturbed communities. Our analysis provides experimental support for the general hypothesis that species pools and local environmental heterogeneity interactively structure plant communities. We highlight empirical gaps that can be addressed by future experiments and discuss implications for community assembly, species coexistence, and the maintenance of biodiversity.     

中国不同地理区域鸟兽物种丰富度的相关性

生物类群之间物种丰富度的相关性研究是当前物种多样性研究中的热点问题之一,目前,中国尚无相关的研究报道。我们收集了中国三种区域类型：动物地理亚区、行政区和保护区的鸟兽名录,分析了行政区与保护区、动物地理区和经纬度带中鸟兽物种数比值及其相关性。 结果表明：不同区域、动物地理区和经纬度带中鸟兽物种数都显著相关。保护区尺度鸟兽物种 数的相关系数为0.818和动物地理区中的华北区为0.768,其他所有区域和地理区域的鸟兽物 种数的相关系数都高于0.850。因此,鸟兽物种数的相关关系在一定程度上具有预测价值。我们发现不同区域鸟兽物种数比值无显著性差异;但是,不同区域间鸟兽物种数 比值差异显著。该比值在中国呈中间低四周高的分布趋势,其中东北地区最高。我们还利用历史累积调查数据与非历史累积调查数据进行了鸟兽物种数比值及其相关性分析,发现利用累积数据计算的相关性低于非累积数据计算的相关性,但利用累积数据计算的鸟兽物 种数比值高于非累积数据计算的比值。最后,探讨了为什么鸟类与兽类的物种数目会相关。我们根据物种－面积公式,S=CA^Z,导出了两个生物类群物种丰富度的相关关 系式。利用全国不同区域数据拟合,得到Z₁/Z₂＝0.913,Z₁/Z₂接近于1。于是 ,C₁/C2可视为近似等于R_am。本研究可推广到其他不同生物类群物种。物种数量的相关关系为快速评估区域的物种多样性提供了一条途径。     

城市公园和郊区公园生物多样性评估的指标

随着城市化进程的加快,城市的生物多样性不可避免地受到城市化的各种影响,城市及其郊区的生物多样性保护越来越受到人们的重视。城市公园与郊区公园中往往具有高度多样化的生境,并保存着某些自然植被片段和动物物种,那里的生物多样性较高。可见,在城市和郊区的生物多样性保护中,公园生物多样性的保护是一个非常关键的环节,而对其生物多样性的评估又是有效保护的基础。目前,我国生物多样性评估方面的研究工作多集中于物种水平,而对生境的研究较少,但实践证明,保护生境比保护物种更为重要。本文介绍了比利时学者Hermy & Cornelis在比利时西佛兰德省的Loppem市立公园的保护实践中构建的一种对城市公园和郊区公园中的生物多样性进行评估的方法。该方法从两个方面展开：生境多样性和物种多样性。在生境水平上,首先对各种生境单元进行分类,这些单元被分为面状、线状和点状要素。针对每种要素,分别计算了Shannon-Wiener多样性指数和饱和度指数。饱和度指数是实际的多样性指数与最大可能的多样性指数之比。在物种水平上,使用了物种数、Shannon-Wiener多样性指数和饱和度指数来评估公园中的高等植物、蝴蝶、两栖动物和饲养的鸟类等物种。这样,就获得了20个生物多样性指标,根据这些指数就可以对Loppem市立公园内的生物多样性进行评估。结合我国生物多样性评估工作的实际要求,文章最后对上述方法进行了讨论,指出该方法对我国公园的生物多样性评估工作具有借鉴意义,但在运用时各地需要结合本地的实际情况。     

Changes in bird communities in Swaziland savannas between 1998 and 2008 owing to shrub encroachment

Aim This study investigates changes in bird communities between 1998 and 2008 in four savanna sites in Swaziland and the extent to which shrub encroachment is responsible for these changes. Location Swaziland, southern Africa. Methods Generalized estimated equations were used to estimate changes in bird species occurrence between 1998 and 2008. Remote sensing of aerial photographs/satellite images was used to assess vegetation changes during the same period. We assessed the role of shrub encroachment for bird communities by testing the relationship between change in species occurrence and species habitat using a general linear model. We also estimated species richness, colonization and extinction and used general linear models to test the effects of vegetation changes on these parameters. Results More than half of the bird species showed a significant change in occurrence between 1998 and 2008: 32 species increased and 29 decreased. Change in species occurrence was significantly explained by species habitat. Species significantly increasing were mainly associated with wooded savanna, whereas species significantly decreasing were mainly associated with open savanna. Species richness decreased significantly, and this decrease was significantly explained by shrub cover increase at the plot scale (from 24% to 44% on average). Extinction at the plot scale was significantly influenced by the loss of grass cover, while colonization at the plot scale was influenced by tree cover increase. Main conclusions This study represents the first evidence of temporal changes in bird communities owing to shrub encroachment in southern Africa. Despite its short time frame (10 years), this study shows dramatic changes in both vegetation structure and bird community composition. This confirms the general concern for southern African bird species associated with open savanna if current trends continue.     

澳门城市栖息地斑块中鸟类群落功能和谱系多样性

了解群落构建过程是生态学的核心和基本问题,这对于解释物种共存和物种多样性的维持,完善生物多样性保护政策至关重要。与传统的物种多样性相比,功能和谱系多样性能够提供更多的信息,特别是在群落构建过程方面提供深刻见解。2014年5月—2017年1月,采用样线法对澳门地区5个城市栖息地斑块中(生态一区、鹭鸟林、赛马场滩涂、关闸口岸滩涂和莲花桥侧红树林)的鸟类进行繁殖季和越冬季的调查,共调查14次。利用鸟类丰富度和多度来表征群落的物种多样性,其中多度以最大值保留法计;功能和谱系多样性分别采用功能丰富度(functional richness:FRic)和Faith'PD。同时,利用基于多度加权的平均成对功能距离(mean pairwise functional distance,MFD)和平均成对谱系距离(mean pairwise phylogenetic distance,MPD)来表征群落的功能和谱系结构。结果表明:共记录98种鸟类,隶属于14目32科,目、科、种中数量最多的依次为,雀形目鸟类最多为47种,鹭科物种数为11种,白鹭多度为849只;鸟类物种丰富度(68种)和PD在生态一区最高,多度在莲花桥侧红树林最高为2940只,MFD和FRic在赛马场滩涂最高,MPD在生态一区最高;斑块面积在鸟类丰富度、多度、FRic和PD中具有普遍重要性,植被面积和滩涂面积则分别强烈影响着MFD和MPD;关闸口岸滩涂和莲花桥侧红树林的鸟类群落SES.MFD显著低于随机值(P <0. 05),鹭鸟林和赛马场滩涂的鸟类群落SES. MPD显著低于随机值(P<0.05),表明关闸口岸滩涂和莲花桥侧红树林鸟类群落功能聚集(functional clustering),可能与生境过滤驱动群落构建有关。栖息地斑块的特征差异导致了鸟类群落构建机制的不同,这是仅仅考虑物种多样性难以提供的信息,说明了研究群落构建机制时考虑多维度多样性的必要性。     

Pyrodiversity interacts with rainfall to increase bird and mammal richness in African savannas

Fire is a fundamental process in savannas and is widely used for management. Pyrodiversity, variation in local fire characteristics, has been proposed as a driver of biodiversity although empirical evidence is equivocal. Using a new measure of pyrodiversity (Hempson et al.), we undertook the first continent‐wide assessment of how pyrodiversity affects biodiversity in protected areas across African savannas. The influence of pyrodiversity on bird and mammal species richness varied with rainfall: strongest support for a positive effect occurred in wet savannas (> 650 mm/year), where species richness increased by 27% for mammals and 40% for birds in the most pyrodiverse regions. Range‐restricted birds were most increased by pyrodiversity, suggesting the diversity of fire regimes increases the availability of rare niches. Our findings are significant because they explain the conflicting results found in previous studies of savannas. We argue that managing savanna landscapes to increase pyrodiversity is especially important in wet savannas.     

Trade‐offs between savanna woody plant diversity and carbon storage in the Brazilian Cerrado

Incentivizing carbon storage can be a win‐win pathway to conserving biodiversity and mitigating climate change. In savannas, however, the situation is more complex. Promoting carbon storage through woody encroachment may reduce plant diversity of savanna endemics, even as the diversity of encroaching forest species increases. This trade‐off has important implications for the management of biodiversity and carbon in savanna habitats, but has rarely been evaluated empirically. We quantified the nature of carbon‐diversity relationships in the Brazilian Cerrado by analyzing how woody plant species richness changed with carbon storage in 206 sites across the 2.2 million km² region at two spatial scales. We show that total woody plant species diversity increases with carbon storage, as expected, but that the richness of endemic savanna woody plant species declines with carbon storage both at the local scale, as woody biomass accumulates within plots, and at the landscape scale, as forest replaces savanna. The sharpest trade‐offs between carbon storage and savanna diversity occurred at the early stages of carbon accumulation at the local scale but the final stages of forest encroachment at the landscape scale. Furthermore, the loss of savanna species quickens in the final stages of forest encroachment, and beyond a point, savanna species losses outpace forest species gains with increasing carbon accumulation. Our results suggest that although woody encroachment in savanna ecosystems may provide substantial carbon benefits, it comes at the rapidly accruing cost of woody plant species adapted to the open savanna environment. Moreover, the dependence of carbon‐diversity trade‐offs on the amount of savanna area remaining requires land managers to carefully consider local conditions. Widespread woody encroachment in both Australian and African savannas and grasslands may present similar threats to biodiversity.     

Effects of monoculture and polyculture practices in oil palm smallholdings on tropical farmland birds

Industrial oil palm expansion has led to dramatic landscape changes that have negatively affected forest biodiversity in the tropics. In contrast to large-scale plantations, oil palm smallholdings may support greater levels of biodiversity through the implementation of multi-cropping system or polyculture. We examined bird species richness, together with community structure, conservation status, and feeding guild of existing smallholdings in Peninsular Malaysia. Based on point transect sampling, we sampled birds in 100 smallholdings that practiced either monoculture or polyculture farming. Our results revealed that bird species richness was significantly greater in monoculture smallholdings than in polyculture smallholdings, but the opposite was true for bird abundance. Non-forest birds constituted the major species of bird communities in oil palm smallholdings. However, we found that the abundances of insectivores and frugivores were greater in polyculture smallholdings than in monoculture smallholdings. In the monoculture models, predictor variables explained 11.31–19.98% of the variation in bird species richness. When polyculture was being practiced, bird species richness increased significantly with the height of ground vegetation cover, distance to major roads, and distance to rice fields. In the polyculture models, predictor variables accounted for 11.71–24.85% of the variation in bird species richness. We also found that bird species richness increased significantly with height of ground vegetation, but it decreased with ground vegetation cover and distance to rivers. The evidence from this study suggests that monoculture and polyculture farming were able to maintain farmland biodiversity in smallholdings, at least for birds, but differed in richness, population, and feeding guild.     

Butterfly populations in two forest fragments at the Kenya coast

Species richness, diversity and composition of butterflies in two Kenya coastal forest remnants, Muhaka and Mrima hill, were investigated. Sixty‐three species were recorded from each forest remnant from a total of 1329 individuals. Species accumulation curves for both forests did not reach an asymptote. High species similarity was recorded between the forest interior and the surrounding matrix, primarily due to invasion of the forest interior clearings by the savanna species. Despite their small sizes, these forest remnants were found to maintain viable populations of true forest butterflies. However, the number of species was less than half that recorded from the larger forest reserve of Arabuko‐Sokoke, located in the same geographical area. Records from Muhaka forest show species unique to it, not found in the larger forest reserves, underscoring the importance of small remnants in the preservation of forest biodiversity. The high species similarity between the forest remnants implied that if habitat corridors were created, gene flow between these remnants and other larger forest reserves would be possible. This would reduce the isolation of true forest butterfly populations within the remnants and potential local extinction.     

Neotropical savanna ants show a reversed latitudinal gradient of species richness,with climatic drivers reflecting the forest origin of the fauna

Aim

To evaluate the extent to which ant species richness in Neotropical savannas varies with macrogeographic variables, and to identify the potential climatic drivers of such variation.

Location

The Cerrado savanna biome of central Brazil, in a region spanning ca. 20° of latitude and 18°of longitude.

Methods

Standardized sampling of the arboreal and ground‐dwelling faunas was performed in 29 well‐preserved savanna sites using pitfall traps. Species were classified according to their habitat affinities: open‐savanna specialists, forest‐associated species or habitat generalists. We used generalized linear models to evaluate the importance of geographic (latitude, longitude and elevation) and climatic (mean temperature and three metrics of rainfall) variables as predictors of species richness.

Results

The total number of species recorded at each site varied more than twofold (from 59 to 144), and latitude was the best geographic correlate of overall species richness. However, contrary to the expected pattern, more species were found at higher than lower latitudes. This reversed latitudinal pattern of diversity occurred for both the arboreal and ground‐dwelling faunas, and for the habitat generalists and forest specialists. The savanna specialists showed a mid‐latitudinal peak in diversity. Overall, there was a significant positive association between rainfall and species richness, but the strength of this relationship varied with ant habitat affinity.

Main conclusions

The Cerrado ant fauna shows a reverse latitudinal gradient in species diversity, and this can be explained by increasing rainfall during the warmest months of the year (and therefore in plant productivity) with increasing latitude. The sensitivity of Cerrado ant diversity to declining rainfall contrasts with the high resilience to aridity of the Australian savanna ant fauna, and this reflects the contrasting evolutionary histories of these faunas. Our findings highlight the importance of historical processes as drivers of intercontinental contrasts in macroecological patterns.     

Presence of Cuckoo reliably indicates high bird diversity: A case study in a farmland area

Here we studied the occurrence of Cuckoo Cuculus canorus and top predators as indicators of biodiversity in agro ecosystems of Western Poland, to identify local hotspots. Bird species richness and land-use diversity were used as measures of biodiversity. The relationship between the presence of Cuckoos and four avian top predators with biodiversity measures were examined using Generalized Linear Mixed Models.Cuckoos were mainly distributed on sites with greater species richness, but were absent from the low species richness sites, while the top predators were distributed uniformly. The performance of the best models using the presence of Cuckoo was 27% higher than the best models using top predators. Our results highlight the predictive capacity of Cuckoos as an indicator of bird species richness than top predators and the usefulness of this species in biodiversity studies. The cookoo is charismatic, widespread across the main types of landscapes, and is easy to detect from its song. Importantly, our findings propose that cookoo can be used as effective and cheap tool to monitor the high bird diversity in different European countries.     

Woody trees,green space and park size improve avian biodiversity in urban landscapes of Peninsular Malaysia

Rapid urbanization in major cities has adversely affected avian biodiversity in both developed and developing countries. Due to over-urbanization and little regard for nature conservation, such cities are usually characterized by poor biodiversity. In contrast to central business district areas, suburbs may support greater levels of biodiversity through an increase in green areas. We examined urban bird species richness, abundance, and composition in Klang Valley, Peninsular Malaysia. We surveyed 141 points for passerines across 80 parks grouped into two different urban zones, namely central business districts and suburbs. Our results revealed that bird richness did not differ significantly (p = 0.994) between central business districts and the suburbs. We found that the abundances of birds were significantly greater in the suburbs than in central business districts. However, species composition was similar between the central business districts and suburbs. We also found that bird richness increased significantly with an increase in size of green areas and park areas, as well as the number of woody trees in both zones. Evidence from this study suggests that creating urban parks and gardens, coupled with tree planting in central business districts, is able to support greater biodiversity, at least for birds in cities similar to those found in the suburbs.     

湖南娄底市城区公园绿地鸟类物种多样性及保护对策

城市公园绿地作为城市生态系统的重要自然组成部分,是鸟类及其他动物的重要生境和载体.快速城市化导致城市公园绿地空间格局剧烈变化,公园绿地因在城市中呈斑块状分布而具有许多岛屿栖息地的特性,对鸟类群落产生了明显的影响.为了摸清娄底市城区的鸟类群落组成及物种多样性,为制定鸟类保护措施提供依据, 2010年11月至 2012年1月采用样带和样方法对城区内7个公园绿地中鸟类物种的分布及其生境进行调查,共记录到鸟类56种,隶属于11目27科.其中留鸟为32种,占57.2%;夏候鸟、冬候鸟各12种,分别占21.4%.东洋界27种,占48.2%;古北界14种,占25.0%;广布种15种,占26.8%.国家Ⅱ级重点保护野生鸟类7种,占物种总数的12.5%.娄底市城区公园绿地鸟类群落物种Shannon指数、Pielou指数、G-F指数分别为1.49、0.85、0.62.珠山公园的物种数(42)、Shannon指数(1.41)、G指数(3.46)、F指数(6.12)、G-F指数(0.43)均最高,而月琴山公园的Pielou指数最高(0.92).对娄底市绿地鸟类资源较为贫乏的主要原因进行了分析,并提出了合理的保护建议.     

An assessment of the efficiency of protection status through determinations of biodiversity hotspots based on endemic bird species,Taiwan

Evaluations of species richness patterns have been performed at diverse scales, and biodiversity hotspots, especially endemism hotspots, have received much attention in conservation biology. We estimated the distributions of endemic bird species based on a 12-yr avian inventory project in Taiwan, identified biodiversity hotspots of endemism on a regional scale based on predictions from the ensemble forecasting framework and frequency histogram approach, and assessed the efficiency of protected areas. The results indicated that the predicted endemism hotspots were mostly located in mid- and high-elevation areas along the Central Mountain Range of Taiwan. An observed endemism hotspot was defined as one in which at least five of Taiwan's 17 endemic bird species were present. This criterion was used because the 5% of the sampled grid squares that were the richest in endemic bird species all had 5 endemic bird species or more. Seventy to seventy-one percent of the observed biodiversity hotspots matched the predicted biodiversity hotspots. This outcome was obtained whether the richness biodiversity in a grid square was based on summed predicted probability or summed predicted richness. The majority of the protected areas for these Taiwanese endemic bird species were national parks, protecting 24.1% of the predicted hotspot areas, whereas nature reserves and wildlife refuges protected less than 7%. Most of the predicted endemism hotspots were not adequately protected. We conclude that the ensemble forecasting framework and the frequency histogram approach are useful for selecting critical habitats and biodiversity hotspots for endemic species and for appraising the efficiency of the protection status provided by governments.     

贵州花溪大学城破碎化林地鸟类多样性与嵌套分布格局

为揭示城镇化进程中生境破碎化对鸟类多样性及分布格局的影响, 本研究于2017-2019年每年的4-8月使用样线法对贵州花溪大学城26块破碎化林地(面积介于0.3-290.4 ha)中的鸟类群落进行了10次调查。共记录到鸟类78种, 隶属于11目37科。其中, 东洋界物种数占56.4%, 古北界物种数占32.1%, 广布种占11.5%; 有中国特有种1种。剔除高空飞行、非森林鸟类及偶然出现物种后, 不同斑块中的鸟类物种数介于12-55之间, 平均每个斑块有23.2 ± 10.5种。线性回归分析显示, 鸟类物种丰富度与林地斑块的面积有显著相关性, 斑块面积越小, 鸟类物种丰富度越低; 斑块隔离度对物种丰富度没有显著影响。基于物种多度分布矩阵的WNODF (weighted nestedness metric based on overlap and decreasing fill)嵌套分析显示, 不同斑块中鸟类群落呈现出反嵌套结构。小斑块中鸟类物种丰富度较低可能与植物丰富度较低、食物资源稀缺和繁育条件不足有关, 但短距离的隔离对鸟类迁入或扩散影响有限。环境过滤效应、种间竞争或优先效应可能导致不同斑块间存在较大的物种组成差异, 从而导致反嵌套格局。因此, 本研究建议在城市规划建设中应注重维持栖息地的完整性, 对不同面积大小的破碎化斑块都应加以保护。