内蒙古中部地区繁殖鸟类多样性调查

2011年5～6月,采用样线法和固定半径样点法对内蒙古中部地区荒漠草原、典型草原及湿地3种生境中的鸟类进行了调查,共记录到繁殖鸟63种,隶属于11目25科,其中留鸟12种,夏候鸟51种。在动物地理区系成分上,古北界鸟类54种(占85.71%);东洋界鸟类9种(占14.29%)。调查结果表明,3种生境的鸟类群落结构在多样性指数上以湿地为最高,其次为荒漠草原,典型草原最低;均匀度指数最高的为荒漠草原,其次为湿地,典型草原最低。     

中昆仑山北坡及内部山原的植被类型

 中昆仑山西始乌鲁乌斯河,东迄安迪河,东西迤逦600余公里,平均海拔高度6000m。该区有野生种子植物52科,211属,398种。植物区系以种类成份单纯、地理成份复杂为特征。北坡中山带和高山带下部年降水量300—500mm,草原带发育完整,尤以中段的策勒山地草原发育最好。草原带以上高寒荒漠不存在,高寒草甸则有一定发育。中昆仑山北坡植被类型的垂直带谱是：1)山地荒漠,自山麓线多在2200—2500m,个别在3000m;2)山地荒漠草原在3000—3200m;3)山地真草原在3200—3600m;4)高寒草原在3600—3800m(阳坡上升到4200m以上);5)高寒草甸在3800—4200m;6)高山垫状植被仅见于东段山地和高寒草甸复合分布;7)高山流石坡稀疏植被在4200—5000m。中昆仑山内部山原极端寒冷干旱,多为砾漠所占据,高寒荒漠和高寒荒漠草原呈片状星散分布。     

海南岛尖峰岭热带森林中几种雀形目鸟的移动

从 2 0 0 0年 5月— 2 0 0 2年 3月 ,用网捕 -环志法和固定样点法研究海南岛尖峰岭几种雀形目鸟的移动和行为。共调查样点 4 89个 ,记录到鸟类 137种。张网 6 4 2 6网小时 ,环志 4 1种 4 2 8只鸟。 8种 2 9只鸟被回收 32次 ,总回收率为 7 5 %。棕颈钩嘴鹛 (Pomatorhinusruficollis)、灰眶雀鹛 (Alcippemorrisonia)等 6种鸟活动高度多在 3m以下 ;白喉冠鹎 (Alophoixuspallidus)在 3 1～ 10 0m活动最频繁 ;银胸丝冠鸟 (Serilophuslu natus)活动高度在 3m以上。灰眶雀鹛的个体移动距离最大 ,为 115 0m ;银胸丝冠鸟平均移动距离最长 ,为6 5 0m。尖峰岭热带森林林下鸟以食虫鸟为主 ,食虫鸟移动的平均距离为 4 4 2 3m (n =2 7) ;而白喉冠鹎等食果鸟大多在环志点附近活动。鸟类移动的平均距离与植被类型有关 :在热带山地雨林原始林中的移动距离最大 ,为 6 86 5m (n =13) ;在热带常绿季雨林中的移动距离最小 ,为 89 6m (n =5 ) ;两者之间存在极显著差异(F3 ,2 8=5 0 5 ,P <0 0 1)。鸟类移动的平均距离与翅长显著相关 (r =0 84 ,P <0 0 5 ) ,但与体重相关不显著(r=0 79,P >0 0 5 )。尖峰岭热带森林林下食虫鸟的活动范围较大 ,要保护好海南岛热带森林林下鸟 ,保存海南岛连片的大面积森林非常重要。     

小叶、中间和柠条三种锦鸡儿的分布式样及其生态适应

确定了小叶锦鸡儿、中间锦鸡儿和柠条锦鸡儿3种植物的分布式样:小叶锦鸡儿为蒙古高原东部-F松辽平原西部-华北山地分布种,中间锦鸡儿为东戈壁-鄂尔多斯高原-黄土高原北部分布种,柠条锦鸡儿为南阿拉善-西鄂尔多斯分布种。小叶锦鸡儿适应分布于蒙古高原典型草原带和森林草原带以及华北山地落叶阔叶林带,在草原带高平原上可形成灌丛化草原的景观,在草原带的沙地上可形成以小叶锦鸡儿为建群种的沙地灌丛植被;中间锦鸡儿适应分布于蒙古高原的荒漠化草原及草原化荒漠带、鄂尔多斯高原的典型草原和荒漠化草原带的沙地及梁地上、黄土高原北部的黄土丘坡上,常形成以中间锦鸡儿为建群种的沙地灌丛植被;柠条锦鸡儿则适应分布于草原化荒漠和典型荒漠带的固定和半固定沙地上。近缘的3种锦鸡儿的地带性分布从东至西或从北向南形成明显的有规律的地理替代分布格局。     

拉萨拉鲁湿地夏季鸟类调查初报

20 0 4年 8月采用样线法调查了拉萨市拉鲁湿地夏季鸟类的种类和数量 ,共记录到 2 6种鸟。鸟类群落中以灰沙燕 (Ripariariparia)、红脚鹬 (Tringatotanus)为优势种 ,优势度明显 (D =0 . 40 8) ,但群落多样性不高 (H′=1 . 5 3 1 )。拉鲁湿地夏季鸟类群落中涉禽和草甸鸟类占主导地位 ,标示着湿地表面水位下降、趋向于草原化的环境变化特点     

西藏高原高寒草地群落植物多样性和地上生物量监测方法的比较研究

以西藏高原高寒草地3种植被类型(高寒草甸、高寒草原和高寒荒漠草原)为研究对象,分别采用样线法、样方法和巢式样方法进行实地调查,记录每条样线上或每个样方内出现的所有物种,并分物种刈割样方内地上部分,通过统计分析比较不同高寒草地群落植物多样性和地上生物量监测方法,以阐明西藏高原高寒草地不同植被类型的最小取样面积和最少样方数或样线长度。结果显示:(1)就物种丰富度而言,400m样线法观测到的高寒草甸、高寒草原和高寒荒漠草原的所有物种数分别占3种方法调查到的总物种数的55%、71%和50%;8m2巢式样方法调查到高寒草甸、高寒草原的总物种数占所有3种方法观测的物种总数的57.5%和57%,而8m2的巢式样方对高寒荒漠草原的调查监测到的物种数最多,其中2m2观测到的物种数就达到所有可能出现物种的83%;20个样方法监测到高寒草甸和高寒草原的物种数最多,占3种方法观测到总物种数的78%和86%,所以对物种丰富度的调查高寒草甸和高寒典型草原至少需要20个样方,高寒荒漠草原需要最小面积不少于2m2的2个样方。(2)就地上生物量而言,由地上生物量与物种数之间的变异关系得出最小样方数为7~11个,而由地上生物量的变异系数可知,在变异系数小于等于5%的前提下,高寒草甸的最小取样面积不小于0.25m2,高寒典型草原和高寒荒漠草原的最小取样面积不少于1m2。研究表明,对于生产力的监测方法而言,高寒草甸采用10个0.5m×0.5m的样方,而高寒草原和高寒荒漠草原采用10个1m×1m的样方为宜;而对于物种丰富度的监测方法而言,高寒草甸以20个0.5m×0.5m的样方和高寒草原20个1m×1m的样方为宜,高寒荒漠草原采用2个不小于2m2样方面积为宜。     

海南岛尖峰岭热带山地雨林林下鸟类群落研究

从 2 0 0 0年 5月到 2 0 0 2年 3月 ,用网捕法对海南岛尖峰岭热带山地雨林 (包括原始林和次生林 )林下鸟群落进行研究。共张网 3 992 .7网· h,捕到林下鸟 3 12只 40种 ,隶属于 6个目 11个科。林下鸟群落虽然以小于 2 5g重的雀形目鸟类占优势 ,但许多个体较大的非雀形目鸟类也到林下活动 ,最大个体重达 3 70 g,大于 10 0 g重的个体占整个林下鸟生物量的比例较大。尖峰岭热带山地雨林中的林下鸟以食虫鸟为主 ,食虫鸟占整个林下鸟种数的 70 .0 %、鸟数量的 77.56% ;食果鸟虽然占第 2位 ,但其所占比例较小。林下鸟的种类组成和密度存在季节变化。留鸟是林下鸟最重要的成分 ,留鸟占鸟类种类的比例超过 85% ,留鸟的捕获数量占整个捕获鸟类数量的比例超过 90 % ;迁徙鸟的种类和数量均较少 ,对林下鸟群落的季节变化影响不大。原始林与演替 40 a后的次生林林下鸟平均网捕率相近但林下鸟群落种类组成不同 ,其种的相似性仅为 0 .3 5。     

新疆阿勒泰地区草地类型及植物多样性的研究

基于33个样地、99个样方的野外调查资料,分析了新疆阿勒泰地区草地群落的植物物种多样性特征。结果表明：草地群落间的植物物种丰富度指数、均匀度指数和多样性指数差异显著,丰富度由山地草原、经山地草甸、荒漠草原、草甸化草原、平原荒漠、高寒草甸到山地荒漠依次下降,均匀度指数由山地草原,经草甸化草原、荒漠草原、平原荒漠、山地草甸、高寒草甸,到山地荒漠依次下降,多样性指数从山地草原,经草甸化草原、荒漠草原、山地草甸、平原荒漠、高寒草甸,到山地荒漠呈下降趋势。在群落多样性梯度上,物种丰富度对多样性的贡献率要比均匀度的贡献率小。草地群落的物种丰富度、均匀度和多样性指数随海拔升高均表现为先上升,后下降,峰值出现在1800～2000m的山地草原,且变化趋势一致。     

宁夏沙坡头自然保护区四种生境夏季鸟类群落变化

1999年夏季采用样线法调查了宁夏沙坡头自然保护区 4种生境鸟的种数和数量 ,并与 1986年用相同取样方法得到的数据 (Liu&Chang ,1990 )进行比较 ,以了解 13年间鸟类群落的变化并探讨其原因。 1999年共记录到 6 7种鸟 ,比 1986年新增 36种 ,同时减少 10种。荒漠生境鸟类的数量减少到不足 1986年的 5 0 % ,但种数、群落多样性和优势度与 1986年接近 ;湿地生境鸟类的种数和数量都增加 1倍多 ,群落多样性和优势度略有增加 ;固沙林生境鸟类的种数从 8种增加到 34种 (增加了食虫、荒漠鸟类 ) ,但数量略减少 ,群落多样性增加 6 7% ,优势度减少 6 3% ;村庄农田生境鸟类种数与 1986年接近 ,数量、群落多样性和优势度都减少。湿地鸟类群落的状态变好 ,是鱼塘水域增加的结果 ;固沙林鸟类群落的状况看似好转 ,但潜伏着虫害所致的荒漠化危机 ;村庄农田生境鸟类群落状态变差 ,与农村传统土房大量消失有关。     

阿拉善主要草地类型土壤有机碳特征及其影响因素

以阿拉善左旗境内贺兰山中段 (西坡 )及其山前地带主要草地类型为研究对象 ,分析了不同草地类型土壤有机碳 (SOC)的分布特征及其与气候因子、植被特征和土壤特性的关系。结果表明 :土壤有机碳含量随海拔高度的降低而逐渐降低 ,其垂直分异规律是 :山地荒漠草原沿土壤剖面依次降低 ,高山草甸、草原化荒漠和沙砾质草原化荒漠 0～ 2 0 cm与 2 0～ 40 cm土层差异不显著 ,但高于 40～ 60 cm土层。 0～ 2 0 cm和 2 0～ 40 cm土层土壤有机碳含量与年降水量、植被盖度、草地生产力、土壤含水量和<0 .0 5mm颗粒含量呈极显著正相关 ,与年均温、土壤 p H值呈极显著负相关 (P<0 .0 0 1)。偏相关分析显示 ,影响 0～ 2 0 cm土层有机碳含量最主要的因素是植被盖度、草地生产力和年降水量 ,而影响 2 0～ 40 cm土层有机碳含量的最主要因素是草地生产力和植被盖度。放牧与围封对荒漠草地土壤有机碳含量有显著影响 ,在重度放牧下 0～ 2 0 cm土壤有机碳含量明显低于轻、中度放牧处理 (P<0 .0 5) ;重度退化草地围封 3 a后土壤有机碳含量比自由放牧草地显著增加。研究区沙砾质草原化荒漠区 0～ 2 0 cm土层土壤有机碳含量在 15a持续过度放牧后下降了 2 5.2 %。     

Relationships between vegetation and bird community composition in grasslands of the Serengeti

The Serengeti–Mara ecosystem holds one of the largest natural grasslands of the world, which is well known for its large herds of mammals. However, the bird community structure of these grasslands has hardly ever been studied. For the first time, a large‐scale study on grassland bird communities has been conducted in all typical open grasslands of the Serengeti National Park. We used ten grassland plots representing a gradient of increasing vegetation height and also including shrubs and trees to analyse the influence of vegetation structure on the composition of grassland bird communities. Three communities of breeding birds were identified in relation to (a) short grass, (b) intermediate and long grass and (c) wooded grasslands. The bird communities of intermediate, long and wooded grassland were very similar, because of identical dominant bird species. Our results suggest that breeding birds of East African grasslands exhibit two contrasting habitat relationships: (1) birds that are restricted to short grass, and (2) species that are tolerant to vegetational shifts from intermediate grass via long grass to early stages of woody vegetation. Because the vegetation is often driven beyond this range in managed tropical grasslands through high grazing pressure or through shrub encroachment, we expect that the long‐grass bird communities will not generally resist anthropogenic disturbance.     

Bird community responses to disturbance in a forestry concession in lowland Bolivia

Bird community characteristics of three sites with different levels of disturbance were studied using transect surveys during the dry season in a subtropical humid forest in Bolivia. One area had been unintentionally burned 4 years prior and selectively harvested (DIS) 1 year prior to sampling. A second area had been selectively harvested 1 year prior to sampling and had no recent history of fire (HAR). Species richness, as assessed by species–time curves and rarefaction, was higher in both altered areas than in undisturbed forest (INT). In general, frugivores and omnivores were more abundant in both altered areas compared to intact forest. Canopy frugivores, understory omnivores and multiple-strata omnivores were most abundant in HAR. Canopy frugivores, near-ground insectivores, understory and multiple-strata omnivores were least abundant in INT, although INT had the highest abundances of canopy insectivores and near-ground omnivores. Richness and abundance of widespread species with low habitat specificity was higher in both areas that experienced disturbance compared to intact forest. Differences in bird community structure between disturbed and intact forest at this site are attributed primarily to the addition of widespread species with less narrow habitat requirements, and possibly to changes in the distribution of different food types.     

Ground vegetation in the Mongolian taiga forest‐steppe ecotone does not offer evidence for the human origin of grasslands

Question: Is the vegetation of meadow and mountain steppes distinct from the ground vegetation of light taiga forests in the transitional zone between these biomes? Location: Western Khentey Mountains, northern Mongolia. Methods: Vegetation was recorded from 100‐m² plots from all dominant types of light taiga forest and dry grassland. Distinctness of ground vegetation was studied with Detrended Correspondence Analysis (DCA). Results: Ground vegetation in the light taiga was significantly different from the herbal vegetation of meadow and mountain steppes. Clear separation was only absent for the Car ex amgunensis meadow steppes that occur in a narrow strip along the forest edge and are partly shaded by trees. Forest and steppe communities followed a moisture gradient according to the DCA ordination with light taiga forests at the moistest sites and steppe communities at the driest sites. Ulmus pumila open woodlands diverged from this pattern, because of their close spatial and phytosociological relationship to mountain steppes. Conclusions: The present results do not support the assumption that grasslands in Mongolia's transitional zone between forest and steppe would generally resemble the ground vegetation of light taiga forests. This contradicts a published hypothesis stating that the vegetation of meadow and mountain steppes would not clearly differ from ground vegetation of light taiga forests in the forest‐steppe transitional zone of Mongolia.     

Adjusting count period strategies to improve the accuracy of forest bird abundance estimates from point transect distance sampling surveys

Although point transect distance sampling methods have become widely used in surveys of forest birds, there has been no attempt to tailor field methods to maximize the accuracy of abundance estimates by minimizing the effects of violations of the method's critical assumptions, which are: (1) birds at distance 0 m are detected with certainty, (2) birds are detected at their initial location and (3) distances to objects are measured accurately. We investigate the effects on abundance estimates for Philippine forest birds of varying the count period from 2 to 10 min, and of including and excluding a pre‐count settling down period. Encounter rates were highly sensitive to count period length but density estimates from 10‐min count periods were, on average, only 13% higher than those from 2‐min periods, and in several cases were actually lower than those from periods of 6–8 min. This was because birds tended to be recorded at greater distances from the recorder as the count period went on, thus ‘stretching out’ detection functions while having little effect on detection rates close to the recorder. For some bird groups, including canopy frugivores and upperstorey gleaning insectivores, density estimates were more than twice as high without than with a settling down period. We suggest that movement away from the recorder is more common than attraction to the recorder, and that unless pilot studies show otherwise, similar studies should not use a settling down period for surveying many species. Count periods that maximized probability of bird detection close to the central point while minimizing the unwanted effects of bird movement during the count period were: 4 min for omnivores, 6 min for nectarivores and upperstorey gleaning insectivores, 8 min for understorey insectivores and canopy frugivores, and a full 10 min for sallying insectivores, ground‐dwellers, carnivores and coucals/koels. We use the results to suggest ‘group‐specific’ count period regimes that could help maximize the accuracy of density estimates from similar studies of tropical forest birds.     

Bird community composition across an Andean tree‐line ecotone

Few studies have found strong evidence to suggest that ecotones promote species richness and diversity. In this study we examine the responses of a high‐Andean bird community to changes in vegetation and topographical characteristics across an Andean tree‐line ecotone and adjacent cloud forest and puna grassland vegetation in southern Peru. Over a 6‐month period, birds and vegetation were surveyed using a 100 m fixed‐width Distance Sampling point count method. Vegetation analyses revealed that the tree‐line ecotone represented a distinctive high‐Andean vegetation community that was easily differentiated from the adjacent cloud forest and puna grassland based on changes in tree‐size characteristics and vegetation cover. Bird community composition was strongly seasonal and influenced by a pool of bird species from a wider elevational gradient. There were also clear differences in bird community measures between tree‐line vegetation, cloud forest and puna grassland with species turnover (β‐diversity) most pronounced at the tree‐line. Canonical Correspondence Analysis revealed that the majority of the 81 bird species were associated with tree‐line vegetation. Categorizing patterns of relative abundance of the 42 most common species revealed that the tree‐line ecotone was composed primarily of cloud forest specialists and habitat generalists, with very few species from the puna grassland. Only two species, Thlypopsis ruficeps and Anairetes parulus, both widespread Andean species more typical of montane woodland vegetation edges, were categorized as ecotone specialists. However, our findings were influenced by significant differences in species detectability between all three vegetation communities. Our study highlights the importance of examining ecotones at an appropriate spatial and temporal scale. Selecting a suitable distance between sampling points based on the detection probabilities of the target bird species is essential to obtain an unbiased picture of how ecotones influence avian richness and diversity.     

蒙古高原草原火行为的时空格局与影响因子

采用GIS空间分析方法和L3JRC遥感卫星数据,研究了2000-2007年间蒙古高原草原火行为的时空分布规律,比较了中国内蒙古自治区和蒙古人民共和国草原火行为的差异,分析了植被、气候与人文因素等对草原火行为的影响.结果表明：不同植被类型间的过火率存在极显著差异（P<0.001）,为草甸草原>典型草原>荒漠草原,蒙古人民共和国草原过火率显著高于中国内蒙古自治区(P<0.001),过火频次的分布格局与过火迹地相一致.草原火行为存在明显的年际变化特征,草甸草原(r²=-0.54,P<0.05)和典型草原（r²=-0.61,P<0.05）的年过火率与年降雨量呈负相关关系;草原火集中在降水较少、风速较大的春、秋两季.中国内蒙古自治区的人口密度和载畜密度远高于蒙古人民共和国,而过火率则相反,表明人文因素,尤其是过度放牧是导致中国内蒙古自治区和蒙古人民共和国火行为差异的主要原因.     

新疆东部天山蝶类多样性及其垂直分布

2006-2008年研究了新疆东部天山蝶类多样性和垂直分布.结果表明:研究区域内共记录蝴蝶7科43属63种,占新疆已记录蝶类种数的24.80％,区系组成主要是古北种,占73％;其次是广布种,占27％,没有发现东洋种.其中蛱蝶科的物种数最多,为11属19种,蚬蝶科的物种数最少,只有1属1种.按海拔将生境分为5个垂直自然带,包括低山灌木草原带、山地森林草原带、亚高山草甸带、高山草甸带、垫状植被带.蝶类物种数和个体数排序为亚高山草甸带＞山地森林草原带＞低山灌木草原带＞高山草甸带＞垫状植被带.采用Shannon-Wiener指数和G-F指数对蝶类物种和科、属的多样性进行了分析评价,结果显示亚高山草甸带的蝶类多样性最为丰富,其次是山地森林草原带和低山灌木草原带,而高山草甸带和垫状植被带的蝶类多样性相对较低,物种和科、属多样性分析结果均一致.蝶类垂直分布明显,物种数和个体数随海拔变化的趋势类似,均为先增加后下降.蝶类区系成分随着海拔升高发生改变,广布种的比例逐渐降低,高山草甸带和垫状植被带只有古北种分布.研究结果显示,生境改变对蝴蝶群落影响明显,保护生境是保护蝴蝶生存的最主要措施.     

Flocking behaviour of foraging birds in a neotropical rain forest and the antipredator defence hypothesis

Randomly encountered foraging birds were recorded in a primary rain forest of French Guiana (13,550 records of 216 species), together with their size, diet and habitat use, to assess the relative frequencies of different types of flocking behaviour and some of their ecological correlates. Overall, 42% of birds foraged singly, primarily carnivores (raptors), nectarivores (hummingbirds) and lek-mating frugivores (manakins, some cotingas). For-aging in pairs (26.6%) was widespread, notably among insectivores in the 17–32-g size class. The remaining 31.4% of records were birds in groups of different composition and function, including, in order of decreasing frequency, (1) multispecies upper canopy flocks (83 member species identified)—the largest and most mobile associations of small insectivores, nectarivores and frugivores, mostly tanagers; (2) understorey mixed species flocks of small insectivores, at midlevels of closed forest interior, with 12 core, obligate members and 74 occasional species, mostly active foliage or bark gleaners and probers sharing a unique set of ecological characteristics; (3) monospecific groups (29 species), either gregarious foragers but solitary breeders (large frugivores in canopy) or also breeding colonially or several permanently group living cooperative breeders; (4) opportunistic gatherings of frugivores at fruiting trees (at least 40 species); (5) army ant followers near ground of closed understorey (29 species of mid- to large-sized insectivores); (6) followers of Red-throated Caracaras Daptrius americanus (23 species, usually canopy frugivores entering understorey with caracaras); (7) two raptors following monkeys. Attributes of vulnerability to predators defined by habitat structure (vegetation density or openness) and foraging behaviour (conspicuousness, speed, degree of vigilance) were important determinants of flocking propensity, at least in flocks that were not attracted by a particular food source. The results suggest that the permanent mixed-species flocks in the mature forest under-storey may be an antipredator defence to compensate for the conspicuousness and reduced vigilance resulting from active foraging behaviour in semi-open vegetation, where early detection of predators is difficult.     

The vegetation of the forest-steppe region of Hustain Nuruu, Mongolia

The vegetation of a forest-steppe region in Hustain Nuruu, Mongolia, was studied by a phytocoenological approach. Eleven plant communities were recognized, comprising four steppe communities, two meadow communities, a tussock grassland, two shrub communities, a scrub community and a woodland community. The botanical and ecological characteristics of the different communities are discussed, with reference to the existing classification of Mongolian plant communities. Analysis of the present data indicates that a refinement or extension of the classification system is desirable, especially concerning the steppe(-related) communities. Discussion of the relative distribution of steppe and forest reveals that in the relatively dry location of Hustain Nuruu grassland and shrubland dominate the natural vegetation (88% of the area). Forest covers ca. 5% of the area, it is limited to sites where ground water is within rooting depth: north slopes above 1400 m (Betula platyphylla woodland) and along erosion gullies (fragmentary Ulmus pumila gallery woodland). Under natural conditions forest cover might reach 12%, but it is speculated that wild ungulates could maintain its extension at a lower level. The importance of forest is greater in forest-steppe regions with higher rainfall, but the factors determining the distribution of grassland and forest are expected to be similar.