黄泥河自然保护区狍冬季栖息地选择

2009年12月—2010年1月,在黄泥河自然保护区采用样线法对狍冬季栖息地选择进行了研究。共设置了47条样线,调查了109个狍利用样方和109个对照样方,测定了海拔、坡度、坡向、坡位、隐蔽级、郁闭度、食物丰富度、灌丛盖度、树胸径、人为干扰距离、林型、裸岩、雪深、倒木和针叶树15类栖息地因子。Baileys法和Mann-WhiteyU检验表明:在黄泥河自然保护区冬季,狍喜欢在坡度平缓、平均海拔602m,位于阳坡或半阴半阳坡的中坡位上雪被较浅,食物丰富度、灌丛盖度和隐蔽级都较高的针阔混交林生境中活动,对倒木因子表现出明显的选择性,避开选择阴坡、裸岩和针叶林生境。在主成分分析中,前5个主成分中的累积贡献率达到88.6%,第一主成分贡献率为30.8%,主要反映利用样方的林型、海拔和隐蔽级的影响,第二主成分贡献率为26.5%,主要反映利用样方的食物丰富度和灌丛盖度影响。     

陕西黄龙山林区褐马鸡繁殖季节中午卧息地选择

2006年5—6月,在陕西黄龙山腹地北寺山林区采取样线法对褐马鸡(Crossoptilon mantchuricum)中午卧息地的选择进行了研究,共观察到28个褐马鸡的卧息地。褐马鸡对林型、坡向和地理特征有明显的选择性,多偏向针叶林、山脊和半阴半阳坡,回避阔叶林、山坡、阴坡和阳坡。对中午卧息地坡位没有明显的选择性。褐马鸡中午卧息地具有坡度小、与林间道路与居民点的距离远、灌丛平均高度较低、灌木密度较小、草本均高较小、乔木层植物盖度以及草本层植物盖度较大等特征。对各种生境因子的主成分分析表明,前6个特征值的累积贡献率达到74.05%,可较好地反映褐马鸡中午卧息地生境特征。根据载荷系数绝对值大小将褐马鸡中午休息地生境选择影响因子分别命名为地理因子、隐蔽度因子、人类活动干扰因子和灌丛密度因子。     

普通鳾的巢位选择和繁殖成功巢特征

普通对巢位具有选择性,利用树种共7种,利用率不同,利用树洞类型有两种,啄洞利用率高,结洞低。洞口朝向在西至西偏北45°方向的树洞利用率最低,其它方向差异不大。洞口处树的直径、洞口纵径、洞内径、洞深和洞周围10m范围,树的密度5个巢位变量在利用和未利用树洞之间差异极显著(P<001),洞口横径,洞口处树干与垂直方向夹角和洞口方向90°角10m范围树的密度差异显著(P<005),其余变量差异不显著(P>005)。23巢平均窝卵数778±095,孵化率8994%,出飞率9627%。30个巢中成功巢和失败巢的11个巢位特征比较发现,洞高和洞口方向90°角10m范围内树的密度差异极显著,洞口纵径和洞口横径差异显著,其余变量差异不显著。     

四川省巴塘县矮岩羊与斑羚冬季生境比较

2007年10～12月,在四川省巴塘县竹巴笼自然保护区,采用样线调查法对矮岩羊和斑羚冬季生境进行研究,利用卡方检验和Mann-Whitey U检验分析其生境选择差异.结果表明,矮岩羊对17种生境因子有选择性,倾向选择中等以上避风性,石质或便石质活动基底,灌丛盖度10%～40%、种数>4种、高度>100 cm,草种数>5种、高度<20 cm或>40 cm,坡度>60°的南坡或西坡,隐蔽级<30%或>60%,水源距离>500 m,裸岩距离<2m,林缘距离1000～1 500 m,1级风,海拔高度2 600～2 800 m,人为干扰距离500～1 000 m,动物干扰距离80～150 m的生境.斑羚对15种生境因子有选择性,倾向选择上坡或山脊坡位,灌丛盖度10%～40%、种数>5种、高度>100 cm,草种数4～5种、高度>40 cm,坡度>60°的南坡或东南坡,南风,隐蔽级>60%,林缘距离<1 500 m,海拔高度>2 800 m,水源距离>1 000 m,人为干扰距离>1 000 m,动物干扰距离80～150 m的生境.因子分析表明,影响矮岩羊生境选择的主要因子为人为干扰距离、海拔高度、林缘距离、水源距离、灌丛高度、隐蔽级、风级和动物干扰距离等生境因子,而影响斑羚生境选择的主要因子为人为干扰距离、海拔高度、林缘距离、水源距离、坡位、灌丛盖度、灌丛高度、隐蔽级、坡向和风向生境因子.虽然两物种在资源生态位上存在部分重叠,但在生境选择利用和空间生态位上皆存在很大差异.     

小相岭大熊猫与放牧家畜的生境选择

利用 Forage Ratio指数对小相岭山系大熊猫与放牧牲畜的生境选择进行了比较研究 ,研究涉及 1 1种生境因子。研究结果表明 ,大熊猫喜欢选择在山体的脊部和中部的凸坡 ,坡向南坡 ,喜欢选择 0～ 2 4 %的灌木盖度 ,喜欢竹子盖度大于 5 0 %的原始针叶林 ,对坡度、乔木高度、乔木郁闭度、灌木高度不存在选择性 ,都为随机利用。放牧牲畜喜欢选择利用复合坡、山体的下部、坡度小于 2 0°的山坡 ;喜欢利用的生境类型是草坡和灌丛 ;选择的森林起源是次生林 ;所利用生境的乔木高度为 5～ 9m,对坡向、乔木郁闭度、灌木高度、灌木盖度、竹子盖度都随机利用。放牧家畜与大熊猫在对生境因子的利用上有许多共同点 ,对许多因子类型大多都是随机利用 ,因而 ,在对一些生境因子的利用上 ,放牧对大熊猫的活动会产生一定的影响。同时 ,它们在生境选择上也存在一定的差异 ,特别是在对植被类型和森林起源的选择上差异较大 ,只要合理的规划和控制放牧活动 ,也就可能达到大熊猫保护与社区经济协调发展的目的     

清凉峰自然保护区梅花鹿秋季对栖息地利用的初步分析

20 0 3年 9～ 1 1月 ,作者在浙江省清凉峰自然保护区 ,对梅花鹿栖息地的利用进行了研究 ,选择 9类生态因子 ,并设置 3 89个 1 0m× 1 0m样方。选择指数的结果表明 ,梅花鹿喜欢选择草甸 沼泽和灌丛、郁闭度较低、食物丰富度高、上坡位、海拔≥ 1 2 0 0m、人为干扰距离 >1 0 0 0m、向阳、坡度平缓的生境。分析表明 ,梅花鹿对灌木盖度的选择以适合为准。主成份分析表明 ,影响梅花鹿栖息地选择的主要因子有 4种 ,依次为 :干扰因子 (包括海拔、坡位和人为干扰距离 )、食物因子 (包括郁闭度、食物丰富度和植被型 )、灌木盖度因子和地形因子 (包括坡度和坡向 )。     

内蒙古东部草原沙狐春季洞穴选择

通过对内蒙古东部草原64个沙狐洞穴的观测,采用主成分分析法,对沙狐洞穴选择作了初步的定量研究。分析结果表明：影响沙狐春季洞穴选择的主要生态因子有7种,依次为：坡位因子（随坡度,坡高的变化而变化）,水源因子,植被因子,微气候因子,食物因子,人为干扰因子和微生境因子,而坡向,洞口朝向及洞道口倾角等影响不明显。     

内蒙古东部草原地区赤狐繁殖期对洞穴的选择

通过对内蒙古东部草原地区赤狐的２５个洞穴观测,运用系统聚类分析的方法,研究了赤狐繁殖期的洞穴选择。结果表明,影响赤狐繁殖期洞穴选择的主要因子是水源,其次是坡向、坡位和坡度,人为干扰、隐蔽程度及洞口朝向等因子对其影响作用不明显。繁殖期赤狐的最适洞穴选择为：阳坡或半阴半阳坡、下坡位、坡度５°～２５°、距水源５００～１０００ｍ。     

西双版纳不同森林类型的树洞密度及其特征

树洞是森林生态系统的重要组成部分,它能为许多动物提供栖息、筑巢、繁殖和躲避天敌的场所。因而,树洞的密度和特征通常被认为是限制树洞巢居动物多样性和丰富度的主要因子,然而目前国内外对热带森林的树洞密度和洞口特征研究较少。选取西双版纳20 hm~2热带森林动态监测样地(包括热带季节雨林和热带山地常绿阔叶林)为研究对象,采用地面观测法调查了所有胸径≥5 cm的活体乔木上的树洞,分析其树洞密度和特征(高度、洞口大小、类型和洞口方位,并探讨树洞在不同森林类型间的差异)。结果表明:(1)热带季节雨林和热带山地常绿阔叶林的树洞密度不存在显著差异;(2)两种森林类型的树洞均以高度较低、洞口较小、干中部洞口为主,受盛行风的影响洞口朝向主要集中在东北方向;(3)树洞高度、类型和洞口方位在两种森林间的分布差异显著(P0.01),而洞口大小不存在明显差异。结果表明森林类型会影响树洞的特征,因而加强森林生境异质性的保护对维持树洞巢居动物的需要具有重要意义。     

吉林黄泥河自然保护区马鹿冬季栖息地选择

2009年12月～2010年1月,在黄泥河自然保护区采用样带法对马鹿冬季栖息地选择进行了研究。共设置了47条样带,调查了72个马鹿利用样方和109个对照样方。结果表明,在黄泥河自然保护区冬季马鹿喜欢选择针阔混交林、食物丰富度和灌丛盖度较高、中等坡度和隐蔽级、远离人为干扰源的生境,避开选择阴坡和针叶林。逻辑斯蒂回归分析揭示坡度、隐蔽级、食物丰富度、坡向、人为干扰距离和林型是影响马鹿栖息地选择的主导因子,灌丛盖度为次要因子。回归模型为:Z=-53.391+0.194×坡度+0.352×隐蔽级+0.5×食物丰富度-0.071×灌丛盖度+1.064×坡向(1)+6.11×坡向(2)+0.004×人为干扰距离+17.305×林型(1)+7.147×林型(2),选择利用概率P(z)=ez/(1+ez),模型正确预测率为94.5%。     

Factors Predicting Den Use by Maternal Giant Pandas

ABSTRACT We studied the denning ecology of giant pandas (Ailuropoda melanoleuca) in the Foping Nature Reserve, China. We identified 17 used and 21 unused cavities of appropriate size to accommodate denning and measured several variables potentially affecting the suitability of these cavities for panda denning. Principal component analysis, combined with traditional univariate tests, indicated that maternal females preferred deeper cavities with a high interior-to-entrance ratio for height and width, suggesting a preference for narrow entrances and roomy chambers. Microhabitat features, including slope and distance to water, were also useful in predicting den use by maternal females. We believe that the availability of suitable dens may limit population size, especially in areas where tree dens have been eliminated by logging of old growth forests. Conservation managers in giant panda reserves can use our data to determine the number of suitable panda dens that are in an area, estimate whether there are enough for the adult female population to use as birthing dens, and—if needed—construct suitable artificial dens to increase the rate of reproduction.     

白颈长尾雉春季扩散活动的影响因子

2002年10月-2003年6月和2003年11月-2004年6月,采用无线电遥测、GPS技术、SAW模型和样方法,对浙江省古田山自然保护区白颈长尾雉的扩散过程及其影响因子进行了研究。结果表明：①白颈长尾雉在春季均存在持续约为16—23d的扩散活动,其扩散直线距离在1．5～2．1km。②扩散过程中白颈长尾雉对其运动路线存在选择性,在其扩散进入和未进入区域之间,草本盖度、乔木种数、灌木种数、灌木枝下高、灌木数量和草本数量存在极显著差异;距水源距离、坡度、乔木数量、乔木枝下高和草本种数存在显著差异。③灌木种数、灌木枝下高、坡度和灌木数量等与障碍有关的因子是影响白颈长尾雉扩散活动的重要因子。     

Finding the right home: distribution of food resources and terrain characteristics influence selection of denning sites and reproductive dens in arctic foxes

We examined 83 arctic fox (Alopex lagopus) dens on Bylot Island (Canada) during the summers of 2003–2005, to determine how arctic foxes select a denning site among potential sites, and a breeding den among existing dens. We compared denning sites to random locations in a 425 km² study area (landscape scale) and to other potential denning sites in a 100 m radius (local scale). Dens were located on mounds or in slopes and were closer to streams than expected. Sites with low snow cover in spring, high ground temperature, high depth to permafrost, and steep and southerly exposed slopes were preferred. Of the 83 dens, 27 were used at least once for reproduction from 2003 to 2005. We show with a resource selection function analysis that an attractive force (distribution of food resources) and an apparently repulsive one (presence of other dens in the vicinity) affected selection of dens for reproduction. We generate testable hypotheses regarding the influence of food and social factors on the denning ecology of arctic foxes. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

喜马拉雅旱獭的洞穴特征及其生态意义

穴居性动物的洞穴对其生存有着重要的影响。为了解喜马拉雅旱獭（Marmota himalayana）利用洞穴特征及其生态意义,于2017年5月至10月以及2018年4月至5月在四川省阿坝州若尔盖县班佑乡多玛村对30对喜马拉雅旱獭繁殖对所利用的洞穴进行了定量研究。按照当年被频繁利用的洞穴（夜宿洞与繁殖洞）与临时利用的洞穴1∶2的比例取样,共测量了90个洞穴的7个物理特征参数,比较了不同类型洞穴的物理特征差异。结果表明：（1）当地喜马拉雅旱獭利用洞穴外径的长轴和短轴分别为59.3 ± 21.9 (16~100) 和45.8 ± 20.5 (18~100) cm,内径内横径和内竖径分别为24.4 ± 4.0 (16~39) 和19.7 ± 3.5 (15~39) cm;（2）洞道首段长为127.3 ± 43.3 (60~240) cm;（3）洞道首段倾斜角度为45.7° ± 9.5° (20°~72°);（4）洞口朝向角度为195.8° ± 96.2° (3°~356°)。除了夜宿洞与繁殖洞临时洞的内竖径有显著性差异,其它不同洞穴类型之间的物理特征基本一致。喜马拉雅旱獭利用洞穴物理特征参数表明其洞穴具有躲避天敌、抵御不良天气、良好的排水性能以及维持洞穴小气候稳定的功能。大部分洞穴之间的物理特征基本一致结合行为观察,说明喜马拉雅旱獭存在年际间的换洞行为。     

典型岩溶流域景观格局动态变化——以云南小江流域为例

根据云南小江流域 1982年的航片和 2 0 0 3年的 TM影像及实地调查资料 ,获得流域两期景观类型图 ,利用 GIS、RS和景观生态学的理论和方法 ,分析了典型岩溶流域景观格局的动态变化及驱动机制。结果表明 :流域 6 10 .12 km2的景观类型发生变化 ,占流域景观总面积的 5 9% ;景观类型变化主要由未利用地向耕地和林地以及林地向耕地的转化 ;流域景观变化速度十分迅速 ,综合变化动态度达 2 .95 % ,园地和耕地景观变化动态度达 34.0 9%、10 .5 5 % ;流域景观的斑块数增加 86 .3% ,平均斑块面积减少 4 6 .1% ,流域景观的基本构型由以大斑块为主体 ,中、小型斑块镶嵌其中转变为以中等斑块为主体 ,大、小型斑块镶嵌其中的构型 ;流域景观多样性指数增长 4 .14 % ,破碎度指数增长 84 .6 % ;未利用地、林地的分离度指数分别增加 114 .5 8%和6 9.6 4 % ,而耕地的分离度指数减少 4 5 .86 % ;流域耕地、建设地重心向东北方向迁移 ,而未利用地、林地、重心向南东、南西方向迁移 ;人文因素是流域景观格局变化的直接驱动力 ,人口增长、经济发展是流域耕地景观变化进而导致系列景观变化最根本的原因 ,而比较经济利益和理智的生态环境保护政策是流域林地景观变化的主要原因     

A Multiscale Assessment of Den Selection by Black Bears in Louisiana

ABSTRACT Understanding den selection for the federally threatened Louisiana black bear (Ursus americanus luteolus) will assist managers in effectively managing bear populations and the landscapes they inhabit. We assessed den selection of 72 female Louisiana black bears at multiple spatial scales in northern and central Louisiana, USA. We used 230 den-years to examine den type preference, microhabitat characteristics of dens, and effects of landscape characteristics on den selection. We also evaluated reuse of tree dens and their availability across several study areas. Bears selected tree dens more frequently (65%) than ground dens. Most (55%) ground dens were associated with standing or downed trees, and most tree dens were in baldcypress (Taxodium distichum; 86%) or surrounded by water (80%). Selection of ground dens was positively associated with landscape metrics related to presence of water, whereas selection of tree dens was positively associated with proximity to edge and greater proportions of swamp and areas containing water. Reuse of tree dens averaged 15% (range = 0–20%) across study areas and our estimates of tree-den availability indicated that tree dens were not a limiting resource for Louisiana black bears in the northern or central portions of Louisiana. Although Louisiana black bears demonstrated plasticity in den selection, we recommend managers use forest management practices that conserve appropriate tree dens and create ground-denning opportunities, because both would promote the recovery of Louisiana black bear populations.     

陕北黄土高原景观破碎化的时空动态研究

景观破碎化受到自然环境背景及社会经济活动的影响,并限制区域发展.为揭示景观破碎化的时空变化特征,整合了MODIS(中分辨率成像光谱仪)影像逐旬数据与多时段景观类型数据, 并对其进行了分析.比较1987～2002年景观破碎化的年际差异表明,陕北黄土高原的景观破碎化过程较缓慢,但具有区域差异,且与景观类型组成息息相关.结果表明,林地的破碎化水平变化显著,而农、草地的破碎化水平变化相对缓慢.年际变化分析有助于说明区域景观破碎化的趋势,而年内季节变化则能帮助认识景观破碎化过程的周期规律.     

Longevity and reuse of black bear dens in managed forests of coastal British Columbia

We evaluated longevity and reuse of denning structures by American black bears (Ursus americanus) in coastal temperate rainforests of British Columbia from 1992 to 2010 to assess potential impacts of forest management on these critical habitat features over time. We identified 67 dens during a 4-yr intensive radio-telemetry study (1992–1995): 40 dens of 21 radio-collared black bears and 27 dens found incidentally. Dens occurred in or beneath large diameter trees or wooden structures derived from trees (i.e., logs, root boles, and stumps; = 143 cm diameter, SD = 49 cm). Longevity of dens varied by type, tree species that formed the den, and forest management that occurred at or near the den. Twenty-four of 28 dens of radio-collared bears that were monitored were still usable in 2010, whereas only 5 of 14 dens found incidentally were still usable in 2010. We assessed reuse of bear dens 3 times following initial identification: during the radio-telemetry study, again in 2000, and finally in 2010. Radio-collared bears reused dens from previous years on 7 of 25 potential occasions during the course of the radio-telemetry study. Upon assessment in 2000 and 2010, 17 of 24 (71%) available dens first used by radio-collared bears were reused at least once between 1993 and 2010. The high rate of reuse may indicate low availability of den structures in our study area. Because black bears in coastal British Columbia only used trees or structures derived from trees for winter dens and forest harvesting reduces the supply of these necessary structures, conservation and recruitment of suitable den trees is necessary if maintaining black bear populations is a management goal in these areas. © 2011 The Wildlife Society.     

Red foxes increase reproductive output of white spruce in a non-mast year

Predators may act as ecosystem engineers by modifying their physical environment through non-trophic interactions. Red foxes (Vulpes vulpes) are ecosystem engineers in the boreal woodlands, a nutrient-poor environment, where their denning activity increases soil nutrient concentrations, affecting the diversity of vegetation around dens. Since dens can persist for many decades and tree growth is enhanced on dens, dens can be used to study the long term impacts of nutrient additions on community and ecosystem processes. We examined the reproductive output of a mast-seeding conifer, white spruce (Picea glauca), on 10 red fox dens and paired control sites at the boreal treeline near Churchill, Manitoba, in July 2019. We estimated cone production in both the current non-mast year (2019) and the previous mast year. The number of cones produced per tree and per hectare was significantly higher on dens than control sites in the non-mast year, but did not differ in the mast year. Higher cone production on dens was partly driven by trees being larger on dens. These results suggest that red fox ecosystem engineering activity affects white spruce reproduction, since increased soil nutrients on dens allow for higher cone production, but the effect of red fox denning is limited by interactions with mast-seeding mechanisms. For example, weather cues may override the effects of denning in mast years, while trees on dens may be able to allocate more resources to reproduction in non-mast years, but store the same amount of resources as trees off dens to produce similarly large cone crops in mast years. Altered resource availability in this nutrient-limited landscape could have additional ecological implications, by affecting the foraging patterns of seed predators and spruce range expansion.