大兴安岭猞猁冬季生境选择

采用机械布点法随机设置样线,对猞猁冬季生境选择进行了研究.包括海拔、植被类型、隐蔽度、坡度、坡位、坡向、距水源距离、距人为干扰距离等因素进行了调查,并利用栖息生境的偏爱指数进行计算分析.结果显示:猞猁冬季喜欢栖息在海拔800～1 000m,食物丰富度＞100 gDM/100 m2、隐蔽度≤0.3、水源距离＜1000m、人为干扰距离＞2 000 m的针阔混交林或针叶林中活动,喜欢活动于坡度较陡的生境,且多集中与上坡位.猞猁对坡向和雪深无明显的选择性.     

麋鹿非繁殖期生境适宜度评价指标探讨

根据麋鹿生境分布特点,将影响麋鹿生境适宜度的因素分为非生物因子、生物因子和干扰因子,运用麋鹿的生物学、生态学研究成果,对我国麋鹿生境适宜度评价指标进行了探讨。在众多影响麋鹿生存的因子中,植被、食物、水源、外界干扰、生境类型、生态安全等被确定为影响麋鹿生境适宜的主要评价因子,制定了麋鹿生境适宜度评估模型,并赋予了相应分值,可为我国麋鹿栖息地评价提供参考。     

基于Maxent模型的长青自然保护区毛冠鹿栖息地适宜性评价

为全面了解长青自然保护区毛冠鹿(Elaphodus cephalophus)的生境状况,利用2018-2020年于辖区内收集的样点数据,应用Maxent模型对长青保护区的毛冠鹿栖息地适宜性进行评价。结果显示：(1)毛冠鹿适宜等级栖息地约占辖区面积的13.9%,最适宜等级栖息地约占10.4%;(2)环境因子是影响毛冠鹿生态适宜性的最重要因素,包括主要河流(33.5%)、小河(16.1%)、主要道路(10%)、林区小道(8.7%)、植被类型(8.6%)、坡向(6.1%);气候因子影响有限,其中影响最大的是最湿季降水量(3.6%);(3)毛冠鹿适宜栖息地为距离主要河流、小河、林区小道分别小于1 200、500、1 000 m,距离主要道路2 500～8 000 m之间,适宜植被类型为盖度适中的针阔混交林,主要活动的坡向为西北、西和西南坡向。本次研究基本明确了辖区内毛冠鹿的分布情况和主要影响因子,为进一步的野生动物管护工作提供理论依据。     

狗獾夏季生境选择

在黑龙江省方正林业局新风林场,通过痕迹检验法和洞穴辨别法对狗獾夏季生境选择进行研究的结果表明：狗獾夏季利用样方法和对照样方在乔木密度、乔木距离、灌木密度、植被盖度、距水源距离生态因子方面差异极显著（P〈0．001）,在乔木高度上差异显著（P〈0．05）,其余的生态因子无显著差异（P〉0．05）;相对于对照样方而言,狗獾夏季更偏爱在海拔322m左右、优势乔木为紫椴、乔木密度6．81左右、乔木高度在12m以上、乔木距离大于4．5m、乔木盖度小、灌木密度较高、植被盖度较低、距水源距离较近、坡位为中坡位的生境下活动;运用皮尔逊相关性检验模型的预测率达到97．2％,说明模型能够很好的反应狗獾夏季生境选择的基本情况。     

临安青山湖景区白鹭栖息地选择探析

以临安青山湖景区的白鹭为研究对象,采用样线法和样方法,对白鹭栖息地多个生态因子进行研究。结果表明,利用样方和对照样方中的水深度(t=-4.607,P=0.000)和距人工干扰距离(t=4.261,P=0.000)变量差异极显著;植被盖度(t=-2.474,P=0.017)变量差异显著;遮蔽度(t=-2.308,P=0.300)变量差异不显著。白鹭觅食地选择偏好为水深0～30 cm、距人工干扰距离50 m、植被盖度0～25%的区域。城市湿地中白鹭栖息生境选择的最大限制性因子为距人工干扰距离,因此,应尽量减少对白鹭的人为干扰,为其提供良好的栖息生境。     

卧龙大熊猫栖息地红腹角雉冬季生境选择的研究

采用样线法和样方法对卧龙＂五一棚＂区域内的红腹角雉（Tragopan temminckii）冬季栖息生境进行了调查。结果显示,红腹角雉冬季喜欢在2 400～2 800 m海拔段东坡陡峭坡面（﹥45°）的中坡位和下坡位活动,活动生境一般位于距水源近（0～100m）、林下植被盖度（0.10～0.15）和竹子盖度（0.6～0.9）较好,大树较多（5～10株.样方-1）的位点。通过与前人对大熊猫（Ailuropoda melanoleuca）生境选择研究的对比,发现虽然红腹角雉与大熊猫同时分布于五一棚相同海拔段和竹子盖度相似的区域,但选择的坡度不同（大熊猫选择20°～40°的坡度）,并且两者在食性上差异显著。对自然因子和主要食物要求的差别,可能正是红腹角雉和大熊猫能长期共存于＂五一棚＂区域的原因。     

塔里木河下游荒漠植被地上生物量空间分布与地下水埋深关系

【目的】研究荒漠植被地上生物量随距河道距离的空间分布特征,并结合地下水埋深数据分析地上生物量与地下水埋深之间的关系,以期为干旱荒漠区生态环境恢复和重建提供理论依据。【方法】以塔里木河下游英苏断面荒漠河岸林植被为对象,于2014年9月下旬在英苏断面布设垂直河道、100 m×100 m的标准地20块,形成长2 000 m的连续样带,记录标准地内乔木、灌木的物种数、总个体数及冠幅、株高、胸径等形态因子,根据胡杨生物量模型和获取的灌木标准枝鲜质量,分别计算胡杨和灌木的地上生物量;将标准地进一步分割为4块50 m×50 m的样地,在每个样地对角线两侧随机布设6~8个1 m×1 m的样方,记录草本种类、个体总数等因子,并将样方内草本齐地面刈割,获取地上生物量数据。结合样带植被群落地上生物量数据和地下水埋深数据,拟合二者之间的方程,并进行显著性检验。【结果】塔里木河下游荒漠植被地上生物量与距河道垂直距离和地下水埋深均显著负相关(P0.05),总地上生物量、乔木层和灌木层地上生物量均随距河距离增大而减少,草本地上生物量则呈"先小幅度增加后持续减少"的单峰型变化趋势;样带内乔灌草总地上生物量主要分布在地下水埋深4 m(距河0~300 m)范围内,地上生物量可达855.06 g·m-2;当地下水埋深在4~5.5 m(距河道300~1 000 m)时,地上生物量为321.08 g·m-2,减少62.45%;当地下水持续降到5.5 m(距河道1 000~2 000 m)时,地上生物量只有110.19 g·m-2,比河道附近减少了87.11%。【结论】塔里木河下游荒漠植被群落组成和地上生物量随距河道距离和地下水埋深变化呈现显著的空间异质性,表明地下水埋深是影响荒漠植被群落组成和地上生物量的一个重要因子,同时也反映出河道作为荒漠河岸林的主要水源控制荒漠植被的空间分布和结构,体现出极端干旱区生态系统空间分布和结构特征的特殊控制机制。     

三江自然保护区丹顶鹤春季觅食生境初步研究

采用样方因子测定法对三江国家级自然保护区丹顶鹤春季觅食生境进行调查研究的结果表明:丹顶鹤春季主要在以苔草、小叶章为主的沼泽湿地中觅食;觅食地植被高度小于40 cm,植被密度低于400株/m2,植被盖度为0～25%,觅食地水深多为5～15 cm,人类干扰距离大于1 500m;人为活动严重影响着丹顶鹤的觅食;春季丹项鹤有在...     

四川黑竹沟国家级自然保护区珙桐和光叶珙桐种群特征及生境适宜性评价

综合运用常规种群调查法和最大熵模型法,对四川黑竹沟国家级自然保护区的珙桐、光叶珙桐种群结构与适宜生境的研究结果表明:保护区内的珙桐、光叶珙桐种群处于初衰型和衰退状态,种群生存空间狭窄。珙桐种群的适宜、次适宜生境面积分别为39.54 km~2和158.75 km~2,主要影响因子为海拔、植被类型和坡度;光叶珙桐种群适宜、次适宜生境面积分别为48.07 km2和176.26 km~2,主要影响因子为海拔和植被类型。     

唐家河国家级自然保护区藏酋猴(Macaca thibetana)的生境选择

2013年3月至2014年2月,在唐家河国家级自然保护区毛香坝区域对对一群数量50只～60只的野生藏酋猴生境选择进行了研究.根据藏酋猴的活动位点,设置了96个20 m×20 m的植物样方,测定了植被类型、乔木密度、乔木胸径、乔木高度、郁闭度、灌丛盖度、地理性、海拔、坡向、坡度、坡位、水源距离、干扰距离等13个生态因子.对该群藏酋猴生境选择喜好程度分析表明,唐家河国家级自然保护区的藏酋猴偏好利用常绿落阔混交林、落叶阔叶林.猴群选择在乔木平均胸径20 cm ～30 cm和平均高度为11 rn～20 m的森林活动.它们不选择郁闭度＜20％的树林,主要位于海拔1 500m～2000m的地带活动.该群藏酋猴主要栖息于山坡面的森林,活动地点的坡度多介于20°～40°之间.该群藏酋猴对水源距离和干扰距离没有严格要求.     

Resource selection of moose (Alces alces cameloides) and their response to human disturbances in the northwestern slope of Lesser Khingan Mountains, northeastern China

Moose (Alces alces cameloides) is typically representative of the fauna of the frigid temperate zone and has been put on the Chinese second priority list of protected animals. The moose of northeast Ch...     

Long-term responses of ecosystem components to stand thinning in young lodgepole pine forest: IV. Relative habitat use by mammalian herbivores

Pre-commercial thinning (PCT) is a silvicultural practice that can provide diverse understory and overstory vegetation conditions. We tested the hypothesis that relative habitat use by snowshoe hare (Lepus americanus), mule deer (Odocoileus hemionus), and moose (Alces alces) would increase in response to enhanced abundance of herbs and shrubs, and species diversity and structural diversity of conifers, in heavily thinned (≤1000 stems/ha) stands, at 12–15 years post-thinning. Replicate study areas were located near Penticton, Kamloops, and Prince George in south-central British Columbia, Canada. Each study area had three young pine stands thinned to densities of 500 stems/ha (low), 1000 stems/ha (medium), and 2000 stems/ha (high), with an unthinned young pine and old-growth pine stand for comparison.

Relative habitat use, based on counts of fecal pellets and pellet-groups, was similar among the five treatment stands for hares (P = 0.24), deer (P = 0.23), and moose (P = 0.16). However, low-density stands (500 stems/ha) had ca. 3–20 times as many deer pellet-groups, and ca. 2–4 times as many moose pellet-groups, than other stands. Low-density stands had significantly greater canopy openness, volume of shrubs <2 m, and horizontal hiding cover <1.6 m than other treatments. Relative habitat use by deer and moose was positively related to understory characteristics such as enhanced abundance of forage and security cover. These results support our hypothesis that deer and moose responded positively to enhanced volume of herbs and shrubs as well as to species diversity and structural diversity of conifers and overall vegetation in heavily thinned (≤1000 stems/ha) stands at 12–15 years post-thinning. Our results suggest that ungulate management would be enhanced if greater emphasis was placed on forage enhancement throughout the year, which differs from current management recommendations which tend to focus on winter range and snow-interception cover.     

基于MaxEnt模型对大花序桉 在我国南方的适生区预测

大花序桉材性优良是我国重要的实木利用树种,本文对大花序桉在我国南方十省(区)的潜在分布区进行预测,并对其适生区进行划定和分析.通过收集大花序桉的地理信息数据,利用最大熵模型(MaxEnt)和ArcGIS空间分析技术,综合相关气候因子,预测划定大花序桉在我国南方十省(区)的潜在地理分布区.结果表明:采用MaxEnt模拟大花序桉潜在地理分布的准确性较高,模型预测准确性的衡量指标训练子集和验证子集AUC值均大于0.88.大花序桉在我国南方的发展空间较大,其中最适宜分布区主要集中在广东、广西、海南、福建沿海,面积依次为广东(11.25×104 km2),广西(9.19×104 km2),海南(2.00×104 km2),福建(1.91×104 km2);适宜区集中在广西、广东、重庆、福建省中部,面积依次为广西(5.87×104 km2)、广东(4.51×104 km2)、重庆(3.64×104 km2)、福建(3.02×104 km2).刀切法(Jackknife)分析结果显示,影响大花序桉潜在适生区分布的主导气候因子为年平均气温、≥10℃积温、最冷月最低温、最冷月均温和极端低温.结合最大熵模型(MaxEnt)和ArcGIS技术,预测和分析了大花序桉在我国南方十省(区)的潜在适生区,阐明了影响其分布的主导气候因子,为该树种在我国的有序推广种植提供科学依据.     

岷山山系土地岭大熊猫栖息地廊道特征及影响因素分析

本文采用景观生态学的斑块理论,根据土地岭区域前后两期森林分布信息和大量的野生动植物以及社会经济信息,详细分析了土地岭区域建立大熊猫栖息地走廊带的植被分布格局、斑块结构、廊道特征及主要影响因素,研究结果显示土地岭区域植被符合大熊猫栖息地建设条件。残余班块分布连续,占据区域森林植被的主体,有利于廊道栖息地恢复。引进斑块面积大,质量差,是廊道栖息地建设的主要改造类型。在众多的社区活动影响中,采笋的负面影响最大,最值得重点关注。基于一些主要因素的分析,作者提出了在土地岭建立大熊猫栖息地走廊带的关键措施。     

Floristic diversity, regeneration status, and vegetation structure of woodlands in Metema Area, Amhara National Regional State, Northwestern Ethiopia

We studied woodland vegetation in broad-leaved deciduous woodlands of Metema in northwestern Amhara regional state, Ethiopia Our objective was to describe plant species composition, diversity, regeneration status, and population structure by a selective approach with asystematic sampling design. A total of 74 quadrats (each for 25 m × 25 m,spaced at intervals of 150 200 m) were sampled along established transect lines following the homogeneity of the vegetation. Vegetation data including cover-abundance, height, diameter at breast height (DBH), and numbers of seedlings and saplings of woody species were analyzed using Excel spreadsheet, Shannon Weiner diversity index, and PAST version 1.62. A total of 87 vascular plant species of 74 genera and 36 families were recorded. The dominant family was Fabaceae represented by 16(18.39 %) species of 13 genera. Shannon Weiner diversity and evenness were 3.67 and 0.82, respectively, which showed that the area was endowed with rich floral diversity evenly distributed. The vegetation structure, as quantified by cumulative diameter class frequency distribution,plotted as an interrupted inverted-J-shape pattern with a sharp decreasein the 2nd diameter class. This indicated poor vegetation structure. The diameter classes frequency distributions of selected species plotted infour general patterns i.e., interrupted Inverted-J-shape, J-shape,Bell-shape and Irregular-shape. In conclusion, although the area showedhigh floral diversity and evenness, woody species including Sterculea setigera, Boswellia papyrifera, and Pterocarpus lucens showed lowest recruitment of seedlings and saplings.     

A study of habitat fragmentation in Southeastern Brazil using remote sensing and geographic information systems (GIS)

The purpose of this work was to study fragmentation of forest formations (mesophytic forest, riparian woodland and savannah vegetation (cerrado)) in a 15,774-ha study area located in the Municipal District of Botucatu in Southeastern Brazil (São Paulo State). A land use and land cover map was made from a color composition of a Landsat-5 thematic mapper (TM) image. The edge effect caused by habitat fragmentation was assessed by overlaying, on a geographic information system (GIS), the land use and land cover data with the spectral ratio. The degree of habitat fragmentation was analyzed by deriving: 1. mean patch area and perimeter; 2. patch number and density; 3. perimeter-area ratio, fractal dimension (D), and shape diversity index (SI); and 4. distance between patches and dispersion index (R). In addition, the folowing relationships were modeled: 1. distribution of natural vegetation patch sizes; 2. perimeter-area relationship and the number and area of natural vegetation patches; 3. edge effect caused by habitat fragmentation. The values of R indicated that savannah patches (R = 0.86) were aggregated while patches of natural vegetation as a whole (R = 1.02) were randomly dispersed in the landscape. There was a high frequency of small patches in the landscape whereas large patches were rare. In the perimeter-area relationship, there was no sign of scale distinction in the patch shapes. In the patch number-landscape area relationship, D, though apparently scale-dependent, tends to be constant as area increases. This phenomenon was correlated with the tendency to reach a constant density as the working scale was increased. On the edge effect analysis, the edge-center distance was properly estimated by a model in which the edge-center distance was considered a function of the total patch area and the SI.     

托里桉在我国南部的潜在地理适生区预测

本文通过收集托里桉的实地栽培点地理数据,运用最大熵软件(Maxent)和地理信息系统技术(ArcGIS),结合12个气候因子数据,预测划定了托里桉在我国南部的潜在地理适生分布区。结果表明:Maxent模拟托里桉的潜在地理分布准确性较高,模型预测训练子集和验证子集AUC值均大于0.87。托里桉最适宜分布区集中在广东和海南沿海、广西沿海和中部及福建南部沿海,面积依次为广东(8.63×10~4 km~2)、海南(2.65×10~4 km~2)、广西(2.22×10~4 km~2)、福建(1.18×10~4 km~2);适宜区集中在广西中南部、广东中北部、福建南部、江西中南部,面积依次为广西(10.17×10~4 km~2)、广东(6.15×10~4 km~2)、福建(2.52×10~4 km~2)、江西(1.43×10~4 km~2)。Maxent刀切法(Jackknife)分析结果表明:影响托里桉适生区分布的主导气候因子为年平均气温、≥10℃积温、极端低温、最冷月最低温、最冷月均温、≥10℃的天数。     

新疆阿尔泰山小东沟林区木本植物群落数量分类、排序及其环境解适

在野外样方调查和主要环境因子测定的基础上,利用聚类分析和DCCA排序技术对新疆阿尔泰山小东沟林区的森林植被进行类型划分,并定量分析植被与环境因子的关系。结果表明:利用聚类分析可将阿尔泰小东沟林区的木本植物群落划分为6个类型(灌丛、欧洲山杨林、苦杨林、疣枝桦林、新疆落叶松林和新疆落叶松与新疆冷杉、新疆云杉的针叶混交林)。DCCA排序分析表明,海拔和坡向等地形因子以及土壤类型、土壤全氮、土壤全磷、土壤水分含量和大石砾含量等土壤因子是影响阿尔泰林区植物分布的主要因子,林区不同群落类型的分布格局主要是由地形和土壤因子的共同作用所控制的。     

Paper birch (Betula papyrifera) shoot selection by moose (Alces alces) following a forest-cleaning experiment

Abstract

In order to maximize food intake per harvesting effort and minimize energy expenditures required to move between feeding patches in nature, herbivores such as moose (Alces alces L.) generally select large plant shoots when browsing in winter. To determine moose preferences for shoots of different morphologies, an experiment was conducted in northern British Columbia in which shoots from birches cut at different times of the growing season were fed in 2 consecutive years to eight human-habituated moose in cafeteria-style feeding trials. The results indicate that moose preferred smaller winter shoots of birches regardless of when the parent plant was cut and also appeared to reject larger shoots containing sylleptic branches. It is argued that the preferences for smaller shoots by moose detected in these trials should be observable under natural conditions, but are generally only supported by literature from some parts of Scandinavia. The findings underscore the importance that factors such as mouth filling per harvesting effort, snow depth and consistency, predators and browse patch distribution must have on foraging decisions made by moose while browsing in the wild. Implications of the findings include the significance of cutting time on the size of shoots produced by birch after cutting, how this affects moose browsing birch and, subsequently, how managers can theoretically use cutting time as a tool in forest cleaning operations to direct the foraging efforts of moose towards or away from forest plantations.     

哈尼梯田核心区水文要素变化特征分析

选用元阳县新街镇1958~1996年的降雨量和蒸发量数据资料,收集哈尼梯田核心区主要河流的产水模数,运用距平分析等方法对梯田核心区水文要素进行分析计算.结果表明,元阳梯田核心区降雨、蒸发年内分配不均匀,年际变化趋势不显著.降雨主要集中在5~10月,占全年降水量的76.50%以上,蒸发量主要集中在3~8月,占全年蒸发量的62.96%以上,计算得出干旱指数为0.768 9,产水模数为63.94万m3/km2.