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131.
七姊妹山自然保护区黄杉林群落学特征   总被引:2,自引:0,他引:2  
黄杉为国家Ⅱ级保护植物,是我国特有的第三纪孑遗的珍贵树种,主要分布在我国亚热带的中山地带。采用Braun-Blanquet的植物社会学调查方法并结合典型样方法对七姊妹山自然保护区的原生黄杉群落进行调查,并对其群落特征进行了分析。结果表明:在2300 m~2的调查样地,共有维管束植物52种,隶属24科38属,群落物种组成主要以杜鹃花科、豆科、五加科、壳斗科等种类为主;群落生活型组成分析显示,该黄杉群落高位芽植物占绝对优势,高位芽植物、地面芽植物占比分别为76.9%、13.5%,地上芽和地下芽植物较少,植物的生活型谱大致呈"L"型;群落重要值分析表明,黄杉重要值为53.6,占较大优势,是群落建群种,乌冈栎、石韦分别是灌木层及草本层的优势种,其重要值分别为24.0、54.8;该黄杉群落物种多样性指数整体较低,除均匀度指数外,优势度指数、多样性指数、丰富度指数总体表现出灌木层乔木层草本层,上坡山脊的规律;种群年龄结构分析表明,七姊妹山自然保护区黄杉种群年龄结构呈"L"型分布,属于增长型种群,在一定时间内,表明黄杉仍为该群落的优势种群,林窗的出现使该黄杉群落保持持续更新。  相似文献   
132.
Abstract. Sustainability is an important quality of the types of agriculture nowadays promoted in central Europe, notably ‘biological agriculture’ and ‘integrated production’. Agronomists, decision-makers and the public generally assume that this agricultural sustainability implies the maintenance of species diversity. However, this assumption often does not hold true. This is shown in a case study of moderately ferti-lized Arrhenatheretum meadows in northern Switzerland. Earlier and more frequent mowing, simultaneous harvesting of all the grasslands in a region, and ecological changes in surrounding arable fields, hedges and other ecosystems often cause a decline in plant and animal species richness, while agricultural yield does not noticeably change. To emphasize the distinction the concept of biocenotic sustainability is proposed for describing the capability of a community to maintain its species composition and structure. For maintaining or attaining biocenotic sustainability. results of modern ecology have to be taken into account, e.g. the theories of island biogeography, minimum viable populations, dispersal, and metapopulations. There is evidence that biocenotic sustainability always implies sustainability of agricultural yield.  相似文献   
133.
唐家河国家级自然保护区川金丝猴生境适宜性评价   总被引:2,自引:5,他引:2  
生境适宜性评价是濒危物种保护的重要基础。川金丝猴(Rhinopithecus roxellana)是栖息于温带森林的、中国特有的珍稀灵长类动物。位于岷山山系的四川唐家河国家级自然保护区是川金丝猴的重要分布地之一,但涉及该地区川金丝猴的生境信息却较缺乏。运用最大熵(Maximum entropy,MaxEnt)模型对四川唐家河国家级自然保护区川金丝猴不同季节的生境适宜性进行了研究,发现四个季节的训练集和验证集的受试者工作特征曲线下面积(Area under the receiver operator characteristic curve,AUC)值均超过0.8,说明模型预测结果较好。结果显示:(1)影响不同季节川金丝猴分布的主要因子是海拔、河流和道路。(2)川金丝猴的适宜生境面积存在季节性变化。其中,春季的适宜生境面积最大,为233.94 km2,占全区面积的58.48%;夏季的次之,为192.75 km2,占48.19%;秋冬季的适宜生境面积相对较低,分别为145.54 km2(占36.39%)和142.63 km2(占35.66%)。(3)川金丝猴的适宜生境分布具有明显的季节性垂直变化。研究揭示保护好完整的森林植被带对川金丝猴的生存具有重要意义,尤其要重视对人为干扰较强的低海拔生境的保护。  相似文献   
134.
福建万木林天然马尾松林分特征   总被引:5,自引:0,他引:5  
福建万木林天然马尾松林为以马尾松占绝对优势的松阀混交林,物种多样性与四周的天然阔叶林相近,林分蓄积量高达984.2m3hm-2,是罕见的、典型的天然马尾松丰产林,为珍贵的自然资源。  相似文献   
135.
2014年4月至11月,在卡拉麦里山有蹄类自然保护区的22个水源地安放66台红外相机,其中在8个野放普式野马(Equus przewalskii)利用的水源地放置了16台红外相机,对野放普氏野马在水源地的活动节律和时间分配进行了研究。16台相机累计工作1 068 d,获得野放普氏野马有效照片2 051张。研究发现,野放普氏野马在水源地不同时段的有效照片数量符合正态分布,且季节间存在极显著差异。野放普氏野马在水源地不同时段的有效照片数量,春季远低于夏季和秋季(P0.05),而夏季与秋季差异不显著(P0.05)。野放普氏野马饮水频次春季极显著低于夏季和秋季(P0.01),夏季与秋季差异不显著(P0.05)。普氏野马在水源地具有稳定的日活动节律,时间分配上呈典型的钟形,13:00~17:00时达到高峰,20:00~次日5:00时快速下降,3:00~6:00时是一天中的低谷,在5:00~13:00时快速上升。不同月份野放普氏野马的日活动差异指数α(t=8.364,df=7,P0.01)和昼行性指数β(t=19.519,df=7,P0.01)均存在极显著差异,且β值为0.660.54,表明野放普氏野马活动以昼间为主。季节间活动差异指数存在极显著差异(单样本K-S检验,t=7.851,df=23,P0.01)。独立多样本Kruskal-Wallis检验季节性活动强度指数γ值差异不显著(χ~2=0.162,df=2,P0.05)。通过在卡山保护区固定水源地的实时监测,初步明晰了野放普氏野马在水源地附近的活动节律及其季节性水源地利用,从而为野放普氏野马的生态学研究及保护措施的制定提供科学依据。  相似文献   
136.
Aspalathus linearis (Burm. F) Dahlg., Fabaceae is cultivated by small- and large-scale commercial farmers of the Cederberg and Bokkeveld Plateau in the Cape Floristic Region of South Africa, for the production of an herbal beverage called ‘rooibos’ or ‘rooibos tea’. Small-scale farmers also harvest A. linearis from the wild and market the tea as an organic and fair-trade certified product. However, little is known about the apparent ecotypes of wild A. linearis. We hypothesized that 1) rooibos ecotypes are ecologically distinct (occurring in different plant communities defined by environmental variables); 2) rooibos ecotypes are functionally distinct due to variance in water use efficiency; and 3) rooibos ecotypes are associated with threatened vegetation types/species, making populations of wild rooibos ecotypes worthy of conservation. Ecotypes of wild rooibos were identified based on plant habit and local knowledge. Plant communities were classified using Twinspan, environmental factors were tested as predictors of ecotype distribution and water use efficiency of ecotypes growing across a rainfall gradient was determined from foliar natural abundance of 13C. Wild rooibos was not generally associated with endangered vegetation types but was associated with plant species having endangered status. Wild rooibos occurred in four plant communities and comprised five wild rooibos ecotypes: shrub, tree, upright, salignus and prostrate types. Although some ecotypes clearly co-occurred, evidence is provided for habitat preference between the ecotypes: Prostrate and upright ecotypes occurred at higher elevations (> 400-600 m). Shrub ecotypes occurred at lower rainfall sites (< 200 mm p.a.) and the salignus ecotype occurred at higher rainfall sites (> 500 mm p.a.). Foliar 13C indicated greater water use efficiencies by ecotypes in relatively drier areas. The extent to which this is a plastic or inherent response requires further investigation. Considering that wild rooibos ecotypes differ both ecologically and possibly also functionally and genetically, it is concluded that populations of wild rooibos ecotypes should be considered as distinct and worthy of conservation. This distinctness should be considered when farmers apply for both harvesting and ploughing rights on land with wild rooibos ecotypes.  相似文献   
137.
The conservation of migratory songbirds is often impeded by a lack of understanding of how populations in breeding and wintering areas are geographically linked (migratory connectivity). In recent years, light‐level geolocators have improved our understanding of migratory connectivity. Such information is valuable for evaluating how conservation efforts align between the breeding and non‐breeding areas of at‐risk species, and help to more effectively prioritize the allocation of conservation funding. Golden‐winged Warblers (Vermivora chrysoptera) are imperiled migratory songbirds, but the extent to which conservation efforts in their breeding and non‐breeding areas coincide with patterns of migratory connectivity are not well known. We used light‐level geolocators to evaluate the extent to which conservation actions targeting Golden‐winged Warblers in Nicaragua and in their breeding range in North America align with patterns of migratory connectivity. We recovered six of 22 geolocators that had been deployed on male Golden‐winged Warblers at the El Jaguar Reserve during the winter of 2015–2016. All six males migrated to breeding areas in the western Great Lakes region that includes eastern Minnesota, northern Wisconsin, southwestern Ontario, and Michigan's Upper Peninsula. All six males also had similar migration routes, with spring stopovers in southern Mexico, Guatemala, and Belize, a trans‐Gulf flight, and a stopover in the region of Louisiana, Arkansas, eastern Oklahoma, and Texas. Our results, in combination with those of previous studies, demonstrate strong migratory connectivity between portions of the breeding and winter distributions of Golden‐winged Warblers currently targeted for conservation. However, additional studies are needed to improve our understanding of the stopover ecology of Golden‐winged Warblers, especially in areas where they remain for extended periods of time. Finally, patterns of migratory connectivity revealed in our study should be used in combination with existing demographic parameters for Golden‐winged Warblers in the western Great Lakes and Nicaragua to help inform full life cycle population models for this imperiled songbird.  相似文献   
138.
树鹨(Anthus hodgsoni)为中日两国政府协定保护鸟类。1999~2001年的4~10月,在历山保护区(东经111°51’~112°6’,北纬35°16’~35°27’)对该鸟的生态作了观察。选定富玉河8km的河谷阶地,每年4月上旬和10月下旬隔日观察树鹨最早迁来和最晚迁离的个体;每年5月和8月以富玉河(海拔1550~1750m)、后文堂(海拔1750~2050m)、舜王坪(海拔2050~2358m)3条路线统计其个体数量。  相似文献   
139.
鄱阳湖自然保护区蚌湖和中湖池苦草冬芽的调查   总被引:4,自引:0,他引:4  
1998年 1 2月对鄱阳湖自然保护区内蚌湖和中湖池苦草冬芽进行调查。苦草生活冬芽的平均长度为 3 .0 5± 0 .5 6 cm,平均直径为 0 .84± 0 .1 4cm,平均鲜重为 1 .0 3± 0 .3 0 g,平均干重为 0 .3 0± 0 .1 0 g,含水量为 70 .6 2 %。生活冬芽在蚌湖和中湖池的平均密度分别为 1 5 .8个 /m2和 2 4 .3个 /m2 。苦草冬芽在蚌湖的分布比较均匀 ,在中湖池各采样点的分布有显著差异 ,这种差异与不同采样点的基质状况有关。苦草生活冬芽在基质中分布最大深度为 3 5 cm,在0— 1 0 cm土层中所占比例最大 ;冬芽死亡数以 2 0— 3 0 cm土层中所占比例最大。冬芽分布深度对其以后的萌发有重要影响。  相似文献   
140.
四川省珍稀濒危植物及其保护   总被引:13,自引:0,他引:13  
四川省由于受第四纪冰川影响相对较小而成为许多古老,特有,珍稀植物的“避难所”,被誉为珍稀植物的“摇篮”。综合《中国珍稀濒危保护植物名录》(第一册)和《国家重点保护野生植物名录》(第一批),四川有珍稀濒危植物105种(计54科83属),其中多数种起源古老,单种科,单种属和少种属占较大比例,特有植物丰富,并且绝大多数具有重要的经济价值或在系统发育研究中具有重要意义,在分析四川珍稀濒危植物致濒机制的基础上,进一步提出了保护对策,即:传统保护与 拯救性保护相结合,加强宣传教育和研究工作并切实减少人为破坏活动。  相似文献   
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