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1.
根据64个植被样方调查资料,分析卧龙自然保护区大熊猫栖息地植物群落多样性特征.结果表明:卧龙自然保护区大熊猫栖息地不同植被类型的物种多样性指数值H'、D和均匀度指数Jsi基本表现出一致的变化趋势:常绿落叶阔叶林>温性针阔混交林>落叶阔叶林>温性针叶林>亚高山针叶林,而物种丰富度S变化为温性针叶林>落叶阔叶林>常绿落叶阔叶林>亚高山针叶林>温性针阔混交林.在不同的植物群落中,由于地形地势、坡度、土壤、水热条件等原因,其物种多样性指数不同,但其多样性测度指标除物种丰富度外均呈现出基本一致的变化趋势.随海拔的升高,大熊猫栖息地物种丰富度、多样性指数和均匀度变化先增加,然后下降,最后趋于平稳.坡度不是影响卧龙野生大熊猫栖息地生物多样性的关键因子.不同的坡向其物种丰富度S变化为西>北>东>南,物种多样性指数H'、D呈现西>南>北>东的递降格局,均匀度指数Jsi呈现南>西>东>北的递降格局.在不同的群落中,物种丰富度变化表现为灌木层>乔木层>草本层,且42.9%群落中乔木层大于灌木层、64.3%群落中乔木层大于草本层、92.9%群落中灌木层大于草本层,落叶针叶林乔木层树种丰富度小于灌木层和草本层,但其灌木层物种丰富度大于草本层.在同一或不同生长型中,物种多样性指数和均匀度指数变化大体一致.  相似文献   

2.
Community forestry is expanding in developing countries but there is limited knowledge of, and contradictory findings about, its contribution to biodiversity conservation. This study aims at increasing the understanding of tree species diversity in community forests compared to National Parks. A forest inventory was carried out in four community forests and one National Park in the mid-hills of central Nepal. The study found that community forestry has contributed to high tree species diversity where forest management communities have interests in multiple species, but most community forests are moving toward promoting limited timber yielding species that have high economic value. Linking community forestry with economic incentives for conserving multiple tree species could therefore be a strategy to conserve biodiversity outside of protected areas.  相似文献   

3.
利用α多样性指数、β多样性指数以及重要值,对松树山主要森林群落(油松)林下灌木层和草本层的物种多样性以及群落结构进行了研究,结果表明:(1)在群落结构方面,松树山油松天然林垂直结构层次分明,划分为乔木层、灌木层和草本层;乔木层油松胸径大部分集中在15 ~25 cm,占全部油松的56.50%;(2)从各层植物组成特征来看...  相似文献   

4.
In this article, we compared the structure, composition, and diversity of trees, shrubs and saplings, seedlings and herbaceous species of community- and government-managed forests in the lowlands of eastern Nepal. Results suggest that among the trees, the community forest was dominated by a single species, Shorea robusta. However, Shorea robusta and Terminalia myriocarpa were codominant in the government forest. Tree density and basal area were higher in the government forest, but shrub/sapling density and basal area were higher in the community forest, suggesting a positive effect of community management on tree regeneration. Overstory species assemblages showed an obvious compositional difference between the forests, but understory species assemblages were less obvious. Plot-level tree and shrub/sapling species richness was higher in the government forest than the community forest. However, seedling-herbaceous species richness was higher in the community forest. The dominance of Shorea robusta trees in the community forest suggests that people involved in managing forests may be more interested in a limited number of economically valuable species while removing less important trees. Such preferential management practices may increase resource heterogeneity within a forest and maintain species diversity in the understory. Thus, community participation in forest management should be encouraged, with guided management techniques and exercises, to achieve maximum forest recovery, provide sustainable ecosystem services, and maintain forest diversity.  相似文献   

5.
桉树人工林昆虫群落结构及其多样性初步调查   总被引:2,自引:0,他引:2  
对桉树人工林系统昆虫种类进行调查和鉴定,记录了桉树人工林昆虫种类共有16目63科106种.从群落物种数来看.鞘翅目的物种丰富度最高(20.56%);从物种的个体数量看,鳞翅目昆虫的数量最多(30.71%);桉树林昆虫总的群落多样性指数为1.3933,均匀性指数为0.9301,鞘翅目的群落多样性指数(0.2937)和均匀性指数(0.2108)都最大.文中就昆虫群落多样性与稳定性的关系以及如何抑制害虫发生等问题进行了讨论.  相似文献   

6.
基于广东省典型低效生态公益林林分类型——马尾松纯林、杉木纯林及针阔混交林群落的样方调查,分别对其物种组成、区系成分、植被结构特征、物种丰富度和多样性进行了研究。结果表明:在18个调查样方中,共记录到维管束植物58科 92属149种,热带亚热带区系特征明显;几种典型低效生态公益林群落垂直结构都相对简单,均尚处于植被演替的较早期阶段;物种丰富度指数为32~66,Shannon Wiener多样性指数值为0.61~3.15,Simpson优势度指数值为0.26~0.89,以及均匀度指数值为0.15~0.89。文章初步探讨了影响生态公益林植物多样性的主要因素和提高不同类型低效生态公益林植物多样性的途径。  相似文献   

7.
2004年8月至9月对北京云蒙山森林公园的雀形目鸟类群落组成以及分布进行了调查,结果显示,该区域共有雀形目鸟类15科41种,其中包括古北型15种,东北型9种,广布型4种,南中国型和东洋型各3种,华北型和全北型各2种,东北型(东部为主)、喜马拉雅-横断山型、季风型各1种;居留性方面,留鸟18种,夏候鸟13种,旅鸟10种。  相似文献   

8.
应用样方调查法,对海南尖峰岭半落叶季雨林的物种组成结构及多样性特征进行研究。结 果表明,在总面积5 000 m2 的样方中,共记录到胸径≥ 1 cm 的植株2 565 株,除 3 个种未确定种名外, 其他分属26 科 42 属 46 种。以大戟科(Euphorbiaceae) 和桑科(Moraceae) 为优势科,以刺桑(Streblus ilicifolius)、布渣叶 (Microcos paniculata) 和鹊肾树 (Streblus asper) 为优势种。当取样面积达到 3 850 m2 或 取样植株数达到 1 800 株时,记录到的物种数有 47 种,占总物种数的 95.92%。样地内所有植株平均胸径 为 6.36 cm,径级分布呈倒“J”型。刺桑、赤才(Lepisanthes rubiginosa) 和粗糠柴(Mallotus philippensis) 的空间分布呈较强的聚集性,布渣叶和鹊肾树的分布较均匀。Shannon-Wiener 多样性指数和Simpson 多 样性指数较低,样地的物种种类较少,植株分布的不均匀。  相似文献   

9.
对湖南省南岳原生性森林群落植物物种进行了研究.结果表明,其多样性水平比较高,接近山地季雨林的水平,其中,群落草本层的多样性水平最低,乔木层和灌木层的较高.在5种不同的原生性森林群落类型中,乔木层和草本层的物种多样性以类型3(包石栎 锐齿槲栎 甜槠 多脉青冈-箬竹-求米草群丛)的最高, 以类型4(甜槠-花竹 云和新木姜子-淡竹叶 莎草群丛)的最低;灌木层物种多样性以类型3(包石栎 锐齿槲栎 甜槠 多脉青冈-箬竹-求米草群丛)的最高, 类型2(长叶石栎 多脉青冈-尾叶山茶-求米草群丛)的最低.植物物种相对多度分布格局的测定结果表明,分割线段模型中的序列-多度模型适宜于拟合乔木层物种与其个体数量之间的关系,对数级数分布模型适宜于拟合乔木层和灌木层;其α指数值较高,说明群落物种多样性水平较高,接近山地季雨林.分析表明, 测定群落植物物种多样性时, 如果仅用1~2个公式计算, 可能会出现错误的结果;此外, 提出了几何级数分布模型--极大值算法.  相似文献   

10.
对东莞板岭生态公益林林分改造所用的55个树种的基径和树高生长量按季节进行调查,为期2年,结果显示:春分~秋分是这些树种的生长峰期.对大多数树种而言,温度对生长量的影响最大,其次是降水、日照时数,春分~夏至期间的水热条件最适宜树木的生长.进一步分析发现猫尾木、吊瓜木、楠木、云南石梓、米老排、香椿、阴香对水热条件较敏感,红锥、密花树、蓝花楹、竹节树、樟树、火力楠、西南荷、格木对水热条件的适应性较强;猫尾木、吊瓜木、云南石梓、石梓、乌墨、木波罗、扁桃性喜高温多雨,生长最高峰出现在夏至~秋分;肖蒲桃、格木、木波罗、乌墨、华杜英受日照时数的影响较大,密花树、猴欢喜、长叶竹柏、蓝花楹、竹节树、扁桃受日照时数的影响较小.这对植物引种和树种选择有一定的指导意义.  相似文献   

11.
Several studies have looked at the relative importance of habitat association of tree species in maintaining tropical tree species diversity at a variety of scales including the importance of edaphic factors. The objective of this study was to test hypotheses on the distribution of important timber species in relation to topographic position and soil chemical parameters. Tree species from a Central African rain forest were selected within a 100-ha plot in southwestern Central Africa Republic. Individuals of Lovoa trichilioides, Nesogordonia papaverifera, Pterocarpus soyauxii, Terminalia superba ≥ 10 cm diameter at breast height (dbh) were inventoried then mapped to topography using a survey laser. A torus translation was performed to test for associations between tree species distribution and topographic position as well as soil mineral nutrients for three of the four species. Trees ≥ 30 cm dbh of all three species showed no association with topographic position. However, the distribution of T. superba was significantly associated with high concentrations of soil mineral nutrients. Evidence from mineral nutrient levels indicates that extrapolating topography to define habitat and soil type can be very misleading. Because many of Central Africa's most important timber species have distributions linked to edaphic factors, it is clear that soils must be considered equally as much as topographic position for management plans of logging concessions within Central African tropical forests.  相似文献   

12.
岷江上游人工油松林群落空间结构:物种丰富度和盖度   总被引:9,自引:0,他引:9  
在岷江上游油松人工林中调查了1hm^2群落空间垂直结构上的乔木、灌木和草本层的盖度和物种丰富度,以及2个100m长样带上的林窗斑块和油松斑块(冠幅相互连接的油松个体被合并为同一斑块)内部的群落水平结构变化。结果发现:群落的垂直空间结构上,乔木层(油松)盖度与灌木层盖度、林下总盖度(灌木和草本层的盖度和),以及林下物种丰富度(物种数量)成显著负相关,灌木层盖度与草本层成显著负相关。林下物种丰富度与总盖度呈显著正相关,但在灌木层和草本层内部,物种丰富度与盖度间没有显著相关性。水平空间结构上,随油松斑块增大,斑块内灌木层盖度下降,草本层盖度上升;物种丰富度约在油松斑块直径为12~15m时达到最大。在林窗内部,物种丰富度和灌木层盖度在林窗边缘高于林窗中央,而草本层盖度在林窗边缘较高。考虑到不同斑块大小支持不同物种的生存,岷江上游油松人工林应建立由不同大小的斑块(林窗和油松斑块)组成的镶嵌式群落.  相似文献   

13.
通过陷阱法调查云南省主要柠檬产区9种类型柠檬园地表蚂蚁群落。采集地表蚂蚁52种2 641头,地表蚂蚁群落结构划分为5组。不同类型柠檬园地表蚂蚁特有种不同,柠檬园BC、BB及LE无特有种,柠檬园BA有1种,其余柠檬园有2~10种。6种以上柠檬园中均出现的物种在不同类型柠檬园中的多度变化明显。对群落结构相似性贡献率≥5%的特征物种分析显示,9种类型柠檬园间地表蚂蚁特征物种明显不同;柠檬园LE、BB及RI的指示物种各有1种,分别为宽结大头蚁Pheidole noda、黑头酸臭蚁Tapinoma melanocephalum及印度大头蚁P.indica。蚂蚁的生物学特性与样地特征相关联,地表蚂蚁通过物种组成及多度变化对不同类型柠檬园做出了响应。9种类型柠檬生产方式不利于地表蚂蚁群落的保护,建议柠檬生产中减少化学农药的使用,一定程度提高植被复杂程度,降低人为干扰,增加柠檬绿色生产技术的投入。  相似文献   

14.
We investigated the effects of herbaceous and woody vegetation control on the survival and growth of planted eastern white pine (Pinus strobus L.) seedlings through six growing seasons. Herbaceous vegetation control involved the suppression of grasses, forbs, ferns, and low-shrubs, and was maintained for 0, 2, or 4 years after white pine seedlings were planted. Woody control involved the removal of all tall-shrub and deciduous trees, and was conducted at the time of planting, at the end of the second or fifth growing seasons, or not at all. Seedling height and basal diameter responded positively and proportionally to duration of herbaceous vegetation control. Gains associated with woody control were generally not significant unless some degree of herbaceous vegetation control was also conducted. Only herbaceous control increased pine crown closure and rate of crown closure. Herbaceous control and the presence of 5000–15,000 stems per ha of young overtopping aspen were associated with reduced weevil (Pissodes strobi Peck.) injury and increased pine height growth. The study suggests that white pine restoration strategies on clearcut sites should focus on the proactive, early management of understory vegetation and the gradual reduction of overtopping cover from woody vegetation to create a seedling light environment that supports acceptable growth with minimal weevil damage.  相似文献   

15.
The achievement of sustainable forest management requires the incorporation of risk and uncertainty into long-term planning. Climatic change will have significant impacts on natural disturbances, species and ecosystems, particularly on landscapes influenced by forest management. Understanding where vulnerabilities lie is important in managing the risks associated directly or indirectly with climatic change. The vulnerability of landscapes to natural disturbances, the resilience of ecosystems and distribution of species are all important components that need to be considered when undertaking forest planning, but climatic change is rarely factored into such planning. In this study, the vulnerability of fire potential, fire regimes, ecosystems and species to climatic change was modelled for a 145,000 ha landscape in the south-central interior of British Columbia, Canada. The results from these analyses were used to guide forest zoning, using the triad zoning framework, and for the development of a “climate-smart” management framework. The use of climate-smart management is advocated as a decision-making framework for managing forested landscapes based on an understanding of landscape vulnerability to future climatic change. From this understanding, the maintenance of ecosystem health and vitality could be achieved.  相似文献   

16.
The impact on tree and amphibian diversity of line-planting of tropical hardwoods—mahogany (Swietenia macrophylla × S. mahagoni) and mahoe (Hibiscus elatus)—was studied in a secondary subtropical wet forest of Puerto Rico. Common coqui (Eleutherodactylus coqui) and melodious coqui (E. wightmanae) are the most frequent frog species; forest coqui (E. portoricensis) is less abundant. Although relative abundance means were slightly greater in the undisturbed forest and during the wet season, differences were not statistically significant suggesting that line-planting did not significantly affect amphibian diversity. The line-planted areas had a slightly higher, but not statistically significant diversity, richness, and evenness of tree species than the unplanted forest. Multi-response permutation procedure (MRPP) showed statistically significant community composition differences between line-planting and control plot trees (T = ?5.89, A = .86; p < .001). But mean similarity among plots in both the line-planted and control plots was relatively low at less than 50% of shared species, indicating high diversity of vegetation in the overall forest area. Canopy cover by tree species greater than 3 cm in dbh was much higher in the undisturbed forest but this difference may be reduced as the young line-planted hardwoods mature. Forest enrichment through line-planting of valuable timber species in secondary subtropical wet forest does not significantly affect tree diversity.  相似文献   

17.
对台湾长翅稻蝗雌成虫与台湾长翅稻蝗和小翅稻蝗雄成虫先后进行48h配对饲养试验,结果表明,在它们交配以后,有足够使4卵块以上的卵受精的精子进入雌成虫,并贮存于其受精囊内.在雌成虫产下4卵块卵以后,仍具有受精能力.在台湾长翅稻蝗♀×小翅稻蝗♂后,以原台湾长翅稻蝗♀×台湾长翅稻蝗♂;或台湾长翅稻蝗♀×台湾长翅稻蝗♂后,以原台湾长翅稻蝗♀×小翅稻蝗♂,所获得的F1代,均为后来交配雄虫的子代.后来交配雄成虫的精子能取代雌虫受精囊内已有的先前交配雄成虫的精子,并使其受精.台湾长翅稻蝗和小翅稻蝗雄成虫交配后长时间的mounting是一种守卫行动.目的在于阻止雌成虫再与其他雄成虫交配,保护其精子免被取代  相似文献   

18.
Woody plant encroachment is a threat to savanna ecosystems worldwide. By exploiting differences in the physiology and seasonality of herbaceous species and encroaching hardwoods, herbicides can be used to control woody shrubs in savannas without causing lasting harm to desirable vegetation. We applied three herbicides and one tank mix to control shrubs following removal of the slash pine (Pinus elliottii Engelm.) canopy and replanting with container-grown longleaf pine (Pinus palustris Mill.) seedlings in a mesic-wet savanna in the southeastern USA. The herbicides tested were imazapyr, sulfometuron methyl, hexazinone, and a hexazinone + sulfometuron methyl tank mix. 4 years after application, no negative effects on understory species richness, diversity, evenness, or community composition were evident in any of the herbicide treatments. Oaks (Quercus spp.), one of the dominant shrub genera on the study site, were resistant to sulfometuron methyl, and this herbicide was therefore ineffective both as a pine release treatment and for enhancing herbaceous species cover. Imazapyr was the most effective treatment overall, leading to significant improvements in longleaf pine seedling growth and also enhancing herbaceous species cover. Both hexazinone and the hexazinone + sulfometuron methyl tank mix provided some seedling growth and understory enhancement as well. In particular, the tank mix significantly increased wiregrass cover relative to the control. Shrubs resprouted quickly following a dormant-season prescribed fire in the fifth year after treatment, indicating that herbicide-related increases in herbaceous cover may be lost if an aggressive prescribed fire program is not implemented.  相似文献   

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