共查询到19条相似文献，搜索用时 281 毫秒
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城市生物多样性保护规划探讨 总被引：4，自引：0，他引：4
依据生物多样性方法和原理,从植物和动物2个方面探讨了城市生物多样性保护规划的内容,提出城市生物多样性保护中值得关注的问题。应根据绿地的功能和生境类型进行植物配置,构建以自然群落为基础的人工群落,是城市绿地系统中植物多样性保护的重点。通过规划栖息地和建设生态廊道的方法可以有效地进行动物多样性保护工作,该文对城市生物多样性保护规划的编制有参考价值。 相似文献
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采用典型样带调查法,在卧龙自然保护区邓生阴坡的岷江冷杉天然林内设置不同海拔梯度的样带,分析岷江冷杉天然林的生物多样性随海拔梯度的响应规律。研究结果表明:岷江冷杉天然林乔木和草本植物的物种丰富度、Shannon-Wiener多样性指数、Pielou均匀度指数和均优丰多样性指数随着海拔升高呈下降趋势,而生态优势度指数呈上升趋势;灌木种随着海拔梯度上升物种丰富度下降,Shannon-Wiener多样性指数、Pielou均匀度指数和均优丰多样性指数则呈现出先降低后升高的趋势,生态优势度指数的变化与之相反;群落所有植物的α多样性随海拔梯度的变化规律与乔木层一致。从β多样性变化来看:随着海拔上升,岷江冷杉林内乔木、草本和所有群落所有植物的相异系数CD和Cody指数均呈下降趋势;而灌木层因为物种数和优势种的改变形成β多样性的双峰变化,这与灌木植物的实际分布是相符的。群落整体的物种差异和更替速率受物种数较多的植被类型影响较大,随海拔升高呈逐渐减小趋势。 相似文献
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香樟群落生物多样性研究 总被引：1，自引：0，他引：1
从保护生物多样性的原则出发,采用生物多样性指数、均匀度、丰富度、优势度等指标,对香樟群落的生物多样性进行测定,分析结果表明：与草本层的多样性指数、均匀度、丰富度、优势度相比较,乔灌层生物多样性指数、均匀度、丰富度均较高,但是优势度低;对香樟群落植物各层的重要值进行计算,结果表明：乔灌层香樟的重要值为59．73357,草本层重要值最高的是铁芒萁,为20．61828。对不同面积的植物多样性指数进行计算,以分析多样性指数对样地面积大小的敏感程度,结果表明：在考虑样地面积对多样性指数影响和精确反映群落物种的多样性方面。Shannon—wiener指数优于NcIntoeh指数。 相似文献
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纬度和海拔是影响生物多样性分布格局最重要的环境梯度，同时关注纬度和海拔梯度的影响对区域生物多样性保护有实际指导意义，然而目前相关研究还较少。在生物热点地区高黎贡山选取不同纬度的姚家坪（25.94°N）、亚坪（27.14°N）和独龙江（27.90°N）三个地点，每个地点在2 000～2 400 m海拔范围采用样线法进行鸟类调查，利用物种丰富度和Jaccard相似性指数分析海拔梯度和纬度梯度上鸟类多样性的分布格局，并比较海拔梯度和纬度梯度对鸟类多样性的影响。结果表明：（1）在纬度梯度上，低纬度的姚家坪鸟类物种数最高，且三个地点之间鸟类物种Jaccard相似性指数均较低，低纬度的姚家坪和亚坪之间鸟类组成相似性略高；（2）在海拔梯度上，姚家坪、亚坪、独龙江鸟类物种数峰值分别出现在2 200 m海拔段、2 400 m海拔段、2 300 m海拔段，且每个地点的不同海拔段间，鸟类物种Jaccard相似性指数均较低；（3）研究区域100m海拔梯度上的Jaccard相似性指数与1°纬度梯度相近。研究结果表明，高黎贡山海拔和纬度空间梯度上鸟类群落的Jaccard相似性指数均较低，整个区域鸟类群落组成差异极... 相似文献
6.
珍稀濒危植物海南粗榧保育群落植被生物多样性研究 总被引：2，自引：0，他引：2
采用样地调查法对海南霸王岭国家级自然保护区海南粗榧保育群落植被生物多样性进行研究,结果表明,霸王岭的海南粗榧群落生物多样性指数较高,虽然不同样方中的乔木层、灌木草本层的生物多样性指数都表现出极显著差异,但同一样方中乔木层和灌木草本层生物多样性指数相差不大;保育群落中的优势种主要有红紫麻(Oreocnide rubescens)、野芭蕉(Musa wilsonii)、药用狗牙花(Ervatamia officinalis)等;保育区内海南粗榧成年和幼体植株生长情况较好。 相似文献
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人为干扰对森林群落及生物多样性的影响 总被引：3，自引：1，他引：3
研究了人为干扰对森林群落及生物多样性的影响,结果表明,人为干扰对多样性影响存在差异,干扰强度在3级以上的群落,生物多样性指数下降,且强度越大,多样性指数越低。2级左右的中度干扰,多样性指数增高,符合生态学“中度干扰假说”理论,但完全未受人为干扰的多优种阔叶林多样性指数也高。人为干扰对群落的数量和类型影响明显,在人口聚居区,群落类型少,人为干扰的垂直空间范围在低地河谷为向上200 m的空间范围,在高地缓坡为聚居带向上和向下各100m的空间范围。 相似文献
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笔者通过测算丰富度指数、均匀度指数和多样性指数,分析了关帝山文峪河流域上游河岸林不同群落类型的生物多样性垂直分布,得出3种指数随海拔的垂直变化皆有一致的表现,即生物多样性在中等海拔处达到最大,符合“中间膨胀”规律（mid-altitude bulge）,也就是在中度海拔处生物多样性最高,这是群落物种组成和人为干扰双重作用的结果. 相似文献
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指出了城市园林绿化建设是城市生态环境建设的主要方式,在城市园林绿化工作中关注生物多样性,创设良好的生态环境,对于城市和谐稳定发展是十分重要的。从生物多样性研究、环境保护技术、自然群落结构等方面探讨了城市绿化中保护生物多样性的方法与策略。 相似文献
11.
Hua-Feng Wang María Vanessa Lencinas Cynthia Ross Friedman Xiao-Ke Wang Jiang-Xiao Qiu 《New Forests》2011,42(1):101-116
Biodiversity in managed plantations has become an important issue for long-term sustainability of ecosystems. The environmental
effects of plantations comprised of fast-growing introduced trees have been vigorously debated. On one hand, monocultures
have been said to exhaust resources, resulting in decreased biodiversity. Conversely, it has been stated that monocultures
may favor regeneration of undergrowth plants from surrounding forests, increasing biodiversity. In order to clarify the effects
of planting Eucalyptus trees on species composition, diversity, and functional type of understory vegetation in Yunnan province, a field trial was
implemented to compare Eucalyptus plantations (EPs) with two other local current vegetation types (secondary evergreen forests (SEs), and abandoned farmlands
(AFs)). Each vegetation type was sampled in each of three elevational ranges (low = 1,000–1,400 meters above sea level (masl),
medium = 1,400–1,800 masl, and high = 1,800–2,200 masl). Sample sites within each elevational range had similar environmental
characteristics (slope, aspect, etc.). Thus, we sampled three vegetation types at each of three sites at each of three elevations
for a total of 27 plots. We calculated relative abundance and importance value of species and diversity indexes to evaluate
differences among local current vegetation types and elevational ranges, employing multivariate ordination analyses and other
methods such as Analyses of Variance (ANOVA) and Indicator Species Analysis. We found that fast growing introduced Eucalyptus plantations led to reduced plant diversity in the study area, and that rare or threatened species were recorded almost exclusively
in the SE plots, being essentially absent from the EP and AF plots. The understory plant diversity did not correlate with
the altitude gradient significantly. Eucalyptus plantations (EPs) have a simpler community structure than that of either secondary evergreen forests (SEs; similar to natural
state) or abandoned farmlands (AFs). No variable significantly explained variation of the understory shrub layer, but soil
moisture-holding capacity and overstory coverage were significant in explaining variation of the understory herb layer, suggesting
that the study of soil physical properties is necessary for better understanding of their importance in Eucalyptus plantations and other local current vegetation types. 相似文献
12.
珠防工程实施初期植物群落变化研究 总被引：1，自引：1，他引：1
通过在珠防工程区的典型地段设置样地并定期进行调查,对工程二期近三年植物群落的变化进行了初步研究,结果表明:珠防工程实施初期造林树种的高、径净生长量都比较小,针叶树普遍较阔叶树的净生长量大,并且随着造林年限的增加,高、径净生长量均表现为增加趋势;通过珠防工程的实施,植物群落朝着稳定的方向发展,生物量不断提高;在人工造林中,造林树种的生物量占总生物量的比重大于灌木、草本生物量;同一时间实施的珠防工程,人工造林的生产力比封山育林高;工程实施初期随造林时间的延长,群落的生产力表现出增加趋势;同一造林时间不同的群落类型,其生产力表现出很大差异:植被盖度及造林树种盖度增加最大,灌木次之,草本最小;植物物种多样性主要表现在草本种类的增加,灌木变化幅度较小,人工造林比封山育林更能促进物种多样性。 相似文献
13.
宝天曼植物群落物种多样性研究 总被引：33，自引：5，他引：33
对宝天曼保护区植物群落物种多样性进行了研究。结果表明 ,物种丰富度指数、多样性指数和均匀度指数在群落梯度上的分布趋势基本一致 ,较好地反映了不同植物群落类型在物种组成方面的差异。草本层物种丰富度指数明显高于乔木层和灌木层 ,草本层物种丰富度指数在群落梯度上的变异最大 ,灌木层次之 ,乔木层最小。乔木层物种多样性指数小于灌木层和草本层 ,草本层和乔木层物种多样性指数在群落梯度上的变异程度明显大于灌木层。灌木层物种均匀度指数大于乔木层和草本层 ,草本层和乔木层均匀度指数在群落梯度上的变异程度大于灌木层。物种丰富度指数和多样性指数的较大值出现在高海拔和低海拔群落 ,较小值多出现在中等海拔群落。物种均匀度指数的较小值多出现在中等海拔群落 ,但其较大值在各海拔群落都有分布。草本层物种丰富度指数和多样性指数的较高值多分布在低海拔群落 ,较小值多分布在中等海拔群落 ;乔木层和灌木层的各种指数以及草本层的物种均匀度指数在海拔梯度上的分布规律不明显 相似文献
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Anna Young-Mathews Steven W. Culman Sara Sánchez-Moreno A. Toby O’Geen Howard Ferris Allan D. Hollander Louise E. Jackson 《Agroforestry Systems》2010,80(1):41-60
Forested riparian buffers in California historically supported high levels of biodiversity, but human activities have degraded
these ecosystems over much of their former range. This study examined plant communities, belowground biodiversity and indicators
of multiple ecosystem functions of riparian areas across an agricultural landscape in the Sacramento Valley of California,
USA. Plant, nematode and soil microbial communities and soil physical and chemical properties were studied along 50-m transects
at 20 sites that represented the different land use, soil and vegetation types in the landscape. Riparian zones supported
greater plant diversity and nearly twice as much total carbon (C) per hectare compared to adjacent land managed for agricultural
uses, but had generally lower soil microbial and nematode diversity and abundance. When woody plant communities were present
in the riparian zone, plant diversity and species richness were higher, and soil nitrate and plant-available phosphorus levels
were lower. Belowground diversity and community structure, however, appeared to depend more on plant productivity (as inferred
by vegetation cover) than plant diversity or species richness. Greater plant species richness, nematode food web structure,
total microbial biomass, woody C storage and lower soil nitrate and phosphorus loading were correlated with higher visual
riparian health assessment scores, offering the possibility of managing these riparian habitats to provide multiple ecosystem
functions. 相似文献
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To test whether the altitudinal limit of tree growth is determined by carbons shortage or by a limitation in growth we investigated non structural carbohydrates and their components starch and total soluble sugars in Pinus cembra trees along an elevational gradient in the timberline ecotone of the Central Austrian Alps. NSC contents in needles, branches, stems, and coarse roots were measured throughout an entire growing season. At the tissue level NSC contents were not significantly more abundant in treeline trees as compared to trees at lower elevations. Along our 425 m elevational transect from the closed forest to the treeline we failed to find a stable elevational trend in the total NSC pool of entire trees and observed within season increases in the tree's NSC pool that can be attributed to an altitudinal increase in leaf mass as needles contained the largest NSC fraction of the whole tree NSC pool. Furthermore, whole tree NSC contents were positively correlated with net photosynthetic capacity. Although our observed NSC characteristics do not support the hypothesis that tree life at their upper elevational limit is determined by an insufficient carbon balance we found no consistent confirmation for the sink limitation hypothesis. 相似文献
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《Forest Ecology and Management》2004,187(1):19-33
Attributes of fine roots (<2.0 mm diameter) were quantified in five southern Appalachian plant communities along an elevational gradient. These attributes include the seasonal dynamics of fine root mass and length, the depth distribution of fine roots, fine root width and, most importantly, the annual appearance and disappearance of fine roots. The principal objectives of this study were two-fold: (1) to compare these attributes of fine roots between plant communities and (2) to compare the results of the two methods used to quantify the attributes: (1) harvesting roots from forest soil with soil cores and (2) photographing roots growing against the windows of minirhizotron boxes. The plant communities that were sampled are characteristic of the region and are designated as follows from lowest elevation (782 m) to highest elevation (1347 m): (1) xeric ridge, (2) cove hardwoods, (3) low elevation mixed oak, (4) high elevation mixed oak, and (5) northern hardwoods. Fine root mass varies seasonally in this temperate region with lowest and highest mass in the spring and autumn, respectively. Fine root mass and fine root mass appearance were lowest in the cove hardwood community and highest in the low elevation mixed oak community. The total length of fine roots was highest in the xeric ridge community and lowest in the low elevation mixed oak community. The high total root length in the xeric ridge community was due to the presence of an exceptionally dense mat of very fine roots found there. The width of these roots was significantly less than that of roots on all other plots. Subsequent regression illustrates two strong patterns in the data. First, fine root mass, fine root mass appearance and leaf production were positively correlated. Second, fine root length and soil moisture were negatively correlated. The accumulation of root mass in these communities was linked to overall site productivity and the development of root length in response to moisture stress. Only the timing of root growth initiation was related to elevation and the associated parameter of soil temperature. The best estimates of fine root appearance and disappearance were generated by harvesting roots rather than photographing them. Some methodological problems with root photography implemented in this study are addressed. 相似文献
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It remains unclear whether the elevational diversity gradients observed in seed plants across different taxonomic levels(family, genus, and species) are driven by the same macro-environmental variables.In this study,seed plant elevational distribution data from the Lancang River Nature Reserve(Yunnan, China) were used to investigate spatial patterns in diversity and their environmental correlates, comparing across taxonomic levels.Environmental variables included energy availability, climate seasonality and environmental heterogeneity.All taxonomic levels(family, genus, and species) were found to have strong elevational richness gradients, with the strength of the gradient weakening at higher taxonomic levels.Spatial patterns in richness were explained by a combination of contemporary environmental variables and the mid-domain effect at all taxonomic levels.The independent effects of temperature-and precipitation-related variables were similar in explaining geographical patterns of family, genus and species richness.Energy,seasonality and heterogeneity variables influenced seed plant spatial richness at different taxonomic levels in similar ways. 相似文献