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241.
242.
ERICA FLEISHMAN GEORGE T. AUSTIN DENNIS D. MURPHY 《Biological journal of the Linnean Society. Linnean Society of London》2001,74(4):501-515
We used comprehensive data on butterfly distributions from six mountain ranges in the Great Basin to explore three connected biogeographic issues. First, we examined species richness and occurrence patterns both within and among mountain ranges. Only one range had a significant relationship between species richness and area. Relationships between species richness and elevation varied among mountain ranges. Species richness decreased as elevation increased in one range, increased as elevation increased in three ranges, and was not correlated in two ranges. In each range, distributional patterns were nested, but less vagile species did not always exhibit greater nestedness. Second, we compared our work with similar studies of montane mammals. Results from both taxonomic groups suggest that it may be appropriate to modify existing general paradigms of the biogeography of montane faunas in the Great Basin. Third, we revisited and refined previous predictions of how butterfly assemblages in the Great Basin may respond to climate change. The effects of climate change on species richness of montane butterflies may vary considerably among mountain ranges. In several ranges, few if any species apparently would be lost. Neither local species composition nor the potential order of species extirpations appears to be generalizable among ranges. 相似文献
243.
Temperature, but not productivity or geometry, predicts elevational diversity gradients in ants across spatial grains 总被引:2,自引:0,他引:2
Nathan J. Sanders Jean-Philippe Lessard Matthew C. Fitzpatrick Robert R. Dunn 《Global Ecology and Biogeography》2007,16(5):640-649
Aim This research aims to understand the factors that shape elevational diversity gradients and how those factors vary with spatial grain. Specifically, we test the predictions of the species–productivity hypothesis, species–temperature hypothesis, the metabolic theory of ecology and the mid-domain effects null model. We also examine how the effects of productivity and temperature on richness depend on spatial grain.
Location Deciduous forests along an elevational gradient in Great Smoky Mountains National Park, USA.
Methods We sampled 22 leaf litter ant assemblages at three spatial grains, from 1-m2 quadrats to 50 × 50 m plots using Winkler samplers.
Results Across spatial grains, warmer sites had more species than did cooler sites, and primary productivity did not predict ant species richness. We found some support for the predictions of the metabolic theory of ecology, but no support for the mid-domain effects null model. Thus, our data are best explained by some version of a species–temperature hypothesis.
Main conclusions Our results suggest that temperature indirectly affects ant species diversity across spatial grains, perhaps by limiting access to resources. Warmer sites support more species because they support more individuals, thereby reducing the probability of local extinction. Many of our results from this elevational gradient agree with studies at more global scales, suggesting that some mechanisms shaping ant diversity gradients are common across scales. 相似文献
Location Deciduous forests along an elevational gradient in Great Smoky Mountains National Park, USA.
Methods We sampled 22 leaf litter ant assemblages at three spatial grains, from 1-m
Results Across spatial grains, warmer sites had more species than did cooler sites, and primary productivity did not predict ant species richness. We found some support for the predictions of the metabolic theory of ecology, but no support for the mid-domain effects null model. Thus, our data are best explained by some version of a species–temperature hypothesis.
Main conclusions Our results suggest that temperature indirectly affects ant species diversity across spatial grains, perhaps by limiting access to resources. Warmer sites support more species because they support more individuals, thereby reducing the probability of local extinction. Many of our results from this elevational gradient agree with studies at more global scales, suggesting that some mechanisms shaping ant diversity gradients are common across scales. 相似文献
244.
245.
大兴安岭不同火烧年限森林凋落物和土壤C、N、P化学计量特征 总被引:2,自引:2,他引:0
测定大兴安岭林区不同火烧年限(火后4、14、40、70和120年内未火烧)、不同坡度(坡地、平地)凋落物和土壤C、N、P含量及其化学计量比,分析火烧对凋落物和土壤养分的长期影响及两者之间的关系.结果表明: 不同火烧年限凋落物和土壤C、N、P化学计量特征差异显著,凋落物C含量变化不大.凋落物N、P含量随火烧年限的增加而增加,在火后4和14年较低,在火后40年恢复到对照(未火烧)水平.凋落物C∶N和C∶P值随火烧年限增加而下降,N∶P值则呈上升趋势.土壤C、N、P含量及其比值随土层深度增加而降低.坡地土壤C含量随火烧年限增加而增加,在火后70年显著高于对照,在平地差异不显著.火烧年限和坡度的交互作用影响土壤P含量和C∶P值.坡地土壤P含量在火后4年高于对照,而平地在火后40年高于对照;坡地C∶P值在火后14年达到对照水平,而平地与对照差异不显著.冗余分析表明,有机质层土壤的坡度效应大于年限效应,矿质层土壤主要受年限效应影响.火后4和14年凋落物及土壤养分含量低于对照,随着火烧年限的增加,植被生长迅速同时凋落物分解加快,凋落物质量及土壤养分质量不断提高,在火后40年恢复到未火烧水平,趋于稳定状态. 相似文献
246.
Ying Tsun-shen 《植物分类学报:英文版》1994,32(5):389-410
The Qinling Mountain Range, which covers an area of ca. 76500km2 and ranges
from 32°05′ to 34°45′ N and from 104°30′ to 115°52′ E, is a major watershed of the
Huanghe and Chang jiang rivers with the highest peak about 3767 m above sea level. The
flora comprises ca. 3124 species in 892 genera, of which 51.9% of species and 4.4% of the
genera are endemic to China. Evoluated in this paper is the importance of the 20 larger fami lies which together contain 65.2% of the total number of species. The phytogeographical
affinities of genera of seed plants in the flora are analyzed and briefly discussed. Among the
native genera of the flora of the Qinling Mountain Range, 220 (26.8%) are tropical, 563
(68.5%) temperate, and 39 (4.7%) endemic to China. It is clear from the figures that
temperate genera play an important role in the flora and vegetation of the Qinling Mountain
Range. The features of the flora include the unusually high proportion of endemic species, a
wealth of Sino-Japanese elements and prominant temperate nature in compsition. On the ba sis of analysis of paleobotanical materials in the Qinling Mountain Range and adjacent areas,
historical distribution of dominant species, and the origin and relationships of Chinese en demic genera occurring there, the flora is of outstanding originality. No doubt, the rich and diverse flora have evolved gradually and autochthonously at least since the latest Cretaceous. 相似文献
247.
本文根据山西省管涔山林区苔藓植物特有种及优势种, 并参考环境特征, 将苔藓植物垂直带划分为:低山苔藓植物带, 针叶林区苔藓植物带、亚高山灌丛草甸区苔藓植物带。 相似文献
248.
用Braun-B1anquet法对西湖山区植被的132个样地进行了群落的分类。初步确定了2个 群丛(木荷群丛与黄连木群丛)、7个亚群丛和6个变型;并对28个鉴别种组进行了分析,它们都较好地反映了群落分类单位的特征和生境条件特点以及植被在空间分布上的连续性变异。 相似文献
249.
秦巴山区蝗虫群落多样性研究 总被引:13,自引:0,他引:13
作者于1995~1997年对秦巴山区蝗虫资源进行了调查。采用Shannon-Wiener提出的多样性指数(H')公式、Pielou提出的均匀度(E)公式及Simpson提出的优势度(C)公式,计算群落的多样性、均匀度和优势度。结果表明,不同地区、不同生境、不同海拔高度及不同月份,秦巴山区蝗虫群落的物种数目、多样性指数值、均匀度及优势度指数值均有明显差异。这主要与蝗虫的生物学特性直接有关,另外也受到环境因素的影响。 相似文献
250.
论武夷山在中国生物多样性保护中的地位 总被引:21,自引:2,他引:19
武夷山位于福建省西北部。其主峰黄岗山海拔2158 m,是中国大陆东南部最高峰。山岭纵横,气候温润,生物种类繁多。已知有高等植物2615种,动物5249种,而且有不少特有和古老、孑遗、珍稀种类。分布到这里的种类有些还出现变异,是国内外闻名的动物新种模式标本产地。是中国东南部重要的物种形成和分化中心,生物的“避难所”。生态系统也很多样。存在不少树龄在200年以上,甚至上千年的古树名木,因而在《中国生物多样性国情研究报告》中被列为中国陆地11个生物多样性保护的“关键区”之一。此外,该地现尚存清康熙和乾隆年间的禁止捕鱼和砍伐林木的刻碑,说明它是中国境内有保护生物多样性优良传统的地区之一。 相似文献