Elevational patterns and determinants of plant diversity in the Baekdudaegan Mountains, South Korea: Species vs. functional diversity

The elevational gradient present in mountainous areas provides the most powerful natural experimental system available to clarify the ecological and evolutionary responses of living organisms to geophysical influences. In this study, we explored the elevational patterns of plant species and functional diversity and the effects of area, mid-domain effect, climatic variables and net primary productivity on the observed diversity patterns along the ridge of the Baekdudaegan Mountains, South Korea. Rapoport’s elevational rule was also evaluated by examining the relationship between elevational range size of plant species and elevation. A total of 802 plant species from 97 families and 342 genera were found in 1100 plots along a 200–-1900-m elevational gradient along the ridge. The elevational patterns of plant species diversity along the ridge of the Baekdudaegan depicted distinctly hump-shaped patterns, whereas the functional diversity decreased monotonically with elevation. The mid-domain effect was the most powerful explanatory variable for species diversity patterns. However, climatic variables were better predictors for functional diversity. Moreover, Rapoport’s elevational rule was not supported. Our study suggests that different elevational patterns may be observed among different diversity measurements even in the same taxon and that there may be fundamental differences in the mechanisms underlying these diversity patterns.     

Response of tree-ring width to rainfall gradient along the Tianshan Mountains of northwestern China

By comparing the long-term tree-ring growths at various geographic scales, we can make clear the effects of environmental variations on tree growth, and get an understanding of the responses of forest ecosystems to the possible changes in global and regional climate. Radial tree-ring growth of Picea schrenkiana and its relationship to air temperature and precipitation were investigated across longi- tude transects on the north slopes of the Tianshan Mountains in northwestern China. Tree-ring samples were collected and residual chronologies were developed for three different regions along a gradient of decreasing precipitation from west to east. Response-function analysis was conducted to quantify the relationships between tree-ring chronologies and climate variables, such as monthly mean temperature and monthly precipitation from 1961 to 1998, using the PRECON software program. The statistical characteristics of the chronologies showed that the three chronologies constructed in this study con- tained significant environmental signals and were well suitable to reveal the impacts of climatic change on tree growth and forest productivity. Annual ring-width variations were similar among the three sites, but the variability was greatest in the east. This research showed that the growth trends of Picea schrenkiana in the Tianshan Mountains have not followed a uniform pattern. Response-function analy- sis indicated that there were significant correlations between tree growth and climatic factors in all the three regions, among which precipitation was the principal. With decreasing precipitation, the response of tree-ring widths to increasing temperature changed from a positive to a negative correlation. As for precipitation, the positive relationship to tree-ring width always dominates. It could be expected that with increased temperature and decreased precipitation, the importance of precipitation to tree growth would increase, and the response of tree growth to environmental changes would also increase. This study emphasizes the importance of regional-scale investigations into the biosphere-climate interac- tions. The results of this research indicated a substantial increment of tree-ring radial growth as a re- sult of warmer and wetter climate in the eastern regions. However, climate change will have less effect on forest growth and primary production in the western regions.     

京西百花山植物群落数量分析

采用双向指示种分析法(TWINSPAN)和除趋势对应分析(DCA)对京西百花山植物群落进行数量分类和排序,并进行了环境解释.TWINSPAN等级分类将百花山50个样方分为10类,代表10个群系.DCA结果同TWINSPAN分析结果比较一致,并且较好地反映了植物群系和环境之间的关系,其中第1轴明显地反映出各个群系的水热梯度的变化,同时也反映出坡向的变化趋势;而第2轴则反映出海拔的梯度变化,表明群系所在地的海拔是决定群系分布的主要环境因素.     

辽东山地老秃顶子北坡植物物种多样性的垂直分布格局

基于野外样方调查数据,以物种丰富度、α多样性指数和β多样性指数为测度指标,分析了辽东丘陵地区相对高差为867 m的中山山地——老秃顶子北坡植物物种多样性沿海拔梯度的分布格局.结果表明：（1）老秃顶子北坡植物物种丰富度的垂直梯度变化规律比较复杂,但总体呈现出了在中海拔地段物种丰富度谷、峰值连续出现的分布格局; （2）老秃顶子北坡植物群落的Shannon-Wiener指数在海拔667-1 267 m森林群落分布段内,随着海拔的升高呈波浪状起伏,其值在1.37-2.07间变动; 在海拔1 267-1 347 m灌丛、草甸群落分布段内,随着海拔的升高呈大幅度增加态势,至海拔1 347 m处达最大值3.95.Si mpson指数在海拔667-1 267 m间,随着海拔的升高其值在0.98-0.99间起伏,没有明显变化; 在海拔1 267-1 347 m间,随着海拔的升高呈明显降低态势,至海拔1 347 m处达最小值0.85; （3）老秃顶子北坡植物群落的Jaccard指数的3个谷值分别反映了海拔767-867 m是落叶阔叶林向针阔混交林的过渡带,海拔1 067-1 167 m是暗针叶林向针阔混交林的过渡带,海拔1 317-1 347 m是灌丛群落向草甸群落的过渡带; 而Cody指数的2个峰值分别反映了海拔1 167-1 267 m是针阔混交林向落叶阔叶林的过渡带,海拔1 317-1 347 m是灌丛群落向草甸群落的过渡带.     

浙江西天目山古树树干健康状况及其随海拔梯度变化规律

古树作为组成和支撑森林和城市生态系统的重要组成部分,为各种动植物的生长提供了条件,为人类社会提供多种生态系统服务。分析古树树干腐烂及空洞状况沿海拔梯度的分布规律及其限制因素,有助于古树管理和保护策略的制定与实施。基于PICUS应力波树木断层图像诊断仪,本研究对浙江天目山国家自然保护区内不同海拔梯度上古树树干的腐烂及空洞情况进行了定量评估。共调研137株古树,结论如下：古树树干胸高断层处腐烂及空洞面积所占比例平均值为18.89%;古树树干腐烂及空洞面积占比在不同物种间存在一定差异;古树树干健康状况与海拔和气候因子之间存在一定的相关性,主要表现为随海拔升高,树干内出现腐烂及空洞的古树增多,且腐烂及空洞面积占比不断增大,这一相关性在不同树种之间也存在差异。     

高黎贡山南段种子植物区系科属的两种不同排序方法及其意义

高黎贡山南段迄今计有种子植物192科,887属,2 807种。将其科属按所含种的绝对数目和区系存在度两种不同排序,以提供完整的高黎贡山南段种子植物区系的区系组成,反映本区系的独特特点和各科属在区系建成中的相对重要性。     

辽宁老秃顶子北坡乔木层物种多样性垂直分布格局

利用乔木层样方的物种重要值矩阵信息,运用TWINSPAN分类方法,科学地划分出辽宁老秃顶子北坡的主要森林群落类型,并采用物种丰富度、α多样性和β多样性等指标,进一步研究了老秃顶子北坡森林植被乔木层物种多样性随海拔梯度的变化趋势．结果表明,老秃顶子北坡森林植被可划分为6个群落类型;乔木层物种多样性随海拔梯度的变化趋势为：随着海拔的升高,物种丰富度基本呈现出先上升后下降的分布格局;α多样性中Shannon—Wiener指数呈波浪式缓慢下降,而Pietou均匀度指数没有明显的变化;β多样性（Cody指数）则随着海拔的升高先上升而后下降．     

木札岭华山松树轮宽度年表的建立及其气候响应

研究秦岭东部地区树轮对气候因子的响应,为该区域森林资源管理及抚育更新提供数据,并为气候重建提供参考。     

How does contemporary climate versus climate change velocity affect endemic plant species richness in China？

Climate change is considered a top threat to biodiversity, but the relative roles of contemporary climate versus the rate of climate change in determining spatial patterns of biodiversity are far from clear. China has a very diverse flora and harbors a high percentage of endemic species, but the mechanisms underlying spatial patterns of plant endemism are poorly understood. This study explores the geographical patterns of a representative sample of 555 endemic seed plant species at the scale of 0.5° latitude × 0.5°longitude. Ordinary least squares and spatial autoregressive models were compared to assess the relationship between richness of endemics and the rate of climate change in the past century, as well as a group of contemporary climate variables. In China, a high level of endemism was associated with high elevation and low rate of climate change. However, contemporary climate had a stronger impact than climate change velocity in the past century on endemic species richness patterns. Specifically,mean annual precipitation and annual range of temperature were important contemporary climatic factors. The rate of change of annual mean temperature, but not that of annual precipitation, also significantly contributed to the spatial pattern of plant endemic species richness. We found no significant relationship between topographic variation and endemic species richness, while temperature variability at multiple time scales was strongly correlated with the species richness pattern. Future work should consider the direction of climate change and incorporate higher-resolution data.     

哀牢山4个海拔梯度树干节肢动物群落比较

作者在2013年4月(干季),运用树干喷雾法调查了哀牢山中山湿性常绿阔叶林2 000,2 200,2 400,2 600 m海拔的树干节肢动物群落.结果显示,所调查树干节肢动物群落隶属于7纲30个类群(目),主要由弹尾目、蜱螨目、蜘蛛目、双翅目、膜翅目、鞘翅目、啮虫目、半翅目同翅亚目、缨翅目等组成.不同海拔间树干节肢动物群落组成显著不同(基于Bray-Curtis相似性),其个体数量(密度)总体呈现出沿海拔升高而上升的趋势,但不同类群的个体密度随海拔梯度表现出不同的分布差异.树种和树皮粗糙度对树干节肢动物群落总体的影响不显著,但对少数节肢动物类群的密度呈现显著影响.表明海拔差异(温度和湿度)对树干节肢动物的影响显著高于微环境差异(树种和树皮粗糙度).     

从适地适树到适钙适树的理论与例证

适地适树是造林学理论与实践的基本原则。实现树种和立地“配对”即适地适树的传统方法是:首先对有林地目标造林树种的生长指标(通常是树高)和根据经验所选定的立地指标(通常包括气候、地形地貌、土壤、植被等)进行相关分析; 然后根据相关结果选定主要立地指标,并依据这些指标对有林和无林地的立地质量进行分类; 最后划分该树种的最适宜、较适宜、一般适宜和不适宜生长的立地类型,以用于指导造林生产活动。但基于经验和相关分析对立地质量进行评价的方法中存在其立地指标因人、因地和因树的改变而无法重复的缺陷。为此,提出以土壤钙的供应潜力作为立地质量的统一指标,以树种最大生长对钙的需求作为树种的生物学特性指标,当树种最大生长的钙需求与立地钙供应潜力相吻合时,树种与立地则满足适地适树原则。依此原理,以辽东栎(Quercus liaotungensis Koidz)为例,建立了基于钙供给与需求平衡的理论数学模型。运用该模型计算造林树种的理论生长指数,通过理论生长指数与最大实际生长量的比值得到适钙适树指数。通过对适钙适树指数与实际生长量进行相关分析验证了适钙适树理论模型的可预测性和真实性。结果表明,用土壤钙供应潜力作为立地质量评价指标可以很好地在造林生产活动中贯彻适地适树原则。适地适树的本质即为适钙适树。     

城市化对哺乳动物丰富度影响的研究 ——以长三角城市群为例

以不透水面占比作为城市化强度(UI)的定量指标,采用全球哺乳动物丰富度网格数据集,结合气候因素和生境特点,研究我国长三角城市群哺乳动物丰富度沿城乡梯度的空间分布格局.通过对比长三角城市群及其所处自然地理区(华东)哺乳动物丰富度的分布格局和驱动因素,分析城市化和背景气候的贡献.结果表明:1)哺乳动物丰富度沿城乡梯度均呈水...     

特大冰冻干扰后常绿阔叶林林木和幼苗的短期动态

【目的】探讨和阐明2008年特大冰冻干扰后广西大明山常绿阔叶林林木和幼苗的短期动态变化规律。【方法】基于2009年建立的3.2hm~2固定研究样地,对特大冰冻干扰后大明山常绿阔叶林林木和幼苗进行连续4年的监测。【结果】林木和幼苗对特大冰冻干扰存在不同的响应与适应,灾后第1年,胸径≥1cm林木的密度和物种丰富度显著增加,之后稍微减少并维持相对稳定;而幼苗则表现为第1年显著增加,之后又显著降低。不同树种对冰冻干扰后的恢复响应存在较大差别,在4年的恢复期中,共有13个科的林木幼苗从调查样方中完全消失,虽然消失的主要是稀有种,但一些群落优势科如樟科(Lauraceae)、山茶科(Theaceae)等的物种也出现不同程度的消失、新增现象。林木密度与林木物种丰富度、幼苗密度与幼苗物种丰富度、林木密度和物种丰富度与幼苗密度和丰富度存在显著正相关关系。【结论】林木的密度与丰富度在较大程度上决定着林下林木幼苗的种类、数量及动态,这是资源有效性和林木生态生物学特性共同作用的结果。     

滇西北哈巴雪山不同海拔长苞冷杉径向生长对气候变化的响应

全球气候变化背景下森林生态系统对气候的响应是被广泛关注的科学问题。以滇西北哈巴雪山为研究区,利用不同海拔长苞冷杉树轮宽度资料建立树轮宽度差值年表,并与气候因子进行分析,以揭示影响哈巴雪山不同海拔长苞冷杉径向生长的关键气候因子。结果表明:高海拔长苞冷杉主要受上年11月最高温和当年2月降水影响,低海拔树木主要受当年5月干旱限制,当年10月温度升高促进树木生长;低海拔树木径向生长与气候因子关系相对高海拔更加稳定,气候重建潜力更高。未来气候变化将有利于高海拔树木生长,低海拔树木可能会受到暖干气候的限制出现生长下降。     

广西不同气候条件下马尾松人工林木本植物组成及多样性特征

马尾松Pinus massoniana人工林广泛分布于我国南部,为了理解马尾松人工林在不同气候条件下的响应特点和分布特征,以中国广西中亚热带、南亚热带和北热带不同气候条件下马尾松人工林的幼龄林、中龄林和过熟林阶段为研究对象,比较分析不同气候条件下马尾松人工林木本植物物种组成及多样性特征。结果表明:(1)所研究的7个林分类型中,共记录到木本植物229种,隶属56科127属,随着中亚热带气候条件向北热带气候条件过渡,马尾松人工林林下热带分布物种占比增大,温带分布树种逐渐减少;(2)在幼龄林阶段,与南亚热带气候条件相比,中亚热带气候条件下马尾松人工林林下灌木层及木本群落整体的物种丰富度相对较高,在中龄林阶段和过熟林阶段,北热带气候条件下马尾松人工林林下木本群落物种丰富度和物种多样性最高,但优势种集中性较低;(3)在幼龄林阶段,南亚热带与北热带气候条件马尾松人工林林下物种差异性最大,在中龄林阶段,中亚热带与北热带气候条件马尾松人工林林下物种相似程度最高。气候条件变化对林下乔木层建群种有着明显影响,而且由于生境条件差异,不同气候条件下物种构成明显不同,在幼龄林阶段不同气候条件对林下木本群落影响最大。     

云南独龙江地区种子植物物种多样性垂直分布格局和Rapoport法则的验证

物种丰富度沿海拔梯度的分布格局是生物多样性研究的热点之一。以独龙江地区种子植物为对象,利用当地植物志资料,结合数字高程模型(DEM)数据,研究了独龙江地区种子植物物种多样性的垂直分布格局,并对Rapoport法则进行了验证。结果表明：随着海拔的升高,物种丰富度和物种密度均呈线性下降趋势,而物种分布幅度呈明显增大趋势,与Rapoport法则一致;进一步分析表明,物种密度随着物种分布幅度的增大而下降;随着年平均温度的升高,物种密度呈明显上升趋势,而物种分布幅度呈减小趋势。     

Density-dependent mortality and the latitudinal gradient in species diversity

Ecologists have long postulated that density-dependent mortality maintains high tree diversity in the tropics. If species experience greater mortality when abundant, then more rare species can persist. Agents of density-dependent mortality (such as host-specific predators, and pathogens) may be more prevalent or have stronger effects in tropical forests, because they are not limited by climatic factors. If so, decreasing density-dependent mortality with increasing latitude could partially explain the observed latitudinal gradient in tree diversity. This hypothesis has never been tested with latitudinal data. Here we show that several temperate tree species experience density-dependent mortality between seed dispersal and seedling establishment. The proportion of species affected is equivalent to that in tropical forests, failing to support the hypothesis that this mechanism is more prevalent at tropical latitudes. We further show that density-dependent mortality is misinterpreted in previous studies. Our results and evidence from other studies suggest that density-dependent mortality is important in many forests. Thus, unless the strength of density-dependent mortality varies with latitude, this mechanism is not likely to explain the high diversity of tropical forests.     

海拔对柴胡主、侧根皂苷含量的影响

北柴胡是伞形科的多年生草本植物,是我国的传统中药材,以根入药,柴胡化学成分中的皂苷对其药用性质起主要影响作用.本文在北京东灵山选取4个海拔梯度(1400、1600、1800、2000m),通过测定野生北柴胡的形态特性、生物量以及皂苷,探讨海拔对柴胡皂苷的影响以及适宜的采收季节.结果表明:随着海拔的升高,土壤含水量增加,柴胡通过降低高度和比叶面积(SLA),增加叶片厚度来适应高海拔低温和强风的环境条件;海拔变化对柴胡的产量和皂苷有不同的影响,在1600m 处总皂苷最高,而在1800m 处有最高的根生物量和单位面积总皂苷;在不同海拔梯度下,柴胡侧根中总皂苷高于主根;在不同的采收期,柴胡皂苷差异显著,7月份开花期总皂苷明显高于9月份收获期.本研究结果将为东灵山种植和道地柴胡采集提供理论依据      

夏季率水浮游动物群落类型及影响因素

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