伊犁河谷北坡垂直分布格局及其与环境的关系——一种特殊的双峰分布格局

针对伊犁河谷北坡山地的植物多样性和土壤因子沿海拔的分布方式进行研究。对研究地海拔1000-2200m植物和环境特征进行调查,选取群落样地总数为44个,共调查到植物种155种,其中乔木7种、灌木18种、草本130种,调查到的群落类型完全涵盖了研究区所有沿海拔上升的群落类型。通过NLFS高级模拟显示总的物种丰富度、Simpson指数、Shannon-Wiener多样性指数、Pielou均匀度指数都与海拔呈现先升高后降低,再升高的一个特殊分布格局。出现了两个较高的物种丰富度地带,其中一个是低山荒漠到落叶阔叶林,另一个是山地草原到针叶林带。土壤养分和盐分也表现出了类似多样性的分布格局。通过PCA和相关分析表明,环境因子控制着物种丰富度和它的分布方式。水分在低海拔比较重要,在高海拔温度比较重要,而由于逆温层的作用,在较高海拔的针叶林带物种多样性出现了上升。物种丰富度与土壤总盐呈现显著负相关关系(r=-0.343),与土壤全盐也呈现显著负相关关系(r=-0.341)。Simpson指数与土壤pH值呈现显著负相关关系(r=-0.465)。Shannon-Wiener指数与土壤电导率呈现显著负相关关系(r=-0.367)。Pielou均匀度指数与土壤电导率呈现极显著负相关关系(r=-0.477),总之,多样性指数和土样盐分表现出了强相关性。这个研究为伊犁河谷植被与植物资源的保护和利用提供重要的科学依据,为河谷区山地植被与环境关系提供基础科学理论,为山地退化植被的修复提供参考案例和可借鉴的基础性数据。     

福建梅花山常绿阔叶林植物物种多样性及其海拔梯度格局

常绿阔叶林是福建梅花山国家级自然保护区地带性植被。采用样带与典型群落调查法对区内的常绿阔叶林14400m2样地展开调查,并对植物多样性海拔梯度格局进行分析,结果表明：（1） 群落植物物种丰富度、Gleason丰富度指数、Simpson指数、Shannon Wiener指数和Pielou均匀度指数的均值分别为64.42、10.75、5.75、3.50、0.58,且这5种指数在各样带间差异极为显著,并随海拔的升高均呈单峰曲线变化,峰值出现在海拔700m~900m。（2） 群落各层次的植物物种丰富度、Shannon Wiener指数均呈现灌木层（包括幼树和层间植物）〉乔木层〉草本层的特征。乔木、灌木层物种丰富度与乔木层Shannon Wiener指数在海拔梯度上的样带间差异极显著,变化趋势与群落相似;灌木层与草本层Shannon Wiener指数以及草本层物种丰富度随海拔梯度变化不明显。因此,梅花山自然保护区常绿阔叶林植物物种多样性的海拔梯度格局呈现单峰分布,并支持中间高度膨胀模式（mid domain model）。     

新疆天山南坡中段种子植物区系垂直分布格局分析

对植物多样性垂直分布格局及其维持机制的研究可以有效揭示植物物种多样性分布特征及其环境影响因子。本文通过野外调查、查阅标本并结合相关文献资料,对天山南坡中段种子植物区系沿海拔梯度的分布格局进行了系统研究。结果显示,在大区域尺度上,科属种的物种丰富度随海拔升高均呈先增加后减少的趋势,且最高值出现在中低海拔1900~2000 m处;不同生活型植物沿海拔梯度的变化格局有所不同,其中,乔木、一年生草本、藤本及寄生植物表现出随海拔升高物种丰富度逐渐降低的趋势,灌木、多年生草本及二年生草本植物物种丰富度则呈先增加后减少的变化趋势;从植物区系地理成分来看,世界分布所占的比重沿海拔梯度升高呈先增加后减少的趋势;温带地理成分所占的比重沿海拔梯度升高呈缓慢上升趋势;古地中海地理成分所占的比重沿海拔梯度升高呈先增加后减少然后再增加的变化趋势;热带地理成分所占的比重沿海拔升高呈逐渐下降的趋势;东亚地理成分所占的比重沿海拔梯度升高呈先增加后减少然后再增加的变化趋势。对该分布格局与当地干旱的气候条件及海拔梯度上热量和水分条件的变化相适应。     

Species Diversity and Altitudinal Gradient Patterns of Evergreen Broad leaved Forest in MeihuashanNational Natural Reserve,Fujian Province

In China, evergreen broad leaved forests (EBLFs) is one of the most important vegetation types which was widly distributed in subtropical area, and it plays a very important role in the global biological diversity and natural environment conservation also. In order to reveal species diversity and altitudinal gradient patterns of evergreen broad leaved forest in Meihuashan National Natural Reserve, Fujian Province. Five altitude transects were set up at a vertical interval of 200m between 375m and 1300m above sea level in the EBLFs distribution areas, and twenty four quadrats(14400m2) had been surveyed. Species richness(S), species richness index (dGl), Simpson index (D), Shannon Wiener index (H′), Pielou evenness index (J) had been used for analysis of species diversity and altitudinal gradient pattern of EBLFs. The average value of S, dGl, H′,J and D were 64.42, 10.75, 5.75, 3.50, 0.58 respectively. The difference of community species diversity index(S, dGl, D, H′, and J) was extremely significant between transects, and the altitudinal gradient patterns of species diversity presented the unimodal variable trend, with a peak in the mid altitude(700m-900m). The species richness and Shannon Wiener index of different layer were ranked as shrub layer (include young tree and the plants between layers)>arbor layer>herb layer. The species richness of tree and shrub layer, and Shannon Wiener index of tree layer were significantly different between at transects, and trends of altitude gradient was similar to community. The Shannon Wiener index of shrub layer and herb layer, and the species richness of herb layer did not change significantly along elevation gradient. Therefore, plant species diversity distribution pattern presented a unimodal variable trend along an elevation gradient, and supported “mid domain model” in EBLFs of Meihuashan National Nature Reserve.     

Altitudinal Pattern of Plant Species Diversity in Shennongjia Mountains, Central China

One hundred and sixty plots, approximately every 100 m above sea level （a.s.1.） along an altitudinal gradient from 470 to 3 080 m a.s.1, at the southern and northern watershed of Mt. Shennongjia, China, were examined to determine the altitudinal pattern of plant species diversity. Mt. Shennongjia was found to have high plant species diversity, with 3 479 higher plants recorded. Partial correlation analysis and detrended canonical correspondence analysis （DCCA） based on plant species diversity revealed that altitude was the main factor affecting the spatial pattern of plant species diversity on Mt. Shennongjia and that canopy coverage of the arbor layer also had a considerable effect on plant species diversity. The DCCA based on species data of importance value further revealed that altitude gradient was the primary factor shaping the spatial pattern of plant species. In addition, the rule of the “mid-altitude bulge” was supported on Mt. Shennongjia. Plant species diversity was closely related to vegetation type and the transition zone usually had a higher diversity. Higher plant species diversity appeared in the mixed evergreen and deciduous broadleaved forest zone （900-1500 m a.s.1.） and its transition down to evergreen broadleaved forest zone or up to deciduous broadleaved forest zone. The largest plant species diversity in whole communities on Mt. Shennongjia lay at approximately 1 200 m a.s.1. Greatest tree diversity, shrub diversity, and grass diversity was found at approximately 1 500, 1 100, and 1 200 m a.s.l., respectively. The southern watershed showed higher plant species diversity than the northern watershed, with maximum plant species diversity at a higher altitude in the southern watershed than the northern watershed. These results indicate that Mt. Shennongjia shows characteristics of a transition region. The relationship between the altitudinal pattern of plant species diversity and the vegetation type in eastern China are also discussed and a hypothesis about the altitudinal pattern of plant species diversity in eastern China is proposed.     

Elevational changes in vascular plants richness,diversity, and distribution pattern in Abune Yosef mountain range,Northern Ethiopia

The aim of this research is to investigate the patterns of vascular plant species richness,diversity,and distribution along an elevation gradient in the Abune Yosef mountain range,Ethiopia.Preferential systematic sampling was employed to collect vegetation and environmental data along the elevation gradient.We found that plant species richness declines monotonically from low to high elevations.Specifically,vascular plant species richness and diversity were lower in the Afroalpine grassland(high elevation)than in the Dry evergreen Afromontane forest and Ericaceous forest(low elevations).In contrast,endemic vascular plant richness was significantly higher in the Afroalpine grassland than in the Dry evergreen Afromontane forest and Ericaceous forest.Elevation showed a significant impact on the richness,diversity,and endemism of vascular plants.According to Sorensen's coefficient,the similarity between Dry evergreen Afromontane forest and Ericaceous forest vegetation types is higher(32%)than the similarity between Ericaceous forest and Afroalpine grassland(18%).Only 5%similarity was recorded between the Dry evergreen Afromontane forest and Afroalpine grassland.Growth forms showed different elevationai richness patterns.Trees and liana increased monotonically up to 3300 m.Shrub and herb richness patterns followed a hump-shaped and inverted hump-shaped pattern along the elevation gradient.The elevation patterns of vascular plant species richness,diversity,and growth form in the present study may be attributed to differences in management intensity,spatial heterogeneity,microclimatic variations,and anthropogenic disturbances.     

辽宁老秃顶子北坡植物群落物种多样性及其与土壤特性的相关性分析

通过沿海拔梯度的系统样方调查,利用物种丰富度、α多样性和β多样性等指标,对辽宁老秃顶子北坡植物群落木本层和草本层物种多样性随海拔梯度的变化趋势进行了研究,并对植物群落物种多样性与土壤特性之间的相关关系进行了初步探索。结果表明:木本植物物种多样性随海拔梯度的升高呈波动式降低的趋势;草本植物物种多样性随海拔梯度的变化趋势为先降低后升高;群落类型间的过渡带是植物物种替换速率较高的地区;老秃顶子北坡土壤类型以棕色森林土和暗棕色森林土为主,土壤有机质含量较高;群落物种多样性与土壤特性之间存在着一定的负相关性。     

山西关帝山森林群落物种、谱系和功能多样性海拔格局

探索和揭示生物多样性的空间格局和维持机制是生态学和生物地理学研究的热点内容, 但综合物种、系统进化和功能属性等方面的多样性海拔格局研究很少。该文以关帝山森林群落为研究对象, 综合物种、谱系和功能α和β多样性指数, 旨在初步探讨关帝山森林群落多样性海拔格局及其维持机制。研究结果表明: 随着海拔的升高(1 409-2 150 m), 关帝山森林群落物种丰富度指数(S)、谱系多样性指数(PD)和功能丰富度指数(FRic)整体上表现出上升的趋势, 特别是海拔1 800 m以上区域。随着海拔的升高, 总β多样性(β_total)和更替(β_repl)上升趋势明显, 而丰富度差异(β_rich)则逐渐下降。不同生活型植物的物种、谱系和功能多样性海拔格局差异较大。随着海拔的升高, 草本植物S和物种多样性指数(H′)上升趋势高于木本植物。影响草本植物S分布的主要因素是地形因子, 而影响木本植物S分布的主要因素是历史过程。随着海拔的升高, 木本植物β_total上升趋势要比草本植物明显。随着海拔的升高, 木本植物β_repl和β_rich分别表现出单峰格局和“U”形格局, 而草本植物β_repl和β_rich则分别表现出单调递增和单调递减的格局。随着环境差异和地理距离的增加, 群落间物种、谱系和功能β多样性显著增加。环境差异(环境过滤)对木本植物的β多样性具有相对较强的作用; 而环境差异(环境过滤)和地理距离(扩散限制)共同作用于草本植物的β多样性。     

拉萨河流域亏组山植物物种丰富度和群落特征研究

为研究草地植物群落、物种丰富度及其分布格局与影响因子之间的关系,该文以拉萨河流域林周县卡孜乡亏组山为研究地点,对山体垂直样带(3900～5100 m)植物群落特征、植物物种丰富度与各影响因子之间的关系进行了研究.研究区域共设置了13个样带(每隔100 m设一个样带),每样带设置0.5 m×0.5 m的5个样方进行植被调...     

澜沧县两栖动物多样性及海拔分布格局

海拔梯度综合了温度、降水等气候因子,是影响物种多样性分布格局的重要环境因子,两栖动物多样性及其海拔分布格局一直是生物地理学和生态学研究的重要内容。为了全面掌握云南澜沧县两栖动物多样性现状及海拔分布格局,在调查并掌握澜沧县两栖动物多样性本底数据的基础上,根据地形地貌和生境的不同,在澜沧县99个10km×10km有效网格中按照分层抽样的方法选取45个网格,每个网格设置3-5条样线,于2016-2017年开展野外调查。调查共发现两栖动物1842只,隶属于2目9科30属60种,以树蛙科为主,占两栖动物物种总数的28.3%,其中云南纤树蛙（Gracixalus yunnanensis）为新种,清迈泽陆蛙（Fejervarya qingmaiensis）为中国新纪录种;调查到中国特有种有15种,三有保护动物有25种,受威胁物种有19种,其中极危物种1种,濒危物种4种,易危物种14种;澜沧县两栖动物在海拔600-2400m范围内均有分布,其中,在海拔1800-2000m之间的范围内调查到的两栖动物物种数目和多度均较高,其次是在海拔1600-1800m和1200-1400m范围内;本次调查记录到的两栖动物物种数是历史记录物种数的3倍,属数比历史记录多了1倍,铃蟾科为新记录科;丰富度较高的网格尤其是丰富度在20以上的网格均处于中高海拔,海拔相对较低和较高的网格丰富度相对较低;两栖动物多样性科、属、种的丰富度在海拔梯度上分布格局不太一致,种丰富度的海拔分布格局大体呈双峰型,是由包括平均降水量、平均温度和植被覆盖指数等环境因子的综合作用,各因子与物种丰富度相关性从大到小依次为平均降水量 > 平均海拔=平均温度 > 植被覆盖指数 > 水网密度指数 > 样线距离水域的平均距离 > 植被类型数量。研究摸清了澜沧县两栖动物的多样性状况,分析了两栖动物多样性海拔分布格局,为澜沧县生物多样性保护提供基础数据。     

Species Diversity and Life-Form Patterns in Steppe Vegetation along a 3000 m Altitudinal Gradient in the Alborz Mountains, Iran

Biodiversity pattern and life-form spectra were studied along a 3,000 m altitudinal gradient from a semi-desert area to the alpine peak of Tochal Mountain. The gradient is located on the southern slopes of Central Alborz with a Mediterranean continental climate. DCA ordination was applied to 1,069 relevés and 7 quantitative variables to discover the relation of diversity and altitude. A biodiversity pattern was obtained by relating values for species richness and Shannon-Wiener’s index to 100-m altitudinal sections. Altitude was determined as the major ecological gradient. Both diversity indices are negatively correlated with altitude and show a decreasing trend beyond a peak in species richness at 1,800–1,900 m a.s.l. towards a very low diversity in the high alpine zone. The biodiversity peak does not match with the potential tree line in the area (2,500–3,000 m a.s.l.). The high diversity in foothills can be related to habitat heterogeneity, longer suitable climatic conditions, and diverse disturbance factors, while unfavorable conditions at high-altitude alpine and low-altitude desert areas reduce the number of species at both extremes. Life-form patterns clearly change along altitudinal gradient. Annuals with decreasing trend, and hemicryptophytes and chamaephytes with increasing trend along the altitudinal gradient are notable patterns of life form in the area. Temperature, soil moisture and nutrients are the main factors that explain the ecological influence of altitude on species diversity and life-form patterns in the semi-arid steppe vegetation of the area.     

Linear declines in exotic and native plant species richness along an increasing altitudinal gradient in the Snowy Mountains,Australia

Abstract Declines in plant species richness with increasing altitude are common, but the form of the relationship can vary, with both monotonic decreasing relationships and humped relationship recorded. However, these different richness to altitude relationships may be due to methods that used different plot sizes/areas and survey efforts. To explore native and exotic plant richness along an altitudinal gradient in the Snowy Mountains of Australia, we consistently surveyed plots that were 120 m² in area at 39 sites ranging from 540 to 2020 m. To relate exotic plant richness to disturbance, we surveyed plots at 16 sites along main roads and 23 sites along minor roads and also compared these 39 roadside plots to 120‐m² plots located in undisturbed vegetation adjacent to the roadside (native plant richness was only surveyed in 25 of these 39 adjacent plots). We found a negative linear relationship between total, exotic and native species richness and altitude for plots on the side of main roads (16 sites) and minor roads (23 sites). For adjacent plots negative linear relationships were significant for all measures of species richness except for native species adjacent to major roads. As the pattern occurred for exotics it is less likely to be due to historical constraints on the species pools. The pattern could be influenced by difference in levels of disturbance along the gradient, although any such gradient in disturbance would have to apply to roadside and adjacent plots on major and minor roads. Therefore, it may be due to other factors such as changes in climate along the altitudinal gradient, although additional sampling including direct measures of climatic conditions, soil and disturbance factors would be needed to determine if this was the case.     

四川小寨子沟森林群落物种多样性的环境梯度分析

运用去势典范对应分析法(DCCA),分析了四川小寨子沟自然保护区森林群落物种多样性指数与环境因子的关系.结果表明,群落物种多样性表现为草本层>灌木层>乔木层;海拔高度是群落乔木层物种多样性分布格局的主导因素,随着海拔高度的上升,乔木层物种丰富度和多样性下降,而均匀度没有明显变化;土壤有机质和土壤全氮代表的土壤养分状况决定着灌木层和草本层物种多样性的分布格局.地形因子(如坡度、坡向等)与物种多样性没有明显的关系.     

Precipitation controls seed bank size and its role in alpine meadow community regeneration with increasing altitude

The Tibetan Plateau has undergone significant climate warming in recent decades, and precipitation has also become increasingly variable. Much research has explored the effects of climate change on vegetation on this plateau. As potential vegetation buried in the soil, the soil seed bank is an important resource for ecosystem restoration and resilience. However, almost no studies have explored the effects of climate change on seed banks and the mechanisms of these effects. We used an altitudinal gradient to represent a decrease in temperature and collected soil seed bank samples from 27 alpine meadows (3,158–4,002 m) along this gradient. A structural equation model was used to explore the direct effects of mean annual precipitation (MAP) and mean annual temperature (MAT) on the soil seed bank and their indirect effects through aboveground vegetation and soil environmental factors. The species richness and abundance of the aboveground vegetation varied little along the altitudinal gradient, while the species richness and density of the seed bank decreased. The similarity between the seed bank and aboveground vegetation decreased with altitude; specifically, it decreased with MAP but was not related to MAT. The increase in MAP with increasing altitude directly decreased the species richness and density of the seed bank, while the increase in MAP and decrease in MAT with increasing altitude indirectly increased and decreased the species richness of the seed bank, respectively, by directly increasing and decreasing the species richness of the plant community. The size of the soil seed bank declined with increasing altitude. Increases in precipitation directly decreased the species richness and density and indirectly decreased the species richness of the seed bank with increasing elevation. The role of the seed bank in aboveground plant community regeneration decreases with increasing altitude, and this process is controlled by precipitation but not temperature.     

Nesting strategies affect altitudinal distribution and habitat use in Alpine dung beetle communities

1. Dung beetles are key contributors to a suite of ecosystem services. Understanding the factors that dictate their distributions is a necessary step towards preventing negative impacts of biodiversity loss. 2. Alpine dung beetle communities were analysed along altitudinal gradients to assess how different components of the community, defined in terms of nesting strategy [dung‐ovipositing Aphodiidae (DOAs), soil‐ovipositing Aphodiidae (SOAs) and two paracoprid (PAR) groups, Geotrupidae and Scarabaeidae] and parameters relevant to dung removal rates (species richness, total biomass and functional diversity), are distributed, and to identify to which environmental factors they respond. 3. Species richness declined with altitude. There was no significant variation in functional diversity or total biomass in relation to altitude. There were significant variations when considered by nesting group: DOA species richness and biomass decreased, SOA biomass increased, and Geotrupidae biomass showed a non‐linear trend, as altitude increased. 4. Functional diversity and total species richness were positively related to vegetation cover. DOA species richness was highest in forest and scrub; SOA species richness was highest in grassland and PAR species richness was lowest in rocky areas. 5. Dung beetle species show different trends in species richness and biomass depending on nesting strategy. Management to promote the dung beetle community should include maintenance of a mosaic of habitat types. Given the likely importance of species richness and biomass to ecosystem functioning, and the complimentary effect of different dung beetle groups, such a strategy may protect and enhance the ecosystem services that Alpine dung beetles provide.     

三江并流地区干旱河谷植物物种多样性海拔梯度格局比较

在滇西北三江并流地区典型干旱河谷段, 在怒江、澜沧江和金沙江的东、西坡共设置了6条海拔梯度样带, 通过标准样地的植物群落调查, 分析各条样带植物的物种丰富度、物种更替率的海拔梯度格局, 并比较了地理和植被变量对分布格局的解释。干旱河谷植被带位于海拔3,000 m以下, 以灌丛和灌草丛为主, 其在各河谷的分布上限自西向东依次升高。植物物种丰富度的分布主要与海拔、流域、经纬度和植被带有关, 沿纬度和海拔梯度升高而显著增加的格局主要表现在草本层和灌木层, 灌木物种丰富度还呈现自西向东显著增加的趋势。怒江的灌木和草本种物种丰富度显著高于金沙江和澜沧江, 三条江的乔木种丰富度差异则不显著。森林带的样方草本物种丰富度显著低于灌草丛带样方, 并且还拥有后者没有的乔木种。不同样带的植物物种更替速率呈现了不一致的海拔梯度格局, 但均在样带海拔下部的灌草丛群落与海拔上部森林群落之间的交错带出现峰值。森林-灌草丛植被交错带在怒江样带处于海拔1,900-2,100 m处, 在澜沧江河谷位于海拔2,300-2,400 m, 在金沙江河谷位于海拔2,700-2,900 m。所有海拔样带的森林段或灌草丛段相对于同一样带不同植被段之间的物种更替程度为最小, 不仅小于同一流域不同样带相同植被段之间物种更替率的均值, 更小于所有样带相同植被段之间的更替率均值。在三条河流6条海拔样带的12个植被带段之间的物种更替变化中, 空间隔离因素可以解释34.2%, 而植被类型差异仅能解释不到0.5%。本研究结果显示了环境差异对不同植被类型物种丰富度的首要影响, 和各河流之间的空间隔离对植物群落构建和物种构成的主要作用。     

辽东栎林不同层植物沿海拔梯度分布的DCCA分析

 为研究北京东灵山辽东栎（Quercus liaotungensis）不同层植物的分布与环境因子之间的关系,对东灵山辽东栎林进行了植物群落学调查。沿 海拔梯度在乔木层、灌木层和草本层各调查119个样方,同时调查了每个样方的环境因子如海拔、坡度和坡位。物种数据采用二元属性数据,对 非数值环境因子进行赋值。对东灵山辽东栎林和各环境因子进行去趋势典范对应分析（Detrended canonical correspondence analysis, DCCA）,结果表明：DCCA 第一轴基本上反映了植物群落所处环境的海拔的梯度变化,第二轴基本上反映了坡位的梯度变化。同时发现辽东栎林 大多数植物分布在低海拔区域。乔木层的物种分布比较均匀。草本层的物种分布重叠率是最大的,说明草本植物的生境相似性很高。低海拔区 域的生物多样性要高于高海拔区域的生物多样性。结合环境因子间的相关关系和DCCA排序结果,发现海拔是影响东灵山辽东栎林物种分布的主 要环境因子。     

新疆东部天山蝶类多样性及其垂直分布

2006-2008年研究了新疆东部天山蝶类多样性和垂直分布.结果表明:研究区域内共记录蝴蝶7科43属63种,占新疆已记录蝶类种数的24.80％,区系组成主要是古北种,占73％;其次是广布种,占27％,没有发现东洋种.其中蛱蝶科的物种数最多,为11属19种,蚬蝶科的物种数最少,只有1属1种.按海拔将生境分为5个垂直自然带,包括低山灌木草原带、山地森林草原带、亚高山草甸带、高山草甸带、垫状植被带.蝶类物种数和个体数排序为亚高山草甸带＞山地森林草原带＞低山灌木草原带＞高山草甸带＞垫状植被带.采用Shannon-Wiener指数和G-F指数对蝶类物种和科、属的多样性进行了分析评价,结果显示亚高山草甸带的蝶类多样性最为丰富,其次是山地森林草原带和低山灌木草原带,而高山草甸带和垫状植被带的蝶类多样性相对较低,物种和科、属多样性分析结果均一致.蝶类垂直分布明显,物种数和个体数随海拔变化的趋势类似,均为先增加后下降.蝶类区系成分随着海拔升高发生改变,广布种的比例逐渐降低,高山草甸带和垫状植被带只有古北种分布.研究结果显示,生境改变对蝴蝶群落影响明显,保护生境是保护蝴蝶生存的最主要措施.     

贺兰山木本植物群落物种多样性的海拔格局

 贺兰山位于中国温带草原和温带荒漠的过渡带,是研究干旱区山地物种多样性海拔格局的理想区域。该文通过样方法调查研究区的森林和灌丛群落,并运用广义可加模型分析物种多样性的海拔分布格局。结果表明：1）海拔是物种丰富度的重要影响因子,一般能解释原始数据30%～40%的变差。2）对于森林和灌丛群落,草本植物都是群落中比例最高的物种, 而且决定了群落总物种丰富度的海拔分布格局。3）森林群落的乔木层物种丰富度在中海拔区域最高,反映了中海拔区域相对优越的水热条件。灌木层和草本层的物种丰富度明显受到乔木层郁闭度的影响,有随海拔升高而降低的趋势。4）灌丛群落的灌木层和草本层物种丰富度均呈单峰格局,皆因低海拔的干旱和高海拔的寒冷抑制了多数物种的生存,仅气候条件适宜的中海拔区域能够生存丰富的物种。     

Environmental correlates of plant diversity in Korean temperate forests

Mountainous areas of the Korean Peninsula are among the biodiversity hotspots of the world's temperate forests. Understanding patterns in spatial distribution of their species richness requires explicit consideration of different environmental drivers and their effects on functionally differing components. In this study, we assess the impact of both geographical and soil variables on the fine-scale (400 m²) pattern of plant diversity using field data from six national parks, spanning a 1300 m altitudinal gradient. Species richness and the slopes of species–area curves were calculated separately for the tree, shrub and herb layer and used as response variables in regression tree analyses. A cluster analysis distinguished three dominant forest communities with specific patterns in the diversity–environment relationship. The most widespread middle-altitude oak forests had the highest tree richness but the lowest richness of herbaceous plants due to a dense bamboo understory. Total richness was positively associated with soil reaction and negatively associated with soluble phosphorus and solar radiation (site dryness). Tree richness was associated mainly with soil factors, although trees are frequently assumed to be controlled mainly by factors with large-scale impact. A U-shaped relationship was found between herbaceous plant richness and altitude, caused by a distribution pattern of dwarf bamboo in understory. No correlation between the degree of canopy openness and herb layer richness was detected. Slopes of the species–area curves indicated the various origins of forest communities. Variable diversity–environment responses in different layers and communities reinforce the necessity of context-dependent differentiation for the assessment of impacts of climate and land-use changes in these diverse but intensively exploited regions.