摘要
研究群落水平上的植物功能性状特征及功能多样性随坡向的变化规律,对认识不同坡向上的植物群落形成过程具有重要意义。以黄土高原不同坡向上的自然草地群落为研究对象,比较研究了植物功能性状(株高和比叶面积)和功能多样性测度指标(功能丰富度、功能均匀度和功能离散度)随坡向的变化规律。研究结果显示:(1)阴坡的株高和比叶面积显著高于其他坡向;(2)一元性状的功能丰富度在不同坡向间均无显著差异;阴坡和半阴坡的多元性状功能丰富度显著高于阳坡;(3)阴坡的株高功能均匀度显著高于半阳坡,而比叶面积功能均匀度在各坡向的差异并不显著;多元性状功能均匀度在不同坡向差异显著,阴坡最高,半阳坡最低;(4)阴坡和半阴坡的株高功能离散度显著高于阳坡和半阳坡,而半阴坡的比叶面积功能离散度显著高于阳坡;半阴坡的多元性状功能离散度Rao指数显著高于阳坡。研究结果暗示了,在阴坡和半阴坡上,植物对群落内的生态位空间和资源利用更充分,种间竞争强度较低,不同物种之间生态位高度分化;而在阳坡和半阳坡上,由于水分等条件的限制植物可占据的生态位空间有限,导致其对占据的生态位空间使用不足,物种间资源竞争较强烈。在群落水平上,研究地区的植物功能性状及功能多样性随坡向的规律性变化,反映了黄土高原植被群落构建过程中坡向因子对功能性状的筛选效应。该研究结果对该区的植被恢复重建的物种选择及植被布局规划具有重要实践意义。
Functional diversity of a plant community, which is based on plant traits, has been proposed as a key component predicting ecosystem functnowledge about how plant functional traits and functional diversity change along with the different slope aspion. Kects at the community level is important for understanding the formation of plant communities under distinct slope aspects. However, to date, previous studies on plant communities in sunny and cloudy slope environments have mainly been descriptive. To our knowledge, no research has dealt with the relationship between the slope aspect and community assembly based on plant functional diversity （i.e., functional richness, evenness and divergence）. In this study, we aimed to uncover the relationship between slope aspects and plant functional traits. Three sampling transects （ 1 m ×5 m） were established on each of four sites facing north, south, east, or west, in Malan Mountain, Loess Plateau. Each of the sampling transects were evenly divided into fifteen 1 m × 1 m plots, and a plot survey was conducted. We measured plant height （H） and specific leaf area （SLA）, and then calculated three types of functional diversity indices （i. e., functional richness, evenness, and divergence） , which included three one-dimensional indices based on single traits （i.e., FRci, FRO, FDvar） and three multi-dimensional indices based on two traits （i.e., FRci, FEve, FDQ）. A comparison of the changing pattern of plant functional traits and the three types of functional diversity was conducted among the four slope aspects （the cloudy, sunny, semi-cloudy, and semi-sunny slope）. Our results indicated that： （1） the value of H and SLA on the cloudy slope was greater than the others; （2） there was no significant difference among the four slope aspects in one-dimensional functional richness indices of H and SLA, while the multi- dimensional functional richness indices of plants on the cloudy slope and the semi-cloudy slope were greater than those of the plants on the sunny slope; （3） on the cloudy slope, the one-dimensional functional evenness of H was significantly greater compared to those on the semi-sunny slope, while that of SLA was not significantly influenced by the slope aspect; the multi-dimensional functional evenness indices of plants on the cloudy slope was greater than those of the plants on semi-sunny slope; （4） the one- dimensional functional divergence of H on the cloudy and semi-cloudy slope were significantly greater than those on the semi-sunny and sunny slope, while that of SLA on the semi-cloudy slope was significantly greater than those on the sunny slope; the multi-dimensional functional divergence index and Rao＇s quadratic entropy of plants was significantly greater on the semi-cloudy slope compared with those on the sunny slope. Our results indicated that for plant traits, more niche space was occupied, more resources were sufficiently exploited, lower competition intensity occured, and a high level of niche differentiation existed on the cloudy and semi-cloudy slopes. By contrast, because of the limitation of all kinds of soil conditions and environmental factors, plant traits occupied less niche space on the sunny and semi-sunny slope, resources were exploited less sufficiently, and competition for resources tended to be stronger. At the community-level, the changing pattern of plant functional traits and functional diversity along the four different slope aspects suggests the existence of an environmental fitter effect on functional traits under the process of community assembly in the Loess region. These findings would have significant practical implications for species selection and vegetation rehabilitation layout planning in the hilly area of the Loess Plateau.
出处
《生态学报》
CAS
CSCD
北大核心
2016年第21期6823-6833,共11页
Acta Ecologica Sinica
基金
陕西师范大学中央高校基本科研业务费(GK201503044)
关键词
坡向
群落构建
功能性状
功能丰富度
功能均匀度
功能离散度
slope aspect
community assembly
functional trait
functional richness
function evenness
functional divergence
