Leaf size, specific leaf area and microhabitat distribution of chaparral woody plants: contrasting patterns in species level and community level analyses
Leaf size, specific leaf area and microhabitat distribution of chaparral woody plants: contrasting patterns in species level and community level analyses
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DOI：
10.1007/s004420100805
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发表时间：
2002-02-01
期刊：
影响因子：
2.7
通讯作者：
Starmer, KP
中科院分区：
文献类型：
--
作者：
Ackerly, DD;Knight, CA;Starmer, KP
我们研究了叶大小和比叶面积(SLA)的变化与22种查帕尔灌木在小尺度坡向和海拔梯度上的分布的关系。从地理信息系统估计了潜在的入射太阳辐射(日照强度)，以量化这些物种在北向和南向斜坡上的小气候亲和力。在群落水平上，叶片大小和SLA都随着日照强度的增加而下降，这是基于沿坡度的样地中物种的平均特性值。然而，叶大小和SLA在不同物种之间没有显著的相关性，这表明这两个性状是分离的，并与沿着这种环境梯度的表现的不同方面有关。就物种个体而言，SLA与物种沿光照梯度的分布呈负相关，常绿树种的SLA显著低于落叶树种。叶片大小与各树种的日照分布呈负相关，但不显著。在群落水平上，叶大小的变异随着日照强度的增加而增大。就个别树种而言，南向坡的树叶大小范围较大，而北向坡则没有小叶树种。这些结果表明，基于群落水平平均值的沿环境梯度的植物功能性状分析可能会掩盖组成物种之间性状变异和分布的重要方面。
We examined variation in leaf size and specific leaf area (SLA) in relation to the distribution of 22 chaparral shrub species on small-scale gradients of aspect and elevation. Potential incident solar radiation (insolation) was estimated from a geographic information system to quantify microclimate affinities of these species across north- and south-facing slopes. At the community level, leaf size and SLA both declined with increasing insolation, based on average trait values for the species found in plots along the gradient. However, leaf size and SLA were not significantly correlated across species, suggesting that these two traits are decoupled and associated with different aspects of performance along this environmental gradient. For individual species, SLA was negatively correlated with species distributions along the insolation gradient, and was significantly lower in evergreen versus deciduous species. Leaf size exhibited a negative but non-significant trend in relation to insolation distribution of individual species. At the community level, variance in leaf size increased with increasing insolation. For individual species, there was a greater range of leaf size on south-facing slopes, while there was an absence of small-leaved species on north-facing slopes. These results demonstrate that analyses of plant functional traits along environmental gradients based on community level averages may obscure important aspects of trait variation and distribution among the constituent species.