College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou 510642, China.
Sci Rep. 2017 Jan 9;7:40387. doi: 10.1038/srep40387.
Understanding global warming effects on forest ecosystems will help policy-makers and forest managers design forest management and biodiversity conservation strategies. We examined the change in woody plant structural diversity in response to topography-associated thermal gradients in a subtropical forest with diverse abundance patterns. We found that energy distribution in a warming trend across slopes had significant effects on woody plant structural diversity. Except for total basal area of the adult trees, plant structural diversity significantly decreased with the increase of heat load. Heat load is significantly and negatively correlated with number of stems, number of species, and the number of stems of the most abundant species (N) for seedlings, saplings, and individuals of all sizes. For the adult trees, heat load is significantly and positively correlated with number of stems and N, and negatively but not significantly with number of species, indicating that large trees may not be as sensitive as seedlings and saplings to warming. Partial correlation analysis, having controlled for elevation, strengthened those relations in most cases. Our results reveal that warming will increase community productivity by enhancing the growth of large trees, but decrease species diversity and inhibit the regeneration of tree seedlings and saplings.
了解全球变暖对森林生态系统的影响将有助于政策制定者和森林管理者设计森林管理和生物多样性保护策略。我们研究了在一个具有不同丰度模式的亚热带森林中，与地形相关的热量梯度对木本植物结构多样性的变化。我们发现，在变暖趋势中，能量分布对木本植物结构多样性有显著影响。除了成年树木的总基部面积外，植物结构多样性随热负荷的增加而显著下降。热负荷与幼苗、幼树和所有大小个体的茎数、物种数和最丰富物种的茎数（N）呈显著负相关。对于成年树木，热负荷与茎数和 N 呈显著正相关，与物种数呈负相关但不显著，表明大树可能不像幼苗和幼树那样对变暖敏感。在大多数情况下，偏相关分析在控制海拔后加强了这些关系。我们的结果表明，变暖将通过促进大树的生长来提高群落生产力，但会降低物种多样性，并抑制树木幼苗和幼树的再生。
