山地表生过程与生态调控重点实验室知识库

近几十年来,气候变暖、大气CO₂浓度升高和干旱对陆地生态系统的影响引起了广泛关注。杨树是世界各国普遍种植的木本植物,研究其对环境变化的响应具有重要的理论和实践意义。本文采用Meta分析（Meta analysis）方法定量总结了增温、大气CO₂浓度升高、干旱对杨树生理生态特性的影响。通过Web of Science、中国知网等中英文数据库检索,共收集了34篇原始文献,获得690个独立样本。结果表明:（1）增温显著提高了杨树的高增长（+78.32%）、叶面积（+58.23%）,促进了地上生物量（+89.59%）和叶生物量的积累（+71.69%）,显著降低了杨树的水分利用效率（-22.61%）和碳同位素（-5.51%）;（2）CO₂浓度升高显著提高了杨树的叶面积（+49.65%）和光合速率（+22.53%）,以及根生物量（+72.36%）,显著降低了杨树的气孔导度（-17.21%）;（3）干旱显著提高了杨树的根冠比（+38.95%）和水分利用效率（+34.52%）,显著降低了杨树的叶面积（-148.53%）,以及总生物量（-70.81%）。从本文收集的文献来看,单独研究大气CO₂浓度升高、增温或干旱对杨树生理生态特性影响的文献较多,关注两两交互或三者协同作用对杨树生理生态特性影响的文献很少,这些环境因子的交互作用对杨树生理生态特性的影响研究应加强。

Populus is one of the most widely distributed species in the world． Their responses to environment changes have become the matter of great concern worldwide in the circumstances of global climate change． Climate change interfere in plant physiology and growth，but its effect has not yet been reviewed statistically for Populus． In
this paper，meta-analysis was used to quantitatively outline the research progress of the effect of environmental factors ( temperature，CO₂ concentration，drought) on physiology and growth of Populus． The results showed that  ( 1) warming significantly increased the height growth ( + 78.32%) ，leaf area( + 58.23%) ，and root biomass
( + 89.59%) ， leaf biomass ( + 71.69%) ，but decreased the water use efficiency ( － 22.61%) and carbon isotope ( － 5.51%) of Populus． ( 2) Elevated CO₂ significantly increased leaf area( + 49.65%) ，the photosynthetic rate ( + 22.53%) ，root biomass ( + 72． 36%) of Populus but decreased the stomatal conductance ( － 17.21%) of
Populus． ( 3) Drought significantly increased root /shoot ratio ( + 38.95%) and water use efficiency ( + 34.52%) but significantly decreased the leaf area ( － 148.53%) ，and total biomass ( － 70.81%) of Populus． According to literature review，the responses were different or even adverse when plants grown under the combination treatments
compared to those grown under single treatment，indicating responses of plants to individual effects of environmental factors ( temperature，CO₂ and drought) can be neutralized by other simultaneous environmental changes． The future research direction about Populus under global climate change was suggested．