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全球气候变化背景下大气环流及水文循环的改变,可导致区域降雨格局变化,作用于区域陆地生态系统物质循环与能量流动过程,从而影响植物群落对降水量变化的生理生态响应。以科尔沁沙地樟子松(Pinus sylvestris var.mongolica)人工林为对象,设置野外降雨变化实验样地(天然降雨(CK)、降雨量减少30%(-30%)、降雨量增加30%(+30%)3种处理)、选择2个不同的生长季降雨格局(DRY-236mm、WET-357mm),研究生长季樟子松针叶的光合速率、蒸腾速率、水分利用效率、叶绿素、脯氨酸、可溶性蛋白、丙二醛(MDA)、SOD活性以及生长变化,分析降雨变化对樟子松人工林的影响。结果表明,樟子松针叶光合、蒸腾速率和水分利用效率与降雨量呈正相关,降雨量变化对樟子松生理生态特征产生显著影响,其中生长季水分胁迫对樟子松生长的影响存在滞后效应,樟子松针叶N含量的变化可反映不同水分变化与土壤养分有效性共同作用模式。
Changes in atmospheric circulation and hydrological cycle in the context of global climate change can lead to changes in regional rainfall pattern and effect on material circulation and energy flow in terrestrial ecosystems, thus affecting the physiological and ecological responses of plant communities to changes in precipitation. In the study area of Pinus sylvestris var. Mongolica plantations in Keerqin sandy land, rainfall was reduced by 30% (-30%) and rainfall increased by 30% (natural rainfall) + 30%), two different growing season rainfall patterns (DRY-236mm, WET-357mm) were selected to study the photosynthetic rate, transpiration rate, water use efficiency, chlorophyll, proline, Soluble protein, malondialdehyde (MDA), superoxide dismutase (SOD) activity and growth of Pinus sylvestris var. Mongolica were analyzed. The results showed that there was a positive correlation between the photosynthesis, transpiration rate and water use efficiency of Pinus sylvestris var. Mongolica and rainfall, and the change of rainfall had a significant impact on the physiological and ecological characteristics of Pinus sylvestris var. Mongolica. There was a lagging effect of water stress on the growth of Pinus sylvestris var. Mongolica , And the change of N content in Pinus sylvestris var. Mongolica can reflect the mode of interaction between different water changes and soil nutrient availability.