气候变化对不同退化程度小叶杨林分生长和内在水分利用效率的调节  

Climate change regulate tree growth and intrinsic water use efficiency of Populus simonii at different levels of degradation

作　　者：王堃莹 邱贵福 刘子赫 孟君 刘宇轩 贾国栋[1,2,3] WANG Kun-Ying;QIU Gui-Fu;LIU Zi-He;MENG Jun;LIU Yu-Xuan;JIA Guo-Dong(School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China;Key Laboratory of National Forestry and Grassland Administration on Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China;State Key Laboratory of Efficient Production of Forest Resources,Beijing 100083,China;Zhangjiakou Saibei Forestry(Municipal State Forestry Administration),Zhangjiakou,Hebei 075000,China)

机构地区：[1]北京林业大学水土保持学院,北京100083 [2]北京林业大学水土保持国家林业和草原局重点实验室,北京100083 [3]林木资源高效生产全国重点实验室,北京100083 [4]张家口塞北林场(市国有林场管理处),河北张家口075000

出　　处：《植物生态学报》2025年第2期343-355,共13页Chinese Journal of Plant Ecology

基　　金：国家重点研发计划(2023YFF1305302);国家自然科学基金(42277062和41977149)。

摘　　要：小叶杨(Populus simonii)作为中国北方重要防护树种,其大面积衰退对生态系统健康发展及防护林持续经营产生了严重影响,探究气候变化背景下小叶杨退化原因可为人工林的管理经营提供参考。该研究调查了张北县3种不同退化程度的小叶杨人工林,将其胸高断面积增量(BAI)、内在水分利用效率(iWUE)、树轮碳稳定同位素比值和气孔调节策略进行对比,从而分析了气候变化对小叶杨生长和iWUE的影响。结果显示:1)CO_(2)浓度和气温是iWUE变化的主要驱动因素,在大气CO_(2)浓度增加、气候变化和生理状况综合影响下,小叶杨的iWUE呈现明显增加趋势,不同退化程度小叶杨BAI均呈先增后减趋势。2)3种不同退化程度小叶杨林分的生长主要受气温影响,大多数情况下研究区iWUE的增加并不能促进树木生长。3)气候变化背景下,衰退树木对干旱更为敏感,干旱胁迫下,退化程度大的林分采取更为严格的气孔策略。4)CO_(2)浓度增加及气温上升的促进作用无法抵消干旱胁迫加剧对树木生理机能的不利影响,长期干旱胁迫可能导致退化树木生长进一步衰退。Aims As one of the important species in shelterbelt forests of the northern China,the large-scale decline of the Populus simonii has a serious impact on the healthy development of the ecosystem and the sustainable management of shelterbelt forests,and the investigation on the causes of P.simonii degradation in the context of climate change can provide a reference for the management of plantation forests.Methods The study investigated three P.simonii plantation forests with different degradation levels in Zhangbei,and compared their basal area increment(BAI),intrinsic water use efficiency(iWUE),tree ring carbon stable isotopes ratio,and stomatal regulation strategies,in order to analyze the impacts of climate change on the growth of P.simonii and its intrinsic water use efficiency.Important findings The results showed that:1)CO_(2) concentration and air temperature were the main drivers of iWUE changes,with a significant increasing trend in iWUE under the combined effects of increasing atmospheric CO_(2) concentration,climate change and physiological conditions.2)The tree growth in the three P.simonii stands with different levels of degradation was mainly determined by air temperature,and in most cases the increase in iWUE did not promote tree growth.3)Declining trees were more sensitive to drought in the context of climate change,and more stringent stomatal strategies were adopted by highly degraded stands under drought stress.4)The negative effects of increased drought stress on tree physiology could not be counteracted by increased CO_(2) concentrations and increased air temperatures,and prolonged drought stress might lead to further decline in the growth of degraded trees.

关 键 词：气候变化 干旱 气孔调节 树轮 稳定同位素 人工林 

分 类 号：S792.11[农业科学—林木遗传育种]