北京市元宝槭和紫丁香叶片的功能性状和生态化学计量比及养分重吸收效率的城乡梯度差异  

Gradient Differences of Functional Traits,Eco-Stoichiometric Ratio and Nutrient Resorption Efficiency of Acer truncatum and Syringa oblata Leaves in Beijing

作　　者：王泽锦 冉堃 于淼[1] 张碧嘉 冀莉 李品 Wang Zejin;Ran Kun;Yu Miao;Zhang Bijia;Ji Li;Li Pin(State Key Laboratory of Efficient Production of Forest Resources Key Laboratory for Silviculture and Conservation of Ministry of Education Key Laboratory for Silviculture and Forest Ecosystem of National Forestry and Grassland Administration Beijing Forestry University,Beijing 100083)

机构地区：[1]林木资源高效生产全国重点实验室、森林培育与保护教育部重点实验室、干旱半干旱地区森林培育及生态系统研究国家林草局重点实验室、北京林业大学,北京100083

出　　处：《林业科学》2024年第2期42-54,共13页Scientia Silvae Sinicae

基　　金：国家自然科学基金项目(32271673)。

摘　　要：【目的】探究城市典型观赏树种养分限制沿城乡环境梯度的响应差异,以期为城市化下的城市森林观赏树种养分管理提供科学依据。【方法】分别于夏季和秋季沿北京城区–近郊–远郊梯度上采集典型观赏树种元宝槭和紫丁香的成熟叶和凋落叶,测定其6种叶片功能性状(叶鲜质量、叶干质量、叶面积、比叶面积、比叶质量、叶片含水率)和6种营养元素含量[(碳(C)、氮(N)、磷(P)、钾(K)、钙(Ca)、镁(Mg)],计算元素的化学计量比值和养分重吸收效率,比较元宝槭和紫丁香在叶片功能性状、生态化学计量特征以及养分重吸收效率上的差异;分析年均温度、年降水量、年均太阳辐射量等环境因子与元宝槭和紫丁香叶片功能性状、生态化学计量特征以及养分重吸收效率的相关性。【结果】叶片功能性状、营养元素含量及其化学计量比值对城市化有显著响应,且存在种间差异。沿城区到远郊梯度,元宝槭和紫丁香成熟期叶鲜质量、叶干质量、叶面积、比叶面积、叶片含水率整体呈上升趋势,而比叶质量降低。凋落期元宝槭叶片的叶鲜质量和叶干质量沿城乡梯度逐渐降低;紫丁香凋落叶的叶干质量和比叶质量在城乡梯度上呈先升高后降低的趋势,叶面积则逐渐变小。2个树种凋落叶的比叶面积均沿城乡梯度先降低后升高。元宝槭和紫丁香成熟叶的N和K含量在近郊低于城区和远郊;元宝槭成熟叶的P和Mg含量在城乡梯度上变化不显著,而紫丁香成熟叶的P和Mg含量在近郊显著高于城区和远郊。元宝槭凋落叶P和Mg含量沿城乡梯度无明显变化;紫丁香凋落叶P含量在近郊显著高于城区和远郊,而Mg含量在远郊显著低于城区和近郊。元宝槭和紫丁香凋落叶K含量在城乡梯度上均先降低后升高。2个树种N、P、K、Ca和Mg 5种营养元素的养分重吸收效率沿城乡梯度无明显差异。【结论】城市�【Objective】The study was intended to explore the response difference of nutrient limitation of typical urban ornamental tree species along the urban and rural environmental gradients,in order to provide a scientific basis for nutrient management of urban forest ornamental tree species under urbanization.【Method】The mature and defoliated leaves of typical ornamental tree species Acer truncatum and Syringa oblata were collected along the urban-suburban-rural gradients of Beijing in summer and autumn,respectively.Six leaf functional traits(leaf fresh weight,leaf dry weight,leaf area,specific leaf area,leaf mass per unit area and leaf water content)and the contents of six elements[carbon(C),nitrogen(N),phosphorus(P),potassium(K),calcium(Ca),magnesium(Mg)]were determined.The stoichiometric ratio and nutrient resorption efficiency were calculated.The differences of leaf functional traits,eco-stoichiometric characteristics and nutrient resorption efficiency between Acer truncatum and Syringa oblata were compared.The correlations of environmental factors such as mean annual temperature,mean annual precipitation and mean annual solar radiation with leaf functional traits,eco-stoichiometric characteristics and nutrient resorption efficiency of Acer truncatum and Syringa oblata were analyzed.【Result】Leaf functional traits,element content and stoichiometric ratio had significant response to urbanization,and there were interspecific differences.In mature stage,along the gradients from the urban area to the rural area,the leaf fresh weight,leaf dry weight,leaf area,specific leaf area and leaf water content of Acer truncatum and Syringa oblata increased as a whole,while the leaf mass per unit area decreased.During the abscission period,the leaf fresh weight and leaf dry weight of Acer truncatum decreased gradually along the gradients between the urban area and the rural area.The leaf dry weight and leaf mass per unit area of Syringa oblata increased at first and then decreased along the gradients from the urban area

关 键 词：城乡梯度 叶片 生态化学计量 养分重吸收 观赏树种 

分 类 号：S718.51[农业科学—林学]