中国东部城市森林阔叶树种叶绿素含量空间特征及其影响因素

Spatial patterns and drivers of leaf chlorophyll content of broadleaved woody plants across urban forests in eastern China

选取中国东部样带9个城市27个公园,在生长季使用叶绿素仪(SPAD-502 Plus)测定了主要阔叶树种新叶与成熟叶的叶绿素相对含量(SPAD值),探究了城市阔叶树种叶片叶绿素相对含量空间特征及其影响因素.结果表明:中国东部城市阔叶树种成熟叶SPAD值显著高于新叶,常绿阔叶树种叶片SPAD值显著高于落叶阔叶树种.中国东部城市阔叶树种新叶和成熟叶的叶绿素相对含量均随纬度降低而升高,主要是由树种组成(以常绿树种比例为指标)变化导致的.本研究相关结果增进了对城市环境中阔叶树种叶片属性大尺度空间规律的认识.

Leaf chlorophyll is associated with plant photosynthesis and vegetation productivity. Previous studies on leaf chlorophyll have mostly focused on plants in natural ecosystems,less is known about large-scale patterns and main drivers of leaf chlorophyll content for woody plants in urban forests. A chlorophyll meter(SPAD-502 Plus) was used to measure chlorophyll content(SPAD values) in both young and mature leaves of broad-leaved woody plants from 27 urban parks in 9 large cities across eastern China. Results showed that SPAD value was significantly higher in mature leaves than in young leaves,SPAD value of evergreen broadleaves was significantly higher than deciduous broadleaves. The chlorophyll content in young and mature leaves of broad-leaved woody plants in eastern China both decreased at higher latitude. The latitudal variation in chlorophyll content in broad-leaved woody plants was mainly due to spatial shift in species composition(as indicated by percentage of evergreen species). These findings improve understanding of large-scale pattern of leaf chlorophyll content in urban forests.