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

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．