Latitudinal, soil and climate effects on key leaf traits in northeastern China

The spatial differentiation of plant functional traits reflects the survival strategies of plants to adapt to climate change. However, the mechanisms that guide this phenomenon, especially along latitude gradients, remain unclear. Leaf traits data, namely specific leaf area, leaf nitrogen content, leaf phosphorus content and leaf dry matter content in northeast China along the latitude was used to identify potential underlying climate and soil drivers of latitudinal gradients in plant traits. (1) Leaf traits of all life forms showed a wide variation across the study locations in northeastern China and the variation was strongly correlated with latitude. The latitudinal interpretation of leaf N and P content spatial differentiation is higher than other functional traits. (2)The latitudinal differences of functional traits were significantly correlated with climatic factors. With the increase of annual average temperature and annual average precipitation (MAT and MAP), specific leaf area (SLA) of leaves increased significantly, while leaf dry matter content (LDMC) decreased significantly (P < 0.05), The N content and P content of leaves showed significant nonlinear changes. The explanation degree of MAT to the spatial differentiation of most leaf traits is higher than the annual average precipitation (MAP). Soil factors also play an important role in shaping the spatial differentiation of leaf functional properties. With the increase of soil N and P content, leaf SLA and leaf N and P content also increased significantly (P < 0.05). The contribution of soil N content is higher than that of soil P content in shaping leaf traits. (3) The independent contribution of climate factors to the latitudinal difference of leaf function was 32.7%, slightly higher than that of soil factors (21.9%). (C) 2020 The Authors. Published by Elsevier B.V.