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Harvard Forest Symposium Abstract 2017

  • Title: Climate warming induces age-related Korean pine (Pinus koraiensis) growth decline in northeast China
  • Primary Author: Xiaochun Wang ()
  • Additional Authors: Zhenju Chen (); Neil Pederson (Harvard Forest); Xiaochun Wang ()
  • Abstract:

    Xiaochun Wang, Northeast Forestry University, Harbin, China, wangxc-cf@nefu.edu.cn

    Neil Pederson, Harvard University, Harvard Forest, Petersham, MA, neilpederson@fas.harvard.edu

    Zhenju Chen, Shenyang Agricultural University, Shenyang, China, zhenjuchen@hotmail.com

    Chen Zhu, Northeast Forestry University, Harbin, China

    Shijie Han, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China, hansj@iae.ac.cn

    Warming in northern China will likely have a significant impact on the productivity of forests. There is a lot of uncertainty in understanding the potential trajectory of productivity in the region because of the diversity of tree species. In association with warming, recent declines in Korean pine (Pinus koraiensis), one of the most key tree species of northeast Asia, makes it appear to be particularly vulnerable to climate change. Here, we use dendrochronological methods to test whether the growth decline of Korean pine in northeast China is 1) related to climate warming or 2) varied with age. To do this, a total of 628 cores from 401 trees at 16 sites were sampled and divided into three age classes: younger (50-130 years), middle (131-210 years) and older trees (>210 years). Our results show a significant decline in basal area increment (BAI) in most sites since the 1980s. Meanwhile, we found the response of growth decline to rising temperature was significantly related to tree age, but in ways that might seem unexpected: BAI of younger trees decreased significantly and sharply (0.44 cm2 year-1, P < 0.0001), still decreased significantly but not so sharply (0.13 cm2 year-1, P = 0.02) for middle trees, with now significant trend for old trees (0.04 cm2 year-1, P = 0.33). The age-related growth decline observed here might be explained by tree species trait, growth rate difference to stress, root system changes, competition or physiological mechanism. Understanding this growth decline is crucial for forest management under climate change and modeling future carbon cycle pattern and forest dynamics.

  • Research Category: Regional Studies; International Research Projects; Historical and Retrospective Studies; Conservation and Management