植物生态学报 ›› 2014, Vol. 38 ›› Issue (3): 270-280.DOI: 10.3724/SP.J.1258.2014.00024

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小五台山青杨雌雄植株树轮生长特性及其对气候变化的响应差异

黄科朝1,2, 胥晓2,*(), 李霄峰3, 贺俊东1,2, 杨延霞1,2, 郇慧慧1,2   

  1. 1西华师范大学生命科学学院, 四川南充 637009
    2西南野生动植物资源保护教育部重点实验室, 四川南充 637009
    3张家口市农业环境与农产品质量管理站, 河北张家口 075000
  • 收稿日期:2013-10-12 接受日期:2013-12-27 出版日期:2014-10-12 发布日期:2014-02-27
  • 通讯作者: 胥晓
  • 作者简介:*E-mail: xuxiao_cwnu@163.com
  • 基金资助:
    国家自然科学基金(31170389)

Gender-specific characteristics of tree-ring growth and differential responses to climate change in the dioecious tree Populus cathayana in Xiaowutai Mountains, China

HUANG Ke-Chao1,2, XU Xiao2,*(), LI Xiao-Feng3, HE Jun-Dong1,2, YANG Yan-Xia1,2, HUAN Hui-Hui1,2   

  1. 1College of Life Sciences, China West Normal University, Nanchong, Sichuan 637009, China
    2Key Laboratory of Southwest China Wildlife Resources Conservation, Ministry of Education, Nanchong, Sichuan 637009, China
    3Agricultural Environment and Agri-Product Quality Management Section, Zhangjia- kou, Hebei 075000, China
  • Received:2013-10-12 Accepted:2013-12-27 Online:2014-10-12 Published:2014-02-27
  • Contact: XU Xiao

摘要:

近年来逆境导致植物雌雄幼苗的生长出现差异被许多控制实验所证实, 而有关气候变化对雌雄异株植物成树生长的潜在影响尚未引起人们广泛的关注。为进一步揭示气候变化对雌雄植株树木径向和密度生长的不同影响, 该文通过树轮生态学的研究方法, 选择小五台山天然青杨(Populus cathayana)种群为研究对象, 对青杨雌雄植株近30年(1982-2011)的树轮生长特性及其与气候的相关性进行了分析。结果显示: 1)在近30年当地气温不断升高的气候条件下, 雌株的年轮最大密度和晚材平均密度均高于雄株(p < 0.05), 但雌雄植株的径向生长无显著差异; 2)雌雄植株年轮最大密度和宽度差值年表的变化趋势具有一致性, 但在年轮最大密度差值年表的变化上雄株波动幅度大于雌株; 3)青杨雌雄植株年轮密度差值年表对温度响应的月份明显不同。雌株年轮最大密度与当年8月的月平均最高气温显著正相关, 而雄株年轮最大密度与当年1月和4月的气温负相关; 4)生长季前的气候变化对青杨雌雄植株的径向生长均有明显的限制作用。此外, 当年6月的高温对于早材生长的限制作用特别明显。上述结果表明, 雌雄异株植物在树木年轮生长方面对全球气候变暖可能具有不同的响应机制, 雌株比雄株更侧重于密度生长。

关键词: 气候变化, 树轮生态学, 雌雄差异, 青杨, 年轮密度

Abstract:

Aims While the phenomena that environmental stresses induce growth differentiations between male and female seedlings are confirmed by many controlled experiments in recent years, the potential impacts on adult trees of dioecious plants caused by climate change have not yet attracted much attention. In order to further reveal the differential effects of climate warming on the dendrological characteristics of female and male trees, a typical dioecious plant, Populus cathayana, was selected as a test material in the study.
Methods Wood samples were taken from 40 adult trees of P. cathayana (including 20 female and 20 male individuals, respectively). We employed the dendroclimatological approach to analyze the gender-specific differences in seven tree-ring variables (i.e. maximum ring density, latewood mean density, earlywood mean density, minimum ring density, annual ring width, earlywood width, and latewood width), and their differential responses to climate factors (monthly mean, minimum and maximum air temperature and precipitation) in Xiaowutai Mountains of China.
Important findings Firstly, with an increase in the local air temperature during the past 30 years (1982-2011), the male and female P. cathayana trees exhibited the similar trend in radial growth but with apparent differences in the pattern of density growth. Compared with the males, the female trees displayed significantly (p < 0.05) higher maximum ring density and latewood mean density. Secondly, there was a similar pattern of variations in the residual chronologies between the male and female trees, but the male trees showed much higher magnitude of variations than the female trees. Thirdly, based on the residual chronologies, it was found that the response months are quite different between the two sexes. For the female trees, maximum ring density had a significant positive correlation with the maximum air temperature in current August. However, the maximum ring density was significantly and negatively correlated with the air temperature in current January and April for the male trees. Fourthly, for trees of both sexes, climate change prior to growing season limited the radial growth while maximum air temperature in current June obviously restricted the growth of earlywood. These results indicate that there are different tree-ring growth strategies between trees of different sexes in response to global warming in dioecious plants, and that the female trees invest more in density growth than the male trees.

Key words: climate change, dendroecology, gender-specific, Populus cathayana, ring density