植物生态学报 ›› 2012, Vol. 36 ›› Issue (11): 1136-1144.DOI: 10.3724/SP.J.1258.2012.01136

所属专题: 生态化学计量

• 研究论文 • 上一篇    下一篇

金沙江干热河谷地区植物叶片中各生源要素的化学计量特征以及异速增长关系

闫帮国, 何光熊, 李纪潮, 纪中华*()   

  1. 云南省农业科学院热区生态农业研究所, 云南元谋 651300
  • 收稿日期:2012-06-11 修回日期:2012-09-04 出版日期:2012-06-11 发布日期:2012-11-09
  • 通讯作者: 纪中华
  • 作者简介: (E-mail: rjsjzh@163.com)

Scaling relationships and stoichiometry of plant leaf biogenic elements from the arid-hot valley of Jinsha River, China

YAN Bang-Guo, HE Guang-Xiong, LI Ji-Chao, JI Zhong-Hua*()   

  1. Institute of Tropical Eco-agricultural Sciences, Yunnan Academy of Agricultural Sciences, Yuanmou, Yunnan 651300, China
  • Received:2012-06-11 Revised:2012-09-04 Online:2012-06-11 Published:2012-11-09
  • Contact: JI Zhong-Hua

摘要:

植物生源要素的化学计量比在生物地球化学循环以及植物生理代谢中具有极为重要的作用。迄今为止, 对植物叶片的N、P元素与其他生源要素含量间相关关系的研究较少, 限制了生态化学计量学的应用广度。为了解金沙江干热河谷地区植物叶片中各种生源要素间的异速增长关系, 该研究通过对当地51个样方中107个样本的测量, 探索个体水平、物种水平和样方水平上各生源要素间的异速增长关系。结果显示: 叶片中各元素的比例N:P:K:S:Fe:Ca为100.00:6.64:88.20:11.59:2.48:91.64, N、P含量分别为11.21和0.744 mg·g -1, 明显低于全国平均值, 而N:P与全国平均值相当, 表明植物生长受到N、P的双重限制。各种生源要素间存在正相关增长关系, 在个体水平上, 植物叶片中N-P大致呈等速增长关系, Fe与Ca元素相对于N、P、K的增长速率显著大于1, Fe的增长速率最大, 依次为Fe > Ca > P > N > S > K; 物种水平上Fe与Ca相对于N、P、K的增长速率显著大于1; 样方水平上, Fe元素相对于N、P、K的增长速率依旧显著大于1, 但Ca、S相对于N的增长速率显著大于1, 元素增长速率为Fe > Ca > P > S > K > N, 其中N相对于P的异速增长斜率与2/3极为接近, K相对于P的异速增长斜率接近3/4。个体水平和样方水平上各种元素间的相关关系以及拟合优度不一致, 表明群落构建在介导不同层次上元素关系中发挥着重要作用。

关键词: 异速相关, 干热河谷, 生源要素, 植物养分, 化学计量

Abstract:

Aims Plant leaf stoichiometry plays critical roles in the photosynthesis rate, growth rate, dynamics of food chains and biogeochemical cycles. Although previous research showed that nitrogen has a scaling relationship with phosphorus, the relationship between elements besides nitrogen and phosphorus rarely have been studied. This project was to explore the scaling relationships between leaf elements (i.e., Fe, Ca, P, N, S, K) at an arid-hot valley.
Methods Leaf samples were collected from 51 plots located 1000-1400 m above sea level in the arid-hot valley of Jinsha River. Biomass in plots was sorted by species and measured. Leaf elemental contents of 107 samples were qualified. Relationships among these biogenetic elements were analyzed by standard major axis at both plot and individual levels.
Important findings There were always positive scaling relationships between studied elements when they were significantly correlated. The power law exponents derived from log-log scaling relations were near 2/3 for nitrogen relative to phosphorus at the plot level. The power law exponents for iron to N, P, K were >2 at the individual level. The rank of increasing rate in scaling relationships was Fe > Ca > P > N > S > K at the individual level. However, it was Fe > Ca > P > S > K > N at the plot level. We found that iron might be an important element in plant growth in the arid-hot valley for the higher increasing rate of investment in iron versus other elements. The differences in scaling relationships among elemental concentrations between the individual and plot levels suggest that community assembly process has an important role in determining plant stoichiometry at different levels of organization.

Key words: allometric relationship, arid-hot valley, biogenic element, plant nutrient, stoichiometry