全球木本植物叶片硅钙生态化学计量学特征

Abstract

收集全球803种木本植物叶片硅（Si）、钙（Ca）数据，研究不同木本植物生活型（常绿植物以及落叶植物、针叶植物以及阔叶植物）叶片Si、Ca元素的化学计量学特征及其与纬度、气候因子（年平均温度，年平均降水量）间的关系。结果表明：（1）全球尺度上木本植物叶片Si、Ca含量存在较大变异性，且含量均低于中国境内的研究结果；（2）不同生活型树种间存在差异，针叶树叶片Si含量及Ca/Si显著高于阔叶树，落叶树叶片Si、Ca含量及Ca/Si均显著高于常绿树种；（3）随着纬度升高、年平均温度及年平均降水量的下降，全球尺度木本植物叶片Si、Ca含量显著升高，而Ca/Si显著下降；（4）不同生活型木本植物对气候因子的响应不同，除针叶及落叶树种的Ca含量外，其余各生活型树种Si、Ca含量与纬度及气候因子显著相关，随着纬度升高而升高，随年平均温度及年平均降水量的升高而降低，且随着年平均温度的降低，常绿及阔叶树种叶片Si含量下降速度显著高于落叶及针叶树种。研究结果能够为全球尺度生态化学计量学模型的发展提供数据基础，有助于更好地理解和模拟区域乃至全球尺度上纬度和气候因子对植物叶片Si、Ca含量的影响。;The ecological stoichiometric characteristics of silicon (Si) and calcium (Ca) play crucial roles in plant nutrient absorption, and thus impact the global biogeochemical cycle of Si and Ca. However, few were known about the stoichiometric characteristics of Si and Ca in the woody plant. In this study, using the collected data of Si and Ca of 803 woody plants in the world from the Plant Trait Database and published literature, the stoichiometric characteristics of Si and Ca in leaves of different woody plant life forms (evergreen plants, deciduous plants, coniferous plants and broad-leaved plants) and their relationships with latitude and climatic factors (mean annual temperature and mean annual precipitation) were investigated using the covariance analysis method. The results showed that:(1) the contents of Si and Ca in leaves of woody plants were highly variable at a global scale, and their contents were lower than those in China. In detail, the global geometric mean content of Si and Ca was 0.28 and 1.73 mg/g, respectively. (2) The contents of Si and Ca are varied among different life forms. The Si content and Ca/Si ratio of coniferous trees were significantly higher than those of broad-leaved trees, and the contents of Si, Ca in leaves of deciduous trees were significantly higher than those of evergreen trees; (3) With the increase of latitude and the decrease of mean annual temperature and precipitation, the contents of Si, Ca and Ca/Si in leaves of woody plants at the global scale increased significantly,while Ca/Si decreased significantly; (4) The responses of Si and Ca contents in leaves of different life forms to climate factors were varied. Except for Ca content of coniferous and deciduous trees, Si, Ca content in the life forms of evergreen plants and broad-leaved plants were significantly related to latitude and climate factors, and increased with the increase of latitude and decreased with the increase of mean annual temperature and precipitation. With the decrease of mean annual temperature, the decrease rate of Si content in leaves of evergreen and broad-leaved trees was significantly higher than that of deciduous and coniferous trees. From the perspective of ecostoichiometric characteristics, this study provides data basis for the development of ecological stoichiometric models at a global scale, and helps to better understand and simulate the effects of latitude and climate factors on the content of Si and Ca in plant leaves at regional and global scales.