Seasonal Variation in Contents of C, N and P and Stoichiometry Characteristics in Fine Roots, Stems and Needles of Larix principis-rupprechtii
We collected 20-year-old Larix principis-rupprechtii from a plantation in Qinling to explore the contents of C,N and P and their ecological stoichiometry characteristics in fine roots,stems and needles in different seasons.The content of C increased first,then decreased and increased again throughout the growing season (May to October).The order of the mean content of C in organs was stems ＞ needles ＞ fine roots.The content of N in fine roots,stems and needles tended to fluctuate during the growing season.The content of P in both needles and fine roots decreased first,then increased and decreased again,then remained stable.The content of P in stems decreased first and then increased,then decreased gradually.The order of the mean content of both N and P in organs was needles ＞ fine roots ＞ stems.The content of N had the greatest variability in fine roots and needles throughout the growing season.The coefficient of variation (cv％) of P was greatest for stems.The variability of C in the 3 organs was the smallest.The changes in C∶N and C∶P ratios were opposite to that of corresponding N,P content in fine roots,stems and needles.The ratio of N∶P peaked in stems and was minimal in fine roots.The order of the cv％ for C∶N throughout the growing season was fine roots ＜ stems ＜ needles and for both C∶P and N∶P was fine roots ＜ needles ＜ stems.Factorial analysis of variation for each parameter,with sampling season and organs as independent variables,showed that the content of C,N and P and C∶N mass ratio mainly depended on the organ.C∶P and N∶P mass ratios were mainly determined by the interaction of organs and season.The mass ratio of C∶N∶P was similar in fine roots (369∶7∶1) and needles (309∶10∶1).The characteristics of C,N and P stoichiometry were relatively stable in fine roots.Quantitative characteristics in fine roots were affected less in different seasons in L.pdncipis-rupprechtii in Qinling,which helps in analysis of the ecological system.
国家科技期刊平台
NSTL
万方数据
维普
