生态学报2017，Vol.37Issue(16)：5461-5473,13.DOI:10.5846/stxb201605150936
黄土高原子午岭林区两种天然次生林植物叶片-凋落叶-土壤生态化学计量特征
C∶N∶P stoichiometry characteristics of plants-litter-soils in two kind types of natural secondary forest on the Ziwuling region of the Loess Plateau
摘要
Abstract
The objectives of this study were to characterize the C ∶ N ∶ P stoichiometry of the "plant-litter-soil" continuum and the nutrient resorption efficiency of plants,which contributes to a better understanding of nutrient cycling and stability in the Ziwuling forest-ecosystems on the Loess Plateau of China.Two types of natural secondary forest sites were selected in the Ziwuling region of the Loess Plateau and the contents of carbon (C),nitrogen (N),and phosphorus (P) concentrations in plants,litter and soils were detected.In the present study,the ecological stoichiometry of the plants-litter-soil continuum,for two types of natural secondary forest-Quercus wutaishanica and Betula platyphylla,shows leaf C,N and P concentrations averaged 468.6,17.1,and 2.1 g/kg,respectively;The C,N and P concentrations were 457.3,12.5,1.6 g/kg in the litter-fall;the soil C,N and P content averaged 17.6,1.4,and 0.5 g/kg.The type Ⅱ (standardised major axis,SMA) regression slope for N vs.P in leaves of B.platyphylla was higher than 1 (P =0.07),indicating an N investment accomplished by P enrichment in fresh leaves.In contrast,the slope for N vs.P in litterfall of B.platyphylla was statistically ＜1 (P＜0.05),and the type Ⅱ regression slope for N vs.P in litterfall of the two species was statistically ＜ 1 (P＜0.05) demonstrating an uneven loss velocity in the litterfall unit N and P content.This means that the process oflitterfall decomposition accompanying the loss of P was not lead to the N loss.A positive correlation was observed be tween litterfall N and soil N (P＜0.01) among two forest types,indicated an increases in the soil N pool as affected by litterfall decomposition.Leaf and soil P was more closely related to each other than either one was to litterfall P.And a rapid mineralization of soil organic matter occurred in both natural secondary forests in the Ziwuling region of the Loess Plateau.The C:N ratio in Q.wutaishanica was 26.7 in litter,which was much lower than the ratio of 44.9 observed for B.platyphylla (P＜0.05).The mean leaf N:P ratio for the two types of natural secondary forest was 7.9,which was below national and global scales found in other research,indicating that the two types of natural secondary forest were N limited.Q.wutaishanica was restricted also by N,but it did not have a high N resorption efficiency,which could be attributed to an inherent characteristic of the species.关键词
生态化学计量学/养分再吸收/土壤/叶片/凋落叶/天然次生林Key words
ecological stoichiometry/nutrient resorption/soil/foliar/litter/natural secondary forest引用本文复制引用
王宝荣,曾全超,安韶山,张海鑫,白雪娟..黄土高原子午岭林区两种天然次生林植物叶片-凋落叶-土壤生态化学计量特征[J].生态学报,2017,37(16):5461-5473,13.基金项目
国家自然科学基金面上项目(41671280) （41671280）
水利部公益性行业科研专项经费项目(201501045) （201501045）
