鼎湖山森林演替和海拔梯度上的土壤微生物生物量碳氮变化

生态学杂志

鼎湖山森林演替和海拔梯度上的土壤微生物生物量碳氮变化

柳杨^1,2,3,何先进^1,2,3,侯恩庆^1,3*#br#

（¹中国科学院华南植物园退化生态系统植被恢复与管理重点实验室，广州 510650； ^2中国科学院大学，北京 100049； ³中国科学院华南植物园广东省应用植物学重点实验室，广州 510650）

出版日期:2017-02-10 发布日期:2017-02-10

Changes in microbial biomass carbon and nitrogen in forest floor litters and mineral soils along forest succession and altitude gradient in subtropical China.

LIU Yang^1,2,3, HE Xian-jin^1,2,3, HOU En-qing^1,3*#br#

(¹Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China; ²University of Chinese Academy of Sciences, Beijing 100049, China; ^3Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China）.

Online:2017-02-10 Published:2017-02-10

摘要/Abstract

摘要：

在广东鼎湖山选取演替（马尾松林、针阔混交林和季风阔叶林）和海拔（沟谷阔叶林、季风阔叶林和山地阔叶林）梯度上的两组森林，采集凋落物层（未分解L层和半分解/腐殖化F/H层）和矿质土层（0～15 cm）的森林土壤样品，测定微生物生物量碳（MBC）和氮（MBN）及其潜在影响因子（包括含水量、总碳、总氮、总磷、可溶性有机碳和可溶性有机氮），探讨演替和海拔对凋落物层和矿质土层微生物生物量的影响及其机理。结果表明，MBC、MBN、MBC/MBN比值以及碳氮磷总量整体上均随有机质分解程度的增加（L层→F/H层→矿质土层）而降低。随演替进行（马尾松林→混交林→季风林），F/H层和矿质土层的MBC和MBN显著增加，而L层的MBC和MBN在混交林显著低于在马尾松林和季风林。随海拔上升（沟谷林→季风林→山地林），L层的MBC和MBN显著减少，而F/H层和矿质土层的MBC和MBN无显著变化。相关分析表明，在L层中MBC和MBN与含水量呈显著正相关；在F/H层中MBC和MBN与总磷和可溶性有机氮含量呈显著正相关；在矿质土层中MBC和MBN与土壤含水量、碳氮磷总量以及可溶性有机氮含量呈显著正相关。本研究表明，演替和海拔梯度上的土壤微生物生物量变化因土层而异，与不同土层的有机质分解程度、空间位置和养分有效性差异有关。

Abstract: Soil microbes play an important role in terrestrial carbon (C) and nitrogen (N) cycles via participating in litter decomposition and the turnover of soil organic matter. In this study, five subtropical forests along successional and altitudinal gradients were selected in Dinghushan Biosphere Reserve, China, including: (1) a pine forest (PF), a pine and broadleaved mixed forest (PBM) and a monsoon evergreen broadleaved forest (MEB) along a successional gradient; (2) a ravine evergreen broadleaved forest (REB), MEB (the same as along the successional gradient), and a mountainous evergreen broadleaved forest (MTEB) along an altitudinal gradient. In each forest, forest floor litters (separating into undecomposed litter (L horizon) and a mixture of fragmented or humified litter (F/H horizon)) and underling mineral soils at 0-15 cm depth were selected in October, 2010. For each litter or mineral soil sample, microbial biomass carbon (MBC) and nitrogen (MBN) and the key associated edaphic properties (e.g. moisture content and the concentrations of total C, total N and total phosphorus (P)) were determined. Results showed that MBC, MBN, MBC/MBN ratio, total C, total N and total P all significantly decreased with the increasing extent of decomposition (L horizon →F/H horizon →mineral soil horizon). Both MBC and MBN in the F/H and mineral soil horizons significantly increased along the forest succession gradient (PF→PBM→MEB). MBC and MBN in the L horizon decreased in the order of PF>MEB>PBM. MBC and MBN of the L horizon but not of the F/H or mineral soil horizon significantly decreased with increasing altitude (RF→MEB→MTEB). Pearson correlation analysis showed that MBC was positively correlated with MBN in all horizons. Both MBC and MBN were positively correlated with moisture content in the L horizon, total P and dissolved organic N in the F/H horizon, and soil moisture content, total C, total N, and total P in the mineral soil horizon. Our results suggest that the relationships between soil microbial properties and edaphic properties depend on soil horizons, and are related to the different extents of organic matter decomposition, spatial location and nutrient availability of different soil horizons.

柳杨1,2,3,何先进1,2,3,侯恩庆1,3*. 鼎湖山森林演替和海拔梯度上的土壤微生物生物量碳氮变化[J]. 生态学杂志.

LIU Yang1,2,3, HE Xian-jin1,2,3, HOU En-qing1,3*. Changes in microbial biomass carbon and nitrogen in forest floor litters and mineral soils along forest succession and altitude gradient in subtropical China.[J]. cje.