水分变化对毛竹林与常绿阔叶林土壤N素矿化的潜在影响

生态学杂志

水分变化对毛竹林与常绿阔叶林土壤N素矿化的潜在影响

宋庆妮¹,杨清培^1**,王兵²,祁红艳¹,欧阳明¹,陈伏生^1

（¹江西农业大学/江西省竹子种质资源与利用重点实验室，南昌 330045; ^2中国林业科学研究院森林生态环境与保护研究所，北京 100091）

出版日期:2013-12-10 发布日期:2013-12-10

Potential effects of soil moisture variation on soil nitrogen mineralization for Phyllostachys edulis forest and evergreen broadleaved forest in a subtropical region of China.

SONG Qing-ni¹, YANG Qing-pei^1**, WANG Bing², Qi Hong-yan¹, OUYANG Ming¹, CHEN Fu-sheng^1

(¹Jiangxi Provincial Key Laboratory for Bamboo Germplasm Resources and Utilization, Jiangxi Agricultural University, Nanchang 330045, China; ^2Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 100091, China)

Online:2013-12-10 Published:2013-12-10

摘要/Abstract

摘要：

水分变化会影响森林土壤氮素矿化作用，进而影响到森林生态系统的结构与功能。本文采用室内好氧培养法，分析了毛竹林和常绿阔叶林土壤氮素在不同水分条件下（15%、30%、45%含水率）的矿化作用（氨化作用和硝化作用）。结果表明：(1)不同水分条件下，2种森林土壤氮素净矿化量累积过程均符合一级动力学模型N_t=N₀（1-e^-kt）；(2)水分变化对模型中矿化势（N₀）影响较大，30%含水率时，毛竹林和常绿阔叶林土壤N₀均最大，含水率降至15%（干旱）或升至45%（涝害）时，毛竹林N₀减少的幅度明显小于常绿阔叶林，前者分别仅减少11.7%、10.4%，但后者分别减少29.0%、30.2%；(3)水分变化对毛竹林土壤硝化作用影响较小，但会抑制常绿阔叶林土壤硝化作用，从而改变土壤氮素矿化格局（净氨化量/净矿化量）。这些发现说明，毛竹林土壤氮素矿化比常绿阔叶林更不易受水分变化的影响，这为全球水分变化下毛竹向常绿阔叶林潜在扩张能力的评价提供了参考。

Abstract: Soil moisture variation exerts strong effects on the soil nitrogen (N) mineralization in forests, and further, affects the structure and function of forest ecosystems. By using laboratory aerobic incubation method, this paper studied the soil N mineralization (ammonification and nitrification) in the Phyllostachys edulis forest (PEF) and evergreen broadleaved forest (EBF) in a subtropical region of China under the soil moisture conditions of 15%, 30% and 45%. The soil cumulative net Nmineralization in the two forests under different soil moisture conditions could be described as N_t=N₀(1-e^-kt). The soil moisture variation had great effects on the soil N mineralization potential (N₀) in the two forests, with the maximum N₀ at 30% soil moisture content for both PEF and EBF. When the soil moisture content decreased to 15% (drought) or increased to 45% (waterlogging), the decrement of the soil N₀ in PEF was obviously smaller than that in EBF, with the N₀ only decreased by 11.7% and 10.4% in PEF, but decreased by 29.0% and 30.2% in EBF under drought and waterlogging, respectively. Soil moisture variation had little effects on the soil nitrification in PEF, but inhibited the soil nitrification in EBF, and thus, altered the soil N mineralization pattern (ammonification/mineralization) in EBF. These findings indicated that the soil N mineralization in PEF was less easily affected by the soil moisture variation than that in EBF, which provided an important reference for the potential expansion of PEF into EBF under the global water change.

宋庆妮1,杨清培1**,王兵2,祁红艳1,欧阳明1,陈伏生1. 水分变化对毛竹林与常绿阔叶林土壤N素矿化的潜在影响[J]. 生态学杂志.

SONG Qing-ni1, YANG Qing-pei1**, WANG Bing2, Qi Hong-yan1, OUYANG Ming1, CHEN Fu-sheng1. Potential effects of soil moisture variation on soil nitrogen mineralization for Phyllostachys edulis forest and evergreen broadleaved forest in a subtropical region of China.[J]. cje.