红豆草与土壤氮含量对大气二氧化碳浓度升高的响应

应用生态学报

红豆草与土壤氮含量对大气二氧化碳浓度升高的响应

周正朝¹;上官周平^1,2

¹中国科学院水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室，杨凌 712100;
²西北农林科技大学，杨凌 712100

收稿日期:2005-12-31 修回日期:2006-09-07 出版日期:2006-11-18 发布日期:2006-11-18

Responses of Onobrychis viciaefolia Scop and soil nitrogen contents to elevated atmospheric CO₂ concentration

ZHOU Zhengchao¹; SHANGGUAN Zhouping^1,2

¹State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,
Institute of Soil and Water Conservation, Chinese Academy of Sciences, Yangling 712100, China;
²Northwest Sci-Tech University of Agriculture and Forestry, Yangling 712100, China

Received:2005-12-31 Revised:2006-09-07 Online:2006-11-18 Published:2006-11-18

摘要/Abstract

摘要： 在封闭的植物培养箱中，通过盆栽实验，研究了红豆草和土壤氮含量对CO₂浓度增加的响应.结果表明，与正常CO₂浓度(355～370 μmol·mol^-1)相比，CO₂浓度升高(700 μmol·mol^-1)，植物生物量增加25.1%(P＜0.01)，但植物体氮浓度降低25.3%(P＜0.001)，植物全氮没有显著的变化.经3个月盆栽实验后，与原始土壤相比，两种CO₂浓度处理土壤全N、NO₃^--N和NH₄⁺-N都有所降低，而土壤微生物氮则显著增加，这可能与植物生长有关.不同CO₂浓度处理土壤NH₄⁺-N浓度基本一致，但在高CO₂浓度下，土壤NO₃^--N浓度显著降低，而微生物生物氮显著增加.对整个土壤-植物系统而言，盆栽实验后，整个系统全氮有少量增加，但变化不显著，特别是在高CO₂浓度条件下，土壤-植物系统全氮最大，这可能与培养材料红豆草为豆科植物，而且在高CO₂浓度下生物量增加，导致氮的固定量增加有关.

Abstract: The effects of elevated CO₂ on terrestrial ecosystem processes are highly related to the N cycling in the ecosystem. In two closed chambers with different CO₂ concentration (ambient CO₂ 355～370 μmol·mol^-1, and elevated CO₂700 μmol·mol^-1), pot experiments were conducted to study the responses of Onobrychis viciaefolia Scop and soil nitrogen contents to elevated CO₂. The results showed that compared with ambient CO₂, elevated CO₂ increased the plant dry biomass by 25.1% (P<0.01), but decreased the plant N concentration by 25.3% (P<0.001), resulting in little change of total plant N. After three months experiment, soil total N, NO₃^--N and NH₄⁺-N under both ambient and elevated CO₂ conditions decreased, while soil microbial biomass N increased significantly. Soil NH₄⁺-N concentration had little difference under ambient and elevated CO₂ conditions, but under elevated CO₂ condition, soil NO₃^--N concentration decreased significantly, while microbial biomass N increased significantly. By the end of the experiment, the total N content of whole soil-plant ecosystem had a slight increase, especially under elevated CO₂ condition, which was probably due to the higher N-fixation capability of O. viciaefolia Scop under CO₂ enrichment.

Key words: Eringonidium graminicola Sundevall, Adonia variegata Goeze, Nabis sinoferus Hsiao, Predation function, Helicoverpa armigera Hubner

周正朝¹;上官周平^1,2. 红豆草与土壤氮含量对大气二氧化碳浓度升高的响应[J]. 应用生态学报.

ZHOU Zhengchao¹; SHANGGUAN Zhouping^1,2. Responses of Onobrychis viciaefolia Scop and soil nitrogen contents to elevated atmospheric CO₂ concentration[J]. Chinese Journal of Applied Ecology.