干旱区生态环境知识资源中心(Arid): 沙地不同树种人工林土壤氮素矿化过程及其有效性

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	沙地不同树种人工林土壤氮素矿化过程及其有效性
其他题名	Comparative nitrogen mineralization and its availability in certain woody plantations in Keerqin Sand Lands, China
	陈伏生; 曾德慧; 范志平; 陈广生
ISSN	1000-0933
出版年	2006
卷号	26 期号:2 页码:341-348
中文摘要	土壤氮素（N）转化是生态系统重要的生态过程之一，可作为生态恢复评价的重要指标。以位于科尔沁沙地东南缘的章古台地区草地、30年生的樟子松（Pinus sylvestris vat．mongolica）、赤松（P.densiflora）和杨树（Populus simonii）人工林为对象。采用PVC顶盖埋管法和离子交换树脂袋法研究了土壤N矿化特征及其有效性。结果表明，生长季内土壤N净矿化量表现为草地（8.06mug／g）和赤松林（9．06mug／g）低于樟子松林（18．36mug／g）和杨树林（17．88mug／g）（P〈0．05）；树脂吸附的无机N表现为草地（283．50mug／g dry resin）和杨树林（297.00mug／g dry resin）最低，樟子松林（440．10mug／g dry resin）居中，而赤松林（835．65mug/g dry resin）最高（P〈0．05）。综合分析林地土壤理化特性、矿化特征和N有效性，表明樟子松、赤松和小叶杨均可作为固沙造林选择树种，其表现为赤松〉樟子松〉小叶杨。认为深入开展生态系统N平衡研究有利于更好地评价固沙林的功能。
英文摘要	The sand-fixation plantations played an important role in cutting down desertification process in northern China. Soil nitrogen mineralization, which is a key ecological process in poor sandy ecosystems, can be used as a basic index to assess ecosystem function of tree plantations. In this study, soil nitrogen mineralization process and its availability were examined by the methods of in situ closed-top PVC tube incubation and ion exchange resin bags under plantations of pine and poplar, and their neighboring grasslands in the southeastern Keerqin region of China. Results indicated that the accumulative net mineralization in growing season （from April 15 to October 15, 2004） in the grassland （8.06mug·g^-1） and Pinus densiflora （9.06 mug·g^-1） plantation was lower than that in both Pinus sylvestris vat. mongolica （ 18.36mug·g^-1） and Populus simonii （ 17.88mug·g^-1） plantations （p 〈 0.05）. The ratios of nitrification rate to net mineralization rate in grassland, P. sylvestris var. mongolica, P. densiflora, and Populus simonii plantations were 0.88, 0.91, 0.82, 0.87, respectively, which indicated that the soil nitrification rate in the study area is more intensive than soil net ammonification processes, and the NO3^--N was the major N form absorbed by plants in the study area, which might due to the higher soil pH values （〉 6.6） and strong human disturbances in the study area. The percentages of net mineralization amount to soil total N contents in grassland, P. sylvestris var. mongolica, P densiflora, and Populus simonii plantations were 2.49%, 4.42%, 2.77%, 4.26%, respectively, implying that N turnover rates in grassland and P. densiflora plantation were very low, while those in P. sylvestris var. mongolica and Populus simonii were relatively higher. The accumulative mineral N absorbed by resin from May 15 to October 1 in both the grassland （283.50 mug·g^-1 dry resin） and Populus simonii plantations （297.00mug·g^-1 dry resin） was the lowest, while that in P. sylvestris var. mongolica （440.10 mug·g^-1 dry resin） was intermediate, and P. densiflora （835.65 mug·g^-1 dry resin） was the highest （p 〈 0.05）. Soil relative nitrification rate （which is expressed by the ratios of the soil NO3^- -N to mineral N） in the grassland, P , P. densiflora and Populus sirnonii plantations were 0.88, 0.87, 0.92, and 0.90, respectively, which also implied that soil NO3^- -N accounted for most of the soil mineral N. From this study, we conclude that the in situ closed-top PVC tube incubation method is more accurate than the ion exchange resin method in measuring seasonal soil N mineralization rate, while it is more convincing to use both methods in exploring both soil N availability and N absorption by plants. Based on the corresponding results, we concluded that the three tree species mentioned above were selective sand-fixation tree species in the study area, and the rank of suitability was P. densiflora, P. sylvestris var. mongolica and Populus simonii. However, to comprehensively assess the ecosystem functions in the study area, the knowledge of N balance in sand-fixation plantations is necessary.
中文关键词	固沙林 ; 土壤氮素 ; 矿化过程 ; 顶盖埋管法 ; 离子交换树脂袋法 ; 科尔沁沙地
英文关键词	sand-fixed forest soil nitrogen mineralization process PVC tube closed-top in situ incubation method ion exchange resin bag method keerqin sandy land
语种	中文
国家	中国
收录类别	CSCD
WOS类目	ECOLOGY ; PLANT SCIENCES
WOS研究方向	Environmental Sciences & Ecology ; Plant Sciences
CSCD记录号	CSCD:2349288
来源机构	中国科学院沈阳应用生态研究所
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/220021
作者单位	中国科学院沈阳应用生态研究所大青沟沙地生态实验站, 沈阳, 辽宁 110016, 中国
推荐引用方式 GB/T 7714	陈伏生,曾德慧,范志平,等. 沙地不同树种人工林土壤氮素矿化过程及其有效性[J]. 中国科学院沈阳应用生态研究所,2006,26(2):341-348.
APA	陈伏生,曾德慧,范志平,&陈广生.(2006).沙地不同树种人工林土壤氮素矿化过程及其有效性.,26(2),341-348.
MLA	陈伏生,et al."沙地不同树种人工林土壤氮素矿化过程及其有效性".26.2(2006):341-348.