干旱区生态环境知识资源中心(Arid): 桂西北喀斯特区原生林与次生林鲜叶和凋落叶化学计量特征

Arid

	桂西北喀斯特区原生林与次生林鲜叶和凋落叶化学计量特征
其他题名	Stoichiometric characteristics of live fresh leaves and leaf litter from typical plant communities in a karst region of northwestern Guangxi, China
	曾昭霞 1; 王克林 1; 刘孝利 2; 曾馥平 1; 宋同清 1; 彭晚霞 1; 张浩 1; 杜虎 1
来源期刊	生态学报
ISSN	1000-0933
出版年	2016
卷号	36 期号:7 页码:1907-1914
中文摘要	研究喀斯特生态脆弱区植物新鲜叶片与凋落叶的元素化学计量学性状,对该地区森林生态系统的恢复与重建具有重要指导意义。在桂西北喀斯特区分别选取了3个原生林群落与3个次生林群落,研究其建群种植物新鲜叶片和凋落叶的C、N、P元素含量及其生态化学计量特征。结果发现,6个群落建群种新鲜叶片C、N、P含量(其平均含量分别为404.3、22.5、1.75 mg/g)均大于凋落叶(平均含量分别为376.5、19.0、1.35 mg/g),鲜叶C:N、C:P、N:P比值(均值分别为17.8、244.9、13.8)均小于凋落叶(均值分别为19.3、315.3、16.3)。6种植物新鲜叶片N、P含量大于凋落叶,而N:P比小于凋落叶,表明喀斯特区植物对N的再吸收率大于P。3个原生林群落建群种鲜叶与凋落叶的平均C、N含量均大于次生林,而P含量则略小于次生林;原生林鲜叶与凋落叶的C:N比均小于次生林,C:P、N:P则大于次生林,推测次生林相对于原生林有更快的生长速率。原生林鲜叶N:P比为1315之间,次生林鲜叶N:P比为11-12之间,次生林鲜叶与凋落叶的N:P比均小于原生林,说明原生林凋落物分解相对较慢,原生林能相对多的保留养分以供植物吸收,更能适应喀斯特石生环境。植物鲜叶和凋落叶的C:N与N:P比值均呈极显著正相关,说明叶片养分元素间具有共变的特性;叶片N、P含量呈正相关关系,表明植物N:P比具有相对的稳定性,这是高等陆生植物C-N-P元素计量的普遍规律,体现了植物群落对环境的适应。
英文摘要	The karst area of southwestern China covers 550,000 km~2,and includes 105,000 km~2 that are experiencing serious rocky desertification and human disturbance. Fortunately, national and provincial conservation and afforestation projects have been developed to mitigate karst rocky desertification. Ecological stoichiometry, which approaches questions by analyzing the balance of many major elements needed by organisms and determines how those elements affect and interact with processes, provides new perspectives for studying ecosystem processes in fields ranging from leaf physiology to ecosystem productivity. In terrestrial ecosystems, the close interaction between the C, N, and P cycles constrains most ecosystem processes;therefore,the N and P status,and the N: P stoichiometry of leaves has been studied intensively to try and determine how these factors limit plant growth. Exploring the stoichiometric properties of the primary elements (C, N, and P) in live fresh leaves and leaf litter is very important and could provide constructive information and guidance for ecosystem recovery and the reconstruction in ecologically fragile karst regions. This study examined the concentration of C-N-P and the related stoichiometry of live fresh leaves and leaf litter in three primary forests and compared them to data from three secondary forest communities in northwestern Guangxi. The results showed that the N and P contents of live fresh leaves in the six forest communities were greater than that of leaf litter. However,the N: P ratios showed opposite results,which indicated that the plant N reabsorption rate in this karst region was larger than that for P. The C, N, and P contents of live fresh leaves in the six forest communities were higher than those of leaf litter. In addition, the mean C and N contents of leaves in the three primary forests were higher than in the three secondary forests. However, P levels were slightly lower in the leaves of primary forests than in secondary forests. The results also revealed that the C:N, C:P, and N:P ratios of live fresh leaves from the six communities were all less than for the leaf litter. In addition,the order of the C, N,and P stoichiometric ratios for both live leaves and leaf litter in the six forest communities was C:P > C:N > N:P, and the C: N ratios of secondary forests were larger than that of primary forests for both live leaves and leaf litter. The C: P and N: P ratios of live leaves and leaf litter in the three secondary forests were all larger than the primary forests,which indicated that the secondary forests had higher growth rates. The N:P ratios of live fresh leaves in the three primary forest communities were between 13 and 15. The N:P ratios of live fresh leaves in the three secondary forest communities were between 11 and 12, which is between the upper and lower limit thresholds for N and P nutrient levels. Therefore, the N and P nutrient status of the three secondary forests (after 28 years of spontaneous recovery) has reached a relatively stable stage through long-term environmental adaptation. A significantly positive relationship was observed between the C: N and N: P ratios of both live fresh leaves and leaf litter. The N and P contents of all community species were positively correlated,and the N: P ratio was positively correlated with N content, but significantly and negatively correlated with P content.
中文关键词	生态化学计量学 ; 喀斯特 ; 鲜叶 ; 凋落叶 ; 原生林 ; 次生林
英文关键词	stoichiometry Karst live leaf litter leaf primary forest secondary forest
语种	中文
国家	中国
收录类别	CSCD
WOS类目	BIOLOGY
WOS研究方向	Life Sciences & Biomedicine - Other Topics
CSCD记录号	CSCD:5682052
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/234760
作者单位	1.中国科学院亚热带农业生态研究所, 中国科学院亚热带农业生态过程重点实验室;;中国科学院环江喀斯特生态系统观测研究站, 长沙, 湖南 410125, 中国; 2.湖南农业大学资环学院, 长沙, 湖南 410128, 中国
推荐引用方式 GB/T 7714	曾昭霞,王克林,刘孝利,等. 桂西北喀斯特区原生林与次生林鲜叶和凋落叶化学计量特征[J],2016,36(7):1907-1914.
APA	曾昭霞.,王克林.,刘孝利.,曾馥平.,宋同清.,...&杜虎.(2016).桂西北喀斯特区原生林与次生林鲜叶和凋落叶化学计量特征.生态学报,36(7),1907-1914.
MLA	曾昭霞,et al."桂西北喀斯特区原生林与次生林鲜叶和凋落叶化学计量特征".生态学报 36.7(2016):1907-1914.