Growth responses of trees and understory plants to nitrogen fertilization in a subtropical forest in China
Growth responses of trees and understory plants to nitrogen fertilization in a subtropical forest in China
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中国亚热带森林树木和林下植物对氮肥的生长响应
DOI：
10.5194/bg-14-3461-2017
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发表时间：
2017-07
期刊：
影响因子：
4.9
通讯作者：
Fang Jingyun
中科院分区：
文献类型：
--
作者：
Tian Di;Li Peng;Fang Wenjing;Xu Jun;Luo Yongkai;Yan Zhengbing;Zhu Biao;Wang Jingjing;Xu Xiaoniu;Fang Jingyun
抽象的。生物圈中活性氮（N）的增加是全球变化的一个值得注意的方面，对陆地生态系统的功能和动态产生了相当大的生态影响。一些观测研究探讨了植物的反应，实验模拟N富集在北方和温带森林。在这里，我们调查如何在中国亚热带森林的优势树木和不同的林下植物对实验N富集。在中国东部亚热带万年青阔叶林中进行了为期3.4年的施氮试验，设3个处理水平，共9块20 m × 20 m样地，分3个区组重复。根据生长形态将植物分为乔木、幼树、灌木（包括乔木幼苗）和地被植物（蕨类植物），测定了乔木和幼树的断面积增量和相对断面积增量，以及林下灌木和蕨类植物的地上生物量。我们进一步分组的优势树种甜槠的个人，分为三个大小级，调查各自的生长响应的N施肥。结果表明，施氮量对林木断面积和地上生物量的绝对和相对生长率没有影响。在C.在N50（50 kg N ha−1 yr−1）和N100施肥小区（100 kg N ha − 1 yr − 1）中，胸径（胸径）为5-10 cm的小树的生长量分别下降了66.4%和59.5%，而胸径> 10 cm的中、大树的生长量没有显著变化。在施氮小区，小乔木、幼树的生长速率以及林下灌木和地被蕨类植物的地上生物量显著下降。研究结果表明，N可能不是该亚热带成熟林的限制性营养元素，N的有效性增加可能加剧森林生态系统中其他营养元素的限制，从而对亚热带天然林的发展产生不利影响。
Abstract. Reactive nitrogen (N) increase in the biosphere has been a noteworthy aspect of global change, producing considerable ecological effects on the functioning and dynamics of the terrestrial ecosystems. A number of observational studies have explored responses of plants to experimentally simulated N enrichment in boreal and temperate forests. Here we investigate how the dominant trees and different understory plants respond to experimental N enrichment in a subtropical forest in China. We conducted a 3.4-year N fertilization experiment in an old-aged subtropical evergreen broad-leaved forest in eastern China with three treatment levels applied to nine 20 m × 20 m plots and replicated in three blocks. We divided the plants into trees, saplings, shrubs (including tree seedlings), and ground-cover plants (ferns) according to the growth forms, and then measured the absolute and relative basal area increments of trees and saplings and the aboveground biomass of understory shrubs and ferns. We further grouped individuals of the dominant tree species, Castanopsis eyrei, into three size classes to investigate their respective growth responses to the N fertilization. Our results showed that the plot-averaged absolute and relative growth rates of basal area and aboveground biomass of trees were not affected by N fertilization. Across the individuals of C. eyrei, the small trees with a DBH (diameter at breast height) of 5–10 cm declined by 66.4 and 59.5 %, respectively, in N50 (50 kg N ha−1 yr−1) and N100 fertilized plots (100 kg N ha−1 yr−1), while the growth of median and large trees with a DBH of > 10 cm did not significantly change with the N fertilization. The growth rate of small trees, saplings, and the aboveground biomass of understory shrubs and ground-cover ferns decreased significantly in the N-fertilized plots. Our findings suggested that N might not be a limiting nutrient in this mature subtropical forest, and that the limitation of other nutrients in the forest ecosystem might be aggravated by the enhanced N availability, potentially resulting in an adverse effect on the development of natural subtropical forest.
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影响因子：
18.3
作者：
R. Q. Thomas;C. Canham;K. Weathers;C. Goodale
通讯作者：
R. Q. Thomas;C. Canham;K. Weathers;C. Goodale
影响因子：
4
作者：
P. Vitousek;R. Howarth
通讯作者：
P. Vitousek;R. Howarth
影响因子：
4.8
作者：
S. Wright;J. Yavitt;N. Wurzburger;Benjamin L Turner;E. Tanner;E. Sayer;L. Santiago;M. Kaspari;L. Hedin;K. Harms;Milton N. García;M. Corre
通讯作者：
S. Wright;J. Yavitt;N. Wurzburger;Benjamin L Turner;E. Tanner;E. Sayer;L. Santiago;M. Kaspari;L. Hedin;K. Harms;Milton N. García;M. Corre
影响因子：
2.7
作者：
BassiriRad, Hormoz;Lussenhop, John F.;Borden, Kara K.
通讯作者：
Borden, Kara K.
DOI：
10.1071/pp9880299
发表时间：
1988
期刊：
Australian Journal of Plant Physiology
影响因子：
--
作者：
W. Thompson;G. Stocker;P. Kriedemann
通讯作者：
W. Thompson;G. Stocker;P. Kriedemann