DOI: 10.1007/s10533-015-0069-4
Scopus记录号: 2-s2.0-84925482855
论文题名: Acacia tree density strongly affects N and P fluxes in savanna
作者: Sitters J. ; Edwards P.J. ; Suter W. ; Olde Venterink H.
刊名: Biogeochemistry
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2015
卷: 123, 期: 2018-01-02 起始页码: 285
结束页码: 297
语种: 英语
英文关键词: Fire
; Herbivore dung
; Nitrogen fixation
; Nutrient balances
; Phosphorus
; Woody encroachment
英文摘要: Studies of nutrient cycling in savanna ecosystems rarely consider how fluxes are affected by local variations in tree density and nutrient redistribution by herbivores. We studied how the density of Acacia zanzibarica trees in a humid savanna ecosystem affected the input of nitrogen (N) through N2-fixation and N and phosphorus (P) outputs through fire and also internal pathways of N and P return through herbivores. We found that N inputs and P outputs both increased with increasing density of N2-fixing trees, the N effect being due to tree density rather than to differences in the rate of N2-fixation. However, total N outputs due to fire did not vary with tree density because losses from the herb layer decreased as losses from the tree layer increased. In contrast, total P outputs did increase with tree density because P losses from the tree layer exceeded those from the herb layer. We suggest that variation in the density of N2-fixing trees coupled with the effects of fire can cause substantial differences in the local N and P balances in savanna vegetation. To some extent, these differences may be evened out by the tendency for browsing herbivores to transfer nutrients from Acacia- to grass-dominated areas. We conclude that encroachment by N2-fixing trees and shrubs has important consequences for ecosystem properties such as N and P dynamics. © 2015, Springer International Publishing Switzerland. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/83565
Appears in Collections: 气候减缓与适应 气候变化事实与影响
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作者单位: Institute of Integrative Biology, ETH Zurich, Universitätsstrasse 16, Zurich, Switzerland; Swiss Federal Research Institute WSL, Zürcherstrasse 111, Birmensdorf, Switzerland; Plant Biology and Nature Management, Vrije Universiteit Brussel, Brussels, Belgium
Recommended Citation:
Sitters J.,Edwards P.J.,Suter W.,et al. Acacia tree density strongly affects N and P fluxes in savanna[J]. Biogeochemistry,2015-01-01,123(2018-01-02)