In:
Annual Review of Ecology, Evolution, and Systematics, Annual Reviews, Vol. 40, No. 1 ( 2009-12-01), p. 613-635
Abstract:
Observations of the tropical nitrogen (N) cycle over the past half century indicate that intact tropical forests tend to accumulate and recycle large quantities of N relative to temperate forests, as evidenced by plant and soil N to phosphorus (P) ratios, by P limitation of plant growth in some tropical forests, by an abundance of N-fixing plants, and by sustained export of bioavailable N at the ecosystem scale. However, this apparent up-regulation of the ecosystem N cycle introduces a biogeochemical paradox when considered from the perspective of physiology and evolution of individual plants: The putative source for tropical N richness—symbiotic N fixation—should, in theory, be physiologically down-regulated as internal pools of bioavailable N build. We review the evidence for tropical N richness and evaluate several hypotheses that may explain its emergence and maintenance. We propose a leaky nitrostat model that is capable of resolving the paradox at scales of both ecosystems and individual N-fixing organisms.
Type of Medium:
Online Resource
ISSN:
1543-592X
,
1545-2069
DOI:
10.1146/ecolsys.2009.40.issue-1
DOI:
10.1146/annurev.ecolsys.37.091305.110246
Language:
English
Publisher:
Annual Reviews
Publication Date:
2009
detail.hit.zdb_id:
2131893-1
detail.hit.zdb_id:
2131661-2
SSG:
12
SSG:
14
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