Abstract
Inorganic nitrogen losses from many unpolluted mature tropical forests are over an order of magnitude higher than losses from analogous temperate forests. This pattern could either reflect a lack of N limitation or accelerated plant-soil N cycling under tropical temperatures and moisture. We used a simple analytical framework of the N cycle and compared our predictions with data of N in stream waters of temperate and tropical rainforests. While the pattern could be explained by differences in N limitation, it could not be explained based on up-regulation of the internal N cycle without invoking the unlikely assumption that tropical plants are two to four times less efficient at taking up N than temperate plants. Our results contrast with the idea that a tropical climate promotes and sustains an up-regulated and leaky - but N-limited - internal N cycle. Instead, they are consistent with the notion that many tropical rainforests exist in a state of N saturation.
Original language | English (US) |
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Pages (from-to) | 9-16 |
Number of pages | 8 |
Journal | Ecology letters |
Volume | 15 |
Issue number | 1 |
DOIs | |
State | Published - Jan 2012 |
All Science Journal Classification (ASJC) codes
- Ecology, Evolution, Behavior and Systematics
Keywords
- Analytical model
- Biogeochemical theory
- Biogeochemistry
- Climate
- N losses
- N saturation
- Nitrogen (N) limitation and cycling
- Plant-soil cycle
- Temperate rainforest
- Tropical rainforest