Book contents
16 - Rainforest mineral nutrition: the ‘black box’ and a glimpse inside it
from Part II - Hydrological processes in undisturbed forests
Published online by Cambridge University Press: 12 January 2010
Summary
INTRODUCTION
This chapter deals mainly with undisturbed tropical rainforests and its aims are threefold:
to summarise the current knowledge of selected topics in rainforest mineral nutrition;
to emphasise the links between hydrology, pedogenesis and rainforest mineral nutrition; and
to identify the most important gaps in knowledge and to suggest the most promising lines of research.
The rainforest nutrient cycle
Nutrients enter the ecosystem with rain, deposition of dust and aerosols, by fixation by microorganisms (in the case of N) above and below ground, and (except for N) by weathering of the substratum (Figure 16.1). The major above-ground pool of nutrients is formed in the tree boles and large branches. There is a flow of nutrients from these and the many other components of the above-ground pool of nutrients to the forest floor in small and large litterfall and in throughfall and stemflow of rainwater, enriched by nutrients from leaves and bark. The nutrients in dead organic matter are released gradually by decomposition, mediated by soil animals and microorganisms. Decomposition can involve immobilisation of nutrients as well as their release. In extreme cases the immobilisation may involve a conversion of the litter to stable organic matter which holds nutrients indefinitely. Such occurs in those forest types that have very wet or acid conditions (such as heath forests, peat swamp forests and upper montane cloud forests) which are described by Whitmore (1984).
- Type
- Chapter
- Information
- Forests, Water and People in the Humid TropicsPast, Present and Future Hydrological Research for Integrated Land and Water Management, pp. 422 - 446Publisher: Cambridge University PressPrint publication year: 2005
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