Service Communautaire d'Information sur la Recherche et le Développement - CORDIS

FP5

NAT-MAN Résumé de rapport

Project ID: QLK5-CT-1999-01349
Financé au titre de: FP5-LIFE QUALITY
Pays: Slovenia

Coarse Woody Debris (CDW) - nutrient storage

The continuing flow of energy through any ecosystem depends upon maintenance of nutrient supplies to the primary producers and since there is only a limited input of nutrients from outside, a balanced cycle within the ecosystem is essential. The objectives of the research on nutrient storage in coarse woody debris (CDW) were:
- To identify the role of beech CWD in nutrient storage;
- To determine the relationships between beech-CWD dimensions, age, decay state and physical-chemical characteristics.

The physical and chemical characteristics of beech CWD were studied in selected forest reserves in the Denmark, Hungary, The Netherlands and Slovenia. Findings indicate that the determined or calculated time for decay differed in different sites: in Hungary the decay phase 6 (most decomposed) was reached in average in 30 years after death, in Slovenia the calculated time for decay was over 52 years, in the Netherlands decay phase 5 was reached in 30 years, while in Denmark the presumed time for total decay was over 50 years since death.

During decomposition, CWD underwent considerable structural and chemical changes, certain components decayed more rapidly than others, the wood became soft and cracked and the density steadily decreased. In all study sites C : N, C : S ratios and pH declined with increasing decay phase classes, while moisture, N, S and P concentrations rose with the decay phase. An increase of concentrations of N, S, P and a decrease in C : N ratio might be applied as indicators for decomposition phases.

From nutrient concentration in CWD, its biomass per ha, time for decay and its role in nutrient cycling in the studied sites was extrapolated. The common conclusion was that CWD not only contributes to biodiversity by its specific dead wood habitat, but also by creating relatively moisture and nutrient-rich microsites that provide specific terrestrial habitats.

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Hojka KRAIGHER, (Head of Department)
Tél.: +38-61-2007804
Fax: +38-61-2573589
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