Publication Date:
2013-01-12
Description:
Forests and the soils beneath them are Earth's largest terrestrial sinks for atmospheric carbon (C) and healthy forests provide a partial check against atmospheric rises in CO 2 . Consequently, there is global interest in crediting forest managers who enhance C retention. Interest centres on C acquisition and storage in trees. Less is directed to understorey management practices that affect early forest development. Even less is paid to the largest ecosystem reservoir of all – the mineral soil. Understorey vegetation control is a common management practice to boost stand growth, but the consequence of this on ecosystem C storage is poorly understood. We addressed this by pooling data from five independent groups of long-term studies in the western US. Understorey control increased overstorey biomass universally, but C contents of the forest floor and top 30 cm of mineral soil largely were unaffected. Net soil C increment averaged 1.3 Mg C ha –1 year –1 in the first decade. We conclude that soil C storage is not affected adversely by vegetation management in forests under a Mediterranean climate. However, understorey shrubs can profoundly affect stand susceptibility to wildfire. We propose that C accounting systems be strengthened by assessing understorey management practices relative to wildfire risk.
Print ISSN:
0015-752X
Electronic ISSN:
1464-3626
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
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