Thinning effects on carbon allocation to fine roots in a Quercus ilex forest.
The dynamics of the fine root system are relevant to calculations of the carbon balance of the ecosystem, and there is also a need to quantify changes in this component caused by disturbances. Mediterranean forest systems have historically been coppiced to obtain charcoal. As a result of the resprouting capacity of holm oaks (Quercus ilex L.), these forests present more than 50% of their biomass below ground (stump + roots > 1 cm in diameter), but the effects of thinning on the fine root system are unknown. Fine root biomass, production, mortality and longevity were studied in a control and a thinned Mediterranean holm oak forest by minirhizotron methodology. Observations of fine roots started 2 years after thinning and continued for almost 3 years. Extraction of 80% of the former basal area of the forest greatly affected carbon allocation patterns. Biomass increased by more than 100%, production increased by 76%, mortality increased by 32% and longevity decreased by around 2 weeks. The greatest differences between treatments were associated with differences in growth during autumn months in the top 40 cm of soil, particularly between 10 and 20 cm depth.
López
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BC
Departament d'Ecologia, Facultat de Biologia, Universitat de Barcelona, Avgda. Diagonal, 645 08028 Barcelona, Spain. bernat@creaf.uab.es
Sabate
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Gracia
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CA
D018533:Biomass; D017753:Ecosystem; D019083:Mediterranean Region; D018517:Plant Roots / Q000502:physiology*; D029963:Quercus / Q000502:physiology*; D012987:Soil; D013696:Temperature; D014197:Trees / Q000502:physiology*; D014867:Water
D012987:Soil; D014867:Water