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.
Departament d'Ecologia, Facultat de Biologia, Universitat de Barcelona, Avgda. Diagonal, 645 08028 Barcelona, Spain. bernat@creaf.uab.es
B C
BC
López
S
S
Sabate
C A
CA
Gracia
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