Effect of aboveground intervention on fine root mass, production, and turnover rate in a Chinese cork oak (Quercus variabilis Blume) forest
Fine root is an important part of the forest carbon cycle. The growth of fine roots is usually affected by forest intervention. This study aims to investigate the fine root mass, production, and turnover in the disturbed forest.
The seasonal and vertical distributions of fine root (diameter ≤2 mm) were measured in a Chinese cork oak (Quercus variabilis Blume) forest. The biomass and necromass of roots with diameters ≤1 mm and 1-2 mm in 0-40 cm soil profiles were sampled by using a sequential soil coring method in the stands after clear cutting for 3 years, with the stands of the remaining intact trees as the control.
The fine root biomass (FRB) and fine root necromass (FRN) varied during the growing season and reached their peak in August. Lower FRB and higher FRN were found in the clear cutting stands. The ratio between FRN and FRB increased after forest clear cutting compared with the control and was the highest in June. The root mass with diameter ≤1 mm was affected proportionately more than that of diameter 1-2 mm root. Clear cutting reduced FRB and increased FRN of roots both ≤1 mm and 1-2 mm in diameter along the soil depths. Compared with the control, the annual fine root production and the average turnover rate decreased by 30.7 % and 20.7 %, respectively, after clear cutting for 3 years. The decline of canopy cover contributed to the dramatic fluctuation of soil temperature and moisture from April to October. With redundancy discriminate analysis (RDA) analysis, the first axis was explained by soil temperature (positive) and moisture (negative) in the control stands. Aboveground stand structure, including canopy cover, sprout height, and basal area, influenced FRB and FRN primarily after forest clear cutting.
This study suggested that the reduction of fine root biomass, production, and turnover rate can be attributed to the complex changes that occur after forest intervention, including canopy damage, increased soil temperature, and degressive soil moisture.
KeywordsAbove structure Fine root biomass Turnover rate Soil temperature RDA analysis
The authors thank Bao Changhu, Wang Chenglei and Wang Rui for assistance in the field and laboratory. This study was financially supported by the National Natural Science Foundation of China (Grant No. 30872018) and Forestry Industry Research Special Funds for Public Welfare Projects of China (201004011).
- Barbhuiya AR, Arunachalam A, Pandey HN, Khan ML, Arunachalam K (2012) Fine root dynamics in undisturbed and disturbed stands of a tropical wet evergreen forest in northeast India. Trop Ecol 53(1):69–79Google Scholar
- Boot RGA (1990) The significance of size and morphology of root systems for nutrient acquisition and competition. In: Lambers H, Cambridge ML, Konings H, Pons TL (eds) Causes and consequences of variation in growth rate and productivity of higher plants. SPB, The Hague, pp 299–311Google Scholar
- Ceccon C, Panzacchi P, Scandellari F, Prandi L, Ventura M, Russo B, Millard P, Tagliavini M (2011) Spatial and temporal effects of soil temperature and moisture and the relation to fine root density on root and soil respiration in a mature apple orchard. Plant Soil 342(1–2):195–206CrossRefGoogle Scholar
- Fairley R, Alexander I (1985) Methods of calculating fine root production in forests. In: AH Fitter (ed) Ecological Interactions in Soil, 4British Ecological Society, pp 37-42, Special publicationGoogle Scholar
- Finer L, Helmisaari HS, Lohmus K, Majdi H, Brunner I, Borja I, Eldhuset T, Godbold D, Grebenc T, Konôpka B, Kraigher H, Mottonen MR, Ohashi M, Oleksyn J, Ostonen I, Uri V, Vanguelova E (2007) Variation in fine root biomass of three European tree species: Beech (Fagus sylvatica L.), Norway spruce (Picea abies L. Karst.), and Scots pine (Pinus sylvestris L.). Plant Biosyst 141(3):394–405CrossRefGoogle Scholar
- Kitajima K, Anderson KE, Allen MF (2010) Effect of soil temperature and soil water content on fine root turnover rate in a California mixed conifer ecosystem. J Geophys Res-Biogeo 115:1–12Google Scholar
- Zhang WH, Lu ZJ (2002) A study on the biological and ecological property and geographical distribution of Quercus variabilis population. Acta Bot Bor-Occi Sin 22(05):1093–1101Google Scholar
- Zhou JY, Lin J, He JF, Zhang WH (2010) Review and perspective on Quercus variabilis research. J NW Fore Uni 03:43–49Google Scholar