NOM quality in forest soils from the NW of Spain: differences between Quercus robur L. and Betula alba L. plantations

摘要

Natural organic matter from forest soils have a significant influence on the ecosystem sustainability as well as on the ecosystem fertility and productivity. Hence, the study of soil organic matter composition (Fernandez et al., 2001; Ussiri y Johnson, 2003), in addition to the processes involved in soil organic matter transformations (Carballas et al., 1979, 1980, 1983; Fernandez et al., 1999), appears as a recommended research line when we want to know the present and future status of the nutrient cycles in forest ecosystems (Nilsson et al., 1995; Sanchez et al., 1997; Fernandez et al., 1999). Even though in recent times concerns about the C retention capacity of soils and their contribution to climate change mitigation by acting as CO2 sinks (Dewar y Cannell, 1992; Hoen and Solberg, 1994; Huntington, 1995; Nabuurs y Mohren, 1995, Malhi et al., 1999, etc.) are increasing, data on the soil organic matter mineralization kinetics in the different types of forest ecosystems typical of the temperate zones are clearly insufficient, factors determining the potential C retention capacity of soils remaining practically unexplored (Murillo, 1994). Therefore, the objective of this research is to study the soil organic matter dynamics of two different types of deciduous forests of the temperate-humid zone (Quercus robur L. or Betula alba L.) located in Galicia (northwestern Spain) in order to compare their potential C mineralization activity.