versión On-line ISSN 0717-9200
URRETAVIZCAYA, María Florencia. Soil characteristics in burned Austrocedrus chilensis forests in Patagonia, Argentina. Bosque (Valdivia) [online]. 2010, vol.31, n.2, pp. 140-149. ISSN 0717-9200. http://dx.doi.org/10.4067/S0717-92002010000200007.
Austrocedrus chilensis is the most important natural conifer in the Patagonian Andes region of southern Argentina where there are 141,000 hectares of mainly pure stands. Fire is the main disturbance in the dynamics of these forests. The objective of the study was to analyze possible differences in chemical, physical and biological soil properties among unburned (NQ), partially burned (PQ) and completely burned (CQ) portions of two A. chilensis stands: one located near El Bolsón city (41º 59 02 S-71º 33 20 W) and the other one near Trevelin city (43º 12 57 S-71º 31 15 W). The stands were burned 21 months and five years before running the studies respectively. The following soil properties expected to influence forest recovery were measured: pH, electric conductivity (EC), organic carbon (C), total nitrogen (N), interchangeable potassium (K), calcium (Ca), magnesium (Mg), and nitrogen in the microorganisms (N-BM) in the upper 10 cm of soil. At El Bolsón study the PQ and CQ portions of the stand had higher pH and EC and less C, N, Mg and N-BM than the NQ portion. These changes may be related to the combustion of the organic matter. These differences were not registered at the Trevelin study; I speculate that at this site soil nutrient content could have been recovered because much more time elapsed between the occurrence of the fire and the installation of the study. It is desirable that after a forest fire the vegetation get reestablished as soon as possible to prevent nutrient loss and hasten the recovery of soils characteristics; this can be facilitated by planting A. chilensis.
Palabras llave : ciprés de la cordillera; natural forest; fire effects; postfire soil conditions.