Dynamics of Carbon and Nutrients in a Successional Forest Sequence in the Mesopotamian Espinal (Argentina)

The Mesopotamian Espinal has been recently modified in several areas of Entre Ríos province (Argentina) due to the advance of the agricultural frontier, producing an important reduction in forest area. Inappropriate forest management had early transformed the native and primary forests into degraded or secondary forests. Deforestation and land abandonment have led to the development of a sequence of successional forest stages. The aim of this work was to assess the effects of forest succession changes on soil properties and nutrients contents of a successional forest sequence in the Mesopotamian Espinal (Argentina) which would be associated with livestock production. To reach proposed objectives, ten soil samples were collected from the depth of 0-10 (A-horizon) and 30-40 cm (B-horizon) from 4 sites in three forest successional sequence. An initial forest (IF) (approximately 20 years at the beginnings of this study), a secondary forest (SF) (mixed forest with trees of between 60 and 80 years old) and a mature forest (MF) with minimal signals of degradation were studied. Results showed soil texture changes during the successional forest process with higher clay and coarse sand but lower silt and fine sand values at the IF stage than MF state. In the same way, an increase in organic matter (as much in the humic- as in the fulvic-fraction) and in most nutrient (nitrogen, phosphorus, calcium, magnesium and potassium) were found. Data showed that whenever forest reach to mature state, soil quality indicators would explain part of the higher plant productivity.