Sensitivity of soil restoration indicators during paramo succession in the high tropical Andes: chronosequence and permanent plot approaches
Fecha
2009-09Palabras Clave
Disturbance, Fallow agriculture, Microbial biomass, Nitrogen, Páramo, pH, Soil organic matter, Spatial heterogeneityMetadatos
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The aim of this study was to analyze indicators of soil restoration during secondary succession in a heterogeneous
valley in the high tropical Andes. A combination of chronosequence and permanent plot methods was used to detect changes in this heterogeneous matrix. Thirty-six
plots with different fallow times (1–9 years) and four noncultivated plots with natural vegetation (pa´ramo) were sampled twice in a 3-year interval (1996 and 1999). The
following soil properties were determined: total C and N, pH, exchangeable bases, cation exchange capacity, and microbial biomass N (MB-N). Using the chronosequence approach, successional increases in soil pH and Mg were
detected, pointing to these variables as indicators of soil restoration during the fallow period. Comparing the noncultivated
pa´ramo with the fallow plots, a significant
decrease in MB-N was found, suggesting that this is a sensitive agricultural disturbance indicator. The permanent plot analysis failed to detect successional trends in any of
the study variables, probably as a result of a lack of sensitivity of the indicators used within the 3-year interval. Nevertheless, a strong acidification was detected by the
permanent plot method when fallow plots were cultivated. We conclude that the size of important soil components such as total soil organic matter or microbial biomass is
not a sensitive soil restoration indicator in these heterogeneous mountain systems but that other integrative variables such as pH could be more sensitive to successional
changes in key soil processes (e.g., nitrification or nutrient losses).
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Información Adicional
Correo Electrónico | lsarmien@ula.ve llambi@ula.ve |
Editor | Restoration Ecology 17(5): 619-628 |
Colación | 619-628 |
País | Venezuela |
Institución | Universidad de Los Andes |