Soil Responses to restoration of a tropical pasture in Veracruz, South-Eastern Mexico.

Background

Changes in land use and land cover may affect soil properties and processes. Conversion of forest to pasture is assumed to result in a decrease in soil nutrients. Restoration to healthy grassland or forest may lead to an increase in soil nutrients. This paper reports on a study on soil responses to restoration of a tropical pasture in Veracruz, Mexico.

Research goals & methods

Investigations were carried out on litter nitrogen and phosphorus and soil carbon, nitrogen, and phosphorus in an active pasture (30 years), a mature tropical rainforest, and two treatments of restoration (cattle exclusion alone and combined with planting of tree seedling) in Veracruz, Mexico. The aim was to outline how the two treatments of restoration affect the recovery of soil nutrient status in the short-term (one year). Litter nitrogen and phosphorus pools were substantially lower in pasture compared to mature forest, largely reflecting differences in litter mass between pasture and mature forest. Pasture soils consistently had lower pools of organic carbon and total nitrogen and ammonium (NH₄₊) than forest soils.

Conclusions & takeaways

Exclusion of grazing and exclusion of grazing plus planted tree seedlings increased nitrogen and phosphorus pools in the litter. In contrast, over the one-year time scale, restoration treatments did not consistently affect soil carbon, nitrogen and phosphorus. The main response to restoration practices was a decrease of NO_3- and extractable phosphorus pools in soils