Short-term responses of native tree species to site conditions after mining in the Central Amazon

Abstract

Restoring mining areas is a hard challenge to tropical silviculture, given the high levels of degradation caused by the removal of forest cover and decrease to soil quality. It is necessary to know the soil limitations for planting and the adequate treatments to revert these limitations and select good-performance species. The monitoring based on functional traits can contribute to the selection of the most suitable species for mining restoration projects. Here, we investigated the functional performance of native tree species as modulated by site conditions after cassiterite mining in the Central Amazon. We planted saplings of seven Amazonian tropical tree species in three site conditions (Stripping, Grasses, and Tailings), and measured soil properties, survival, growth, and 15 photosynthetic leaf traits ten months after planting. Silvicultural treatments enhanced the chemical properties in all site conditions (e.g. increase in bases saturation), and physical properties in some site conditions (e.g. reduction of penetration resistance in Stripping). The performance (survival and growth) and traits changed more among species than sites. Species with high photosynthetic resource use efficiency had better performance. Pseudobombax munguba was the species with the highest performance and can be indicated as a key species for the efforts of restoration in the region. Select species with traits similar to those of P. munguba can lead to greater success in restoration projects of mining areas in the Amazon.