Grassland afforestation with Eucalyptus affect Collembola communities and soil functions in southern Brazil

Afforestation of subtropical grasslands increased during the last decade and their impacts on soil biota and functions are not well known. Here we investigated the effects of grassland afforestation with Eucalyptus on soil Collembola communities in southern Brazil. By using paired transects (native grassland vs. plantation), we assessed Collembola taxonomic and functional composition and diversity and their relations with plant diversity and soil microbial and physical-chemical parameters. Eucalyptus plantations significantly decreased plant richness, soil pH, and soil temperature. Microbial biomass, soil basal respiration and enzyme activities were negatively affected by grassland afforestation, which may indicate an effect on decomposition, soil fertility, and carbon stock. At a regional scale, grassland afforestation diminished the richness, and at a local scale changed the taxonomic and functional composition of Collembola communities. An environmental filtering mechanism is suggested triggering trait turnover from open (grassland) to a closed canopy habitat (tree plantation). While grassland presented high abundance of larger, eyed, and pigmented Collembola, Eucalyptus favored smaller, blind, and non-pigmented Collembola with shadow-adapted sensorial structures. Our results on afforestation effects in subtropical grasslands are similar to those described for temperate zone, and may underpin the development of conservation strategies for land-use on subtropical grasslands.

Automated summary

The afforestation of subtropical grasslands with Eucalyptus significantly decreased plant richness, soil pH, and soil temperature. It also negatively affected microbial biomass, soil basal respiration, and enzyme activities. Grassland afforestation altered the taxonomic and functional composition of Collembola communities.