Effects of temporary agroforestry systems and weeding techniques on the control of invasive species in Atlantic Forest restoration

Abstract

The restoration of tropical forests is greatly in demand but is limited by the lack of feasible technologies. Forest restoration can be associated with a temporary, productive herbaceous layer. Here, we compared the use of temporary agroforestry systems (tAFS) with conventional forest restoration through seedling planting. We quantified the growth estimators of native forest tree species and the effectiveness of the two methods for controlling invasive grasses. Seedlings of 20 native tree species were planted in 72 rows of 60 m each, totaling 1148 individuals. The restoration methods of planting tree seedlings only or trees coupled with herbaceous species (annual crops), along with weed control methods (mechanical and chemical), were systematically established in 12 plots (7920 m2 for conventional techniques and 7920 m2 for tAFS) per treatment (3960 m2 each) and analyzed in a nested design using generalized mixed models. The chemical control of weeds was conducted using herbicides, and the mechanical control consisted of semimechanized mowing. The tAFS showed greater relative growth in both the height and diameter of native trees in comparison with the conventional method. Within the conventional restoration technique, chemical management led to an increased height of native trees and a decreased invasive biomass, but tAFS showed no differences between the invasive control methods. tAFS was efficient in ensuring the success of the tree seedlings and diminishing the invasive biomass, concomitant with the production of annual crops in tropical forest restoration.