Conservation potential of shade-tolerant forest species in agricultural mosaics in the eastern Brazilian Amazon

Igor Do Vale,Fábio Miranda Leão,Alessio Moreira Santos,Izildinha Souza Miranda,Graciliano Galdino Alves Dos Santos,Mariana Gomes Oliveira,Luiz Gonzaga Da Silva Costa,Danielle Mitja

doi:10.1590/1809-4392201902772

Abstract

ABSTRACT Shade-tolerant forest species are among the most susceptible to habitat loss in agricultural mosaics, where a variety of croplands is connected to forests at different levels of anthropogenic disturbance. We aimed to evaluate the community similarity of shade-tolerant species among different land use types across agricultural mosaics with different levels of disturbance. The study was conducted in three municipalities in southern and southeastern Pará state, in eastern Amazonia. A multiple-community similarity measure based on the Horn similarity index was used to compare land use types and assess the resilience of shade-tolerant species towards forest loss and disturbance at the landscape level. High shade-tolerant species similarity was found between mature forest fragments that underwent different levels of disturbance in all three agricultural mosaics, but secondary forests had lower similarity with mature forest in the most fragmented and altered mosaic. Shade-tolerant species showed very low density in croplands, but the same group of species seemed to colonize agricultural fields of annual crops and clean pasture, as they showed high community similarity. Another group of species was present in invaded pastures, probably due to the effects of time since land abandonment after woody species colonization. Mixed tree plantations were more similar to mature and secondary forests than other types of croplands. Shade-tolerant species similarity was higher among land use types inserted in agricultural landscapes that maintained conserved forest fragments. Our results suggest that the conservation of mature forests and landscape connectivity are crucial to the maintenance of shade-tolerant species in agricultural mosaics.

Highlights

Land use change has been considered as the main cause of global biodiversity loss (Newbold et al 2015; Barlow et al 2016)
Many of the remaining forest fragments are embedded in landscapes that contain different types of land use, forming an agricultural mosaic, where a variety of croplands is connected to forests at different levels of anthropogenic disturbance (Do Vale et al 2018)
The land use types where we found highest proportions of shade-tolerant species were exploited forests at Palmares II and conserved forests at Maçaranduba (84% of the species and 90 % of the individuals) and Travessão 338 (89% of the species and 95% of the individuals)

Summary

Introduction

Land use change has been considered as the main cause of global biodiversity loss (Newbold et al 2015; Barlow et al 2016). Competition with pioneer herbaceous species, absence of animals that disperse seeds, and disturbances during soil preparation for planting crops contribute to the loss of shade-tolerant species (Hooper et al 2005; Esquivel et al 2008). This species impoverishment in agricultural mosaics can result in profound consequences for forest restoration, such as erosion of diversity and shifts in the functional composition of forests in anthropogenic landscapes, and provision of forest ecosystem services (Da Silva and Tabarelli 2000; Van Breugel et al 2013)

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Conclusion