Forest restoration assessment in Brazilian Amazonia: A new clustering-based methodology considering the reference ecosystem

Abstract

Techniques for forest restoration have been widely developed over the past decades, allowing the reestablishment of vegetation in extreme cases such as surface mining. However, there are still issues related to management and monitoring that require further understanding, especially concerning comparisons with reference ecosystems. In this study, hierarchical agglomerative clustering (HAC) with uncertainty estimation is proposed as a methodology for forest restoration assessment. For this purpose, analysis was made of phytosociological variables for 27 plots located in reforested closed mines and in the Amazon forest reference ecosystem. The technique grouped the reference ecosystem separately from the reclamation sites. The HAC was affected by dependency among the analyzed variables, and heterogeneity was observed for all the phytosociological parameters in the cluster groups formed by the mining locations. However, each group showed specific characteristics related to the different environmental conditions and the forest restoration performance. The results demonstrated that HAC with uncertainty estimation was more suitable for defining groups, compared to the classical approach, offering a promising methodology for evaluation of the outcomes of forest restoration and for guiding management actions in disturbed tropical forests.

Soil Seed Banks in Two Environments of Forest Restoration Post Bauxite Mining: Native Tree Plantation and Natural Regeneration

“…However, bauxite mining causes punctual impacts due to the suppression of vegetation and the removal of superficial layers of soil, which, despite not occupying large territorial extensions (such as agriculture and livestock), can cause imbalances in the environment [3,4] .…”

Survival, growth and regeneration of forest species in mining areas in the Eastern Amazonia

“…However, this obstacle can be minimized with the correct selection of species for restoration, considering their adaptability, information on rapid growth [34], production of resources to attract wildlife [4] and high litter production [24,33] for soil cover. In addition, it should also be considered that a total modification of the environment will provide micro sites which are totally different from those prior to suppression, and that these environments may favour a particular group of species [9]. Thus, it is necessary that the selection and planting of species consider information about establishment and growth in sites near the mined areas, increasing the chance of survival of the seedlings after planting, thereby reducing the implementation costs.…”

“…For this reason, continuous monitoring of the performance of planted species and natural regeneration in mining areas [3] is fundamental. It is possible to diagnose species adaptation, survival and growth through monitoring data, and then use this information to establish groups with similar growth characteristics and suitability for initial implantation [9,27].…”

The use of circularity index of soil aggregates to differentiate degraded stratate

“…Na maioria das vezes, as atividades de recuperação visam recolocar uma cobertura vegetal na área explorada, e essas atividades incluem operações que vão desde a estética paisagística, até a revegetação completa da área, procurando manter as espécies típicas da região. Naturalmente essa definição não preenche todas as circunstancias que envolve a recuperação ambiental de uma área, principalmente sob o aspecto ecológico (LONGO, 2011, Lei et al, 2016FENGLER et al, 2017). Desta forma, é necessário um plano de gestão com atividades de recuperação que permitam melhorar a qualidade do solo para o desenvolvimento da vegetação no local alterado (PECHE FILHO, 2017;CARVALHO et al, 2019).…”