Potential for Forest Restoration and Deficit Compensation in Itacaiúnas Watershed, Southeastern Brazilian Amazon

Abstract

The conservation and restoration of native vegetation is vital for providing key hydrological services (i.e., maintaining high water quality, atmospheric humidity, and precipitation patterns). However, this research area lacks fine-scale studies at the watershed level to evaluate opportunities for forest restoration and deficit (the shortfall of forest required to be restored or compensated), as well as the implications for watershed management. We provide the first fine-scale estimation of forest and deficit distribution, integrating permanent preservation areas (APPs, in Portuguese) and legal reserves (RL, in Portuguese), according to Brazilian environmental law, for the 41,300 km2 Itacaiúnas watershed in the Brazilian state of Pará, which has lost 50% of its vegetation cover. Using 30 m- and 10 m-resolution imagery, a multi-temporal land use classification was performed by geographic object-based image analysis (GEOBIA). The results were combined with a set of Brazilian regulations on the conservation and restoration of APPs and RL to assess patterns of forest cover and legal compliance. We found that the total RL deficit (4383 km2) was higher than the total forest surplus (above legal obligation) (3241 km2). However, most of this deficit (56%) could be compensated by protecting a forest area in another property within the Amazon biome, while 44% must be legally restored. Only 4% of the total forest surplus can be legally deforested, and the remaining 96% is already protected by law but can be used to compensate for areas under the deficit. We also found that, despite 57% (3017 km2) of the total APP being forested, only 26% (1356 km2) of the APP must be restored and 17% (881 km2) can remain deforested (consolidated areas). The 2012 law revision reduced the obligation to restore RL and APPs. This change could affect hydrological and ecological services. Compensation mechanisms could be used to protect forest within the Itacaiúnas watershed, rather than in the biome, to reduce further deforestation pressure.

Terrestrial water storage and Pacific SST affect the monthly water balance of Itacaiúnas River Basin (Eastern Amazonia)

“…Location of the Itacaiúnas River Basin in the Brazilian Legal Amazon, land use and land cover classification (Nunes et al ., ) and location of the meteorological station of Marabá [Colour figure can be viewed at wileyonlinelibrary.com]…”

Comparison of sediment rating curves and sediment yield in subbasins of the Itacaiúnas River Watershed, Eastern Amazon

“…Recent studies conducted in the region defined five main types of land use and land cover (Souza Filho et al 2015, 2016, 2018Zappi, 2017;Nunes et al, 2019): tropical forest (dense rainforest) and metallophile savanna dominate the untouched landscape and account for ~48% of the area, which is primarily concentrated in conservation units and indigenous lands; vast grasslands for cattle raising (deforested areas) currently occupy much of the landscape (~51%), whereas urban areas and open pit mining regions occupy restricted areas (Figure 2).…”

Diagnóstico ambiental de reserva legal e áreas de preservação permanente da estrada de ferro Carajás, PA (2018)

“…A metodologia utilizada neste estudo foi a mesma apresentada por (NUNES; CAVALCANTE; et al, 2019) em um estudo de mapeamento de passivo ambiental na bacia hidrográfica do rio Itacaiúnas, Pará. A diferença está no mapeamento das APPs, pois neste trabalho consideramos somente APPs de rios e reservatórios, que correspondem a mais de 90% das APPs desta região (NUNES;CAVALCANTE;. O ano de referência do mapeamento da cobertura do solo foi 2018.…”

“…O segundo passo seria definir as áreas prioritárias para a recomposição destas áreas, de acordo com o objetivo da recomposição, para ajudar a guiar os esforços de recomposição da vegetação. Porém, a implementação efetiva desta recomposição em larga escala depende de vários fatores, como os discutidos por (NUNES;BARLOW;NUNES;CAVALCANTE;NUNES et al, 2016): segurança jurídica, problemas fundiários, incentivos do governo para proteger a floresta remanescente e a recomposição de áreas críticas, fortalecimento de mecanismos de compensação e de pagamentos por serviços ambientais e fortalecimento da cadeia produtiva dos produtos oriundos da floresta e de áreas em processo de recomposição.…”