Assessing regional‐scale variability in deforestation and forest degradation rates in a tropical biodiversity hotspot

Abstract

Deforestation and forest degradation are major drivers of global environmental change and tropical forests are subjected to unprecedented pressures from both. For most tropical zones, deforestation rates are averaged across entire countries, often without highlighting regional differentiation. There are also very few estimates of forest degradation, either averaged or localized for the tropics. We quantified regional and country‐wide changes in deforestation and forest degradation rates for Madagascar from Landsat temporal data (in two intervals, 1994–2002 and 2002–2014). To our knowledge, this is the first country‐wide estimate of forest degradation for Madagascar. We also performed an intensity analysis to categorize the magnitude and speed of transitions between forest, vegetation matrix, cultivated land and exposed surface. We found significant regional heterogeneity in deforestation and forest degradation. Deforestation rates decreased annually in lowland evergreen moist forest by −0.24% and in all other vegetation zones. Forest degradation rates had annual increases in the same period in lowland evergreen moist forest (0.09%), littoral forest (0.06%) but decreased in medium altitude moist evergreen forest (−0.25%), dry deciduous forest (−0.23%) and scelrophyllous woodland (−0.61%) in the same period. Despite these regional differences, higher rates of deforestation and forest degradation were consistently driven by rapid and large‐sized conversions of largely intact forest to cultivated lands and exposed surfaces, most of which occurred between 1994 and 2002. These results suggest that while targeted conservation projects may have reduced forest degradation rates in some areas (e.g. medium altitude moist evergreen forest), the drivers of land cover change remain intense in relatively neglected regions. We advocate a more balanced approach to future conservation initiatives, one recognizing that deforestation and forest degradation, particularly in tropical Africa, are often driven by region‐specific conditions and therefore require conservation policies tailored for local conditions.

Exemplifying Stratified Deforestation in Four Protected Areas in Madagascar

“…With the CBD post-2020 framework being decided in 2021, there is still little evidence for Madagascar on the effectiveness of the protected area network for protecting its biodiversity heritage. While deforestation continues unabated (e.g., [15,18]), studies conducted by Eklund et al [19] or Yesuf et al [20] concluded that PAs in Madagascar could slow down deforestation. While Madagascar now has a network of protected areas across its main forests, only a few sites receive the bulk of attention from research, tourism, and NGOs [15,16,21].…”

Law Enforcement and Community Participation in Combating Illegal Logging and Deforestation in Indonesia

“…Deforestation has had a wide impact on environmental, economic, institutional and socio-political aspects, especially those related to the accessibility and biodiversity of forest resources [7]. The rate of deforestation in Indonesia continues to occur due to various factors such as illegal logging, forest fires, weak control and supervision of the operationalization of the licensing system in forest area management, conversion of forest area functions to plantations, settlements and/or other non-forestry development purposes, all of which cannot be denied to have caused damage and destruction to forest resources [8].…”

Methods for prioritizing protected areas using individual and aggregate rankings

“…The native vegetation of the island is treated in detail elsewhere (Gautier et al 2018, Lowry II et al 2018, with specific reference to the PA system of Madagascar. Loss of natural forests is the greatest threat to the terrestrial biodiversity of the island, and the pressure remains considerable (Vieilledent et al 2018, Yesuf et al 2019.…”