Combining global tree cover loss data with historical national forest-cover maps to look at six decades of deforestation and forest fragmentation in Madagascar

Vieilledent, Ghislain; Grinand, Clovis; Rakotomalala, Fety A.; Ranaivosoa, Rija; Rakotoarijaona, Jean-Roger; Allnutt, Thomas F.; Achard, Frédéric

doi:10.1101/147827

Cited by 86 publications

(185 citation statements)

References 55 publications

(109 reference statements)

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“…It is possible that roadinduced deforestation is overestimated in our study because the data source includes deforestation not caused by humans, as well as conversions from primary forests to, for example, plantations, which are considered forests by some countries. In the absence of better data, however, Hansen et al (36,37) have been accepted and used as a proxy for deforestation in the literature.…”

Section: Assumptionmentioning

confidence: 99%

A better Amazon road network for people and the environment

Vilela¹,

Harb²,

Bruner³

et al. 2020

Proc. Natl. Acad. Sci. U.S.A.

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The rapidly expanding network of roads into the Amazon is permanently altering the world’s largest tropical forest. Most proposed road projects lack rigorous impact assessments or even basic economic justification. This study analyzes the expected environmental, social and economic impacts of 75 road projects, totaling 12 thousand kilometers of planned roads, in the region. We find that all projects, although in different magnitudes, will negatively impact the environment. Forty-five percent will also generate economic losses, even without accounting for social and environmental externalities. Canceling economically unjustified projects would avoid 1.1 million hectares of deforestation and US$ 7.6 billion in wasted funding for development projects. For projects that exceed a basic economic viability threshold, we identify the ones that are comparatively better not only in terms of economic return but also have lower social and environmental impacts. We find that a smaller set of carefully chosen projects could deliver 77% of the economic benefit at 10% of the environmental and social damage, showing that it is possible to have efficient tradeoff decisions informed by legitimately determined national priorities.

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Section: Assumptionmentioning

confidence: 99%

A better Amazon road network for people and the environment

Vilela¹,

Harb²,

Bruner³

et al. 2020

Proc. Natl. Acad. Sci. U.S.A.

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“…Many extant vertebrate species have populations in the east and west, but lack representation in the Central Highlands today (Goodman & Raherilalao, 2014;Muldoon & Goodman, 2010), which is largely depauperate of native vegetational communities. Much forest has been lost by burning and clearing for agriculture (McConnell & Kull, 2014); 44% of the island's natural forest cover has disappeared since 1953 (Vieilledent et al, 2018). Despite the Central Highlands being a fairly large region, its natural forests comprise only 2.6% of the nation's total (Dufils, 2003).…”

Section: Introductionmentioning

confidence: 99%

A new late Pleistocene subfossil site (Tsaramody, Sambaina basin, central Madagascar) with implications for the chronology of habitat and megafaunal community change on Madagascar's Central Highlands

Samonds

Crowley

Rasolofomanana

et al. 2019

J Quaternary Science

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Madagascar is a complex ‘biodiversity hotspot’ with a rapidly dwindling biota. The Late Quaternary subfossil record includes many extinct species whose loss is attributed to natural climate change and human impacts. Investigation of the chronology of these events is challenging because few localities document pre‐Holocene communities not impacted by humans. Caves with extinct lemurs of large body size comprise some of Madagascar's richest subfossil sites, but provide only a limited window into the island's past. Open highland sites may have fewer primates, but may better document other megafauna, and allow the analysis of the role of the Central Highlands as refugia and as corridors for the dispersal of vertebrates before and after human arrival. Here we present a new subfossil site, Tsaramody (Sambaina basin, Central Madagascar), a high‐altitude wetland area that preserves a diverse late glacial and postglacial vertebrate community. Tsaramody bears testimony to fluctuations in the highland flora during the transition from glacial to postglacial conditions, and the composition of a highland vertebrate community before humans arrived. We compare its biota to those of other sites to begin to document the decline and disappearance of megafauna from some of Madagascar's open ecosystems – wetlands dominated by hippopotamuses and crocodylians. © 2019 John Wiley & Sons, Ltd.

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“…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.…”

Section: Study Settingmentioning

confidence: 99%

“…The estimation of two distinct measures of deforestation (forest cover loss and acceleration in forest cover loss) also proved useful. It helped to identify sites that have lost a high proportion of their forest cover and to highlight instances where deforestation has worsened in recent years (Vieilledent et al 2018). For these reasons, prioritization schemes should apply measures of pressure and/or threat to habitat conservation alongside measures of biodiversity and knowledge-based variables (Campagnaro et al 2018).…”

Section: Environmental Conservation 119mentioning

confidence: 99%

Methods for prioritizing protected areas using individual and aggregate rankings

et al. 2020

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Despite their legal protection status, protected areas (PAs) can benefit from priority ranks when ongoing threats to their biodiversity and habitats outpace the financial resources available for their conservation. It is essential to develop methods to prioritize PAs that are not computationally demanding in order to suit stakeholders in developing countries where technical and financial resources are limited. We used expert knowledge-derived biodiversity measures to generate individual and aggregate priority ranks of 98 mostly terrestrial PAs on Madagascar. The five variables used were state of knowledge (SoK), forest loss, forest loss acceleration, PA size and relative species diversity, estimated by using standardized residuals from negative binomial models of SoK regressed onto species diversity. We compared our aggregate ranks generated using unweighted averages and principal component analysis (PCA) applied to each individual variable with those generated via Markov chain (MC) and PageRank algorithms. SoK significantly affected the measure of species diversity and highlighted areas where more research effort was needed. The unweighted-and PCA-derived ranks were strongly correlated, as were the MC and PageRank ranks. However, the former two were weakly correlated with the latter two. We recommend using these methods simultaneously in order to provide decision-makers with the flexibility to prioritize those PAs in need of additional research and conservation efforts.

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Combining global tree cover loss data with historical national forest-cover maps to look at six decades of deforestation and forest fragmentation in Madagascar

Abstract: 2014 (corresponding to a rate of 1.08%/yr). This increase is probably due to rapid 18 population growth (close to 3%/yr) and to poor law enforcement in the country. 19Around half of the forest (46%) is now located at less than 100m from the forest 20 edge.

Cited by 86 publications

References 55 publications

A better Amazon road network for people and the environment

A better Amazon road network for people and the environment

A new late Pleistocene subfossil site (Tsaramody, Sambaina basin, central Madagascar) with implications for the chronology of habitat and megafaunal community change on Madagascar's Central Highlands

Methods for prioritizing protected areas using individual and aggregate rankings

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