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Remote sensing observations such as normalized difference vegetation index (NDVI) trends can provide important insights into past and present land condition. However, they do not directly provide comprehensive information about our representation of land degradation and the processes at work. This study aimed to analyze vegetation productivity underlying factors in order to assess land degradation and to highlight the impact of definitions on its quantitative assessment, using Mozambique as casestudy. Land productivity change were first analyzed using NDVI time-series (2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015)(2016), and a two-step framework was then used to understand the main factors of these productivity changes. The impact of land degradation's definition was assessed based on four types of stakeholder, with different priorities in terms of ecosystem services. The results show that 25% of the country display a significant land productivity decrease, while only 3% display a land productivity increase. A large part of these land productivity changes (>61% of the decrease, and >98% of the increase) is directly assigned to human activities, such as native forest growth or tree plantations (for the increase), or forest degradation, deforestation and loss of grassland productivity (for the decrease). We showed that the fraction of degraded land varies according to stakeholders' definitions, ranging from 12% to 20% of the Country, much less than the 39% estimated by Tier 1 United Nations Convention to Combat Desertification. This study provides a sound methodological framework for assessing land degradation status that could help stakeholders to design national and locally relevant land degradation mitigation policies or programmes.

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Narrow-ranging species are usually omitted from Species distribution models (SDMs) due to statistical constraints, which may be problematic in conservation planning. The recently available high-resolution climate and land use data enable to increase the eligibility of narrow-ranging species for SDMs, provided their distribution is well known. We modelled the distribution of two narrow-ranging species for which the distribution of their occurrence records is assumed to be nearly comprehensive and unbiased (i.e., the Critically Endangered Manapany day gecko Phelsuma inexpectata and the Endangered golden Mantella frog Mantella aurantiaca). We predict a dramatic decline in climate suitability in the whole current distribution area of both species by 2070, potentially leading to a complete extinction even in the most optimistic scenario. We identified the areas with the best climate suitability in the future, but these remain largely suboptimal regarding species climatic niche. The high level of habitat fragmentation suggests that both species likely need to be at least partly translocated. We propose to consider the use of spatially explicit guidelines for translocation and habitat restoration in order to leave the species a chance to adapt and persist. The effect of climate change remains understudied for the extreme majority of rare and highly threatened species. This study suggests that the level of threats of data-poor and narrow-ranging species already identified as threatened may be underestimated, especially in heterogeneous tropical environments. We stress the need to consider the option of implementing proactive actions for threatened narrow-ranging species.

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The phenology of tropical forests is tightly related to climate conditions. In the Amazon, the seasonal greening of forests is conditioned by solar radiation and rainfall. Yet, increasing anthropogenic pressures (e.g. logging and wildfires), raise concerns about the impacts of forest degradation on the functioning of forest ecosystems, especially in a climate change context. In this study, we relied on remote sensing data to assess the contribution of solar radiation and precipitation to forest greening in mature and fire degraded forests, with a focus on the 2015 drought event. Our results showed that forest greening is more dependent on water resources in degraded forests than in mature forests. As a consequence, the expected increase in drought episodes and associated fire occurrences under climate change could lead to a long-term drying of tropical forests.

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