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Temperature is a core component of a species’ fundamental niche. At the
fine scale over which most organisms experience climate (mm to ha),
temperature depends upon the amount of radiation reaching the Earth’s
surface, which is principally governed by vegetation. Tropical regions
have undergone widespread and extreme changes to vegetation, particularly
through the degradation and conversion of rainforests. Since most
terrestrial biodiversity is in the tropics, and many of these species
possess narrow thermal limits, it is important to identify local thermal
impacts of rainforest degradation and conversion. We collected
pan-tropical, site-level (< 1 ha) temperature data from the
literature to quantify impacts of land-use change on local temperatures,
and to examine whether this relationship differed above-ground relative to
below-ground and between wet and dry seasons. We found that local
temperature in our sample sites was higher than primary forest in all
human-impacted land-use types (N = 113,894 day-time temperature
measurements from 25 studies). Warming was pronounced following conversion
of forest to agricultural land (minimum +1.6°C, maximum +13.6°C), but
minimal and non-significant when compared to forest degradation (e.g. by
selective logging; minimum +1°C, maximum +1.1°C). The effect was buffered
below-ground (minimum buffering 0°C, maximum buffering 11.4°C), whereas
seasonality had minimal impact (maximum buffering 1.9°C). We conclude that
forest-dependent species that persist following conversion of rainforest
have experienced substantial local warming. Deforestation pushes these
species closer to their thermal limits, making it more likely that
compounding effects of future perturbations, such as severe droughts and
global warming, will exceed species’ tolerances. By contrast, degraded
forests and below-ground habitats may provide important refugia for
thermally-restricted species in landscapes dominated by agricultural land.
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