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Thermotolerance in tropical plants
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Thermotolerance in tropical plants
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The frequency and severity of extreme temperature events – high temperature and drought is predicted to increase in future climates. It is therefore essential to understand the vulnerability of species to extreme temperatures and drought. Currently it is not understood how different plant communities, or plant functional types vary with respect to temperature tolerance.
Our knowledge of the upper temperature limits of tropical plants comes from a limited number of studies where tropical species are highly under-represented. Moreover, tropical systems may be particularly vulnerable to future warming as tropical species are already living closer to their absolute thermal maxima, and likely have narrower thermal niche breadths due to long term adaptation to relatively stable temperatures. Thermotolerance in tropical trees Our recent results suggest that tropical trees are precariously close to upper thermal limits, and likely going to be severely affected by future warming. Importantly, thermotolerance differed between evergreen and deciduous trees and was related to leaf functional traits and photosynthetic rates. Additionally, drought stress increased temperature tolerance, and species with high drought tolerance were also more thermotolerant. These results suggest that deciduous, and fast growing species with low leaf mass per area will be more negatively affected by increased temperatures and drought. This will likely lead to directional changes in species composition in seasonally dry forests towards greater relative abundance of slower growing evergreen species. Such directional changes in species composition would alter vegetation atmosphere-feedbacks and could further exacerbate global warming Seasonal variation in Thermotolerance Thermotolerance in tropical herbaceous plants Quantifying thermotolerance in leaves A demo by Urmi Poddar |
Geographic coverage of studies that have examined thermotolerance in tropical plants is sparse
Thermotolerance was positively related to leaf mass per area (LMA) in 41 woody species from Pune, Maharashtra. In more recent work we saw similar results for 38 woody species from the Northern Western Ghats, and also for 55 herbaceous plant species from this region.
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