MaxEnt modelling for predicting the potential distribution of a near threatened rosewood species (Dalbergia cultrata Graham ex Benth)

Climate change will affect ecological factors that influence species distribution patterns at different spatial and temporal scales. We applied MaxEnt to predict how climate change will influence the distribution of ecologically and economically important tree species Dalbergia cultrata Graham ex Benth. D. cultrata is distributed across the tropical and subtropical zone of the Indo-China peninsula and southern Yunnan province in China.

In recent decades, natural regeneration of D. cultrata has decreased drastically to only a limited region due to human disturbance, inter-species competition and other threats. Understanding the habitats requirements of this species, evaluating habitats quality, and predicting potential habitats are essential to ensure its conservation. We used the MaxEnt model to simulate habitats suitability and future species distribution under predicted climate change scenario using ten environmental variables. Our results showed that the modelled distribution of D. cultrata is mainly influenced by isothermality (Bio3), temperature annual range (Bio7), precipitation of wettest month (Bio13), and precipitation of warmest quarter (Bio18), suggesting that this species is sensitive to temperature and precipitation fluctuation. These findings indicated D. cultrata is likely to be highly vulnerable to climate change.

Subsequent simulations of habitats suitability under doubled CO₂ levels was calculated. Overall, our results show that habitats of high suitability for D. cultrata is predicted to decrease in the face of climate warming. Populations at the species range edge will be particularly vulnerable to climate change. We discuss the implications of our analysis for conservation priority setting and future restoration strategies for this important high value species across the Indo-China region. International and regional cooperation will be critical to successful conservation of this species.

Liu, Y.; Huang, P.; Lin, F.; Yang, W.; Gaisberger, H.; Kettle, C.; Zheng, Y.