Potential distribution of Mikania micrantha Kunth in India − evidence of climatic niche and biome shifts

- Climatic niche shift of Mikania micrantha is evident in India.
- The species was found to occupy a novel biome in India.
- Predicted distribution identified new areas climatically suitable for its invasion.
- Niche and biome inconsistencies emphasize careful interpretation of model output.

Native to Latin America, Mikania micrantha is considered as one of the top invaders in the moist tropical zones of the Pacific and Asian countries, including India. This study was conducted with two specific objectives − first, to examine the niche and biome conservancy of M. micrantha between its native and Indian ranges and second, to understand the potential distribution of this invasive plant in India. Principal Component Analysis of climatic variables associated with known occurrences of M. micrantha in India and native ranges indicated significant shifts in climatic niche of M. micrantha in India. Temperature and precipitation seasonality were found to be the driving factors for the niche shift in India. Our study also revealed that in India M. micrantha invaded a novel biome viz. the temperate broadleaf and mixed forest, which was present but unoccupied in the native range. Given the climatic niche shift, both Indian and native occurrence data were used to model the potential distribution of this weed in India using MaxEnt. The predicted distribution identified that a larger extent of the Indian landmass is climatically suitable for M. micrantha growth. High climatic suitability of some of the urban centers of India adds to the risk of further spread of this plant into 'still to be invaded' areas. The niche and biome inconsistencies of M. micrantha in India highlight the need for further investigation of the underlying mechanisms and careful interpretation of its potential distribution.

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