Assessing the Impact of Climate Change on Black Pepper (Piper nigrum L.) Distribution in Kerala through MaxEnt Modelling

Abstract

Black pepper (Piper nigrum L.) is an important spice crop of Kerala, whose productivity depends on climatic variation. The present study assesses the current and future climatic suitability of black pepper in Kerala using the MaxEnt model. Nineteen bioclimatic variables from the CHELSA database and topographic variables were used to predict the distribution of the species, and seven uncorrelated bioclimatic variables and four topographic variables were selected to run the model under current and future climate scenarios, SSP1-2.6, SSP 3-7.0, and SSP5-8.5 for the mid-century (2041-2070) and end-century (2071-2100) time periods. Model output was reclassified with a 0.38 threshold to demarcate suitable and unsuitable areas. Spatial suitability distribution was analyzed across twenty-three Agro-Ecological Units of Kerala to quantify area gain, loss, and no-change regions. The results showed a notable shift in suitable areas under high-emission scenarios, especially in lowland AEUs, indicating the potential contraction of suitable zones due to climate change. The study points to the vulnerability of traditional pepper-growing areas and emphasizes the need to adopt adaptive management strategies along with climate-resilient varietal selection for sustainable black pepper cultivation in Kerala.