Influence of Climate on Morphology and Selected Biological Properties of Garcinia kola (Heckel) in Nigeria

Abstract

Garcinia kola is a highly valued medicinal species indigenous and play a significant role in sustaining rural livelihood in West and Central Africa. Despite its everyday use, there is limited information on its morphological, proximate, and phytochemical variation, highlighting a critical knowledge gap for its conservation and sustainable utilisation. This study investigated the morphological, phytochemical, and proximate characteristics of Garcinia kola across two distinct vegetation zones in Nigeria: the rainforest of the Swamp Research Station of the Forestry Research Institute of Nigeria (FRIN) in Onne, Rivers State, and the derived savanna, located in Ibadan, Oyo State. Data collection spanned from 2017 to 2021, with a focus on key morphological parameters. Five mature trees were purposively selected based on the availability of the tree stands with desirable characteristics in each study site. Additionally, fresh leaf samples were subjected to phytochemical screening to identify the presence of metabolites. A proximate analysis was also conducted to determine the levels of protein, fat, moisture, ash, and carbohydrates. The collected data were evaluated using multiple linear regression (MLR) modelling in R software. Species in derived savanna shows higher mean leaf and seed characteristics, primarily influenced by relative humidity, precipitation, WS2M, and GWETTOP. Combinations of T_Mean, RH2M, WS2M, GWETTOP, and precipitation significantly influenced proximate composition. The species in rainforest ecosystem generally exhibits higher ash, crude fibre, and crude protein. Varying combinations of T_Mean, RH2M, WS2M, GWETTOP, and precipitation influenced phytochemical constituents. The study concludes that prevailing climatic conditions had influences on the yield, and biochemical composition of G.kola in the distinct ecological zones.