Environmental variables drive medicinal plant composition and distribution in various forest types of subtropical region in Pakistan

Abstract

Analyzing the ecological distribution patterns of medicinal plants under the influence of environmental variables can provide important information about how these plants are affected by environmental factors. This analysis can also serve as a conceptual foundation for medicinal plant management strategies. We examined the composition and distribution of medicinal plants as well as how and which environmental factors influence the plant communities in subtropical forest types from Pakistan. 11 forest sites over the course of two years (2020−2021) were sampled, measuring 10 environmental variables and documenting medicinal plants that were present in the study area. Plants data viz.; cover, density, and frequency were recorded from randomly selected sites through quadrat method. Soil parameters i.e., pH, nitrogen, phosphorus, electrical conductance, potassium and soil organic matter were recorded from each site. After calculating importance value index for each species, the data was analyzed utilizing a multivariate ordination approach. The most prevalent family observed during present investigations were Asteraceae followed by Fabaceae and Solanaceae. The life form spectra outcomes exhibited the predominance of the therophyte species, followed by chamaephyte species. The results of the regression analysis exhibit that soil organic matter, nitrogen, potassium, and phosphorus have a positive influence on medicinal plant richness, while electrical conductance (EC) and soil pH have a negative influence. Canonical correspondence analysis revealed that the soil parameters and anthropogenic factors (grazing pressure, land degradation, over-collection) had a significant (p ≤ 0.002) effect on the distribution of medicinal plants. The seasonal pattern of the life cycle revealed its peak during the spring season (41%), followed by monsoon (32%). The leaf size spectra results showed dominance of microphylls, over nanophylls and leptophylls. The results would be significant in establishing plant conservation strategies in Pakistan, especially due to over-exploitation of medicinal plants and the negative effects of climate change make it imperative to protect them on prior basis.