Influence of forest zoning on Liana species composition and diversity in Mabira forest reserve, Uganda.

Abstract

Lianas, a polyphyletic guild of woody climbing plants, are an essential component of tropical forests accounting for nearly 25%–35% of the woody species and 10%–40% of all woody stems. Although studies on the ecology of Africa's tropical forests have increased dramatically in recent years, the influence of forest management zoning on lianas is less explored, limiting our understanding of management approaches impact on liana population dynamics in Afrotropical forests. This study explored the influence of management gradient (i.e., zoning) on liana species composition and diversity in Mabira Forest Reserve, Uganda. The general objective of this study was to assess the influence of management gradient (i.e., the difference in management zones) on liana species composition and diversity to inform sustainable forest management practices that prioritize forest ecosystem integrity, biodiversity conservation, and community involvement. Three strata were sampled i.e., (nature conservation, buffer, and recreation zones) and four transects measuring 100m each were laid in each stratum running from the South to the North direction. On each transect, five plots were laid each measuring 50m x 20m, and a total of 60 plots (60,000 sqm) were sampled. Species composition and alpha diversity were computed using the vegan package, and their variation among zones and the influence of environmental factors was determined using regression models in R software. A total of 55 liana individuals belonging to 27 families, and 88 host trees belonging to 32 families were recorded across the studied management zones. Liana species composition significantly varied among the zones (Global RANOSIM = 0.518, p = 0.001), with the lowest dissimilarity being between the Production and Nature conservation zones. Liana abundance and richness did not vary significantly among management zones (p > 0.05). Liana species evenness was lower in the Buffer zone (0.61 ± 0.04) than in the Production (0.75 ± 0.02) and Nature conservation zone (0.79 ± 0.02; F = 10.628, p < 0.001). Liana alpha diversity based on the Shannon-Weiner Index was highest in the Nature zone (1.80 ± 0.05; F = 12.701, p < 0.001) followed by Production (1.60 ± 0.05) and Buffer zone (1.33 ± 0.09). While only species composition varied significantly among the forest management zones (Global RANOSIM = 0.158, p = 0.001)