A point-in-time inventory of chikanda orchids within a wild harvesting wetland area in Mwinilunga, Zambia : implications for conservation

Abstract

Despite continued wild harvesting, there is limited data that provides estimates on the availability of African edible orchids as a resource, and that identifies the ecological drivers of their dynamics. This study was designed to investigate the relationship between distance from surface water and the diversity, frequency, and population density of chikanda orchids in a harvesting wetland in Mwinilunga, Zambia. Vegetation sampling was conducted using an interrupted belt transect design. Eight 50 m transects were systematically placed and positioned perpendicular (90o) to a stream within three separate orchid communities. Individual plant count was recorded within the 0–10 m, 10–20 m, 20–30 m, 30–40 m, and 40–50 m distance zones. Results showed a statistically significant decrease in the Shannon’s Diversity Index between the distance zones in all three communities (p < 0.05). Mean ranks for orchid taxa frequency and density across the distance zones were significantly different for communities 1 and 2 but not 3 and communities 1 and 3 but not 2, respectively. However, there was a medium to large effect size for distance on frequency and a small to large effect size for distance on density in all three communities. These results suggest that distance from surface water influences the frequency and density of orchid taxa occurring in wetland ecosystems. This implies that for conservation purposes, it may be important to focus on areas close to water when establishing orchid sites for the species investigated in this study.