Effects of different rangeland management practices on vegetation metrics and wildlife abundance in a semi-closed ecosystem in north-central Kenya

Abstract

Rangelands contribute at least 30% of terrestrial net primary productivity, making them an important part of natural ecosystems despite low and unpredictable rainfall regimes. Rangelands are sensitive to anthropogenic activities, making management interventions key to maintaining forage quality and quantity for wildlife. This study explored the effects of mowing of grasslands and carrying away (MO), prescribed grazing (PG), and unprescribed grazing (UG) on above-ground biomass, basal gaps, and wildlife abundance at Lewa Wildlife Conservancy in Meru, Kenya. Data collection was done 18 months after treatment for PG and MO, while UG was continuous. Treated blocks were selected in a systematic and random way, while adjacent untreated plots acted as controls. Blocks were divided into 100 m × 100 m grid cells using ArcMap 10.8.1, where sampling plots were drawn. T-statistics and analysis of variance (ANOVA) tests were used to test statistical significance. We found a significant reduction in the above ground biomass between MO and its control (t = 4.886, p = 0.003) and between UG and its control (t =5.487, p = 0.007). No significant change was observed between PG and its control (t = 1.192, p = 0.287). MO increased wildlife abundance (t = -4.670, p = 0.003), while PG (t = 0.589, p = 0.583) and UG (t = -0.262, p = 0.803) showed no difference compared to their controls. The mean length of basal gaps between MO and its control decreased (t = 7.069, p = 0.001), while those between UG and its control increased (t = -4.053, p = 0.001), with no effect observed between PG and its control (t = 1.882, p = 0.061). This study recommends the use of mowing of grasslands and carrying away on rangelands as it positively influence the metrics under investigation.