Current vegetation structure and composition of woody species in community‐derived categories of land degradation in a semiarid rangeland in Kunene region, Namibia

Abstract

Land degradation has put the world's rangelands under intense pressure and reduced their capacity to provide vital services to those who solely depend on them for survival. With the current pressures on rangelands, worldwide, there is an urgent need to survey the present condition of rangelands. Such detailed surveys can identify where improvement programmes can be emphasised; whether it be reseeding, stock control, sociological restraints or other actions. To combat rangeland degradation, management systems are more effective when they account for community perceptions and practices. This study aims to assess the current status of woody plants in different categories of degradation as perceived by herders in Kunene, Namibia. Furthermore, we wished to compare the perception of degradation by herders with the measured ecological condition. With the help of herders, sites representing different categories of degradation (low, moderate, high and protected) were identified and 10 plots of 400m 2 each were established in each category. Species diversity, density, basal area and regeneration of woody plants increased sequentially along the degradation gradient (high to low). Vegetation attributes such as species diversity, seedling density and standing basal area increased with increasing distances from the villages. Although the herders' perception of degradation, for high and moderate degradation, matches the ecological results, the low degradation sites show signs of bush encroachment, a type of degradation that the herders did not perceive as degradation. Colophospermum mopane, a known encroacher species across Namibia, was the dominant species in the moderate and low degradation sites. Pechuel-loeschea leubnitziae, which is also known to be an indicator of degradation, was the dominant species in the high degradation sites. The findings highlight the present and future threats the study area is facing and form the basis for current restoration research.

Impact of Human Settlements on Diversity of Range Vegetation

“…A study conducted in Nama-Karoo rangelands revealed twice as many species at sites near human and animal populations as compared to sites far from human population [53]. It is an established fact that the sites having higher degradation are usually dominated by one or two species, while the sites having lower degradation depict higher diversity [54]. These results corroborate with the current study, as the sites near to human populations were dominated by a single species making up most of the individual plants, while the sites away from population had more variety in terms of grazing species.…”

Precipitation, vegetation productivity, and human impacts control home range size of elephants in dryland systems in northern Namibia

“…Anthropogenic disturbances have caused significant changes in vegetation structure and composition in Kunene, which will only further degrade the landscape without intervention (Inman et al, 2020 ). Degradation and restriction of movement could further endanger this population.…”

Assessing Extensive Semi-Arid Rangeland Beef Cow–Calf Welfare in Namibia: Part 1: Comparison between Farm Production System’s Effect on the Welfare of Beef Cows

“…It may be that the discrepancy lies in the effects of phosphate deficiency [ 30 ], which is widespread, but whose distribution and severity varies between the different areas included in the present study. For example, sandy soil around Okakarara areas has significantly lower phosphate than that at the harder and drier sand around Opuwo area (3.35 mg P/kg; [ 17 ], vs. 12.4 ± 1.7 mg P/kg; [ 20 ]), while the available soil phosphorus threshold is intermediate (≤ 10 mg kg -1 DM; [ 30 ]). A comprehensive investigation in the suspected phosphate deficiency related deaths of cattle is warranted and would help to unravel this question.…”

“…From the selected eight villages, a selection of 2–5 herds per village farm was included in the study (total n = 18 herds; Table 1 ). The area vegetation is classified as mopane savannah with shrubland-woodland mosaic vegetation partly with rocky and bare mountains [ 20 ]. Annual rainfall in the area ranged between 50–320 mm (~2/3 in January–March) and average annual temperature was 21.6 °C; ranging from 10 °C in winter to 30 °C in summer [ 18 ].…”