Abstract

MLONZI, Voice  and  RUWANZA, Sheunesu. Role of Vachellia karroo as a nurse plant in old fields targeted for passive restoration. Bothalia (Online) [online]. 2024, vol.54, n.1, pp.1-13. ISSN 3078-8056.  https://doi.org/10.38201/btha.abc.v54.8.

BACKGROUND: In degraded environments such as old fields, nurse plants can facilitate the growth of targeted restoration plant species by ameliorating extreme environmental conditions, creating nutrient-rich microclimates and protecting recruiting plants from grazing. AIM & OBJECTIVES: This study examined the role of Vachellia karroo (Hayne) Banfi & Galasso as a nurse plant on soil physical and chemical properties and vegetation diversity in old fields targeted for passive restoration at the Tanglewood research farm in the Eastern Cape, South Africa. METHODS: Soils were quantified for physical and chemical properties in 48 plots measuring 25 m² (5 × 5 m) that were located under and outside 24 V. karroo nurse plants in old fields. In addition, detailed vegetation surveys were conducted in the above-mentioned plots. RESULTS: Our results show that soil total nitrogen (N) and carbon (C) concentrations were higher under than outside V. karroo nurse plants. Soil penetration resistance and water-repellency levels were lower under than outside V. karroo nurse plants, however, monthly variations were also observed. Species richness and Shannon-Wiener diversity were higher under than outside V. karroo nurse plants, with species such as Searsia crenata, Azima tetracantha, Asparagus africanus and Opuntia sp. frequently occurring under V. karroo nurse plants. CONCLUSION: The study concludes that V. karroo nurse plants have a positive effect on some soil physical and chemical properties and vegetation diversity. It is recommended that V. karroo needs to be included in future old field restoration strategies if passive restoration at Tanglewood research farm is to be successful.

Keywords : nurse plant syndrome; ecological restoration; plant-to-plant facilitation; pioneer plants; soil nutrients.

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