Abstract

BERNER, J.M.; CLOETE, B H.  and  SHUUYA, T.. A baseline assessment of the photosynthetic potential of Welwitschia mirabilis using the JIP-test for monitoring and conservation purposes. Bothalia (Online) [online]. 2021, vol.51, n.1, pp.1-7. ISSN 2311-9284.  http://dx.doi.org/10.38201/btha.abc.v51.i1.9.

BACKGROUND: Welwitschia mirabilis is highly specialised to survive the harsh climate of the Namib Desert. Changes in land use, such as the expansion of mining activities, may endanger their survival. OBJECTIVES: The purpose of this study was to understand the photosynthetic potential of W. mirabilis plants to provide a baseline for future long-term monitoring, and for future comparison to determine plant health status after the onset of mining operations METHODS: The study was conducted in a population of W. mirabilis on the Welwits-chia Plains. Chlorophyll a fluorescence data were used to measure plant photochemical potential and analysed using the JIP-test. RESULTS: Significant differences in the photosynthetic potential was observed for W. mirabilis plants located in different catchments. The partial parameters of the PI_ABS values were also significantly lower, which indicated that all aspects of photosynthesis were influenced CONCLUSION: PI_ABS values can serve as a baseline for future long-term monitoring studies to detect any changes in the health status of W. mirabilis that might result from land use change.

Keywords : chlorophyll a fluorescence; JIP-test; photosynthesis; PI_ABS; Welwitschia mirabilis; Welwitschia Plains.

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