Climate change threatens Namibia's desert plants
Study reveals 90% decline in Euphorbia damarana amid climate crisis
The findings are concerning, as it could threaten the survival of several animal species that feed on these plants, especially during drought periods.
The global temperature rise due to climate change has made it difficult even for specialised, desert-adapted plant species to survive.This is the finding of a new study on three species of Euphorbia (milk bush) from different parts of Namibia's arid regions.
Professor JJ Marion Meyer and his team compared aerial images from 1967 to 1969 with current satellite images to determine whether the Euphorbias that existed at that time are still alive today.
They found a shocking decline of 90% in Euphorbia damarana near Brandberg in the north-west, 88% in Euphorbia gregaria near Klein Karas in central southern Namibia, and 61% in Euphorbia gummifera near Garub in the south-west. This is concerning, as it could threaten the survival of several animal species that feed on these plants, especially during drought periods.
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During a field visit to verify these results, they found only very few (0-5) Euphorbia seedlings at any of these sites. Additionally, they noted that Euphorbias growing on rocky soil thrive better than those on dunes, possibly because sandy soils retain little water after rainfall.
"During the soil examination of the deceased Euphorbia species, bare circular patches (fairy circles) were repeatedly observed, where their remains were found. The dead plant remains found in these newly formed fairy circles could be clearly identified as Euphorbia species based on their morphology and analyses," the study states.
Meyer and his team have hypothesised that the fairy circles are caused by dead Euphorbia damarana and other large succulent Euphorbia species.
The results are interpreted against the backdrop of temperature changes recorded in these areas since 1950, which show an increase of 2°C at midday and an average annual rise of 1.3°C, higher than the global increase of 1°C during the same period.
This study complements previous work showing that Welwitschia and quiver trees are threatened by climate change, as their current ranges are becoming too hot and dry for even these desert dwellers to thrive.