The quiver tree (Aloe Dichotoma) has been declared a particularly endangered plant species at the climate conference in Copenhagen. The International Union for Conservation of Nature and Natural Resources (IUCN) had the quiver tree and nine other plant and animal species added to the 'Red List'. They argued that in southern Namibia quiver trees were dying in large numbers due to rising temperatures caused by worldwide climate change. According to IUCN the mean annual temperature in southern Namibia is about 1.2°C higher today than it was 100 years ago.
| Although climate change on a global scale is a fact, experts feel that the heat theory concerning quiver trees in the south of Namibia still lacks proof. IUCN draws upon a study in which South African researcher Wendy Foden participated. Already years ago Foden advocated the controversial theory that the consequences of climate change had been felt in southern Namibia all along for the past 100 years: it had become hotter, which had caused entire populations of quiver trees to die off. Other researchers criticized that Foden’s theory is entirely based on computer simulations of climate development while long-term data on temperature and rainfall at the sites of dying or dead quiver trees is not provided.
Some botanists who are familiar with the region's flora offer a different explanation for the death of quiver tree clusters: All the trees of the population in question are likely to have germinated at the same time and are therefore dying of old age at more or less the same time. The reason why clusters of trees of the same age exist may be that this plant possibly needs several good rainy seasons in succession to survive the critical phase of developing into a young tree: this stem succulent has to reach a certain height before it is able to store enough water for surviving periods of drought. In Namibia’s arid south, however, the quantity of rain strongly fluctuates from year to year and even between locations. Large gaps between successive generations of plants could thus be |
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Quiver tree: steeled against drought with water storage in the trunk |
explained by the fact that sometimes it takes decades before a given location receives sufficient rain for several years in succession.
. Already several years ago Gondwana started a quiver tree project which includes research and cultivation.