Category: Genetic erosion

There were two interesting articles about trees in Kenya in the Money section of this morning’s Daily Nation. Not online, though, so I’ll have to summarize. One piece describes how farmers in Nyeri are adopting a number of short-statured mango varieties from South Africa and Israel, apparently including things called Apple, Kent, Vydke and Tommy. This is not a mango-growing region, but these particular varieties have been found to be a good fit on the small farms of the area, to yield heavily and early, and to be good for juice. So now there’s no need to truck mangoes in from the coast. Good for Nyeri farmers, perhaps not so good for coast farmers? This may not be a zero-sum game: I don’t know enough about the supply of, and demand for, mango in Kenya to predict what will happen, but I would try to conserve those coastal varieties ex situ somewhere just to be on the safe side.

Then there was also a piece on how the Tree Biotechnology Project has been successful in cloning a number of indigenous trees (including for example Prunus africana, whose bark feeds a large international market for a prostate cancer drug) and providing planting materials to farmers. It seems previously the project’s focus has been on eucalypts. This is expected to take pressure off wild populations and contribute to reforestation, but there was nothing in the Daily Nation article about the downside of planting large areas of genetically identical clones. However, this is clearly a problem the project recognizes, as you can see for example by reading on page 28 of this brief on some of its activities:

Planting large areas of single clones will have the effect of decreasing rather than increasing biodiversity, and the risk of narrowing the genetic base needs to be managed to avoid growing pest and disease problems. Mondi has a policy to restrict planting of a single clone to no more than 5% of any planting area, and the project is adhering to this policy. In order to maintain biodiversity, the project team will select a wide range of local tree species of economic value and will feed these into the clonal production system through adaptive tissue culture research. Once the capacity to adapt the techniques of micro-propagation to different species is fully in place, there will be great potential for the project to multiply and disseminate a wide range of improved germplasm of different tree species, including those that are under threat of over-exploitation and extinction, such as ebony.