One of the more insidious forms that loss of biodiversity can take is the reduction of genetic diversity within a particular species. The species itself may not go extinct -- in fact, it may thrive, at least for awhile -- but the individual members show little genetic difference, putting them all at risk from disease or environmental stresses that, in a more natural environment, would only harm a fraction of the species. The usual cause of this plant cultivation. But a report out today in the Proceedings of the National Academy of Sciences finds that small-farm cultivation of the jocote plant in Central America has actually protected the species' genetic diversity.
Researchers at Washington University in St. Louis report that farmers and families in Central America actually have saved genetic variation in the jocote (ho-CO-tay), (Spondias purpurea), a small tree that bears fruit similar to a tiny mango. And they've done this by taking the plants out of the forest, their wild habitat, and growing them close to home for family and local consumption. [...] The authors say that, through multiple domestications in arenas such as living fences -- fences made of plants like jocotes -- crops, orchards, trees cultivated in backyards and forests, genetic diversity in the jocote has been preserved.
This points to one of the less-often-recognized values of small farms (vs. large-scale industrial agriculture): greater likelihood of preservation of species diversity. And this kind of genetic resilience is exactly what we want in a time of global environmental change.