It was over two years ago that we mentioned a meta-meta analysis of ecoagriculture. Since then we’ve had Prof. Olivier de Schutter, the U.N. Special Rapporteur on the right to food, weighing in, among other celebrities. Now David Suzuki, no less, tells us about yet another review, with much the same bottom line:
…our review supports the claim that the solutions to the problems of widespread food insecurity and biodiversity loss need not be mutually exclusive, and that it may be possible to address both using appropriate alternative agricultural practices.
Here I just want to throw something else into the mix. We know from yet another recent meta-analysis that there are recognizable socioeconomic patterns to the distribution of infraspecific crop diversity on farm. A study has just been published which suggests that the number of species cultivated by a traditional society can be predicted by latitude, environmental heterogeneity (mainly altitude), and the commitment of the society to agriculture (as opposed to herding, foraging and exchange). Does this mean there are some intrinsic limits to the level of intra- and inter-specific agrobiodiversity a given agricultural system will support? And if so, what does that mean for ecoagriculture in that region?
Luigi: The prediction of diversity based on latitude and altitude for crop species is the same as for all species. The higher you go or the closer to the poles, the fewer wild species of plants and animals. I’m not sure there is a generic explanation for this – but it seems the greater the environmental stress, the fewer are the species/crops that are adapted. One result of getting close to the ecological limits is monodominance – one species capturing all the resources and excluding others. There are lots of examples of this, particularly for grasses. It is possible to argue that, at least, many of our cereals were domesticated from wild monodominant species: easy to gather and perhaps easy to manage once the ecological factors determing monodominance were understood by proto-farmers. I’ve been tinkering with this idea for more than a decade, but there needs to be far more research of the type Dorian Fuller is doing on rice to make progress.
De Schutter’s review is spurious. It depends on Pretty’s analysis of supposed `sustainability’ which has now been morphed into `agroecology’. The bulk of Pretty’s evidence is from average 50ha mixed farms in Latin America, evidence that cannot be transposed to small farms in Africa.