Threats To Agricultural Biodiversity

Source: Food and Agriculture Organization of the United Nations, 2013, Ruth Raymond and Amanda Dobson, Bioversity International,   "The Youth Guide to Biodiversity" 1st Edition (Chapter 9) Youth and United Nations Global Alliance. Reproduced with permission.

Chapter 9. Verbatim.

With the advent of modern agriculture, untold numbers of locally adapted crop varieties were replaced by genetically uniform, high-yielding modern varieties. In China, for example, between 1949 and 1970, the number of wheat varieties grownby farmers dropped from about 10 000 to 1 000. Farmers in India once grew 30 000 rice varieties.

Today, 75 percent of India’s rice crop comes from just 10 varieties. Only 20 percent of the maize varieties known in Mexico in 1930 can be found there now. Overgrazing, climate change and changes in land use are also taking a toll on the diversity still available in the wild relatives of crops and other wild species.

Extinction is a natural process. Species have emerged,flourished, and died out over the ages. What is alarming is that, due mainly to human activity, today’s rate of extinction is thousands of times greater than the rate at which new species appear. This threatens the life-sustaining systems of our planet.

The Impact Of Climate Change

As the world’s human population increases, environmental problems are intensifying. Climate change may bring about drastic changes in the world’s ecosystems and threatens to destabilise weather patterns, leading to an increase in the incidence of severe storms and droughts.

Agricultural biodiversity is our best hope for dealing with the threat that climate change poses to agriculture. Farming systems will definitely have to adapt as weather patterns change. The good news is that the most diverse farms – those that have and use the most diversity – will be better able to withstand the shocks and unpredictability of climate change. 

Using agricultural biodiversity to develop crop varieties that can withstand high temperatures or that are  drought-tolerant could help farmers deal with the effects of climate change, allowing them to grow their crops even as conditions get harsher.

The bad news is that climate change will have an impact on what we grow and where we grow it. The consequences could be dire for people living in the most vulnerable regions of the world. Recent research found that by 2055, more than half of the 43 crops studied – including cereals such as wheat, rye and oats – will lose land suitable for their cultivation. This loss  will be particularly large in sub-Saharan Africa and the Caribbean, regions that have the least capacity to cope. And wild crop relatives – an important source of diversity – are also at risk. 

In 2007, scientists used computer modeling to predictthe impact of climate change on the wild relatives of staple food crops. They found that, in the next 50 years, as many as 61 percent of the 51 wild peanut species analysed and 12 percent of the 108 wild potato species analysed could become extinct as a result of climate change.