Endangerment of Plant Genetic Resources
Wild plant genetic resources are primarily at risk from disturbance, stress, fragmentation and loss of habitats, partly as a consequence of encroachments from settlement and transport. Risk factors include eutrophication of soil and waterbodies, pollutant inputs, a drop in groundwater level and land consolidation. The impacts of climate change and increased UV radiation have been difficult to assess so far. Changes in agricultural practices and the abandonment of farming have posed and still pose the greatest risk to domesticated plant genetic resources.
The range of cultivated species is subject to ongoing change. At variety level, old varieties are constantly replaced by new ones. The FAO estimates that in the course of the last century, some 75 % of the genetic variability of crops has been lost world-wide (gene erosion) and the loss of wild plant populations continues apace.
For important agricultural crops part of the disappearing diversity is safeguarded via ex situ conservation in genebanks. For many other crops the disappearance of varieties in cultivation implies the irrecoverably lost of genes, gene combinations and therefore of genetic diversity.