Chapter 10 biodiversity hotspots an idea first proposed in 1988 by environmental scientist Norman Myers. These ?ecological arks? are areas especially rich in plant species that are found nowhere else and are in great danger of extinction. deforestation the temporary or permanent removal of large expanses of forest for agriculture, settlements, or other uses. ecological restoration the process of repairing damage caused by humans to the biodiversity and dynamics of natural ecosystems. old-growth forest an uncut or regenerated primary forest that has not been seriously disturbed by human activities or natural disasters for 200 years or more. overgrazing occurs when too many animals graze for too long and exceed the carrying capacity of a rangeland area. pastures