Edge species :
decrease biodiversity.
only exist in areas that have been altered by humans.
require the unique homogenous edge environment.
may require conditions found in both of the bordering ecosystems.
The conference on 'The human environment' held from 5 to 16 June 1972 was held in :
Stockholm, Sweden
Tbilisi, Soviet Union
Rio de Janeiro, Brazil
Kyoto, Japan
What was the stump jump plough’s innovation?
Improving wheat yields
Revitalising the industry
Fertilizing the soil
Genetic modification