00585nam a2200205   450000500170000000600040001700700040002100800040002502000180002904000090004705000200005610000140007624500650009026000420015530000200019744000650021750000500028265000230033270000240035520221011142848.0000000000  a9780050032039  aUOEL  aGF75b.T58 1990  aTivy, Joy  aHuman impact on the ecosystem /cby Joy Tivy and Greg O'Hare  aEdinburgh :bOliver and Boyd,cc1990.  a243 p. :b ill.  aConceptional frameworks in geographypedited by Marsden W.E.  aincludes bibliographical reference and  index  aEcosystemxEcology  aO'Hare Gregeauthor