000			022550000a22003130004500
904			_aBCO
905			_aC
908			_aJ
909			_aAS
914			_aFORES
914			_aRIBRE
914			_aSILVI
082	0	4	_a22023
100	1		_9114645 _aSADER, S.A.
100	1		_981770 _aJOYCE, A.T.
260			_c1988
520			_aForest are changes associated with life zones, slope gradients, and transportation networks was examined within the framework of a geographically referenced data base for Costa Rica. Locations of forest boundaries and other landscape attributes were digitized from available map sources. Differential rates of primary forest clearing associated with these variables were derived for four reference periods between 1940 and 1983. Deforestation occurred predominantly in tropical dry and moist life zones during the early reference periods; in intermediate periods, tropical and premountane moist and wet zones were affected. By 1983, only the less accessible high-rainfall zones in rugged terrain retained relatively undisturbed forest. The relationship between total primary forest cleared and slope gradient began as inverse and did not approach linearity until the last reference period, when improved transportation routes had penetrated the northeastern lowland Atlantic region. Road development that provided access to the forest was an important agent of change in all reference periods. By 1977, all major regions of the country had been penetrated by roads, and only high mountain forests were relatively inaccessible. Significant gaps exist in the data base because forest maps represent only broad zones, and location of regenerating forest were not available. The historical data will be used to direct satellite monitoring toward landscapes of predicted change to quantitatively assess forest change dynamics
650	1	4	_9143616 _aDEFORESTACION
650	1	4	_92064 _aCOSTA RICA
691			_9143618 _aDEFORESTATION
691			_aCOSTA RICA _92064
692			_aDEBOISEMENT
692			_aCOSTA RICA
773	0		_tBiotropica (EUA) _d1988 _gv.20(1) p.11-19
040			_aCR-TuBCO _cCR-TuBCO _bEs
245	1	0	_aDeforestation rates and trends in Costa Rica, 1940 to 1983
942			_cANA
003			CR-TuBCO
999			_c55879 _d55879