We simulated a shelterwood forest regeneration treatment by reducing basal area,and monitored the response of an avian community in oak–hickory forest on the southern Cumberland Plateau,northern Alabama,USA.We used f...We simulated a shelterwood forest regeneration treatment by reducing basal area,and monitored the response of an avian community in oak–hickory forest on the southern Cumberland Plateau,northern Alabama,USA.We used five treatments:control(no removal),clear-cut(100%removal),and 25,50,and 75%removal of basal area.Territory mapping was used to quantify bird community between mid-April and July of both 2002 and 2003.Microclimate variables were recorded at each plot.The residual basal area and canopy cover showed three distinct conditions after treatment:closed canopy,open forest,and clear-cut.The microclimate varied among treatments:air temperature was highest in clear-cut plots and lowest in control plots,whereas soil moisture had the opposite pattern.A total of 71 bird species were detected,with 36 of them defending territories.Territory density,species richness,and Shannon diversity index differed among the treatments;the relationship between these bird community indices and the level of basal area removal was quadratic,lowest in the clear-cut plots and highest in the intermediate levels.Although species richness was similar among the control,25,50,and 75%removal treatments,species composition varied.The richness difference among treatments became smaller in the second year post-treatment(2003)with an increase in bird density and richness occurring in the clear-cut plots.展开更多
基金TheresearchwasfundedbygrantsfromtheNationalScienceFoundation (No BSR 90 2 0 5 3 0 ) ,theNationalGeographicSocietyandtheNa tionalParkServicetoFRMandSigmaxiGrant in aid ,USDAForestService,andAlabamaA&MUniversitytoYW
文摘We simulated a shelterwood forest regeneration treatment by reducing basal area,and monitored the response of an avian community in oak–hickory forest on the southern Cumberland Plateau,northern Alabama,USA.We used five treatments:control(no removal),clear-cut(100%removal),and 25,50,and 75%removal of basal area.Territory mapping was used to quantify bird community between mid-April and July of both 2002 and 2003.Microclimate variables were recorded at each plot.The residual basal area and canopy cover showed three distinct conditions after treatment:closed canopy,open forest,and clear-cut.The microclimate varied among treatments:air temperature was highest in clear-cut plots and lowest in control plots,whereas soil moisture had the opposite pattern.A total of 71 bird species were detected,with 36 of them defending territories.Territory density,species richness,and Shannon diversity index differed among the treatments;the relationship between these bird community indices and the level of basal area removal was quadratic,lowest in the clear-cut plots and highest in the intermediate levels.Although species richness was similar among the control,25,50,and 75%removal treatments,species composition varied.The richness difference among treatments became smaller in the second year post-treatment(2003)with an increase in bird density and richness occurring in the clear-cut plots.
