84 William C. McComb and Robert L. Rumsey 



Picloram-based herbicides are desirable for creating forest openings 

 because of their low toxicity to many vertebrates (Kenaga 1969), but we 

 could find no studies that compared bird use of picloram-created clear- 

 ings with use of clearcut or uncut areas. Our objectives were to: 1) com- 

 pare the relative abundance and diversity of winter birds and breeding 

 birds among 4-year-old herbicide-created forest clearings, 4-year-old 

 clearcuts, and mature untreated areas, 2) evaluate the effect of edge 

 creation on bird use of habitats, and 3) identify the characteristics of 

 habitats used by common species. 



STUDY AREA AND METHODS 



Snag Ridge Fork watershed, in the University of Kentucky's 

 Robinson Forest, Knott and Breathitt counties, Kentucky, contains a 

 second-growth mixed-mesophytic forest typical of much of the central 

 Appalachians (Carpenter and Rumsey 1976). Ridges are dominated by 

 shortleaf pine, Pinus echinata\ pitch pine, P. rigida; chestnut oak, Quer- 

 cus prinus; and scarlet oak, Q. coccinea. South-facing slopes are domi- 

 nated by hickories, Carya spp.; white oak, Q. alba; black oak, Q. velu- 

 tina; and sourwood, Oxydendrum arboreum. North-facing slopes are 

 dominated by northern red oak, Q. rubra; cucumbertree. Magnolia 

 acuminata; and yellow-poplar, Liriodendron tulipifera. 



Fifteen of 18 0.4-ha square plots were treated in the watershed. 

 This included four plots on each of a north-facing slope, south-facing 

 slope, and ridge-top, which were randomly assigned one of the follow- 

 ing hand-broadcast herbicide treatments applied in May 1976: 23 kg/ ha 

 TORDON 10k; 45 kg/ha TORDON lOK; 68 kg/ha TORDON lOK; or 

 90 kg/ ha M-3864. TORDON lOK is a pelletized picloram-based (10% 

 4-amino-3,5,6-trichloropicolinic acid) herbicide and M-3864 is a 5% pic- 

 loram pellet. (Mention of trade names is for identification and does not 

 imply endorsement by the Kentucky Agricultural Experiment Station, 

 Lexington.) A fifth plot on each aspect was clearcut (all stems cut, no 

 residuals); fallen trees were not removed. A sixth plot on each aspect 

 was established as a control in the untreated forest at least 75 m from 

 any treated plot. Plots were located along the contour, and treated plots 

 were 15 m to 50 m apart. 



Fifteen stations were established perpendicular to the contour 

 through the center of each plot. Thirty environmental characteristics 

 (Table 1) chosen based on Anderson and Shugart (1974), Stauffer and 

 Best (1980), and Crawford et al. (1981) were measured at each station. 

 Estimates of cover of rocks, logs, leaves, canopy, and midstory followed 

 methods described by James and Shugart (1971). Environmental char- 

 acteristics other than understory vegetation were measured in May 

 1980. Understory vegetation was quantified on one 4-m^ circular plot 

 (radius = 1.2 m), 2 m away from each station along the contour in 



