. Current topics in forest entomology : selected papers from the XVth International Congress of Entomology, Washington, , 1976. Forest insects Congresses. Figure 3.—Comparison of stand structure of mountain pine beetle depleted lodgepole pine forest following an outbreak, 1972-73, and three years later, 1975. The difference between the two cruises is greater when the data are converted to board feet volume 5 inches dbh and more: Board feet volume in trees >5 -inches dbh Year Lodgepole pine Live Dead Total 1975 1972 Diff. 5103 4894 +209 7050 6110 +940 12153 11004 +1149 Year Other species
. Current topics in forest entomology : selected papers from the XVth International Congress of Entomology, Washington, , 1976. Forest insects Congresses. Figure 3.—Comparison of stand structure of mountain pine beetle depleted lodgepole pine forest following an outbreak, 1972-73, and three years later, 1975. The difference between the two cruises is greater when the data are converted to board feet volume 5 inches dbh and more: Board feet volume in trees >5 -inches dbh Year Lodgepole pine Live Dead Total 1975 1972 Diff. 5103 4894 +209 7050 6110 +940 12153 11004 +1149 Year Other species Live Dead Total 1975 1972 Diff. 1797 1705 +92 173 835 -662 1970 2540 -570 Year Total Live Dead Total 1975 1972 Diff. 6900 6599 +301 7223 6945 +278 14123 13544 +579 The important factor here is that al- though some trees, particularly lodgepole pine, continued to die (mostly windthrow and secondary insects), there was a net increase of 301 bd. ft., with lodgepole volume increas- ing by more than 200 bd. ft. Now that the stand has stabilized somewhat, and barring a natural catastrophe, gains should continue to outstrip the losses. The implications of this exceptionally heavy tree mortality on forest fire hazard and management is evident. These data eventually will be converted to tons of fuel per acre as criteria for on-the-ground fuel loading and other fire hazard classifications. Table 5 shows the reproduction component as estimated during the 1972-73 and 1975 surveys. The overall level of stocking for all tree species is more than adequate, but personal observations indicate large varia- tions in both distribution and abundance between areas. Some form of supplemental stand examination may be required to specifi- cally identify those areas inadequately stocked or in need of conversion. 38. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfe
Size: 1905px × 1311px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionameri, bookcollectionbiodiversity
