. Insect and disease conditions in the United States, 1979-83 : what else is growing in our forests?. Forest insects United States; Trees Diseases and pests United States; Plants Disease and pest resistance. Spruce Budworm anadromous fish, such as salmon and trout, that require cool water when they swim upstream to spawn. The impact of defoliation on recreation is not as great as on other resources: there are few campgrounds and picnic areas in spruce-fir stands. More often, recreation areas are in hardwood stands. Trend From 1979 to 1983 Defoliation has fallen since the current outbreak peake
. Insect and disease conditions in the United States, 1979-83 : what else is growing in our forests?. Forest insects United States; Trees Diseases and pests United States; Plants Disease and pest resistance. Spruce Budworm anadromous fish, such as salmon and trout, that require cool water when they swim upstream to spawn. The impact of defoliation on recreation is not as great as on other resources: there are few campgrounds and picnic areas in spruce-fir stands. More often, recreation areas are in hardwood stands. Trend From 1979 to 1983 Defoliation has fallen since the current outbreak peaked at million acres ( million ha) in 1978. In 1979, defoliation declined (table 1 and fig. 4). Although the outbreak peaked in 1978, tree mortality lags 2 to 5 years behind severe defoliation. Heavy losses began in the New England States about 1981. During 1982, 50 percent—or more—of the trees in an area of approximately 240,000 acres Table 1. Number of acres of all ownerships defoliated by the spruce budworm in the Northeastern United States from 1979 to 1983 Region/ State 1979 1980 1981 1982 1983 New England: Maine New Hampshire Vermont Lake States: Michigan Minnesota Wisconsin Total Acres 5,900,000 5,000,000 4,000,000 3,800,000 6,000,000 70,000 90,000 42,000 39,000 5,800 101,923 110,715 96,466 153,852 178,086 258,822 150,000 141,300 859,500 103,000 439,000 161,000 110,000 84,000 129,140 126,700 0 145,952 127,000 20,920 6,622,045 6,602,215 4,493,466 4,248,692 6,477,758 Source: Aerial surveys conducted by the USDA Forest Service and State agencies. The USDA Forest Service data compiled by the Northeastern Area, St. Paul and Durham Field Offices. (97,200 ha) in Maine were killed by spruce budworm. On another 300,000 acres (121,500 ha), 10 to 25 percent of the trees were dead, killed by spruce budworm. In 1983, budworm-caused mortality Figure 4. Areas of budworm-caused defoliation in the United States from 1979 to 1983. 1979 1980 1981. Please note that these images are
Size: 1859px × 1345px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionameri, bookcollectionbiodiversity
