Historical and current forest landscapes of eastern Oregon and Washington Part I: Vegetation pattern and insect and disease hazards.

Abstract

We analyzed historical and current vegetation composition and structure in 49 sample watersheds, primarily on National Forests, within six river basins in eastern Oregon and Washington. Vegetation patterns were mapped from aerial photographs taken from 1932 to 1959, and from 1985 to 1992. We described vegetation attributes, landscape patterns, the range of historical variability, scales of change, and disturbance hazards. Forest cover increased eight percent in three river basins, but remained relatively unchanged in the other basins. Forests became more dense in vertical and horizontal canopy structure as understory cover increased with regeneration, of mostly shade-tolerant species. The distribution of forest age classes and structure has changed, with smaller area in early-seral and old forest stages and greater area in multiple-canopy young and mature stands. The percentage of visible dead trees increased in all river. basins. Landscape pattern has become more diverse and fragmented over time in five of the six river basins. Insect and disease hazards changed little, usually < 10 percent, at the river basin scale because there was considerable variation at the watershed scale, where large changes in hazards were common.

Truffle abundance and mycophagy by northern flying squirrels in eastern Washington forests

“…Potential losses from silviculture or prescribed fire are trivial compared to the large-scale losses of forest that following 5000-60,000 ha stand replacement fires have occurred in the area during the last decade (Gaines et al, 1997). Moreover, dry forest silvicultural practices to restore or maintain stable fire regimes and fuel management also aim to restore single-story large ponderosa pine forests (Hann et al, 1997;Lehmkuhl et al, 1997;Hessburg et al, 1999) and associated wildlife (Lehmkuhl et al, 1994;Wisdom et al, 2000) that have declined during the last century.…”

Tamm Review: Management of mixed-severity fire regime forests in Oregon, Washington, and Northern California

“…The available studies compare vegetation attributes from early and late 20th-century, stereo aerial photographs to determine the key changes in landscape patterns (Everett et al, 1994a(Everett et al, , 1994bLehmkuhl et al, 1994). Huff et al (1995) documented corresponding changes in fuel patterns, potential fire behavior, and smoke production.…”

Dry forests and wildland fires of the inland Northwest USA: Contrasting the landscape ecology of the pre-settlement and modern eras

“…Thereafter, a number of additional qualitative and quantitative assessments were undertaken to detail changes that had occurred in the Inland West Hann et al, 1997;Hessburg et al, 1999a;Huff et al, 1995;Lehmkuhl et al, 1994;O'Laughlin et al, 1993;Perry et al, 1994;SNEP, 1996;USDA, 1993). But forest ecologists and fire scientists were well aware of the importance of historical fires to these environments decades before this time (e.g., see Arno, 1976Arno, , 1980Arno and Allison-Bunnell, 2002;Cooper, 1961a,b;Daubenmire and Daubenmire, 1968;Gruell et al, 1982;Hall, 1976;Morris, 1934a,b;Pyne, 1982;Soeriaatmadja, 1966;Weaver, 1959Weaver, , 1961.…”