|Miller, Richard - OREGON STATE UNIV|
Submitted to: Society for Range Management Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: October 1, 2003
Publication Date: January 24, 2004
Citation: Bates, J.D., Miller, R., Svejcar, A.J. 2004. Long-term succession after cutting western juniper [abstract]. Society for Range Management. Paper No. 20. Technical Abstract: Cutting of western juniper woodlands is used to restore shrub and herbaceous productivity and composition in the northern Great Basin. This study assessed successional dynamics for twelve years following juniper cutting. A randomized block design, with four 0.9 ha blocks was developed. Half of each block was cut in late summer 1991. Biomass, cover, and density of understory species were compared between cut and uncut woodland, and were also compared among three zones in the cut treatment; old canopy, under juniper debris, and intercanopy. Total biomass, cover, and density increased (p<0.001) in cut plots over time and were grater (p<0.001) in the cut when compared to woodland controls. Biomass increased from 360 kg/ha in 1993 to 1080 kg/ha in 2003 in the cut treatment. Biomass was 10 times greater in the cut versus woodland control. In the sixth year after cutting (1997), debris and canopy locations were dominated by annual grasses. By 2003 perennial grass biomass was 2 times greater than annual grass in these zones. In intercanopy zones of the cut treatment perennial grasses were the dominate functional group with higher cover and biomass than other functional groups in all years. Shrub cover and density increased (p<0.05) between 1997 and 2003 in the cut treatment. Retaining juniper debris on site did not benefit establishment and growth of perennial grasses when compared to intercanopy and canopy zones. Densities of perennial grasses remained stabe at 10 plants/m2 since 1997. Microsite was an important determinant of successional dynamics in the cut treatment over time.