US Forest Service Research and Development How do Mastication and Thinning Treatments Impact Pinyon-Juniper Ecosystems? - Rocky Mountain Research Station - RMRS - US Forest Service

  • Rocky Mountain Research Station
  • 240 West Prospect
  • Fort Collins, CO 80526
  • (970) 498-1100
USDA US Forest Service
Home > Research Highlights > Mastication Impacts
 

How do Mastication and Thinning Treatments Impact Pinyon-Juniper Ecosystems?

Pinyon-juniper woodlands are a dominant vegetation type throughout the western United States. Woodlands traditionally have been viewed as having a low risk of wildfires because of the lack of ground cover and low stand densities. However, stand densities can be high and wildfires will occur naturally given conditions of low hunmidity, high teperatures and wind speeds, and an ignition source. Pinyon-juniper woodlands are found adjacent to cities, towns, and rural developments throughout the Southwest. Drought and insect infestations have resulted in high pinyon mortality increasing fuel loadings and the risk of wildfires. Managers are attempting to reduce stand densities in the wildland-urban-interface areas by thinning trees and piling and burning slash or by using heavy equipment to mechanically masticate dead trees and to reduce densities of live trees. Mastication treatments are being conducted in woodland and forests throughout the West but have not been fully studied to determine the impacts on these ecosystems. However, there are concerns that mastication, which leaves a large amount of woody material on the soil surface, will adversely affect soil nutrient dynamics and soil microbial communities. Will masticated area be readily occupied by non-native invasive species? How do the impacts of mastication compare with traditional but more expensive thinning treatments?

A study has been developed by scientists from RWU-4651 and 4302 in cooperation with land managers at the Forest Service-BLM Dolores Service Center to evaluate mechanical mastication and thinning-piling-burning treatments on pinyon-juniper woodlands in southwestern Colorado. The study was initiated in August 2005 and is funded by the Joint Fire Science Program. The design consists of three blocks located throughout the District, each containing three 35-acre plots, one masticated using a hydro-mow machine, one thinned using chainsaws and one left as a control. Pretreatment sampling of the overstory, understory and soil characteristics was completed in the fall of 2005 and the plots were treated in the fall 2005 and winter 2006. The current activities in the summer of 2006 have to resample the stand and soils to determine the immediate impacts of the treatments, and to set the basis for evaluations in 2007.

Rocky Mountain Research Station
Last Modified: Monday, 28 April 2008 at 17:17:03 EDT (Version 1.0.5)