This section explores the tools available to land managers for combating conifer encroachment. Scoll down the page to read each sub-section, or click the Land Management Tools drop-down navigation to go diretly to a sub-section.
Begin by watching the video below to hear Jeremy Maestas (Sagebrush Ecosystem Specialist, USDA Natural Resource Conservation Service) introduce tools available to land managers for addressing conifer encroachment.
There are a variety of tools available to address the problem of conifer encroachment, both on the desktop and in the field. From the desktop or before going out into the field, very important data layers are now readily available from the Sage Grouse Initiative (http://map.sagegrouseinitiative.com/).
Select a tab below to learn about some of the available layers.
This product provides a high-resolution estimate of tree canopy cover on a per acre basis. Data are in 1m spatial resolution suitable for analysis in a GIS.
Thematic raster data represents tree canopy cover (% cover per acre) in the following classes:
This product represents the probability of cultivation relative to climate, soils, and topography. Independent models were produced for each county and county-level predictions were merged for state coverage. Thematic raster data represents risk in seven classes from low to high.
The Field Guide for selecting the most appropriate treatments recommends considering the following questions to determine which areas to treat (Miller et al. 2014). Click on each question for additional detail.
Generally speaking, areas with higher resilience and resistance have a higher probably of success of any given treatment compared to areas with lower resilience and resistance. Lower resistance and resilience sites may require additional treatments or follow-up.
Areas in PACs or near occupied habitat, specially designated areas such as focal areas, sage-grouse leks, brood-rearing habitat, or winter range should be higher priorities for treatment. Local knowledge on which areas are important can also be very useful in identifying the importance of an area.
Using conifer treatments to create areas of suitable habitat that link otherwise isolated populations is very helpful on a landscape scale.
Leaving juniper debris on the ground after mechanical treatments can intercept runoff and increase infiltration, as well as reduce evaporative loss of soil water (Miller et al. 2007).
Examples of cost-benefit matrices are Table 1 from GBFS #4, “Common conifer treatment options, costs, and trade-offs” or SageSTEP “Guide to Vegetation Treatment Costs for Land Management in the Great Basin Region".
Retreatment is more likely on low resistance and resilience sites.
Many restoration treatments by either mechanical means or prescribed fire require adequate post-treatment grazing management to be successful.
Begin by watching the video on the right to hear advice on conifer removal from Jeremy Maestes.
To help with determining treatment sites consider using maps of tree cover, combined with lek locations to help identify areas to target.
For example, this figure shows a map delineating potential treatment areas in central Oregon (from Great Basin Fact Sheet #4). Areas with high conifer cover are shown in purple and dark blue and known lek locations are indicated with a green dot. Potential treatment areas, outlined in the black and white lines, have been specifically delineated to be near known lek locations and to encompass areas with a low % of conifer cover. The references cited earlier suggested these areas will have the highest probability of success in terms of restoring habitat value for sage-grouse.
Once the treatment areas have been identified, there are a variety of tools that may be used for treatment of conifer encroached areas.
Before exploring the various tools, listen to Rick Miller describe the tools for managers dealing with conifer encroachment.
Mechanical tools that surgically remove trees while retaining the shrub community and understory cover are the best options. Mechanical tools include chipping, shredding, and combinations of these tools. In general chaining is not recommended as it often causes sagebrush removal as well.
Advantages of Mechanical Treatments:
Disadvantages of Mechanical Treatments:
When to use Mechanical Treatments:
(Miller et al. 2014)
Prescribed fire is a tool for controlling conifer expansion. Key considerations include the extent of treatment, site resilience, species composition, and spatial distribution of fire. While prescribed fire is a cost effective tool for greatly reducing woodland cover, the full restoration of shrub-steppe communities from mature woodland is a long-term process. Mechanical removal of conifers where sagebrush is still intact can produce more immediate benefits for sagebrush wildlife and should be considered first.
Watch Jeremy Maestas explain when to use prescribed fire as a treatment.
Advantages of Prescribed Fire:
Disadvantages of Prescribed Fire:
When to use Prescribed Fire:
(Miller et al. 2014)
Deciding not to treat is an acceptable decision in some cases! For example:
Click Case Studies to review land management actions in practice.