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Juniper Management Effectiveness Monitoring

Overview

In the late 1990s OWEB began providing grants to fund watershed restoration projects, including those controlling western juniper. In recent years there has been a growing interest in controlling juniper in order to improve forage production for grazing livestock, restore hydrologic function to rangelands, and protect sagebrush habitat. This increased awareness of the negative impacts of juniper expansion has resulted in a steady rise in the number of grant applications for juniper removal and management projects. Because OWEB's limited available funds and the seemingly unlimited acres needing juniper treatment in central and eastern Oregon, OWEB contracted with CSR Natural Resources Consulting, Inc. (NRCI) to complete several juniper removal studies and to provide educational opportunities to OWEB staff, Regional Review Team (RRT) members, Soil and Water Conservation Districts (SWCDs), and Watershed Councils (WCs).

Please see the Documents section for the Field Guide and for reports relating to each heading below.

CSR NRCI developed a field manual that provides guidance to OWEB Field Representatives and technical review teams, SWCDs, and WCs for identifying and designing OWEB-funded juniper treatment projects. The final document was submitted to OWEB in September 2007 and was then reviewed and field tested by OWEB staff, Regional Review Team members, and SWCD and WC staff.

CSR NRCI monitored the effectiveness of juniper removal projects. Evaluations occurred in 2006 and 2007 in Wheeler and Crook counties for Phase I and in Klamath, Lake, Harney, and Grant counties for Phase II. Juniper treatment sites were evaluated using the rangeland health assessment, vegetation and soil surveys, and when possible a “control” or untreated adjacent juniper site. Results of both Phase I and II evaluations demonstrated the variability of treatment types and levels of success among OWEB juniper removal projects.

General recommendations developed based on both evaluations include:

  1. Conduct juniper management workshops and provide a juniper management document for OWEB regional staff, RRT members, SWCDs, and WCs.
  2. Provide technical assistance when possible to landowners and grantees developing juniper management projects.
  3. Continue to support juniper monitoring and research at both the project and watershed scale.

CSR NRCI contrasted past management methods of western juniper (Juniperus occidentalis) with an emerging ecologically based, landscape-scale approach that addressed the site-specific treatment needs of a watershed in which juniper had encroached or was in the process of in-fill.

The report details the geologic history, climate, soils, potential, and vegetation of the Crooked River Watershed of Central Oregon and reviews juniper control efforts conducted over a stretch of 60 years. A discussion of the emerging science, ecological principles, and landscape-scale approach to watershed prioritization is intended for use in developing a strategy for the enhancement of the semi-arid watersheds of Oregon. The report concludes with a set of recommendations aimed at stimulating an acceleration of cooperative landscape-scale projects in the region and the State.​

In 1994, the Camp Creek Paired Watershed Study was initiated to provide long-term, verifiable data that would be collected systematically to test the hypothesis, “Does the removal of western juniper change the hydrologic function of a watershed?" ​This study occurred in 2 adjacent watersheds of about 260 acres each, Mays and Jensen, located about 60 miles southeast of Prineville, Oregon. Approximately 20% of the total study area is in private ownership with the remainder under the management of the Prineville District, Bureau of Land Management. In October 2005, following 11 years of monitoring various parameters (vegetation, groundwater, spring flow, soil moisture, etc.), all “post-European aged trees” (those less than 140 years old) were cut in the Mays watershed. The trees in Jensen were left uncut; thus, Jensen became the “control” watershed.​​

In October 2022, the OWEB Board funded an open solicitation monitoring grant for OSU to meet the needs to maintain this long-term watershed-scale monitoring effort. At 20 years post-treatment, partners are at a critical time to improve the understanding of the expected longevity of the treatment and identify critical thresholds that warrant discussing adaptive management strategies to maintain the health of restored ecosystems. This recently funded project aims to assess the long-term effectiveness of juniper stand reduction on soil, water, and vegetation variables in the treated areas compared to the untreated. Funding will also help to replace failing equipment and install an enhanced sensor network to continue monitoring the hydrological response to juniper removal. The main partners for this project are the OSU Department of Animal and Rangeland Sciences, Crook County, BLM-Prineville District, Hatfield Hyde Land Trust, and OSU-Extension.

Contact

Please direct questions or comments to Ken Fetcho, Effectiveness Monitoring Coordinator, 971-345-7018.

Documents

Field Guide

Removal Project Evaluation

Crooked River

Camp Creek

Herbicide Application