Integrating Low-Tech Process-Based Restoration with Invasive Vegetation Management in High Desert and Southwest Riverscapes
Joseph Leonhard1*, John Leary2
1The Nature Conservancy, Grand Junction, CO, USA; joseph.leonhard@tnc.org
2RiversEdge West, Grand Junction, CO, USA; jleary@riversedgewest.org
Riparian restoration often treats low-tech process-based restoration (LTPBR) and invasive vegetation management as two separate interventions. However, a growing number of practitioners are integrating these approaches to achieve synergistic benefits in degraded riverscapes. The Nature Conservancy (TNC), in partnership with the Bureau of Land Management (BLM) and local communities, is implementing coordinated LTPBR and invasive vegetation removal projects across Southeast Utah and Northwest Colorado.
On West Coyote Creek near Moab, Utah, TNC removed invasive tamarisk (Tamarix spp.) prior to LTPBR implementation. After allowing the biomass to cure for over a year, TNC is repurposing the woody material, along with soil and other vegetation harvested on-site, to construct structures that slow flow, spread water, promote native vegetation recruitment, and reduce channel incision.
In Colorado, TNC is working with RiversEdge West, the BLM, and the White River Alliance, a local watershed organization, to restore Yellow Creek, a tributary to the White River near Meeker, applying the same integrated approach. TNC is using cured cut piles from invasive treatments (tamarisk) to build LTPBR structures, adding fresh vegetation as needed to improve sediment capture. Additionally, TNC is using live tamarisk weakened by beetle infestation in structure construction, with ongoing monitoring to assess resprouting. Observations from downstream beaver ponds indicate that inundation may suppress tamarisk regrowth, offering a potential natural control mechanism.
This holistic strategy offers stacked restoration benefits to many wadable streams of the desert Southwest suffering from both invasive species and process-based impairments such as channel incision. A robust body of case studies, monitoring data, and research is still needed to confirm the replicability of this relatively novel approach. TNC and partners are collecting monitoring data and encourage practitioners to experiment with a similar integrated approach to better understand risks and benefits and to develop evidence-based best management recommendations. TNC welcomes input from others working in LTPBR and invasive species control to enhance riparian restoration.