Lessons Learned from Riparian Restoration Update on Cottonwood Pole Planting

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1 March 1, 2017 Lessons Learned from Riparian Restoration Update on Cottonwood Pole Planting Colorado Plateau Native Plant Program Annual Meeting Shannon Hatch Tamarisk Coalition

2 Our Vision TAMARISK COALITION Restore Connect Innovate We envision healthy and self-sustaining riparian ecosystems throughout the American West resilient to invasive plant species and supported by enduring communities of stewards Mission Advancing the restoration of riparian lands through collaboration, education & technical assistance

3 Our Partners Agencies and organizations Land managers Private citizens Universities, colleges Nonprofit organizations Foundations Watershed groups

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5 Who and what is the DRRP? One River. Many Hands. Goal Shifting the riparian corridor towards a healthier, more selfsustaining path

6 DRRP Project Area 200 miles of the Dolores River and its tributaries in southwestern Colorado & eastern Utah 2 states, five counties, 4 BLM field offices, and 30+ private lands

7 What has the DRRP done? 1. Removed over 1,500 acres of tamarisk 2. Conducted over 500 acres of plantings 3. Hired and trained nearly 300 young adults through Conservation Corps programs 4. Raised over $6.5 million towards restoring the riparian corridor to a healthier state

8 How are we restoring the riparian corridor to a healthier state? Planting native grasses, shrubs, forbs, and trees Documenting lessons learned through Science & Monitoring Subcommittee

9 Cottonwood pole planting suitability assessment Potential for (re-) establishment of cottonwoods in tamarisk removal sites Pole plantings in sites meeting pre-determined threshold conditions

10 Cottonwood pole planting suitability assessment Criteria: Groundwater depth < 9 feet (length of corer) Groundwater and soil salinity < 4 ms > 2 feet dry soil Soil texture 21 sites visited, 14 sites chosen 231 holes sampled 123 poles planted 7 groundwater wells installed

11 Cottonwood pole planting suitability assessment Dr. Cynthia Dott from Fort Lewis College completed study to determine survival factors Close to 50% survival after first year; however, Of 62 with identifiable pit data, 43 were dead Thus small sample size for living trees (19)

12 Water Depth in Well (ft) Cottonwood pole planting suitability assessment - Results Expectations: 1) Groundwater depth will be key! Water table depth at planting (ft) (P=.405) Dead Slide Dr. Dott Alive

13 Cottonwood pole planting suitability assessment - Results Expectations: 2) Soil texture will be key! Because clay-rich soils will limit permeability & thus water infiltration But no; based on these data there were no differences in survival of poles in 3 soil categories: Clay-dominated Loamy Sand-dominated Slide Dr. Dott

14 Soil Salinity (ms) Water Salinity (ms) Cottonwood pole planting suitability assessment - Results Expectations: 3) Soil/water salinity will be key? Bottom soil salinity (ms) (P<.001) Pit water salinity (ms) (P=.001) Dead Alive Dead Alive Slide Dr. Dott

15 Cottonwood pole planting suitability assessment - Conclusions No Surprise: Soil salinity in planting holes a key limiting factor Surprise: Soil salinities below the 4mS threshold were still too high (even >1.5 ms) Additional Surprise: Groundwater depth not implicated BUT Slide Dr. Dott

16 Cottonwood pole planting suitability assessment - Conclusions GW data very limited Study initiated during severe, prolonged drought If water was limiting for ALL poles, increasing sensitivity to other stressors..like salinity Slide Dr. Dott

17 Resources DRRP Restoration Resource Dryland Restoration Guide

18 Cross Watershed Network XWN is a peer-topeer learning network that provides virtual and in-person venues to connect watershed practitioners to their peers across boundaries in the arid West.

19 THANK YOU. CONTACT Shannon Hatch DRRP website: drrpartnership.org