Water temperature, flow, and Chinook salmon responses to climate change and riparian restoration in the …and, canopy gaps

Snohomish Basin Salmon Recovery Technical Committee meeting April 6, 2021

Matt Baerwalde, Aimee H Fullerton, Ning Sun, Hongxiang Yan

Funded by With the US BIA additional Tribal support from Resilience WA Dept. of Program Ecology Models Comparisons

Global Climate Ensemble Historical vs. Future

Habitat Management Scenarios River Flow

Water Temperature

1. Spawning 1. Growth 2. Emergence 2. Survival Salmon 3. Movement Salmon Response 4. Growth 3. Phenology 5. Mortality 4. Population resilience 6. Outmigration 10 Global Climate Models DHSVM Website: https://dhsvm.pnnl.gov/

DHSVM GitHub: https://github.com/pnnl/DHSVM-PNNL

Contact: Ning Sun ([email protected]) Channel Width Map Riparian Buffer Width Map

Channel width map was developed based on survey data from Department of Fish & Wildlife (1754 points) and Washington Department of Ecology (41 points). Riparian buffer width map was developed based on ArcMap imagery and field surveys. DHSVM-RBM Predictions Climate Change Effects Riparian Scenarios

We evaluated four riparian vegetation scenarios:

(1) Baseline: existing landscape conditions

(2) Least protective aka Degradation: conservation of high quality riparian areas and degradation of other areas

(3) Partial restoration: conservation of high quality areas and partial restoration of lower quality riparian areas, and

(4) Full restoration: full restoration of all riparian areas Riparian Scenarios Riparian scenario effects Climate change scenarios Individual Based Fish Model Riparian vegetation scenarios

Inputs Model Outputs* DHSVM-RBM spawning & spatiotemporally phenology -explicit incubation water temp. movement & & flow biological growth/size + interactions & spawning bioenergetics WDFW locations mortality survival

*calibrated with empirical data Phenology Fish size Riparian restoration (both partial and full scenarios) benefitted potential yearlings Figure 9. Longitudinal change (future minus historical) in seasonal growth potential. Plots show medians (dark lines) and 95% percentiles (shaded areas) across 10 global climate models, versus distance upstream from the river outlet to . Works…in the works

1) Yan, H., N. Sun, A. Fullerton, and M. Baerwalde. 2021. Greater vulnerability of snowmelt-fed river thermal regimes to a warming climate. Environmental Research Letters. https://doi.org/10.1088/1748-9326/abf393

2) Fullerton, A.H., N. Sun, M.J. Baerwalde, B.L. Hawkins, and H. Yan. Mechanistic simulations suggest riparian restoration can partly counteract climate impacts to juvenile salmon. Manuscript in review at Journal of the American Water Resources Association. Modeling streamflow and water temperature responses to forest canopy gap treatment scenarios in the Snoqualmie river basin DHSVM-RBM 3.2 snowmelt module

Figure 4. Monthly mean stream temperature changes between two simulations (with snowmelt minus without snowmelt) from March to August over 2001–2013. Snoqualmie Snowpack

Basin Mean SWE from Oct.1 to Sep.30 based on 10 GCMs for historical period (1993-2005) and future period (2087-2099) Snoqualmie 7-DADMax Exceedances Over Time and Space Snoqualmie Canopy Gap modeling approach

•Used calibrated & validated Snoqualmie DHSVM-RBM to conduct sensitivity experiments over a 2-year historical period (2011/10– 2013/09)

•Explored streamflow and water temperature response in both the mainstem and tributaries across the Snoqualmie River Basin (i.e., basin outlet, North Fork, Middle Fork, South Fork, and Tolt)

•Applied a suite of varying canopy gap treatments, e.g. gap size and location, aspect and elevation Sensitivity Analysis: 11 gap scenarios, 54 runs

Outlet Num Variable SA Description treated basin treated canopy treated basin treated canopy Annual Flow summer flow summer flow summer avg. 7DADMAX 7DADMAX area (acres) area (acres) area (%) area (%) Change(%) change (%) efficiency Temp Diff Diff (C) efficiency 1 >728m, gap=90m, all aspect & slope, current height (25/30m) 171801 48581 38.9 11.0 1.44 11.71 1.06 -0.38 -0.47 -0.04 2 Elev band >932m, gap=90m, all aspect & slope, current height 128078 36215 29.0 8.2 0.73 8.42 1.03 -0.23 -0.55 -0.07 3 >1106m, gap=90m, all aspect & slope, current height 84796 23849 19.2 5.4 0.16 3.88 0.72 -0.10 -0.29 -0.05 4 60m, >728m, all aspect & slope, current height 171801 21641 38.9 4.9 0.52 4.07 0.83 -0.19 -0.22 -0.04 Gap 5 90m, >728m, all aspect & slope, current height 171801 48581 38.9 11.0 1.44 11.71 1.06 -0.38 -0.47 -0.04 Diameter 6 120m, >728m, all aspect & slope, current height 171801 86563 38.9 19.6 2.82 23.76 1.21 -0.64 -1.14 -0.06 7 south & all slope, gap=90m, >728m, current height, 62714 17666 14.2 4.0 0.66 5.13 1.28 -0.15 -0.29 -0.07 Aspect/ 8 south & slope>13°, gap=90m, >728m, current height, 53881 15458 12.2 3.5 0.57 4.47 1.28 -0.12 -0.13 -0.04 Slope 9 south & slope>24°, gap=90m, >728m, current height, 37540 10600 8.5 2.4 0.41 3.18 1.33 -0.06 -0.17 -0.07 10 10m, elev>728m, all aspect & slope, gap=90m 171801 48581 38.9 11.0 9.29 20.06 1.82 -0.53 -0.77 -0.07 Canopy 11 25/30m (current), elev>728m, all aspect & slope, gap=90m 171801 48581 38.9 11.0 1.44 11.71 1.06 -0.38 -0.47 -0.04 Height 12 40m, elev>728m, all aspect & slope, gap=90m 171801 48581 38.9 11.0 -3.88 6.18 0.56 -0.28 -0.52 -0.05 13 >932m, gap=120m, all aspect & slope, current height 128078 64481 29.0 14.6 1.55 17.49 1.20 -0.41 -0.75 -0.05 14 Combin. >932m, gap=120m, south & all slope, current height 46815 23407 10.6 5.3 0.72 8.10 1.53 -0.19 -0.40 -0.08 15 >932m, gap=120m, south & slope>13°, current height 40632 20316 9.2 4.6 0.61 6.93 1.51 -0.13 -0.27 -0.06 Canopy Height: tree height site potential—25/30m Elevation and Gap Diameter: 2 most important variables Aspect and Slope can further increase the canopy gap efficiency: south-facing and steeper slopes are more sensitive than north-facing and mild slopes Two leading canopy gap scenarios for long-term evaluation of the effectiveness of canopy gaps for enhancing summer (JJA) streamflow and reducing stream temperature in future climate (2031–2060):

1) elevation > 932 m & gap diameter = 120m on all slopes; 2) elevation > 932 m & gap diameter = 120m on only south-facing slopes. What about the ?

2 scenarios S1) elevation > 932 m & gap diameter = 120m on all slopes; S2) elevation > 932 m & gap diameter = 120m on only south-facing slopes. Into 4 scenarios S Elevation (m) Gap Diameter (m) Aspect Including Wilderness?

S1 ≥932 120 - Y S2 ≥932 120 - N S3 ≥932 120 south Y S4 ≥932 120 south N And what about climate models?

Previously 10 GCMs used

3 GCMs for long-term canopy gap evaluation (2030-2060)

1) best case (MIROC5, larger winter precipitation & lower summer air temperature over the basin), 2) worst case (HadGEM2-ES365, smaller winter precipitation & higher summer air temperature), 3) median case (bcc-csm1-1-m, median winter precipitation & median summer air temperature) Long-term canopy gap evaluation (2030-2060)

• 4 canopy gap scenarios and 1 baseline scenario (total 5)

• 3 selected GCMs (climate)

• 15 long term runs

Snoqualmie Canopy Gap pilot—analysis & conclusions

4 Evaluation Metrics: Summer [JJA] mean flow change (%) 7-DADMax difference (°C) Flow efficiency (%/%) 7-DADMax efficiency (°C/%)

In general, all four canopy gap treatments can increase basin outlet summer (June–August) mean streamflow and reduce basin outlet 7-DADMax (highest yearly value of the average of seven consecutive daily maximum temperatures); however, treatment benefits vary by treated locations and climatology. Snoqualmie Canopy Gap pilot—analysis & conclusions

4 Evaluation Metrics: Summer [JJA] mean flow change (%) 7-DADMax difference (°C) Flow efficiency (%/%) 7-DADMax efficiency (°C/%)

In general, larger treatment area results in greater effect on streamflow and temperature. Snoqualmie Canopy Gap pilot—analysis & conclusions

4 Evaluation Metrics: Summer [JJA] mean flow change (%) 7-DADMax difference (°C)

In general, larger treatment area results in greater effect on streamflow and temperature.

S1: elev.≥932m, gap=120m, all slopes S2=S1, but no Alpine Lakes S3=S1, but only south-facing slopes S4=S3, but no Alpine Lakes

16.00

(%) 14.00

12.00

Changes 10.00

Flow 8.00

6.00

Summer 4.00

2.00 Outlet 0.00 2031-2040 2041-2050 2051-2060

Figure 7. Basin outlet summer flow changes (compared to baseline) averaged over a 10-year period for the four canopy treatment scenarios. The error bars represent the range of three GCM models.

S1: elev.≥932m, gap=120m, all slopes S2=S1, but no Alpine Lakes S3=S1, but only south-facing slopes S4=S3, but no Alpine Lakes

1.20

1.00

Efficiency 0.80

Flow 0.60

0.40 Summer

0.20

Outlet 0.00 2031-2040 2041-2050 2051-2060

Figure 8. Basin outlet summer flow efficiency (%/%) averaged over a 10-year period for the four canopy treatment scenarios. The error bars represent the range of three GCM models. Table 9. Impacts of four canopy gap treatment scenarios on summer flow at basin outlet averaged over the period 2031–2060. The red color suggests the highest efficiency among the four scenarios for each GCM.

Name GCM ac. treated % treated JJA flow change (%) Summer Flow Efficiency (%/%)

HadGEM 7.9 0.54 S1 bcc-csm 64,474 14.6 10.2 0.70 MIROC5 11.2 0.77 HadGEM 3.0 0.48 S2 bcc-csm 27,802 6.3 4.3 0.68 MIROC5 4.9 0.78 HadGEM 3.1 0.57 S3 bcc-csm 23,604 5.3 4.0 0.75 MIROC5 4.4 0.82 HadGEM 1.1 0.44 S4 bcc-csm 10,662 2.4 1.5 0.62 MIROC5 1.7 0.71 Temperature – 7 DADMax at basin outlet

MIROC5 bcc_csm HadGEM2

Linear (MIROC5) Linear (bcc_csm) Linear (HadGEM2)

32.0

(°C) 30.0

28.0

26.0 7DADMAX

24.0

Outlet 22.0

20.0

Baseline 2025 2030 2035 2040 2045 2050 2055 2060 2065

Figure 9. Baseline (no canopy gap) basin outlet 7-DADMax (°C) from 2031 to 2060 using the three selected GCMs. 7-DADMax: the highest yearly value of the average of seven consecutive daily maximum temperatures.

S1: elev.≥932m, gap=120m, all slopes S2=S1, but no Alpine Lakes

S3=S1, but only south-facing slopes S4=S3, but no Alpine Lakes

0.000

(°C)

-0.050

-0.100 Difference

-0.150

DADMax - 7 -0.200

Outlet -0.250

2031-2040 2041-2050 2051-2060

Figure 10. Basin outlet 7-DADMax (°C) difference (scenario minus baseline) averaged over a 10- year period for the four canopy treatment scenarios. The error bars represent the range of three GCM models. 7-DADMax: the highest yearly value of the average of seven consecutive daily maximum temperatures.

S1: elev.≥932m, gap=120m, all slopes S2=S1, but no Alpine Lakes S3=S1, but only south-facing slopes S4=S3, but no Alpine Lakes

0.000

-0.002 -0.004

-0.006

Efficiency -0.008 -0.010 -0.012 DADMax -

7 -0.014

-0.016 Outlet -0.018 -0.020 2031-2040 2041-2050 2051-2060

Figure 11. Basin outlet 7-DADMax efficiency (°C/%) averaged over a 10-year period for the four canopy treatment scenarios. The error bars represent the range of three GCM models. 7-DADMax: the highest yearly value of the average of seven consecutive daily maximum temperatures. Table 10. Impacts of four canopy gap treatment scenarios on 7-DADMax at basin outlet averaged over the period 2031–2060. Red color suggests the highest efficiency among the four scenarios for each GCM.

Treated Treated 7DADMax 7DADMax Num. GCM Canopy Area Canopy Area Efficiency Diff (°C) (acres) (%) (°C/%) HadGEM -0.104 -0.007 S1 bcc-csm 64474 14.6 -0.148 -0.010 MIROC5 -0.182 -0.012

HadGEM -0.029 -0.005 S2 bcc-csm 27802 6.3 -0.040 -0.006 MIROC5 -0.048 -0.008

HadGEM -0.039 -0.007 S3 bcc-csm 23604 5.3 -0.056 -0.011 MIROC5 -0.071 -0.013

HadGEM -0.008 -0.003 S4 bcc-csm 10662 2.4 -0.010 -0.004 MIROC5 -0.016 -0.007

Source:

Yan, H. and Sun, N. Modeling the streamflow and water temperature responses to forest canopy gap treatment scenarios in the Snoqualmie river basin. 2020. Report to . DHSVM-RBM Canopy Gap Model Verification Analysis

•NHC, inc. – Linux

•PNNL and NHC results generally highly consistent DHSVM-RBM Canopy Gap Model Verification Analysis

•NHC, inc. – Linux

•PNNL and NHC results generally highly consistent

•Updated, up to date, model versions DHSVM-RBM Canopy Gap Model Verification Analysis

•NHC, inc. – Linux

•PNNL and NHC results generally highly consistent

•Updated, up to date, model versions

•Occasional large discrepancies—machine? rounding? DHSVM-RBM Canopy Gap Model Verification Analysis

•NHC, inc. – Linux

•PNNL and NHC results generally highly consistent

•Updated, up to date, model versions

•Occasional large discrepancies—machine? rounding? •Some years, treatment may have detrimental effect. IN CONCLUSION:

•Riparian restoration can partly, but not completely, offset the expected increases to water temperature caused by climate change IN CONCLUSION:

•Riparian restoration can partly, but not completely, offset the expected increases to water temperature caused by climate change.

•“Partial restoration” has almost as much benefit as “full restoration.” IN CONCLUSION:

•Riparian restoration can partly, but not completely, offset the expected increases to water temperature caused by climate change.

•“Partial restoration” has almost as much benefit as “full restoration.” But, caveat: degradation counteracts protection IN CONCLUSION:

•The uplands matter, too! IN CONCLUSION:

•The uplands matter, too!

•Basin-scale management of land cover, combined with riparian restoration, has synergistic potential to offer streamflow and temperature benefits to stream systems. Acknowledgements:

Aimee Fullerton (NOAA) Ning Sun (PNNL) Hongxiang Yan (PNNL) Brooke Hawkins (University of Michigan) SnoSCAT (Snoqualmie Science Coordination and Advisory Team) David Hartley (NHC, Inc.) Chad Drake (NHC, Inc.) Ingria Jones (WA Dept. of Ecology) Bureau of Indian Affairs Tribal Resiliency; WA Ecology Snoqualmie Indian Tribe END We developed the following riparian scenarios to model:

1) Current conditions

2) Full restoration of basin-wide riparian buffer to 150+ m buffer

3) Reserve the areas with 100-150+ m buffer, and change the rest of the buffer area to 5-10 m.

4) Reserve the areas with 100-150+ m buffer; Change buffers with width 40-100 m in Forested areas (but not in Agricultural or Residential areas) to the 100-150+ m wide buffer; In Agricultural or Residential areas, reserve the areas with 40-100 m buffer; And below Snoqualmie Falls/Tokul Creek confluence, change areas with 0-20 m buffers to 20-40 m buffers.