Prior: Climate Change and Disturbance in the Lake Tahoe Basin

Abstract: Managing large forested landscape in the context of changing climate regimes and altered disturbance regimes presents new challenges and will require an integrated assessment that incorporates forest disturbance, management, succession, and the carbon cycle. Successful management requires information about the inherent trade-offs among multiple objectives and improved awareness of the opportunities for spatially optimizing management on the landscape. We are evaluating the effects of fire suppression, wildfires, bark beetle outbreaks, and forest fuel (thinning) treatments on the long-term potential for Lake Tahoe forests to sequester carbon in a global change context.

Funding: Sierra Nevada Public Lands Management Act (SNPLMA)

Collaborators: Robert Scheller, Charles Maxwell, Louise Loudermilk, Alec Kretchun, Peter Weisberg (UNR), Jian Yang (UNR), Alison Stanton, Carl Skinner (USFS), Matt Hurteau (Penn State)

Status: Completed

Links: Tahoe Science Consortium, GitHub Repository of Inputs

Results: We encourage interested parties to read the publications listed below, which to date represent the findings of our Tahoe climate change research. Broadly speaking our research has revealed the following:

- Due primarily to landscape legacy effects of historic logging of the Comstock Era in the late 1880's, C sequestration in the Lake Tahoe Basin may continue throughout the current century, and the forest will remain a C sink (Net Ecosystem Carbon Balance > 0), regardless of climate regime

- Fuel treatments were most effective when continuously applied and strategically placed in high ignition areas. Treatment type and re-application interval were less influential at the landscape scale, but had notable effects on species dynamics within management units.

- Forest productivity in the Basin has a nonlinear relationship with moisture stress, and that growth patterns are likely best explained by a combination of moderate moisture sensitivity and mortality caused by bark beetles.

- Fuel treatments have the potential to ‘bend the C curve’, maintaining carbon resilience despite climate change and climate-related changes to the fire regime. Simulated fuel treatments resulted in reduced fire spread and severity.

- Bark beetles reduce resilience, increase uncertainty, and tip the C balance of the landscape towards becoming a C source (losing C to the atmosphere).

Publications (Attached Below):

Scheller, R.M., A.M. Kretchun, E.L. Loudermilk, M.D. Hurteau, P.J. Weisberg, C. Skinner. 2018. Interactions Among Fuel Management, Species Composition, Bark Beetles, and Climate Change and the Potential Effects on Forests of the Lake Tahoe Basin. Ecosystems 21:643-656.

Loudermilk, E.L., R.M. Scheller. P.J. Weisberg, A.M. Kretchun. 2016. Bending the carbon curve: fire management for carbon resilience under climate change. Landscape Ecology

Kretchun, A.M., E.L. Loudermilk, R.M. Scheller, M.D. Hurteau, S.M. Belmecheri. 2016. Climate and bark beetle effects on forest productivity: linking dendroecology with forest landscape modeling. Canadian Journal of Forest Research. 10.1139/cjfr-2016-0103

Yang, J., P.J. Weisberg, T.E. Dilts, E.L. Loudermilk, R.M. Scheller, A. Stanton, C. Skinner. 2015. Predicting wildfire occurrence distribution with spatial point process models and its uncertainty assessment: a case study in the Lake Tahoe Basin, USA. International Journal of Wildland Fire 24: 380-390.

Loudermilk, E. L., A. Stanton, R. M. Scheller, T. Dilts, P. J. Weisberg, C. N. Skinner, and J. Yang. 2014. Effectiveness of fuel treatments for mitigating wildfire risk and sequestering forest carbon: A case study in the Lake Tahoe Basin. Forest Ecology and Management 323: 114-125.

Loudermilk, E.L., R.M. Scheller, P.J. Weisberg, J. Yang, T. Dilts, S.L. Karam, C.N. Skinner. 2013. Carbon Dynamics in the Future Forest: The Importance of Climate-Fire Interactions and Long-Term Successional Legacy. Global Change Biology 9: 3502-3515.