Tanner Harris, PWS

Senior Biologist


Tanner is a broadly trained ecologist with experience in ecology, botany, plant physiology, wetland delineation, soil science, environmental chemistry, restoration planning, environmental permitting, and native plant horticulture.  Much of his previous work focused on plant-soil relationships on serpentine soils and other harsh substrates such as mine tailings, rock outcrops, and vernal pools.  Tanner is a recognized expert in serpentine ecology and has co-authored numerous peer-reviewed papers on the subject.

At WRA, Tanner manages technical field efforts throughout California, including rare plant surveys, vegetation mapping, biological resource assessments, wetland delineations, and drywash mapping on sites ranging from a few to many thousands of acres.  Tanner prepares restoration and management plans for major, long-term restorations such as the 600-acre Ballona Wetlands restoration project in Los Angeles or the nearly 1-mile of dune restoration being developed for Broad Beach in Malibu.  Tanner also manages environmental permitting for a range of projects, including for both private and municipal clients.  He has experience preparing and implementing USACE Section 404 Nationwide Permits, RWQCB Section 401 Water Quality Certifications, CDFW Lake and Streambed Alteration Agreements, USFWS Section 7 Biological Consultations, CalTrans Natural Environment Studies, and Local Coastal Plan Coastal Development Permits.

As a Professional Wetland Scientist, Tanner is a wetland delineation instructor for the San Francisco Bay National Estuarine Research Reserve’s Coastal Training Program, teaching courses in both basic and advanced wetland delineation.  Tanner also provides internal delineation training for WRA’s technical staff.



Favero-Longo, S. E., E. Matteucci, M. Morando, F. Rolfo, T. B. Harris, and R. Piervittori. 2015. Metals and secondary metabolites in saxicolous lichen communities on ultramafic and non-ultramafic rocks of the Western Italian Alps. Australian Journal of Botany 63: 276-291.

Rajakaruna, N., R. S. Boyd, and T. B. Harris. 2014. Synthesis and Future Directions: What have harsh environments taught us about ecology, evolution, conservation and restoration. In Plant Ecology and Evolution in Harsh Environments. Pp. 393-409. Nova Science Publishers, Inc., NY, USA.

Rajakaruna, N., R. S. Boyd, and T. B. Harris, eds. (2014). Plant Ecology and Evolution in Harsh Environments. Nova Science Publishers, Inc., NY, USA.

Barton, J., Ciccotelli, B., Gall, J. E., Olday, F. C., Connery, B., T. B. Harris, A. M. Fryday, and N. Rajakaruna. 2014. Lichens of six vernal pools in Acadia National Park, ME, USA. Evansia 31: 31-39.

Harris, T.B., N. Rajakaruna, S.J. Nelson, and P.D. Vaux. 2012. Stressors and Threats to the Flora of Acadia National Park, Maine: Current Knowledge, Information Gaps, and Future Directions. Journal of the Torrey Botanical Society 139: 323-344.

Ciccotellii, B., T. Harris, B. Connery, N. Rajakaruna. 2011. A preliminary study of the vernal pool vegetation of Acadia National Park, Maine, USA. Rhodora 113: 260-279.

Rajakaruna, N., T. Harris, S. Clayden, A. Dibble, and F. Olday. 2011. Lichens of Callahan Mine, a copper and zinc-enriched Superfund site in Brooksville, Maine, USA. Rhodora 113: 1-31.

Harris, T. and W. Manning. 2010. Nitrogen dioxide and ozone levels inside urban tree canopies. Environmental Pollution 158: 2384-2386.

Pope, N., T. Harris, and N. Rajakaruna. 2010. Vascular plants of adjacent serpentine and granite outcrops on the Deer Isles, Maine, USA. Rhodora 112: 105-141.

Rajakaruna, N., N. Pope, J. Perez-Orozco, and T. Harris. 2010. Ornithocoprophilous plants of Mount Desert Rock, a remote bird-nesting island in the Gulf of Maine, USA. Rhodora 111: 417-447.

Harris, T. and N. Rajakaruna. 2009. Adiantum viridimontanum, Aspidotis densa, Minuartia marcescens, and Symphyotrichum rhiannon: Additional serpentine endemics from eastern North America. Northeastern Naturalist 16: 111-120.

Rajakaruna, N., T. Harris, and E.B. Alexander. 2009. Serpentine geoecology of eastern North America: A review. Rhodora 111: 21-108.

Briscoe, L.R.E., T. Harris, E. Dannenberg, W. Broussard, F. Olday, and N. Rajakaruna. 2009. Bryophytes of adjacent serpentine and granite outcrops on the Deer Isles, Maine, USA. Rhodora 111:1-20.

Harris, T., F. Olday, and N. Rajakaruna. 2007. Lichens of Pine Hill, a peridotite outcrop in eastern North America. Rhodora 109: 430-447.

Conference Presentations:

Harris, T.B. 2015. Using development to protect rare serpentine-associated plants: A case study in the San Francisco Bay Area. Oral presentation at California Native Plant Society Conference, San Jose, California, January 13-17, 2015

Harris, T.B. 2014. Conservation of serpentine-endemic species in the San Francisco Bay Area, CA, USA. Oral presentation at the Seventh International Conference on Serpentine Ecology, Sabah, Malaysia, June 9 – 13, 2014

McCarthy, A. and T.B. Harris. 2014. Developing an adaptive management approach for the Ballona Wetlands. Oral presentation at Headwaters to Ocean Conference, San Diego, CA, May 27 – 29, 2014

Harris, T.B., J.A. Albertine, and W.J. Manning. Nitrogen dioxide and ozone levels inside urban tree canopies. Poster presented at Urban Environmental Pollution 2010, Boston, MA, June 20 – 23, 2010

Harris, T.B. and N. Rajakaruna. Adiantum viridimontanum, Aspidotis densa, and Minuartia marcescens, additional serpentine endemics from eastern North America. Poster presented at the Sixth International Conference on Serpentine Ecology, College of the Atlantic, Bar Harbor, ME, June 16 – 23, 2008

Rajakaruna, N., T.B. Harris, and E.B. Alexander. Geoecology of serpentine in eastern North America: Critical information gaps and future directions. Oral presentation at the Sixth International Conference on Serpentine Ecology, College of the Atlantic, Bar Harbor, ME, June 16 – 23, 2008

Harris, T.B., E. Dannenberg, N. Pope, L. Briscoe, A. Thrall, F.C. Olday, and N. Rajakaruna. Plant life on metal-enriched soils in Maine: involving undergraduate students in ecological research. Poster presented at Maine Space Grant Consortium Annual Meeting, University of Southern Maine, Portland, ME, April 20, 2007

Thrall, A., N. Pope, E. Dannenberg, K. Tompkins, P. Pavicevic, T.B. Harris and N. Rajakaruna. Plant-Soil Relations on Serpentine Outcrops of Deer Isle, Maine in Northeastern United States. Poster presented at Maine Space Grant Consortium Annual Meeting, University of Southern Maine, Portland, ME, April 20, 2007

Harris, T. B., F.C. Olday, and N. Rajakaruna. Lichens of a Peridotite Outcrop in Eastern North America: An Investigation into the Lichen-Serpentine Relation. Oral presentation at the Botanical Society of America Annual Meeting at California State University, Chico, CA, July 28 – August 3, 2006


The Nature Conservancy, Jalachichi Ponds Restoration Plan, Jack and Laura Dangermond Preserve, Santa Barbara County, California

Petersen Ranch Wetland Mitigation Bank, Los Angeles County, California

Ballona Wetlands Restoration, Los Angeles County, California

Spirit Rock Meditation Center Biological Services, Marin County, California

Golden Gate Bridge, Highway, and Transportation District, Corte Madera Reserve Restoration, Corte Madera, California

Broad Beach Dune Restoration, Malibu, California

Westside Retention Basin Maintenance Project, Santa Clara, California

Runnymede Storm Drain Improvement Project, East Palo Alto, California

City of Burlingame Storm Drain Capitol Improvement Project, San Mateo County, California

The Sea Ranch Water Company Rare Plant Survey, ESHA Assessment, and Coastal Development Permit, Sonoma County, California

Marin Country Day School Creek Restoration, Marin County, California

Chabot Space and Science Center Vegetation Management Implementation Plan, Oakland, California


MS, Plant and Soil Science, University of Massachusetts, Amherst. 2010

BA, Human Ecology, College of the Atlantic, Maine. 2006

Specialized Training:

Flora of Santa Rosa Island, Steve Junak, Jepson Herbarium Workshops. 2015

Flora of Baja California, Jon Rebman, Jepson Herbarium Workshops. 2015

Arid Alkaline Wetlands, Jim Teaford. 2013

Desert Washes and Waters, Jim Teaford. 2013

Field Indicators of Hydric Soils, Wetland Training Institute. 2012

Poaceae Workshop, Travis Columbus, Jepson Herbarium Workshops. 2012

Hydric Soils, Peter Veneman, UMass Amherst. 2010

Wetland Delineation, Peter Veneman and Ralph Tiner, UMass Amherst. 2010


Professional Wetland Scientist

California Native Plant Society

Southern California Botanists

California Botanical Society

Society of Wetland Scientists

International Serpentine Ecology Society

New England Botanical Club