Peter Baye Coastal Plant Ecologist Annapolis, California Sonoma County Riparian Vegetation: Selected Aspects Related to Salmonid Habitat Restoration in Gravel Mining Pits Hanson Russian River Restoration Project Feasibility Study National Marine Fisheries Service – Santa Rosa, California Scientific Working Group Meeting #1 March 5, 2013

Reciprocal influence of fluvial landforms and riparian vegetation Landform evolution influences riparian vegetation – Local geomorphic controls: sediment load, disturbance intensity gradients, disturbance frequency & recovery intervals (Lennox & al. 2007, Harris 1987, McBride & Strahan 1984) – Sediment texture (% fines) – Sediment surface relative to groundwater (hyperhoeic flow) during low- flow/dry season: aquatic-wetland-mesic vegetation gradient Riparian vegetation influences landform evolution – Sediment trapping, off-channel sediment storage, floodplain accretion: vegetation roughness and stabilization on bar crests, floodplains – Lateral sedimentation gradients (bank margin-backwater; levee pattern) – Large woody debris trapping (reciprocal influence: LWD nucleation of pioneer vegetation, riparian woodland trapping of LWD) – Backwater marsh and pond/laguna formation (historical)

Riparian vegetation formations Riparian woodland, scrub (bank, floodplain) Floodplain marsh, wet meadow, & alluvial grassland (bank, floodplain) Pioneer fluvial shoreline & marsh vegetation (bar, bank, ridge/swale) Aquatic Vascular Plant communities

Riparian vegetation formations RIPARIAN WOODLAND, SCRUB Most studied phase of riparian vegetation; most emphasis in restoration Mature monitoring methodology example: UC Extension Lennox et al Development of vegetation and aquatic habitat in restored riparian sites of California’s North Coast rangelands. Restoration Ecology 19: Dominant (over-represented?) riparian vegetation type Ecological services: Canopy shade (temperature regulation), Trophic support (leaf litter, invertebrate productivity) Refuge (predator escape; root and shoot structure) LWD recruitment (production, trapping) – root, branch, trunk structure

Riparian vegetation formations Emergent marsh, wet meadow, alluvial grassland Rhizomatous sod-forming vegetation; geomorphic agent (perennial regeneration of surface roughness: vertical accretion, sink for fines) Leaf litter mat, duff: invertebrate production Historic decline: grazing, aggradation, mining, cessation of annual burning (Pomo) Aquatic Vascular Plant communities Least studied; mostly historic (native) or nuisance (invasive non-native) Submerged (SAV), floating (FAV) Low-velocity or lotic off-channel, deep channel pool margin Historic decline Pioneer fluvial shoreline vegetation (gravel, sand bar) Herbaceous, graminoid, ruderal, mesic vegetation (weedy) Includes disturbance-dependent woodland/scrub element (Salix, Populus, Alnus) - colonization of moist mineral sediment, organic debris Sorting by sediment texture, groundwater elevation (capillary fringe)

Linear-leaf v. floating broadleaf pondweeds Linear-leaf (Stuckenia pectinata; most common) Floating broad-leaf (Potamogeton nodosus; most common native pondweed)

Submerged Aquatic Vegetation (SAV) Potamogetonaceae (pondweeds) prevalent Mostly 19 th /early 20 th century records within Russian River – least studied riparian (aquatic) vegetation type Perennial, colonial in shallow to deep clear water Intolerant of high turbidity, high sedimentation, summer drawdown or sediment dewatering, unstable bed Linear-leaf and floating broadleaf taxa Heteromorphic: plastic pond and flowing water forms, submersed and emergent leaf forms Structure contrasts with exotic SAV: slender elongated sub-canopy shoots

Russian River Riparian Landscape positions SAV subhabitats “lagunas” – backwater floodplain marsh ponds, choked floodplain drainage (mostly historic) relict or side channels, oxbows; low-velocity stable side channel banks, high groundwater Resistant clay outcrops in high-velocity channel banks (rhizome refugia) backbarrier coastal lagoon near Jenner (modern core populations of SAV) depth tolerance proportional with water clarity

Submerged Aquatic Vegetation (SAV) potential salmonid habitat interactions, comparison with Chesapeake SAV Potential juvenile salmonid prey base – Invertebrate trophic support (SAV herbivores): – Zooplankton consume detritus (low lignin) Daytime water oxygen diffusion (linear-leaf) Nocturnal local hypoxia Potential canopy epiphytic filamentous algal blooms Canopy shade inhibition of water column phytoplankton production Temperature stratification: warmer surface, shaded bottom (leaf canopy at surface) Predator refuge for juveniles? – complex canopy edge

Potential SAV metrics in riparian settings Riparian landscape distribution (in- channel, backwater) Size-class distribution: mid-summer colonies emergent at water surface Canopy (water surface) cover – Fine-scale (within canopy) – Coarse-scale (colony polygon) Canopy structure (shoot density colony margin line-intercept) Canopy invertebrate prey base (biomass or productivity) Primary production (biomass)

Floodplain marsh, wet meadow (Cyperaceae spp. dominance) ecological services high organic productivity: SOM and litter mat invertebrates (salmonid prey – overbank flows) fine sediment trap (stratified rhizome/sediment)- ungrazed tall canopy High soil shear strength: erosion resistance (bank, floodplain surface) Shallow groundwater, clonal Cyperaceae swards: inhibition of invasive shrub & Arundo recruitment; rapid recovery after sedimentation events Less common restoration: floodplain grassland (Central Valley)

Floodplain marsh, wet meadow (Cyperaceae spp. dominance)

Selected literature Baltz, D.M. and P.B. Moyle The influence of riparian vegetation on stream fish communities of California. In: Warner, R.E. and K.M. Hendrix, eds. California Riparian Systems – Ecology, Conservation, and Productive Management. University of California Press. Harris, R.R Occurrence of vegetation on geomorphic surfaces in the active floodplain of a California alluvial stream. American Midland Naturalist 118: Lennox et al Development of vegetation and aquatic habitat in restored riparian sites of California’s North Coast rangelands. Restoration Ecology 19: McBride, J.R. and J. Strahan Fluvial processes and woodland succession along Dry Creek, Sonoma County, California. In: Warner, R.E. and K.M. Hendrix, eds. California Riparian Systems – Ecology, Conservation, and Productive Management. University of California Press.