Riparian: Definition, please? Living or located on the bank of the river. R-I-P-A-R-I-A-N. Riparian.

Substrate....

Glossary

Riparian plant community: Living or located on the bank of the river

Substrate variation: Different types of surfaces on which organisms grow or are attached

Bioengineering: in this case, structures engineered to assist with revegetation of the streambanks

Geomorphic surfaces: on the top layer of the earth

Alluvium: clay or silt or gravel carried by rushing streams and deposited where the streams slow down

Alluvial river system: a river that carries and deposits sediment

Topographical diversity: a wide variety of natural and man-made features in the surface of the earth

Microsites: small environments (for example, downed tree crowns, stumps, treefall pits)

Microtopography: very small scale (roughly organism sized) variations in the height and roughness of the ground surface

Restoration Progresses with Milltown Riparian and Floodplain Revegetation

The revegetation plan for the Milltown Dam restoration area focuses on creating conditions that will support riparian plant community development through natural river and floodplain processes. Active revegetation treatments include floodplain grading and substrate variation, plant salvage and transplant, bioengineering, seeding, containerized planting, browse protection, and weed managent.

Floodplain grading is intended to create geomorphic surfaces such as bankfull floodplain, low terrace, high terrace and uplands that naturally occur along an alluvial river system in western Montana as well as creating topographical diversity.

Incorporating lower elevation shrub and cottonwood planting and island depressions (swales), combined with surface roughening and wood placement, results in protected microsites where plants can become established. Diverse microtopography is intended to reduce competition from invasive species which thrive on simple, uniform surfaces. In addition, adding roughness to floodplain surfaces increases the ability of these surfaces to trap cottonwood and willow seeds that naturally colonize on exposed alluvial material.

Plant Salvage and Transplant

Mature native shrubs and sod were salvaged from within project construction boundaries for use in various revegetation techniques. Salvaged plants have the advantage of being adapted to site conditions, having mature and extensive root systems, and are mature enough to quickly add natural vegetation function to streambanks and floodplains once transplanted.

Shrubs were salvaged from within construction boundaries both prior to construction and during construction. Prior to construction, shrubs were salvaged while dormant and staged out of the way of construction until they could be transplanted or incorporated as part of revegetation techniques such as sod brush trenches or planted on bankfull benches behind bioengineering structures. Shrubs salvaged during construction were immediately transplanted into newly constructed wetlands and streambanks. Approximately two acres of wetland sod were salvaged and placed in a staging area for use in later project phases. (see accompanying photos for examples)

Weed Management

A weed management plan was prepared for the project that addresses areas within and outside of the river channel and floodplain construction boundaries. Inside the construction boundaries, pre-construction treatments focus on reducing existing weed densities to limit spread during construction and reduce potential hindrances to revegetation. Post construction treatments will focus on limiting the spread and abundance of weeds and promoting the success of revegetation activities by limiting competition to planted material.

The weed management plan for areas outside of the construction area is to maintain a buffer around the restored area. Weed management was initiated in 2006 and will continue for several years.