Riparian Areas. 101 An overview. Prepared by: Jacque Sorensen, M.Sc. TRU Department of Natural Resource Sciences

Transcription

1 Riparian Areas 101 An overview Prepared by: Jacque Sorensen, M.Sc. TRU Department of Natural Resource Sciences February 11, 2015 Presented for the Gardom Lake Planning Committee

2 Today s focus Riparian Areas 101 What is a riparian area and why are they so important? How do they function? Threats to riparian areas Effects of land-use activities Invasive species What can we do to protect them?

3 What is a riparian area? Upland The transitional zone between land and a waterbody (interaction of water, soil, and vegetation) Diverse plant and wildlife communities Riparian Aquatic Boundary is determined by how far the waterbody influences the vegetation (vegetation is distinctly different than upland) Courtesy of

4 What is a riparian area? Highly variable! All share vegetation that is distinctly different from upland ecosystem, moist soils Courtesy of

5 What is a riparian area? THOMPSON RIVERS UNIVERSITY Image source:

6 Riparian function: Illustration by Soren Henrich; adapted from BC Riparian Areas Regulation Implementation Guidebook, available at:

7 Riparian function: Shade & Shelter Overhanging vegetation keeps water temps cool and constant (important for fish!) THOMPSON RIVERS UNIVERSITY Woody debris (stumps, fallen logs etc.) provide habitat complexity and cover for fish Important refuge for wildlife during drought or extreme weather

8 Painted turtles basking on fallen tree at Gardem Lake Photo source:

9 Riparian function: Food supply Rapid growth of riparian plants provide forage and food for wildlife (grazing animals, migratory birds etc.) THOMPSON RIVERS UNIVERSITY Supplies food to aquatic system in the form of litter and invertebrates Photo source :

10 A complex stream bank or lakeshore will trap coarse and fine sediment during flood or run-off events This also serves to rebuild and maintain shoreline and provide new substrate for plants to colonize. THOMPSON RIVERS UNIVERSITY Riparian function: Traps sediment Courtesy of for educational

11 Riparian function: Filters water Riparian forests can reduce Nitrogen by 90% and Phosphorus by 50% (Gilliam 1994). Wet, fine textured soils, high in O.M, low in O 2 Adapted from Evans et al fertilizers, manure, sewage, compost are all sources of nutrients (nitrogen, phosphorus, carbon etc.) that can make their way into waterbodies

12 Riparian function: Filters water Nutrients & other contaminants are trapped, taken up by plants themselves or degraded by biological processes e.g. denitrification = conversion of nitrate (NO 3- ) to nitrogen gas (N 2 ) in Image Source: Huel, D Streambank Stewardship: A Saskatchewan Riparian Project. Saskatchewan Wetland Conservation Corporation.

13 Riparian function: Filters water Poorly developed root systems allow contaminates to easily move into water Image Source: Huel, D Streambank Stewardship: A Saskatchewan Riparian Project. Saskatchewan Wetland Conservation Corporation.

14 Riparian function: Stabilizes Dissipates energy and reduces shore erosion from flood, runoff, or waves Deep rooting vegetation & large woody debris are important components Courtesy of for educational use

15 Land-use activities: Agriculture Urban & rural development Resource Extraction Transportation Recreation Photo: Brian Heise Louis Creek near Kamloops active erosion on bank

16 Photo: Jacque Sorensen Bank stabilization at Tranquille River, Kamloops, BC.

17 Riparian function: Maintains biodiversity In addition to plants, a diversity of animals live in and around riparian areas Many species rely on riparian habitat that provides cover and accessibility to water (especially nesting waterfowl) Riparian areas = small portion of the landscape but disproportionately important!

18 Threats to riparian areas Land-use activities: Agriculture Urban & rural development Resource Extraction Transportation Recreation Photo credit : Jacque Sorensen

19 Threats to riparian areas Poor watershed management We have learned what not to do! Restoration can be very difficult & expensive better to maintain function and prevent degradation Atleo River watershed, B.C. (from Northcote & Hartman 2004) Photo: Jacque Sorensen

20 Threats to riparian areas Invasive species: Next to habitat loss, invasive species are the most significant threat to biodiversity. Yellow flag-iris and Purple loosestrife are riparian examples Spread rapidly Outcompete Reduce function Yellow flag-iris and Purple loosetrife are water-loving plants Photos courtesy of Invasive Species Council of BC Photo: Jacque Sorensen

21 Yellow flag-iris research at TRU Photos by Wendy Gardner Dr. Catherine Tarasoff and her team are looking at cost-effective methods of removing flag-iris at Vaseux Lake Based on previous lab research that showed iris cannot survive >40 days under dark, anoxic conditions Photos courtesy of Invasive Species Council of BC Photo: Jacque Sorensen

22 Development Threats & to Recreation: riparian areas Alteration of foreshore (removal of veg & woody debris, importing sand etc.) Access points Boat wake erosion Noise Etc. etc Photo credit: Photo: Jacque Sorensen

23 What can we do to protect them? Educate the public about the value of riparian areas Foster development plans that maintain a functioning riparian buffer Avoid removing large trees and woody debris Limit the number and size of access points Monitor and remove invasive plants to conserve biodiversity

24 Thank-you Questions? Contact info: Jacque Sorensen, M.Sc. TRU Department of Natural Resource Sciences Phone: