Riparian Buffers and Stream Restoration

Transcription

1 Riparian Buffers and Stream Restoration

2 Why focus on riparian areas?

3 Link land and water on any given site and link landscapes together in a watershed Riparian corridors protect the circulatory system of the Bay Watershed

4 400 years of land use has resulted in fragmented natural systems, altered streams, and a loss of watershed resilience

5 Is it Restoration or a BMP? Restoring forests or other natural habitats where they have not existed often for centuries and using natural riparian functions as a pollution treatment practice in our agricultural landscapes.

6 Important functions of riparian buffers Ensure channel structure and stability sediment and gravel storage, bank and bed stability, habitat structure, diversity, aid in the restoration of stream banks. Capture overland storm flows removal of sediment, phosphorus, nitrate, and toxics, filter inorganic chemicals Filter groundwater Nitrate removal, recharge, dissolved phosphorus removal Store floods and moderate downstream reduce downstream damage, sediment and nutrient processing in floodplain Instream nutrient processing hyporheic process Aquatic habitat - moderate temperature, food supply Wildlife Habitat - shelter, water, food, diversity

7 Welsch, 1992 USDA Riparian Forest Buffer

8 Controlling the aquatic environment Trees and other woody plants define stream structure and bank stability, and availability of valuable habitats

9 Watershed Tea 75% of all energy inputs are derived from riparian buffer vegetation. Dissolved Organics Others (twigs,leaves,, etc.)

10 Food web from organic chemicals, to bacteria, microscopic fauna, macroinvertebrates to fish to

11 Native stream organisms (bacteria, diatoms, microscopic algae) evolved on a diet of tree leaves.

12 Stream Continuum Linkage and interdependence of biological communities we all live downstream

13 Shade As water temperature increases, streams have less ability to hold oxygen & support aquatic life. A cropland stream with no shade is up to 13 degrees F warmer than a forest stream.

14 Moderating the impacts of flooding on channel structure and downstream pollution. importance of riparian vegetation structure.

15 Buffers cannot be totally effective if the underlying causes of channel erosion are not addressed storm water!

16 Nutrients, Sediment, and other chemical pollutants Reducing chemical water quality problems is a key role of buffers. Buffers serve as: Filters Sinks Transformers

17 Pollution sources Upstream sources Contributing area Adjacent land use - surface and subsurface flow Direct inputs rain, air, livestock,

18 Nitrogen retention is based primarily on biological removal Storage of nitrogen in plant biomass. Long term forest Storage. Shorter term grass and marsh retention. Biological transformation through denitrification and conversion to organic nitrogen. Importance of organic carbon supply.

19 Instream Processing is 6-8 x greater in a buffered stream Nutrient Processing continues in the aquatic system if healthy biological communities

20 Wooded stream is wider and shallower with more interactive surface (4-10X). Streams narrow and deepen in managed pasture. Loss of 75% of stream bottom area.

21 Buffers are a last line of defense

22 Forest Buffer Goals & their Importance to Restoring the Chesapeake Bay

23 Past Progress 900 miles/year target Data source: US Forest Service/Chesapeake Bay Program

24 States relying on past and future buffer acres Forest Buffers rank second of all nonpoint source BMPs needed to meet TMDL targets. Data Source: Chesapeake Bay Program Modeling Team (Sweeney)

25 TMDL targets for forest buffers Total New Acres Needed Acres/year needed Delaware Maryland New York Pennsylvania 89, Virginia 80, West Virginia TOTAL 185,860 14,295 Data Source: Chesapeake Bay Program and 2012 data from USDA Farm Services Agency acres/year = 1191 miles/year of 100 ft wide buffers

26 October 20,

27 CREP Riparian Forest Buffers New CP22 Contracts 27

28 CRP Riparian Forest Buffers (CP22) in Chesapeake Bay Watershed Cumulative Acreage at End of Fiscal Year

29 Riparian Forest Buffer Acres Varies by County

30 Emerging Issue: Expiring Contracts CP-22 Acres expiring Data Source: USDA Farm Services Agency

31 Summary Impressive Progress but Decreasing Trend States and Feds rely heavily on Forest Buffers in WIPs and new Bay Agreement Much More is Needed A FACTOR OF 10!! Barriers to accomplishment require creative solutions

32 Riparian Buffer Restoration requires a long term view 40 year old restored pasture in Avondale, PA