Floristic Development Patterns in a Restored Elk River Estuarine Marsh, Grays Harbor, Washington
- BATTELLE (PACIFIC NW LAB)
- Washington State Department of Fish and Wildlife
We describe the changes in the floral assemblage in a salt marsh after reconnection to estuarine tidal inundation. The Elk River marsh in Grays Harbor, Washington, was opened to tidal flushing in 1987 after being diked for approximately 70 years. The freshwater pasture assemblage dominated by Phalarais arundinacea (reed canary grass) converted to low salt marsh vegetation within 5 years, with the major flux in species occurring between years 1 and 4. The system continued to develop through the 11-year post-breach monitoring period, although change after year 6 was slower than in previous years. The assemblage resembles a low salt marsh community dominated by Distichlis spicata (salt grass) and Salicornia virginica (pickleweed). Because of subsidence of the system during the period of breaching, the restored system remains substantially different from the Deschamsia cespitosa (tufted hairgrass)-dominated reference march. Use of a similarity index to compare between years and also between reference and restored marshes in the same year revealed that similarity in floral composition between year 0 and subsequent years decreased with time. However, there was a period of dramatic dissimilarity during years 1 to 3 when the system was rapidly changing from a freshwater to estuarine condition. Similarity values between the reference and restored system generally increased with time. Somewhat surprisingly, the reference marsh showed considerable between-year variation in similarity, which indicated substantial year-to-year variability in species composition. Based on accretion rate date from previous studies we predict that full recovery of the system would take between 75 and 150 years.
- Research Organization:
- Pacific Northwest National Lab., Richland, WA (US)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- AC06-76RL01830
- OSTI ID:
- 15002668
- Report Number(s):
- PNNL-SA-37599; TRN: US200418%%9
- Journal Information:
- Restoration Ecology : the journal of the Society for Ecological Restoration, Vol. 10, Issue 3; Other Information: PBD: 15 Sep 2002
- Country of Publication:
- United States
- Language:
- English
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