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Bio 126 Marsh and Wetlands. Current state:. In California we have lost 90% of our wetlands. Much of the Great Central valley was a seasonal marsh. Our Largest lakes with miles of marshy shoreline were by Bakersfield. They had 2,100 miles of marshy shoreline.
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Current state: • In California we have lost 90% of our wetlands • Much of the Great Central valley was a seasonal marsh • Our Largest lakes with miles of marshy shoreline were by Bakersfield. They had 2,100 miles of marshy shoreline • 40% of the SF Bay has been filled in with land. • Rivers have been channelized, shoreline reduced
Types of Marshes: • Salt water – marine or sea water marshes – along bays and sea shore • Mangrove swamps, important for island building in warm waters • Brackish – mix of salt or sea water and fresh water – locations may vary by seasonal flow • Estuaries – river meets a bay, or sea • Fresh water – along streams and lakes
Ecological Roles of Wetlands: • High productivity • Filters water – Laminar flow • Fisheries • Migrating & resident birds • Food, cover, nesting sites • Traps nutrients, pollutants
Salt Marsh Plants • Halophytes at leading edge • Plants adapted to salty conditions • Many have Salt glands • Succulents have swollen tissues that store water – like Pickleweed
Anatomy of Salt Marsh • Open sea water • Mudflats – still under water • Salt marsh – above ground by inches, right next to mudflats. • Salt content of soil high • Fresh water marsh, higher up, and farther back from mud flats • Salt content of soil very low
Mudflats • Forms new land by silting, • Limited by high-tide line • Area still under water at high tides • Wind blows dust, plant trap sediments settling down & slowly build up soil • Differences in compaction create tidal meanders – deeper channels • Highest salt content – same as sea • Eel grass and sea lettuce- dominants • Wading birds eat animals in mud
Salt Marsh edge with sea water • Cordgrass dominates • Hollow stems, 2-3 ft. tall • Rhizomes trap detritus, and sediments add to soil • Highly productive • Has nitrogen fixing bacteria in roots • Few things eat cordgrass • Fuels a detrivore based food chain • Decays in mud, microorganism eat detritus • Worms, snails, fish larvae eat microorganisms • Birds, larger fish, eat worms etc.
Salt Marsh farther inland • Salt in soil is less than 2% • Saltgrass most common • Other salt-tolerant species may be present such as: • Saltbush • Sea Blite • Marsh Grindelia – a “gum weed”
Fresh Water Marsh • On inflow of creeks into salt marshes • Around lakes streams inland • Deltas of rivers
Fresh Water Marsh Plants • Floating plants – microphytes • Duckweed and Water-ferns • Water hyacinth an introduce weedy species • Tule – Bullrush small spike of flowers and seeds • Triangular stems up to 6 ft. • Cattails – column of small flowers / feather seeds • Round hollow stems up to 10 ft. • Can not tolerate water deeper than 4 ft. • Shrubs and Trees – Riparian areas • may include Willows, Alder, Cottonwood, Sycamore
Good website to view marshplants • www.msnucleus.org/.../ mudslough/mudplants.html
Marsh Birds • Northern Harrier • Rails • Black Phoebe • Kingfishers • Egrets, Herons • Ducks • Western Meadowlark • Smaller Waders: Stilts, Avocet, Peeps Brewers and Red-winged Black birds
Other Marsh Animals • Black-tailed Jack Rabbit • Tule Elk • Racoons • Skunks • Muskrats • Otters • Salt Marsh Harvest Mouse • Norway Rats • Introduced red fox – hunts marsh birds
A new Dawn for the Delta • Glen Martin • SF Chronicle December 30, 2005
