Saltmarshes and Mangroves Flashcards
Productivity of Salt Marshes
250-2000 grams of carbon fixed /M^2/Yr
More variable than mangroves because of temperature fluctuations
More productive than most terrestrial systems
Productivity of Mangroves
370-450 grams of carbon fixed/M^2/Yr\
more productive than most terrestrial systems
What are mangroves?
Tropical, saline intertidal estuarine forest
Trees with exposed roots, in soft sediments
Turbid, organic-rich waters
Importance of Mangroves
High community diversity
Trap sediments, increase water quality outside the mangal
Little spatial coverage but stabilize the shoreline
True Mangrove Species
50+ species, 20 genera, 16 families of plants
The majority are in two families: white mangroves and red mangroves
Mangrove Tree anatomy
Prop roots: support the structure of the tree
Flowers: These are used for pollination
Snorkel Roots: transport oxygen to the root system, create a thin oxygen-rich layer around them
Mangrove Reproduction
Viviparous reproduction
Seeds germinate and embryos grow on trees
Dart-shaped embryonic propagule drops down and roots in mud or carried by the tide to a new location
Mangrove Loss and Replanting
Total loss around 30-40% with 1.5-5% lost each year
Shrimp farming is a major contributor to the reduction
Replanting has a poor success rate and they are not as complex or effective
Saltmarsh ecosystems
Coastal halophilic ecosystems
Founded by flowering grasses, sedges rushes that are rooted in soft sediments
Salt marshes have terrestrial origins
Similar adaptations for soft sediment rooting, salt exclusion, anoxia
High community biodiversity, low grass diversity
Saltmarsh biogeography
Mid to high latitudes
Take over from mangroves when the temperature gets too cold
Spartina
The iconic salt marsh plant genus
This is generally restricted to the east coast
Invasive in BC, pushing out oyster beds
Saltmarsh plant structure
Aboveground stem and leaves and belowground rhizomes
Rhizomes take up nutrients and connect members of clonal plants together
They can sexually reproduce but asexual reproduction is the primary way of growing
How do salt marshes form
They start out as mudflats that are colonized by plants
Arrive as seeds or rafting (rhizome with the shoot)
Root in mud and form more through cloning
Form barriers that trap sediment and peat, more grasses are able to colonize
They are ecosystem engineers
Patterns of sediment deposit change as they grow: forms heterogeneous landscape. Considerable depth variation
