1. 하구및 연안생태Coastal management
2014 년 가을학기

2. Salt marsh productivity?
Rate and factors affecting productivity of salt marsh
Spartina alterniflora
Remarkably high
Important for estuarine food chains
increase in spring flowers  dies
dead biomass increase
no live biomass in winter above 38 N
decreasing trends of standing stock from gulf of Mexico to new England
productivity: 200 ~ 6000 g dry wt/m2/yr
Short term variation
CO2 exchange method
low in high tide : activity is low ? ; probably not

3. Below ground production
difficult to distinguish “live” from “dead”
almost always greater than above gound
Method problem
Tagging
Follow both dead and live biomass

4. Factors affecting marsh production
solar radiation temperature, tides, nutrient concentrations, soil types, drainage, oxygen concentration, pH

5. Factors affecting marsh production
solar radiation temperature, evapotransportation
Direct: solar energy
Indirect: temperature  metabolic rates  evapotransportation change
shows latitudinal gradient
Wetland vegitation is not water limited and actual evapotransportation is almost same as PE (potential evapotransportation) : PE is closely related to temperature
General relationship between productivity versus air temp.
Low winter temp, ice formation

6. Tides
Tidal subsidy !!
positive relationship between tidal range and production
gated marsh had low standing crop.
can be a stress in very high range
difference in stream side and inland marshes is greater in high tide.: complete drainage in stream side; dye experiment
Percolation rates difference with the spartina

7. Nutrients
Nitrogen addition increased the growth of S. alterniflora (not P)
inland marshes had greater effects than stream side

8. Oxygen in sediment soil O2 conc. Is important for plant growth
anoxic soil  H2S toxicity; inhibit respiration and nutrient uptake
metaboilc pumping of O2 by marsh plant
Fertilization increased Eh
Interactions
degree of anoxia is mild: malate (less toxic) accumulate: reused by spartina when aerobic condition reoccur alcoholic fermentation is not stimulated
Anoxia severe : fermentation occur ethanol produced  lost of energy reduced growth

9. Salinity S. alterflora and Distichlis spicata: salt obligates
S. patens : facultative halophyte
S. alterflora : best in 10 ppt
Can survie 30~40 ppt with aeration and N addition
Osmotic stress (water loss) and cell membrane damage
Membrane permeability change with salinity: nutrient uptake and water loss problem; increased permeability reduces ion selectivity
Selectively concentrating preferred ions
Salt removal via salt glands : salt deposit on the tips of S. alterflora.
Low railfall: make high salinity and reduced nutrient delivery

10. PH, nature of soil S. alterflora : optimal at PH 6
Fine clay: higher nutrient level
Soil density: high in stream side: input of mineral sediment during high tide
New soil brings new nutrients

11. Age, herbivore
age of a plant stand affects its productivity: as a marsh ages, there is increasing belowground biomass ; nutrient is tide up.
Direct hervivory is low; les than 5%
High productivity due to C4 plant; high light and temperature saturation level (30~35 versus 25 C)
C3: phosphoglyceric acid
C4: oxaloacetic acid
- Less transpiring in C4 plants; less salt build up.

12. Mangrove productivity
similar patterns are evident with salt marsh
the highest among the forest ecosystem
high productivity in riverine to low values in scrub forest
Litterfall is strongly correlated with forest structure.
Correlation with freshwater and nutrient, and decreased salt content

13. Mangrove productivity
factors that control mangrove productivity: similar to salt marshes: no latitudinal gradient (occurs only at tropical zone)
Flooding regime, lower salinity, higher nutrient level. Lower H2S level.
Increased freshwater brings high nutrient and low salinity