2Figure 1: Primary production, vertical flux and regeneration of nutrients in a coastal marine ecosystem. Also shown are some of the involved organisms such as phytoplankton, zooplankton, higher trophic levels and benthic organisms. The massive and narrow vertical arrows indicate scenarios of substantial and insignificant vertical flux.
3Figure 2 :Direct relationship between dissolved inorganic N input and phytoplankton biomass, as mean annual chlorophyll a content
4Figure 3: Conceptual figure, showing the various watershed and airshed anthropogenic nutrient sources, their input to estuarine and coastal waters via freshwater discharge, the establishment of hypoxia due to freshwater overlaying denser saltwater and the stimulation of primary production (eutrophication) and algal booms due to coastal nutrient enrichment. Note the linkage between nutrient enriched primary production and hypoxia as phytoplankton sink into stratified bottom water. Also, note potential negative impacts of hypoxia on bottom dwelling finfish and shellfish as well as submersed aquatic vegetation communities, all of which require oxic conditions.
5Figure 4 : Examples of phytoplankton blooms resulting from excessive nutrient loading is estuarine and coastal waters.
6Figure 4 (con.) : Examples of phytoplankton blooms resulting from excessive nutrient loading is estuarine and coastal waters.
7Figure 4 (con.) : Examples of phytoplankton blooms resulting from excessive nutrient loading is estuarine and coastal waters.
8Figure 5 : Impacts of excessive primary production
9Figure 6 : Impacts of anthropogenically - enchanced nutrient loading on coastal biogeochemical, trophodynamics and water quality, Note the numerous potenially negative feedbacks which come into play in response to increased eutrophication (i.e. accelerating primary productiion)
10ผลผลิตเบื้องต้นคืออะไร the synthesis of organic material from inorganic compounds, such as CO2 and watersimply the rate at which phosynthesis proceedsprimary producersphytoplanktonmacroalgae : Cladophora sp., Enteromorpha sp.aquatic plants : sea grassmangroves
11องค์ประกอบของผลผลิตเบื้องต้น Gross primary production(Pg)rate of photosynthesis, not reduced for losses to excretion or to respiration in its various formsNet primary production(Pn)gross primary production less losses to respiration by phytoplanktonNet community production(Pnc)net primary production less losses to respiration by heterotrophic microorganismsgramms or moles of carbon fixed per unit volume , or per unit area, of water per unit timeg-C m-2 yr-1
12วิธีการหาผลผลิตเบื้องต้น Light-dependent change in dissolved oxygennet production : accumulation of oxygen in a light bottlerespiration : consumption of oxygen in a dark bottlegross primary production : net production – respirationLight-dependent change in dissolved inorganic carbonlike the light-dark oxygen methodprecision less than bulk oxygen methodsrequired extra procedures, such as filtration
13วิธีการหาผลผลิตเบื้องต้น (ต่อ) The 14C methodmost commonly measuredvery sensitive and good precisionThe 13C methodused 13C tracerThe 18O methodChlorophyll a methodgross primary production