| dbo:abstract |
Low-nutrient, low-chlorophyll (LNLC) regions are aquatic zones that are low in nutrients (such as nitrogen, phosphorus, or iron) and consequently have low rate of primary production, as indicated by low chlorophyll concentrations. These regions can be described as oligotrophic, and about 75% of the world's oceans encompass LNLC regions. A majority of LNLC regions are associated with subtropical gyres but are also present in areas of the Mediterranean Sea, and some inland lakes. Physical processes limit nutrient availability in LNLC regions, which favors nutrient recycling in the photic zone and selects for smaller phytoplankton species. LNLC regions are generally not found near coasts, owing to the fact that coastal areas receive more nutrients from terrestrial sources and upwelling. In marine systems, seasonal and decadal variability of primary productivity in LNLC regions is driven in part by large-scale climatic regimes (e.g. El Niño-Southern Oscillation) leading to important effects on the global carbon cycle and the oceanic carbon cycle. The naming of these regions follows the same format as the more widely known high-nutrient, low-chlorophyll (HNLC) regions, which display high macro-nutrient concentrations but unusually low primary production and chlorophyll concentrations, usually due to lack of micro-nutrients, usually iron-limitation. While the LNLC terminology appears synonymous with oligotrophic, literature in recent decades has predominantly used the term to define oligotrophic ocean areas (as opposed to lakes, rivers, or other bodies of water) in discussions about dust and iron fertilization. Occasionally, LNLC refers to “low nitrate, low chlorophyll,” which has a similar meaning. (en) |
| rdfs:comment |
Low-nutrient, low-chlorophyll (LNLC) regions are aquatic zones that are low in nutrients (such as nitrogen, phosphorus, or iron) and consequently have low rate of primary production, as indicated by low chlorophyll concentrations. These regions can be described as oligotrophic, and about 75% of the world's oceans encompass LNLC regions. A majority of LNLC regions are associated with subtropical gyres but are also present in areas of the Mediterranean Sea, and some inland lakes. Physical processes limit nutrient availability in LNLC regions, which favors nutrient recycling in the photic zone and selects for smaller phytoplankton species. LNLC regions are generally not found near coasts, owing to the fact that coastal areas receive more nutrients from terrestrial sources and upwelling. In ma (en) |
