BIOLOGY 2F03 Lecture Notes - Pecos River, Continuum Concept, Submersed
Document Summary
Life in freshwaters rivers: temperate (thames) vs tropical (darling) ratio of min:max flow = 1:3 vs 1:5. Greater impact on sediments and organisms in tropics. Life in freshwaters (running) chemistry of rivers depends on land and climate: the salinity of the pecos river, nm (desert) is 500 times higher than the salinity of the rio negro, amazon (tropical) Rio negro: very clear but very dark, doesn"t have much salt. Amount of water, much more precipitation in the tropics. Age of the areas, how long the soils or rocs have been exposed to the climate. Salinity may be 500 times greater when river flows through desert. Next animals (shredders) chew and shred leaves. Organisms capable to chopping the leaves, bark whatever falls into the mountain stream collectors: let others do the work. Predators: independent of the initial source of food. Grazers: very few grazers because theirs very little nutrients in the water, no light, no algae.
