a community of organisms where there are several interconnected food chains.
Two Types of Food Webs Chapter 47 Producers (photosynthesizers) Energy Input: Energy Input: herbivores carnivores decomposers decomposers detritivores Energy Output Energy Output energy losses as metabolic heat & as net export from ecosystem Producers (photosynthesizers) decomposers detritivores Transfers: Transfers: energy in organic wastes, remains Grazing Food Web Detrital Food Web Producers (Photosynthesizers) Producers (Photosynthesizers) Herbivores Carnivores Decomposers Decomposers Detritivores
Overview of Hydrologic Cycle Atmosphere Ocean Land evaporation from ocean 425,000 precipitation into ocean 385,000 evaporation from land plants (evapotranspiration) 71,000 precipitation onto land 111,000 wind-driven water vapor 40,000 surface and groundwater flow 40,000 Figure 47-15 Page 853
EVAPORATION PRECIPITATION TRANSPIRATION dripping, trickling down along stems falling through to ground interception by plants surface pooling, etc. infiltration of soil moisture in soil seepage, percolation groundwater storage DEEP OUTFLOW overland flow lateral flow base flow STREAM OUTFLOW Fig. 47-16, p.853
Carbon moves through the lower atmosphere and all food webs on its way to and from its large reservoirs.
Earth’s crust holds the vast majority of carbon.
The Ocean is the next largest reservoir.
Most of the annual cycling of carbon occurs between the ocean and the atmosphere.
Carbon moves into and out of ecosystems mainly when combined with oxygen.
Ex. Carbon dioxide, bicarbonate, and carbonate.
Carbon Cycle - Marine incorporation into sediments diffusion between atmosphere and ocean bicarbonate and carbonate in ocean water marine food webs marine sediments combustion of fossil fuels death, sedimentation uplifting sedimentation photosynthesis aerobic respiration
Carbon Cycle - Land photosynthesis aerobic respiration terrestrial rocks soil water land food webs atmosphere peat, fossil fuels combustion of wood sedimentation volcanic action death, burial, compaction over geologic time leaching, runoff weathering combustion of fossil fuels
Ammonification – soil fungi and bacteria decompose nitrogen-containing compounds ammonia and ammonium.
Nitrification – bacteria convert ammonia and ammonium to nitrite and nitrate, which plants can absorb.
Denitification - conversion of nitrate and nitrite to gaseous nitrogen (N 2 ) or nitrogen oxide (NO 2 ) certain soil bacteria.
Overview of Nitrogen Cycle gaseous nitrogen (N 2 ) in atmosphere NO 3 - in soil nitrogen fixation by industry fertilizers NH 3 - ,NH 4 + in soil 1. Nitrification leaching uptake by autotrophs excretion, death, decomposition uptake by autotrophs nitrogen fixation leaching ammonification 2. Nitrification dentrification nitrogenous wastes, remains NO 2 - in soil food webs on land