Factors limiting primary Coriolis effect: object at Earth rotates productivity equator is moving east at 24,000 west to east miles per day. If it moves north, Terrestrial: the earth beneath moves more Liquid water, light, N, P slowly, so it veers right. If it moves from north towards equator, also goes right. Reverse Marine productivity: is true in southern hemisphere. N, P, Fe, light at depth… Northeast trade winds pile the Atlantic against Central America •Most of the ocean is “liquid desert” •Importance of upwellings along western Return flow coasts of continents is the Gulf Stream topex-www.jpl.nasa.gov/science/ images/el-nino-la-nina.jpg Winds displace ocean water off the west coast of North In a normal year, the trade Westerly trade winds and South America, causing upwelling: cold, nutrient rich winds blow westward and water pulled up to replace displaced surface water. push warm surface water near Australia and New North South Guinea. When warm water builds up in the western Pacific Ocean, nutrient-rich cold water comes up off the west coast of South America and increases fisheries Nutrient upwelling productivity. upwelling During an El Niño event, the trade winds weaken and warm, nutrient-poor water occupies the entire tropical Pacific Ocean. Rich Heavy rains that are tied to the warm fisheries water move into the central Pacific Ocean and cause drought in Indonesia and Australia. This also alters the path of the atmospheric jet stream over North and South America. Energy flows—a small fraction of solar radiation (ca. 1%) is fixed by (Organic compounds Nutrients (N,P) and carbon photosynthetic organisms, but once energy is dissipated as heat, it is never contain C and H) recovered by ecosystem (except as passive energy savings for transport— e.g. ocean or air currents driven by heat and used by organisms). CO (NH2) 2 Materials cycle—atoms (H, O, C, N, Ca, P ) created in stars, used again and C6H12O6 again, end up in different pools, fluxes transfer atoms between pools. Stocks (pools, compartments) and flows (fluxes) Input - Output = Change in Storage (= 0 at equilibrium) Campbell, Turnover time: if system is in equilibrium so input (vol time-1) = output p. 1209 (vol time-1) = q, residence time or turnover time, T = Volume/q Inorganic CO input storage output 2 + NH4 NO - Yellow system has 3 input storage output shorter turnover time Available to biota Unavailable than blue system. 1 Terrestrial (bottom-heavy) pyramid of trophic level biomass Clean water, and fish— Two ecosystem services brought to you by: Inverted pyramids of trophic level biomass (Elton 1927): suppress sustain Energy (carbon) budgets for an P n / ( P n-1) P organism or a N Efficiency of Herbivore Carnivore Microbivore Detritivore trophic level (N) RN trophic consumer transfer for Production N-1 = AN Not consumed + ingested secondary production Invert Ingested = feces EN excreted + assimilated Allocations IN Assimilated = used for that ectotherm maintenance (respired) compete I = ingestion Vert Vert Not + used for production with growth A = assimilation F = egestion consumed (new tissue or offspring and = P ) R = respiration Dead N reproduction P = production P N-1 organic (defense, endotherm matter stress) Vert Vert Food produced Begon et al. 1997 Food quality is an important factor affecting production efficiency Hydrologic cycle: Carbon cycle (Campbell p. 1211) Evaporation = Precipitation Transfer processes: atmospheric transport, runoff Most serious consequence of greenhouse warming will be the redistribution of water in space and time: reduced snowpack storage in Sierra increased intensity of storms flashiness of runoff…. 2 Phosphorus Phosphorus cycle, Cambell p. 1212. Fig. 27.3, Krebs P residence time: algae: days-weeks animals: days-years soils: months-millenia ocean sediments: millions of years The Nitrogen Cycle http://www.physicalgeography.net/fundamentals/9s.html Human activities (fossil fuel combustion, synthetic fertilizers, cultivation of legumes, industrial meat production) have more than doubled the natural input rate of fixed (bioavailable) nitrogen (Vitousek 1997). Importance of land cover in retaining N high in the landscape V. Smil 1997. Scientific American. Curious —Hubbard Brook Experiment fate of Franz Haber* German chemist, awarded Nobel Prize 1919 for ammonia synthesis. Haber-Bosch synthesis of ammonia from nitrogen and hydrogen, combined at high Gene temps and pressuresÆ explosives for WWI Likens but world fertilizers soon thereafter, allowing human population to exceed 6 billion…. p. 1214 Campbell deforested *also developed Tree weaponized chlorine gas cutting used in WWI, stream completed Losses during floods hoping to limit overall suffering by control bringing about a quicker resolution to the war. 3 Ecosystem efficiency: organic production/nutrient flux (mass time-t / mass time-t ) Forests more efficient at producing wood from nutrients if these are retained (!) input storage output ATV tracks storage input output Terrestrial nutrient and soil retention degraded by wind erosion in desert after loss of desert crusts River retention and ecosystem efficiency increase as spiral length decreases: River Continuum Concept Vannote et al. 1980 Stream spiraling (Newbold, Webster): downstream transport with periodic Channels widen cycling by local biology--short spiral downstream. length, in retentive streams, means If aquatic algae and more biotic production per atomic flux plants are light limited (per atom going down system) due to in headwaters, less able wetlands, logs, permeable beds, to take up and retain structural complexity. nutrients. But heterotrophic bacteria that get their carbon from leaves might backflows increase nutrient retention Sinks: Eutrophic (river, lake estuary): nutrient rich, likely to Carpenter et al. outflow produce noxious or harmful algal blooms (cyanobacteria, toxic 1999 Ecological food web dinoflagellates) Applications sediment Internal recycling* sequestration Mesotrophic – intermediate nutrient concentrations Oligotrophic – low nutrient concentrations, very clear water (“good” water quality for humans and fish) Inputs from watershed Lakes Easier for Blue wind to stir Green nutrients in shallow basin, making such lakes easier to eutrophy *Rate of recycling from sediments increases as organic deposition lower oxygen 4 Bioaccumulation of DDT, PCBs, Hg, and other toxins Explaining lags to managers…. Carpenter et al. 1999 Basin morphometry determines shape of recycling curve, and whether eutrophication is irreversible Campbell, p. 1218 Pyramid Lake Mercury (Hg) enters food chain after it is Clear water state: methylated (in presence of organic matter) Steamboat Cr Reno’s sewage + Hg Æ CH3ClHg Truckee R. Truckee Green water, eutrophic state: Tahoe stabilized or maintained by: Transport of *nutrient sequestration in long-lived Hg into high top predators; desert food *upslope vectoring of nutrients web by birds by mobile scavengers and predators and lizards (salmonids, birds, bats, bears); feeding on *terrestrial vegetative cover; emergent *frequent scour and flushing that maintain aquatic insects edible taxa at lower trophic levels Switch from oligotrophic to eutrophic state: Land conversion -loss of wetlands, forests -erosion, fine sediment loading -sewage, agrochemicals Water management (extraction, impoundment, Eutrophic state stabilized, diversion): maintained by: -loss of flushing flows, habitat *internal nutrient cycling enhanced by hypoxia; N2 N2 *loss of higher trophic levels due to hypoxia and inedible algae *more bank erosion with loss of rooted terrestrial vegetation; *nitrogen fixation by cyanobacteria that dominate under high P 5.