Fig. 12-20, p. 289
Chapter 4 Environments and Life 2
Guiding Questions What factors determine the ecological niches of species, and by what means do species obtain nutrition? What factors govern the geographic distribution of species? What factors govern the distribution of aquatic life? 3
On land growth of plants is largely limited by water. In the ocean growth of plants is limited by nutrients and/or light.
Fig. 13-8, p. 306
What is productivity? It is photosynthesis. Sometimes referred to as primary productivity. In its simplest form, focusing on the carbon: CO 2 + H 2 O CH 2 O + O 2 Carbon dioxide Water Carbohydrate Oxygen
And it s really part of a larger carbon cycle. Photosynthesis (light) CO 2 + H 2 O CH 2 O + O 2 Chemical (oxidative) energy Respiration
Fig. 13-5a, p. 303
Fig. 13-5c, p. 303
Fig. 13-6a, p. 304
Fig. 13-7c, p. 305
Surface Water Temperature (SST)
Surface Water Phosphate Concentrations NOAA-NESDIS-National Oceanographic Data Center- Climatology
Fig. 12-6a, p. 276
Examples of where there are high rates of photosynthesis in surface ocean water: Nearly all continental margins Near River Mouths: Congo, Amazon, Mississippi Coastal Upwelling: Peru, Namibia & NW Africa Open ocean; low latitudes: Equatorial Pacific, Indian Ocean (Arabian Sea), Open ocean; high latitudes: North Atlantic and Pacific, Southern Ocean (polar fronts, convergent and divergent zones)
Net Production and Precipitation Net production increases rapidly with increasing precipitation, but levels off at higher values Figure 8.8, p.287
Ocean Surface Currents Midlatitude gyres contribute to zonal asymmetry in subtropics: cold on west coasts, warm on east coasts
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Ecology Ecology Study of the factors that govern the distribution and abundance of organisms in natural environments Habitats Environments on or close to Earth s surface inhabited by life Terrestrial Aquatic Marine Freshwater 23
Ecology Ecologic niche The way a species relates to its environment, including food, nutrients, physical and chemical conditions Life habit The way a species lives within its niche Limiting factors Naturally occurring, restricting condition (physical and chemical) Competition Shared drive for limited resources Predation 24
Ecosystem Ecosystem Organisms of a community and the physical environment they occupy Population Group of individuals that belong to a single species and live together in a particular area 25
Ecologic community Ecosystem Populations of several species living in a habitat Producers Photosynthesizing organisms; foundation of community Consumers Herbivores: feed on producers Carnivores: feed on other consumers 26
Biota Ecosystem Fauna: animals and protozoans of an ecosystem Flora: plants and plantlike protists Food chain Sequence of consumption for producers to consumers 27
Fig. 12-8, p. 277
Ecosystem Food web More complex than simple food chain More common Several species occupy each level Parasites Feed on living organisms Scavengers Feed on organisms that are already dead 29
Ecosystem Diversity The variety of species that live together within a community Lower in more difficult habitats Predation influences diversity Heavy can reduce diversity Moderate can increase diversity by reducing competition Opportunistic species Species that specialize in invading newly vacated habitats 30
Biogeography Distribution and abundance of organisms on a broad geographic scale Limiting factors Diversity increases toward equator Barriers can affect dispersal 31
Climate Classification (Köppen)
Atmospheric Circulation Net transport Air sinks at the poles, rises at the equator Simplified model No tilt No Coriolis effect 33
Atmospheric Circulation Actual pattern is more complex Three circulation cells Trade winds, westerlies, easterlies Intertropical convergence zone Northern, southern trade winds converge near equator Changes seasonally 34
Temperature Variations Atmosphere retains heat Solar radiation Absorbed and turned into heat energy Reflected 6-10% ocean 5-30% forest 45-95% ice and snow 35
Terrestrial Realm Vegetation follows climatic zone Tropical rain forest Desert savannahs Temperate forests Polar tundra 36
Climate Zones Circulation features are tied to regional climate Rising air associated with lots of precipitation
Temperature Patterns Stronger seasonal heating and cooling on land produces asymmetry Poleward distortion of isotherms over northern high latitude oceans Equatorward distortion over subtropics
January July Precipitation (mm/month) Very wet over tropics Seasonal shift (N/S) Monsoon regions Extremely dry subtropical highs Midlatitudes get more summer rain July rainfall looks like a map of forest cover
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Terrestrial Realm Tropical Climates 18 20 C (64 68 F) 0 30 latitude Tropical Rain Forest Dense vegetation 42
Terrestrial Realm Deserts Dry trade winds remove moisture 20 30 north and south of the equator < 25 cm rain/year Little vegetation Savannah, grasslands Too dry to support forests 43
Poles Defined by ice sheets and glaciers today Absent or reduced at times in the past Terrestrial Realm 44
Terrestrial Realm Glaciers Ice in motion Glide and spread Present at high latitudes and high elevations near equator 45
Tundra Limited water Grasses, sedges, lichens, shrubs dominate Cannot support tall trees Evergreen coniferous forests South of tundra Spruce, pine, fir Terrestrial Realm 46
Terrestrial Realm Temperate forests Longer summers, slightly warmer Deciduous trees Maples, oaks, beeches Mediterranean climate Dry summers, wet winters Common 40 N and S of equator Californian, Mediterranean region 47
Climate Climate Controls distribution of species globally Has changed through time Plate tectonics and other changes affect climate 48
Climate Altitude Similar to latitudinal gradient At base Deciduous forest On slopes Evergreen forest Tundra above treeline At top Glaciers 49
Mountains Rain shadow Prevailing winds bring moisture Precipitation on windward side Aridity on leeward side Climate Rain shadows common on east side of North American mountain chains 50
Seasonal Change High heat capacity of water Less change in ocean temperatures than on land Monsoon Circulation Summer winds flow onshore; bring rain Winter winds offshore Climate 51
Plants as Climate Indicators Sensitive indicators of change Cycads Tropics and subtropics today Fossil distribution allows reconstruction of climate patterns 52
Plants as Climate Indicators Leaf Margins Tropics Smooth, waxy margins Temperate climates Jagged margins 53
Ocean currents Wind driven Follow atmospheric patterns Trade winds Push waters west; form equatorial currents Equatorial countercurrents Return flow Gyres Clockwise in Northern Hemisphere Gulf Stream Marine Realm 54
Circumpolar current Circles Antarctica Very cold Marine Realm 55
Marine Realm Polar circulation Sea ice leads to more saline water Cold, dense waters sink Antarctic waters Flow north at depth Arctic waters Flow south at depth 56
Ocean circulation Waves Surface waves Tides Marine Realm Wind driven Break when seafloor interacts at shallow depths Cause major movement of water in oceans Due to rotation of solid Earth beneath bulges of water produced by gravitational attraction of the moon 57
Continental Shelf Submarine extension of continental landmass Shelf break Edge of shelf ~200 m w.d. Continental Slope Continental Rise Abyssal Plain Marine Realm 58
Marine Realm Near shore Barrier islands Marshes Epicontinental seas 59
Photic Zone Region of ocean where enough light penetrates to permit photosynthesis Pelagic life Plankton Phytoplankton Zooplankton Nekton Benthic life Suspension feeders Deposit feeders Marine Realm 60
Marine Realm Marine Biogeography Tropical Subtropical Transitional Subarctic 61
Marine Realm Corals Most require warm water Common in tropics Reef builders Coral polyp Builds coral cup Connected to other polyps Symbiotic relationship with algae 62
Marine Realm Salinity Limiting factor near shore Oceanic 35 ppt Brackish Lower than marine Bays, lagoons Hypersaline Higher than marine Hot arid climates 63
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GlobalProd_Seawifs.mpg NASA/Goddard Space Flight Center, The SeaWiFS Project and GeoEye, Scientific Visualization Studio SeaWiFS Ocean Biosphere: 1997 to 2006
seawifs-6year.mpg 67
SeaWiFS Biosphere OceanProd_SeaWifs.mpg NASA/Goddard Space Flight Center, The SeaWiFS Project and GeoEye, Scientific Visualization Studio
NAtlBloom_Seawifs.mpg NASA/Goddard Space Flight Center, The SeaWiFS Project and GeoEye, Scientific Visualization Studio SeaWiFS Biosphere: North Atlantic
Amazon_NAfr_Seawifs.mpg NASA/Goddard Space Flight Center, The SeaWiFS Project and GeoEye, Scientific Visualization Studio SeaWiFS Biosphere: Amazon River
Congo_SeaWifs.mpg NASA/Goddard Space Flight Center, The SeaWiFS Project and GeoEye, Scientific Visualization Studio SeaWiFS Biosphere: Congo River & Namibia