Download Ch 50 condensed Notes

Ch 50 Mini Notes
I. General Info.
A. Ecology Definition & Types
1. Ecology- scientific study of the interactions between organisms and the environment
2. Organismal ecology- structure, physiology, and behavior let organisms meet environmental challenges
3. Population ecology focus is on how many individuals of a species can live in an area
a. population members of the same species living in same area at same time
4. Community ecology species interactions in a community
a. community- populations of different species in an area
5. Ecosystem ecology- energy flow and chemical cycling among biotic and abiotic components
a. ecosystem the community (biotic factors) & abiotic factors in an area
6. Landscape ecology- arrays of ecosystems and how they are arranged in a geographic region
a. Landscape- interconnected ecosystems
7. Global ecology- influence of energy and materials on organisms in whole biosphere
a. biosphere- the sum of all the planet’s ecosystems
8. Environmental Issues- Ecology aids scientific understanding of environmental issues
a. Events that occur in ecological time affect life on the scale of evolutionary time
b. Rachel Carson- started modern environmental movement with book Silent Spring in 1962
B. How are species distributed?
1. Biogeography studies what limits geographic distribution of species
2. Two factors- abiotic or nonliving factors
and
biotic or living factors
-Temperature
- Wind
-Interactions with other species
-Water
- Rocks & soil
-Predation
-Sunlight
- Latitude
-Competition
3. Distribution- where you find a species
4. Dispersal- movement of individuals out from densely populated areas – affects distribution
a. Potential range- all the area that a species could occupy
b. Natural range- all the area that a species does occupy
c. Natural Range Expansions- how dispersal influences distribution
d. Species Transplants- organisms intentionally or accidentally relocated from original distribution
o can disrupt the communities or ecosystems where they are introduced
5. Habitat selection-the selection of a specific habitat by a species; is influenced by
a. Climate- Long term prevailing weather conditions in an area: temp., water, sunlight, & wind
1)
Temperature- affects biological processes
2)
Water- desert organisms adapt to low water conditions
 Salinity- how much salt in the water- for aquatic biomes
 Salt concentration affects water balance through osmosis
3)
Sunlight
 Light intensity and quality affect photosynthesis
 Water absorbs light; in aquatic environments most photosynthesis occurs near surface
4)
Wind
 Air flowing close to Earth’s surface creates global wind patterns
b. Rocks & soil- Soil characteristics can limit distribution of plants and thus animals; these include
-Physical structure
- pH
-Mineral composition
C. Regional, Local, and Seasonal Effects on Climate- role of water & physical landscape
1. Global climate patterns are due to solar energy and planet’s movement in space
a. Sunlight intensity -More heat and light per unit of surface area reaches tropics
b. Global air circulation & precipitation patterns -Warm wet air flows from tropics toward poles
2. Location (or point of view)
a. Macroclimate- weather patterns on the global, regional, and local level
b. Microclimate- very fine patterns, like those found underneath a fallen log
3. Bodies of water- Oceans & their currents, also large lakes moderate climate of nearby land environments
a. Daytime- air rises over warm land ; breeze blows from water to land
b. Night time- land cools so air rises over the warmer water; breeze blows from land to water
4. Mountains- Mountains affect amount of sunlight reaching an area, local temperature, and rainfall
a. Rising air releases moisture on the windward side of a peak and creates a “rain shadow” as it
absorbs moisture on the leeward side
5. Seasonality- angle of the sun causes seasonal changes
a. Lakes- seasonal temperature change causes seasonal “turnover” of water
II. Aquatic Biomes
A. Biomes- major ecosystems covering large geographic regions; Biotic & abiotic factors dtmn nature of biome
1. Aquatic biomes account for the largest part of the biosphere (area)
• Oceans - about 75% of Earth’s surface; have huge impact on biosphere
2. Stratification of Aquatic Biomes-Aquatic biomes are stratified into zones or layers defined by light
penetration, temperature, and depth
a. photic zone- upper layer; gets enough light for photosynthesis
b. aphotic zone- lower layer; gets very little light
c. benthic zone- organic and inorganic sediment at bottom of all aquatic zones
d. benthos communities of organisms in the benthic zone
e. Detritus, dead organic matter falls from productive surface water: important source of food
f. abyssal zone- most extensive part of ocean; depth is 2,000 to 6,000 m
g. thermocline- temp. boundary separates warm upper layer from cold deep water
h. turnover - semiannual mixing of upper oxygenated water w/ lower, deoxygenated, nutrient rich
waters
B. Aquatic Biomes - characterized by their physical environment, chemical environment, geological features,
photosynthetic organisms, and heterotrophs
Lakes
1. Oligotrophic lakes are nutrient-poor & oxygen-rich
2. Eutrophic lakes are nutrient-rich and often depleted of oxygen if ice covered in winter
a. littoral zone shallow, well lighted layer; has rooted and floating aquatic plants
b. limnetic zone-deep, poorly lighted layer; small drifting animals (zooplankton) eat phytoplankton
Wetlands- covered by water at least some of the time; support plants adapted to water-saturated soil
1. One of the most productive biomes; have diverse invertebrates and birds
Streams and Rivers – land based flowing water
1. Currents – a major factor; diverse populations of aquatic organisms
Estuaries- transition area between river and sea- Salinity varies with the rise and fall of the tides
1. Estuaries are nutrient rich, highly productive & very bidoverse
Intertidal Zones- shoreline between high & low tide marks
1. extreme variations in temperature and salinity and mechanical forces of wave action
Oceanic Pelagic Zone -open blue water, constantly mixed by wind-driven oceanic currents
1. covers approximately 70% of Earth’s surface
2. Phytoplankton and zooplankton are the dominant organisms + free-swimming animals
Coral Reefs- formed from calcium carbonate skeletons of corals (phylum Cnidaria)
1. Corals require a solid substrate for attachment
2. mutualistic relationship- Unicellular algae live in tissues; coral gets food, algae gets protection
Marine Benthic Zone- seafloor below surface of coastal waters, consists of
a. neritic zone- coastal waters close to shore
b. pelagic zone- deep water
c. abyssal zone- very deep water
 Organisms are adapted to continuous cold and extremely high water pressure
 deep-sea hydrothermal vents- volcanic origin on mid-oceanic ridges; here the
autotrophs are chemoautotrophic prokaryotes
III. Terrestrial biomes- affected by climate & disturbance
1. disturbance -such as a storm, fire, or human activity; can alter biome pattern
A. Climate and Terrestrial Biomes- Climate determines why terrestrial biomes are found in certain areas
1. climograph- plot of temperature and precipitation in a region; shows changes in climate over distance
2. climate affects animal distribution
B. General Features and the Role of Disturbance
1. Terrestrial biomes usually grade into each other, without sharp boundaries
a. Ecotone area of intergradation
2. Vertical layering- ex. a forest has an upper canopy, low-tree layer, shrub understory, ground layer of
herbaceous plants, forest floor, and root layer
3. Terrestrial biomes- characterized by distribution, precipitation, temperature, plants, and animals
C. The biomes are:
Tropical Forest - vertically layered and competition for light is intense
1. tropical rain forests-rainfall relatively constant, while in
2. tropical dry forests precipitation is highly seasonal
3. millions of animal species- with ~5–30 million undescribed insects, spiders, and other arthropods
Desert - Precipitation is low and highly variable, generally less than 30 cm per year;
1. deserts may be hot or cold
2. Desert plants are adapted for heat and desiccation tolerance, water storage, and reduced leaf surface area
Savanna- precipitation and temperature are seasonal
1. Plants- Grasses and forbs make up most of the ground cover
2. Animals- insects and mammals such as wildebeests, zebras, lions, and hyenas
Chaparral- has seasonal extremes- cool and rainy winters and hot dry summers
1. Plants- shrubs, small trees, grasses, and herbs; may be adapted to fire and drought
2. Animals- amphibians, birds and other reptiles, insects, small mammals and browsing mammals
Temperate Grassland- are found on many continents; cold and dry winters, wet and hot summers
1. Plants-, grasses and forbs, are adapted to droughts and fire
2. Mammals include large grazers and small burrowers
Northern Coniferous Forest - Also called taiga- largest terrestrial biome; found in No. America & much of far
northern Europe; has long cold winters & hot summers
1. Plants- evergreen trees
2. Animals include- migratory and resident birds, and large mammals
Temperate Broadleaf Forest- Cool winters & hot, humid summers are; year round rain and snow
1. Plants- deciduous trees in No. America, evergreens in Australia
2. Animals- Mammals, birds, and insects; many mammals hibernate in the winter
Tundra- covers expansive areas of the Arctic; alpine tundra exists on high mountaintops at all latitudes
1. Winters are long and cold while summers are relatively cool; precipitation varies
2. Permafrost, a permanently frozen layer of soil, prevents water infiltration
3. Vegetation is herbaceous (mosses, grasses, forbs, dwarf shrubs and trees, and lichen) and supports birds,
grazers, and their predators