Biology 2 Chapter 52

Salinity

Most aquatic organisms are restricted to either freshwater or saltwater habitats by their limited ability to osmoregulate. Few animals and plants in high salinity areas.

Streams and Rivers

Most prominent physical characteristic is their current. headwater streams are generally cold, clear, turbulent and swift. Father downstream things warm up and settle down. Salt and nutrient level of streams and rivers increased from the headwaters to the mouth. Headwaters are generally rich in oxygen. Large fraction consists of dissolved or highly fragmented material that is carried by the current from the forested steams. Headwater streams that flow through grasslands or deserts may be rich in phytoplankton or rooted aquatic plants. In streams flowing through temperate or tropical forests, organic matter from terrestrial vegetation is the primary source of food for aquatic consumers.

Dispersal

Movement of individuals away from their area of origin or from centers of high population density.

Thermocline

Narrow layer of abrupt temperature change that separates the uniformly warm upper layer from more uniformly cold deeper waters.

Rachel Carson who wrote book Silent Spring

"The control of nature is a phrase conceived in arrogance, born of the Neanderthal age of biology and philosophy when it was supposed that nature exists for the convenience of man. " Seminal to the modern environmental movement (1907-1964). Warned that widespread use of pesticides such as DDT was causing population declines in many more organisms than the insects targeted for control. Led to new environmental ethic to lawmakers and the public.

3. Global Climate Patterns (4 important factors)

1. Latitudinal variation-The tropics (23.5 N latitude and 23.5 S latitude). Earth is at an obligue angle farther North and South thus sunlight strikes more diffuse. 2. Seasonal Variation in Sunlight Intensity- March and September equinox. Equator faces the sun directly neither pole tilts towards the sun more. 12 hours of light 12 hours of darkn. June solstice. Northern hemisphere tits towards sun and has longest day and shortest night, vice versa for southern hemisphere. December solstice- Northern hemisphere tilts away thus has longest nights and shortest days. 3. Global air circulation and precipitation patterns- Strong sunlight near equator causes evaporation and thus warm wet air mosses to release content in tropical regions. High altitude air masses now dry descend toward earth absorbing mosisture and creating arid environments around 30 degrees north and south.. Air then rises again and creates large rainfall at latitudes 60 degress serly flows. and south. Back down taking up moisture and creating rainless, bitterly cold climates of the polar regions. 4. Global wind pattern- Land near the equator moves faster that that at the poles, deflecting the winds from vertical paths creating more easterly and westerly flows. Cooling trade winds from the east to west in the triopcs. Prevailing westerlies blow from west to east in the temperate zones defined as the regions between the Tropic of Cancer and the Artic Circle.

detritus

A major portion of food in the benthic zone that is dead organic matter

Levels of ecological research

A. Organismal- Study of the physiology, structure and (animals) behavior of an organism and how these features allow the organism to meet the challenges posed by its environment. B. Population- Study of the population size and how and why it changes through time. C. Community- Group of populations of different species living in an area. Examines how the interactions between species such as predation and competition affect community structure and organization. D. Ecosystem- Community of organisms in an area and the physical factors which those organisms interact. Emphasizes energy flow and chemical recycling between organisms and their environment. E. Landscape- mosaic of connected ecosystems. Focuses on the factors controlling exchange of energy materials, and organisms across multiple ecosystems. F. Global- Biosphere- the sum of all the planet's ecosystems and landscapes. Examines how the regional exchange of energy and materials influences the functioning and distribution of organisms across the biosphere.

Northern Coniferous Forest

Acroos northern NA and Eurasia. edge of artic tundra. Largest terrestrial biome on Earth!!!!! Annual precipitation generally ranges from 30 to 70 cm. and periodic droughts are common. Some of northern US are temperate rain fore=sts. Cold and long winters. Summers may be hot. Diversity of plants in the shrub and herb layers is lower than in temperate broadleaf forests.

Ecoton

Area of intergradation. Terrestrial biomes generally grade into each other without sharp boundaries.

Terrestrial Biomes- Tropical Forest

Average air temperature of 25-29 degrees C. Broadgreen evergreen trees are dominant in tropical rain forests. Trees in dry forests drop their leaves. Animal diversity is higher in tropical forests than in any other terrestrial biome. 200-400cm annual rain. Dry forests deasonal precipitation that is about 150-200cm annually.

Disturbance

Biome patterns are modified by this. Example is storm, fire, or human activity. That changes a community. Ex. Frequent fires kill woody plant and keep savanna from becoming the woodland.

Example of dispersal

Cattle egret moving from Africa and Southwestern Europe to North eastern South America then Central Ameria and North America. Today span all around America

Information about abiotic factor of temperature

Cells die at 0 degrees celsius and the proteins of most organisms denature at temperatures above 45 degrees C.

Microclimate

Cleared areas have greater temperature extremes. Low lying ground is usually wetter than high ground.

Water

Desiccate (dry out). Terrestrial organisms face a nearly constant threat of desiccation.

Highly seasonal precipitation

Dry winters, and wet summers. between 3-100cm precipitation. Periodic drought is common. Cold winters and hot summers. Grasses and forbs domiate. Deep fertile soils.

Savanna

Equatorial and subequatorial regions. Average of 30-50cm. warm year round but some variation. Dominant herbivores are insects, especially termites.

Effect of Large body of water

Ex. So Cal. Warm air from land rises. Cool, dry ocean breezes are warmed when they meet land absorbing the moisture and creating a hot, arid climate pattern inland. During a hot day warm air from land draws a cool breeze from the water across the land and at night air over the warmer water now warmer, rises drowing cooler air from the land back out over the water replacing it with warmer air from offshore.

Climate change (long-term)

Ex. The American beech will move northword. It must move 7-9 KM but only does .2 per year which suggests we will need to help.

Tundra

Expanisve areas of the Arctic. Accounting for 20% of earths land surface. High winds and low temperatures create similar plant communities, called alpin tundra on very high mountaintops.Mostly herbaceous. Permafrost restricts growth of plant roots.

Habit selection is one of the most well understood ecological processes, T or F?

False. It is not well understood.

Coral Reefs

Formed largely from the calcium carbonate skeletons of corals. live in the photic zone of relatively stable tropical marine environments with high water clarty, primarily on islands and along the edge of some continet. Sensitive to water not below 18 not above 30. Deep-sea do exist and have as much diversity. Require high oxygen levels. Fringing reef on young high island, then barrier reef then coral atoll as island submerges. Unicellular algae live within the tissue of corals, forming a mutualistc relationship that provides the corals with organic molecules. Diverse red and green algae.

Temperate Broadleaf forests.

Found mainly in the midlatitudes of the Northern Hemisphere with smaller areas in New Zealand and Australia. 70-200 cm annually. Fall throughout. Winter around 0, 35 summer. Few epipytes. Distinct vertical layers. including a closed canopy, one or two strata of understory strees a shrub layer, and an herbaceous strtum.

Wetlands

Habitat that has been inundated by water at least some of the time and that supports plants adapted to water-saturated soil. Some wetlands are inundated at all times, whereas other flood infrequency. Water and soils are periodically low in dissolved 02 due to high organic production by plants and composition by microbes and other organisms. *Basin (shallow); Riverine (along shallow and periodically flooded banks of rivers); Fringe (coasts of large lakes and seas, water flows back and forth. Include both freshwater and marine biomes. ***Among most productive biomes on earth. ***Almost 90 percent depleated.

Climograph

Impact of climate on the distribution of organisms can be represented by a plot o fthe temperature and pricipitation. In northern coniferous forests.

Sunlight

In aquatic environments every meter of water depth selectively absorbs about 45% of red light and 2% of blue light. Most photosynthesis occurs relatively near the surface.

biotic

Living factors like predation, parasitism, resource competition and other factors that exist in the relationship of living organisms

Biomes

Major terrestrial or aquatic life zones, characterized by vegetation type in terrestrial biomes or the physical environment in aquatic biomes.

Abiotic

Nonliving factors like temperature, salinity, climate, precipitation, altitude and so forth.

Desert

Occur in bands hear 30 degrees north and south. Generally less than 30 cm of annual rain. May exceed 50C temp or fall below -30C.

Abyssal zone

Part of benthic zone that lies between 2,000 and 6,000 m below the surface.

Intertidal zones

Periodically submerged and exposed by the tides, twice daily on most marine shores. Generally high oxygen and nutrient levels and are renewed with each turn of the tides. Sandy intertidal zones exposed to vigorous wave action generally lack attached plants or algae. Oil pollution has caused a lot of problems.

What are two common biotic factors that limit distribution of species?

Predators and Herbivores.

Example of herbivore limiting distribution

Sea urchins limit distribution of seaweeds. W.J. Fletcher, near Sydney Australia tested the hypothesis that sea urchins are a biotic factor limiting seeweed distribution.

Turnover-

Semiannual process where oxygenated water from lake's surface goes to bottom and nutrient-rich water from the bottom goes up. Both spring and autmn. Essential!

Mountains

South facing slopes in the Northern Hemisphere receive more sunlight than nearby north-facing slopes. Deserts commonly occur on leeward side.

Benthic zone

Substrate at the bottom of all aquatic biomes (made up of sand and organic and inorganic sediments. Occupied by communities of organisms collectively called the benthos. A major portion of food in this area is dead organic matter called detritus.

Biomes usually exhibit extensive patchiness, with several distinct communities represented in any particular area, T or F?

T

Marine communities, in particular, illustrate the limitations on species distribution that result from abiotic factors of degree of light, distance from shore, open water or near bottom, T or F?

T

Major components of climate

Temperature, precipitation, sunlight, wind

Estuary

Transition area between river and sea. Often, higher density seawater occupies the bottom of the channel and mixes little with the lower-density river water at the surface. **Nutrients from the river make estuaries, like wetlands, among the most productive biomes. Crucial area of reproduction for some organisms. Crucial feeding areas for waterfowl and some marine mammals.

Aquatic Biomes- Lakes

Tropical lowland lakes have a thermocline year-round. Salinity, O2 concentration, and nutrient content differ greatly among lakes and can vary with season. Oligotrophic lakes- O2 rich; nutrient poor. Eutrophic lakes- Nutrient rich oxygen poor. High rates of decomposition in deeper layers of eutrophic lakes cause periodic 02 depletion. Oligotrophic lakes (big lake near mountain maybe remember picture) typically have less surface area relative to their depth than eutrophic lakes have. Littoral zone- the shallow, well lighted waters close to shore with rooted aquatic plants. Limnetic zone- water is too deep for rooted aquatic plants- inhabited by a variety of phytoplankton and cyanobacteria.

Natural range expansions clearly show the influence of dispersal on distribution but opportunities to observe such dispersal directly are rare, T or F?

True! Rare indeed.

Ecologists rarely conduct transplant experiments across geographic regions, T or F?

True. It can disrupt the natural habitat.

Oceanic pelagic zone.

Vast realm of open blue water constantly mixed by wind-driven oceanic currents. Because of higher water clarity, the photic zone extends to greater depths than in coastal marine waters!!!!! Average depth of 4000 m with the largest depth being 10000 meters. Dominant photosynthetic organisms are phytoplankton, including photosynthetic bacteria. Photosynthetic plankton account for about half of the photosynthetic activity on earth!!!!! Most abundant heretrophs are zooplankton.

Temperate Grassland

Veldts of SA, Puszta of Hungary, and pampas of Argentina and Steppes of Russian dna plans and paraires of central NA.

Rocs and Soil

Water chemistry, ph, nutrients, toxis.

Great ocean conveyor belt

Water is warmed at the equator and flows along the ocean surface to the North Atlantic, where it cools, becomes denser and sinks thousands of meters. The deep cold water, my not return tot he oeacn surface for as long as 1,000 years.

Bodies of water

West coast of northern Europe has a mild climate because of the Gulf Streem which carries warm water fromt eh equator. Norwest Europe is warmer than New Engladnd even though NE is farther south.

Flowchart of factors limiting geographic distribution.

Why is species X absent from an area 1. Does dispersal limit its distribution? Yes- Area inaccessible or insufficient time. 2. Does behavior limit its distribution? Yes- Habitat Selection. 3. Do biotic factors (other species) limits its distribution? Yes-predation, parasitism competition, disease. 4. Do abiotic factors limit its distribution? Chemical factors- H20 Salinity, pH, Soil nutrients, etch. Physical factors- Temperature, light, soil structure, fire, moisture.

Maine benthic zone

consists of the seaflow below the surface waters of the coastal, or neritic, zone and offshore, pelagic zone. **Except for shallow-near coastal areas, the marine benthiz zone receives no sunlight. Oxygen is present. Soft sediments cover bottom. Deep-sea hydrothermal vents have chemoautotrophic prokaryotes that oxidize H2S, hot water with dissovled sulfate.

Water biomes

freshwater and marine are distinguished on basis of physical and chemical differences. Marine biomes typically have salt concentrations that average 3% while freshater is less than .1% Oceans are largest marine biome (75%) of earth's surface. Evaporization of water from oceans provies most rainful and marine alge and photosynthseitic biology provide substantial oxygen and consume sunstanial CO2.

Chaparral

midlatitidue coastal regions. Rainy winters with long, dry summers. Dominated by shrubs and small trees.

Vertical layering of forests-

upper canopy, low-tree layer, shrub understory, ground layer of herbaceous plants, forest floor, root layer.