bio 2 - ch 36 climate and biosphere (post)

climate

prevailing weather conditions in a particular region

• dictated by temp and rain which are influenced by: variations in solar radiation, topography and proximity to water

topography

the physical features or “the lay” of the land

• ie mountains

biome

a particular mix of plants and animals that are adapted to living within a specific range of environmental conditions in a given area

• characterized by climate and geography

• defined by mean annual temperature and mean annual precipitation

terrestrial ecosystems

• Distribution of the biomes and their corresponding communities of organisms is determined by three things

1. differences in climate

2. water

3. defining topographical features

• biomes change with altitude and latitude due to temp

tundra biome

• permafrost

• very cold and dark most of the year—short growing season, precipitation is minimal

• vegetation for short growing season

  • lichens, short grasses, mosses, dwarf shrubs

• animals - few live all year round

where is the tundra biome found?

encircles the arctic region just south of the ice covered polar seas in the Northern Hemisphere and covers about 10% of Earth’s land surface

animals that live in a tundra

Ptarmigans, musk ox, migratory birds, caribou, reindeer, and wolves

permafrost - tundra biome

• is the layer below the topmost layer of Earth that is always frozen

• prevents water drainage; bogs and pools form in the summer

pattern of biome distribution

coniferous forests

they have long, cold, snowy winters with warm and humid summers

• temperate rain forests

• taiga

• montane ___ forests

where are coniferous forests found

in the taiga and montane along the Pacific coast of NA as far south as northern CA

montane coniferous forests

a second location of coniferous forest biome

•Near mountaintops just above deciduous forest

•Wolverine and mountain lion in montane coniferous forest

taiga - coniferous forests

• have the cone bearing trees like spruce, fir, and pine - well adapted to the cold

• animals that live near lakes and streams: Bears, deer, moose, beavers, muskrats, wolves, birds

where can taiga coniferous forests be found?

in the northern part of NA and Eurasia

temperate rainforest - coniferous forests

• Plentiful rainfall

• rich soil

• have some of the tallest conifer trees

• Coastal redwoods

• Small sections are considered

• Mosses and ferns grow on tree trunks

where can temperate rainforest - coniferous forests be found?

found on the western coast of the United States and Canada

temperate deciduous forest

• moderate climate with high rainfail

• well defined seasons

• tress like oak, beec, and maple

  • tall ones form canopy

  • understory trees - ones just below tallest ones

• fruit , nuts, and berries

• lichens and ferns

• lots of ground animals and amphibians and reptiles

where can temperate deciduous forests be found?

found south of the taiga in eastern NA, eastern Asia, and much of Europe

where can tropical rain forests be found?

found in areas of SA, Africa, and the Indo-Malayan region

tropical rain forest

• most common type of tropical forests

• lots of rain

• uniformly warm

• lots of species diversity

• complex structure with many levels of life

• densely populated

• insects, tree dwellers, birds, amphibians, reptiles, primates, and carinvores

epiphytes

• plants that grow on other plants

• Have own roots and absorb materials from canopy

soil in tropical forests

Soil is not as rich as that of temperate deciduous forest

•Nutrients rapidly recycled

•Removing trees for agriculture causes erosion

shrublands

tend to occur along coasts that have dry summers and receive most of their rainfall during the winter

• lots of shrubs that are small with thick evergreen leaves coated with a waxy material to prevent loss of moisture

• withstand arid conditions

• regrow after fires quickly

• heat needed for some seed germination

• chaparral - shrub in Mediterranean shrubland, Cali, South Africa, and Australia

• animals: include coyotes, jackrabbits, lizards, deer, roadrunners, gophers, and other rodents

grassland

• enough rain for grass but not for forests but too much for desserts

• have crops like wheat, corn, and soybeans - natural ones have declined as such

• includes temperate grasslands and savannas

• well adapted to changing environments

  • can handle some grazing, flooding, drought, and fire

  • grass growth is seasonal

• in areas with more rainfall there can be tall grass but if not its short

temperate grasslands

• includes: russian steppes, american pampas, and NA prairies

• •Bison and pronghorn antelope once were abundant in prairies

  •Now, mice, prairie dogs, and rabbits typically live below ground

  •Aboveground, hawks, snakes, badgers, coyotes, and foxes feed on the smaller animals

savannas - type of grassland

• grassland with some trees

• relatively cool, dry season followed by a hot and rainy season

• acacia

• african savanna

• variety in big herbivores

• carnivores

acacia

a typical savanna tree, sheds its leaves during the dry season

desert

usually found at latitude of about 30 degrees in both hemispheres (N and S)

• days are hot because of little clouds cover but nights are cold because heat escapes to the atmosphere easily

• some have wet periods and dry periods

• some have vegetation

  • Succulent, spiny cacti and nonsucculent woody shrubs (sagebrush and ocotillo)

    • Exception: The Sahara has little or no vegetation

animals in the desert

•Many are nocturnal, to avoid heat

•Reptiles and insects have waterproof outer coverings to conserve water

•Insects may pass through all stages of development while there is rain

•Reptiles and snakes are typical desert vertebrates

Other animals include some running birds, rodents, coyotes, and hawks

What are the two types of aquatic ecosystems?

• freshwater (inland) ie lakes

• saltwater (marine) ie oceans

what is brackish water?

a mix of fresh and salt water - coastal ecosystems

mountain streams and riveres

• are bodies of freshwater found in high elevations.

• Frozen precipitation at high elevations melts and flows down toward the sea

• Cold and tend to be low in nutrients and biodiversity

• As the water makes its way to lower elevations, it accumulates nutrients and becomes warmer

• Species: mayflies and trout

lakes

• fresh water

• Classified by nutrient abundance

• Oligotrophic (nutrient-poor) lakes—small amounts of organic matter

  • Low productivity

• Eutrophic (nutrient-rich) lakes—plentiful amounts of organic matter

  • High productivity due to location near nutrient-rich regions

  • May be enriched by agricultural or urban runoff

• Eutrophication can be caused by large inputs of nutrients

deep lakes in the summer

•the surface layer that is warmed (24°–25°C) due to solar radiation and is less dense

•Thermocline—the middle layer decreases 1°C per meter of depth

•Hypolimnion—the cold, lowest layer (5°–8°C)

*the differnces in temp prevent “mixing”

fall overturn in lakes

• Upper epilimnion becomes cooler than hypolimnion

• Surface water sinks and deep water rises

• This continues until the temperature is uniform throughout the lake

• Wind assists water circulation, so mixing occurs

• In winter, floating ice prevents further water cooling below, which stays at 4°C

  • Aquatic organisms can live through the winter

spring overturn in lakes

• As ice melts, cooler water on top sinks below warmer water

• This continues until the temperature is uniform throughout lake

• Winds aid in circulation and mixing

• As surface waters absorb solar radiation, thermal stratification occurs by summer

lakes influence on seasonal distribution of fish and other aquatic life

• caused by vertical stratification and seasonal change of temperatures in a lake basin

• Cold-water fishes move to the deeper water in summer, upper water in winter

• Phytoplankton growth at the surface is most abundant after mixing

  • Phytoplankton use up nutrients in epilimnion during the summer and release oxygen

  • Decomposition in hypolimnion uses up oxygen and releases nutrients

wetlands

areas that hold some amount of water during part of the year; classified by their vegetation

marshes

•Frequently or continually inundated by water

•Rushes, reeds, and other grasses provide excellent habitats for waterfowl and small mammals.

•One of the most productive ecosystems on Earth

swamps

Dominated by either woody plants or shrubs

•Common swamp trees include cypress, red maple, and tupelo.

The American alligator is a top predator

bogs

• Characterized by acidic waters, peat deposits, and sphagnum moss

• They receive most of their water from precipitation and are nutrient-poor

• •Cranberries, orchids, and insectivorous plants such as Venus flytraps and pitcher plants

• Moose in northern USA and Canada

wetlands and their value

• purify waters by filtering them and by diluting and breaking down toxic wastes and excess nutrients

• absorb storm waters and overflow from lakes and rivers, protecting farms, cities, and towns from the devastating effects of floods

• Humans have historically channeled and diverted rivers and filled in wetlands → hurt ecosystems

life zones

used for lakes and ponds

• littoral zone

• limnetic zone

• profundal zone

• benthic zone

littoral zone - life zones

shallow edge zone of a pond or a lake

•Aquatic plants rooted; microscopic organisms cling to plants and to rocks; insect larvae

limnet zone - life zones

open water, lit by sunlight

•Fishes, plankton (microscopic phytoplankton and zooplankton), water striders (surface)

profundal zone - life zones

deep, dark water

•Zooplankton, fishes, insect larvae, pike predators

bethnic zone - life zones

lake bottom

•Includes the benthos: crayfishes, snails, clams, worms, insect larvae

estuary

• a partially enclosed body of water where fresh and saltwater mix

• Abundance of nutrients, but rapid changes in salinity

• Feeding grounds of many birds, fishes, shellfishes

• “nurseries” → Half of all marine fish mature in estuaries

types of estuaries

Coastal bays, tidal marshes, fjords, some deltas, and lagoons

• Associated with salt marshes, mudflats, mangroves

seashores

Rocky or sandy and are constantly bombarded by the sea

• littoral zone

littoral zone of seashores

between high and low tidal marks— divided into three zones

upper portion of littoral zone of seashores

barnacles are attached tightly to stone

midportion of littoral zone of seashores

brown algae known as rockweed may overlie the barnacles

lower portion of littoral zone of seashores

oysters and mussels are attached to the rocks by filaments

• Limpets and periwinkles

below littoral zone of seashore

• macroscopic seaweeds anchor to the rocks

• Animals that live on sandy shores cannot attach to shifting and unstable surfaces → bury themselves

• Some remain underground, others surface at night to  feed

  • Ghost crabs and sandhoppers feed at night at low tide

  • Sandworms and sand (ghost) shrimp remain within the burrows  and feed on detritus

oceans

• Have a major role in redistributing heat in the biosphere

  • Air takes on the temperature of the water below, and then warm air moves from the equator to the poles

  • Influence the wind patterns

oceans in the Northern Hemisphere

• currents circulate clockwise

  • moves warm water from equator to poles

  • The Gulf Stream brings tropical Caribbean water to the east coast of North America and higher latitudes of western Europe

  • Without the Gulf Stream, Great Britain would be as cold as Greenland

oceans in the Southern Hemisphere

• Currents circulate counterclockwise

• The Humboldt Current circulates cold, nutrient-rich water northward along the West Coast of South America

• An upwelling occurs when cold offshore winds cause nutrient-rich waters to rise and take the place of warm, nutrient-depleted water

• Waters enriched by upwelling support fisheries of Peru and Chile

  • When the Humboldt Current is not as cool, stagnation occurs, and fisheries decline

pelagic division

Organisms in the open waters of the ocean can be classified in this division and in provinces

• Neritic province—shallow waters over continental shelf

• Oceanic province—open water, several depth zones

neritic province - pelagic division

• Abundant sunlight and inorganic nutrients allow a large concentration of organisms

  • •Phytoplankton provide food for zooplankton and small fishes

  • The small fishes are food for larger fishes

• coral reefs

coral reefs

• areas of high biological abundance in shallow, nutrient-poor, tropical waters

• They include calcareous red and green algae and colonies of stony corals

• Many corals contain symbiotic zooxanthellae

coral reefs populations - pelagic division

• The crevices and caves provide shelter for filter feeders (sponges, sea squirts) and scavengers (crabs and sea urchins).

• Many small fishes live there; some feed directly on corals, others feed on plankton or detritus.

• Larger fishes, such as snapper, feed on smaller fishes.

• Top predator fishes include the shark, barracuda, and moray eel.

oceanic province - pelagic division

• This province lacks the inorganic nutrients of the neritic province, but sunlight is available.

  • •Has a lower concentration of phytoplankton

• epipelagic zone

• mesopelagic zone

• bathypelagic zone

epipelagic zone of oceanic province in pelagic division

photosynthesizers are eaten by zooplankton, which are eaten by herring and bluefishes, which are, eaten by larger mackerels, tunas, and sharks

•Whales and other mammals also occur here

mesopelagic zone of oceanic province in pelagic division

carnivores such as squids and lantern fishes

bathypelagic zone of oceanic province in pelagic division

complete darkness

•Carnivores and scavengers

benthic division

includes organisms that live in or on the oceanic soil

• sublittoral zone

• bathyal zone

• abyssal zone

sublittoral zone of benthic division

continental shelf

•Seaweed, algae, clams, worms, crabs, sea stars

bathyal zone of benthic division

• continental slope underwater - seafloor

• high pressure and low temps in total darkness

• Organisms depend on detritus that falls from above

  • sponges, echinoids, sea stars all adapted to scarce food and muddy sediments

abyssal zone zone of benthic division

abyssal plain

High pressure and cold water

Many invertebrates live at soil-water interface

•Sea lilies, sea cucumbers, tube worms

oceanic ridges in abyssal plain - benthic division

Along axes of the ridges, crustal plates spread apart.

•Molten magma from Earth’s core rises.

Seawater percolates through hydrothermal vents.

Seawater is heated, causing sulfate to react with water and form hydrogen sulfide (H₂S).

Free-living or mutualistic chemoautotrophic bacteria use electrons from (H₂S) to reduce bicarbonate to organic compounds to support this ecosystem.

•Includes huge tube worms and clams