Ch 3 The Biosphere
explain how lake depth and area affect composition of biological communities (nutrient availability)
-Deep lakes with relatively small surface area tend to be nutrient-poor. -Shallow lakes with relatively large surface area tend to be nutrient rich.
Hot deserts: -location -variation of temperatures and moisture -abundance vs diversity of animals and plants -water availability, how this affects plant form -special characteristic (think about climate diagram)
-In high pressure zones at 30°N and S (descending air of Hadley cells) -High temperatures, low moisture (precipitation) -Sparse vegetation and animal populations -Abundance may be low but species diversity can be high. -Low water availability constrains plant abundance and influences form -we have insufficient precipitation for plant growth all year long
In deserts, what are the plant growth forms and their main characteristic? (2; include locations of each) This is an example of_
-Many plants have succulent stems that store water. -Convergence of this form is shown by cacti (Western Hemisphere) and euphorbs (Eastern Hemisphere). -example of convergence because of succulent stems and protecting spines because of the climates similarities, which both apply same pressures
why irrigation for agriculture has failed in deserts?
-because of salinization
what plant growth form is found in Arizona?
-cacti and shurbs, suculent stems or leaves
what are the two types of plankton?
-phytoplankton -zooplankton
why plants are great indicators of biomes?
-plants are immobile, so in order to occupy a site successfully for a long time, they must be able to cope with its environmental extremes as well its biological pressures, such as competition for water, nutrients, and light -Plant growth forms are therefore good indicators of the physical environment
what zones have subfreezing temperatures? (2)
-polar zones -temperate zones
what 4 factors by climate zones affect distribution of terrestrial biomes?
-precipitation and temperature -water availability and soil temperature
subtropical regions (moisture)
-rainfall becomes more seasonal, with pronounced dry and wet seasons
deciduousness
-seasonal shedding of leaves
forbs (environment (temperature), what special about leaves)
-seasonally cool/cold (NO in warm areas) -forbs are broad-leaved herbaceous (nonwoody) plants
sclerophyllous shrubs (moisture and climate, variation of what, and what kind of leaves they have)
-seasonally dry/moist and warm/cool climates (in places that have both seasonality in both moisture and temperature) -they have tough, leatheery leaves
what growth form describes? (2)
-size and morphology
deciduous leaves are a solution to_in the_zone
-the extended periods of freezing weather -temperate zone
which biomes have periods of insufficient precipitation for plant growth? (3; state which one has the greatest)
-tropical seasonal forests and savannas -hot deserts (they contain the greatest; all year round) -Temperate shurblands and woodlands
biological zones in freshwater ecosystems are associated with _of the water (5)
-velocity -depth -temperature -clarity -chemistry
evergreen broad-leaved trees (environment (moisture and temperature), what special about leaves)
-wet, warm year-round -evergreen leaves in tropical regions carry out photosynthesis year-round. Broad leaves
deserts (pressure and what phenomena happen here)
-zones of high pressure -rain-shadow effects of large mountain ranges
list the 7 major plant growth forms
1. sclerophyllous shrubs 2. deciduous trees 3. grasses, sedges 4. cacti and shrubs; succulent stems or leaves 5. needle-leaved evergreen trees 6. evergreen broad-leaved trees 7. forbs
what are the 9 biomes that will be discussed in this chapter?
1. tropical rainforest 2. tropical seasonal forest and savanna 3. hot desert 4. temperate grassland 5. temperate shrubland and woodland 6. temperature deciduous forest 7. temperate evergreen forest 8. boreal forest 9. tundra
convergence
Evolution of similar growth forms among distantly related species in response to similar selection pressures.
riffles
Fast moving water with coarse particles on the stream bed.
what plays an important role in determining vegetation structure of montane grasslands and savannas?
Fire plays an important role in determining vegetation structure of montane grasslands and savannas.
Mountain Biological zones (what zone, how works)
On a temperate-zone mountain, the biological communities that occur from the base to the summit resemble those found along a latitudinal gradient.
Streams and rivers are _(what and define it) systems.
Streams and rivers are lotic (flowing water) systems.
how are the axis of climate diagram scaled?
The axes are scaled so that 1°C corresponds to 2 mm of precipitation.
succulence
development of fleshy water storage tissue
pools
Deeper water, with slower flow and finer sediments (at bottom).
lentic
no flow of the water
explain how precipitation and temperature together work on plants? (distribution of biomes) (2)
Precipitation and temperature act together to influence water availability and water loss by plants.
Temperate Evergreen Forest: -location (4) -diversity -special character of leaves and soil -precipitation and seasonality
-30° to 50°N and S, coastal, continental, and maritime zones -Lower diversity than tropical and deciduous forests -Leaves tend to be acidic, and soils nutrient-poor -They receive high rainfall amounts and have mild winters.
Temperate Deciduous forests: -location -special characteristic of plant growth in here -plant growth form (special ones) (3) -species diversity -special characteristic (think about climate diagram)
-30° to 50°N, on continental edges (east in N america) with enough rainfall for tree growth (more water than is found in grassland; difference between precipitation and temperature lines in is greater) because trees require more water than grass do -Leaves are deciduous in winter -Oaks, maples, and beeches occur everywhere in this biome -Species diversity lower than tropical rainforests -subfreezing temperature (June to March; December)
what happened about 10,000-20,000 years ago in north america regarding its diversity? reasons (2)?
-About 10,000-13,000 years ago, many of the North American large mammals went extinct very rapidly. -Nearly all the animals that went extinct were large mammals. -Causes of the extinction are a mystery. Hypotheses include rapid climate change and the arrival of humans in North America.
Tundra: -location -temperature and precipitation -summer and days variation -vegetation (6) -what phenomena happens -special character (think about climate diagram)
-Above 65° latitude, mostly in the Arctic -Cold temperatures, low precipitation (due to polar cells) -Short summers with long days -Vegetation is sedges, forbs, grasses, low-growing shrubs, lichens, and mosses (no more trees-->treeline) -Widespread permafrost -has the greatest amount of subfreezing temperatures (number 1)
in river continuum concept, as stream size increases, what happens to food? (important source of food)
-As streams increase in size, detritus from riparian vegetation decreases and becomes less important as a food source; fine organic matter and algae become more important. -small stream will have large amounts of detritus from riparian vegetation -particle size decreases as you increase the size of the stream
what is better in determining distribution of biomes? (average or extreme temperature and precipitation)
-Average annual temperature and precipitation can predict biome distributions quite well, but seasonal variation is also important. -Climate extremes can sometimes be more important than average conditions.
Tropical Rainforest: -latitude -localization of these areas -temperature -annual precipitation (mm) -variability -what is special about it? -plant growth forms (2)
-Between 10°N and 10°S -regions are around equator -Annual precipitation > 2000 mm (spread evenly) -warm -No seasonal changes (precipitation and temperature consistent year around) -High biomass, high diversity—about 50% of Earth's species -Broadleaved evergreen and deciduous trees
Temperate shrublands and woodlands: -location -type of plant growth form (2) -what kind of climate (temperature and moisture) -what is needed to maintain biome? -special characteristic (think about climate diagram)
-Between 30° and 40°N latitude -Evergreen shrubs and trees [also sclerophyllous, which have tough, leathery, and stiff leaves] -Mediterranean-type climates—wet winters and hot, dry summers -Fire is common and helps maintain the biome -we have a season of insufficient precipitation for plant growth (june to august)
Template grasslands: -location -seasonality (temperature and moisture) -plant growth form, reason for having this kind (2) -special characteristic (think about climate diagram)
-Between 30° and 50°N latitude -Warm, moist summers and cold, dry winters -Grasses dominate; maintained by frequent fires and large herbivores such as bison -we have subfreezing temperature (January to March; December)
Deciduous trees (what 3 types of environments found (moisture and temperature), variation in what, and what is special about they leaves)
-Moist, seasonally warm/cool or cool/cold on fertile soils or warm, seasonally wet/dry -we have variation in seasonality but not so much in moisture because we need a lot of moisture to grow these trees -decidious plants drop their leaves during cold or dry periods
Needle-leaved evergreen trees (environment (2) (moisture and temperature), example of place where they can be found, variation of what, what special about their leaves, 1 example of tree)
-Moist, seasonally warm/cool or cool/cold on infertile soils -can be found in top of mountain ranges because we have more rainfall (moist) and seasonality of temperature -evergreen plants retain their photosynthetic tissues year-round. Their leaves have needles -example: pine trees
Tropical seasonal forest and savannas: -location -variability (what causes this variability) -temperature -special characteristic (think about climate diagram) -plant growth forms (3)
-North and south of the wet tropics. A little bit off of the equator -Wet and dry seasons (seasonal rainfall) associated with movement of the Intertropical Convergence Zone (ITCZ) -warm temperatures -we have a season in which water is limiting plant growth (June to August) -Shorter trees, deciduous in dry seasons, more grasses and shrubs
pelagic zone (definition and animals found in it)
-Open water (water in the middle of the lake) -dominated by plankton
what is a good indicator of climatic conditions and disturbances in biomes? why?
-Plants occupy sites for a long time and are good indicators of climatic conditions and disturbances. -they are sensitive to temperature and precipitation
where shrublands occur? (2) include example
-Shrublands in continental interiors occur in rain shadows (leeward side of mountain ranges) and seasonally cold climates. -the Great Basin between the Sierra Nevada and Cascade Mountains
what is noted regarding the distribution of plant growth forms? how we call this?
-Similar growth forms occur in similar climates on different continents, even though the plants may not be genetically related. -convergence
Tropical Seasonal Forests and Savannas includes: (3 types of ecosystems)
-Tropical dry forests -Thorn woodlands—trees have heavy thorns to protect from herbivores -Tropical savannas—grasses with intermixed trees and shrubs
what two types of information you can get from a climate diagram? (include color areas)
-When the precipitation curve falls below the temperature curve, water availability limits plant growth. (yellow area) -These graphs also show when temperatures are below freezing for extended periods. (blue area below 0 degrees C)
Biomes (what are them and how they are categorized)
-are large-scale terrestrial communities shaped by the physical environment. -These areas have similar climate, temperature, precipitation reigns, and similar vegetation -categorized by dominant plant forms and characteristics such as leaf deciduousness or succulence.
which biome is the most human influenced on earth?
-because of long history of agriculture and grazing, temperate grasslands
benthic zone (what it is, what kind of organisms are found in here, and what they feed on (2))
-bottom of the stream, lakes, or ocean -organisms are bottom dwellers and include many kinds of invertebrates. -some feed on detritus and others some predators
plants in general found in the deserts (3)
-cacti -euphorbs -drought deciduous shrubs and grasses
river continuum concept (what describes)
-describes changes in biological communities with stream order and channel size. -describe changes in ecosystem of stream as we go from small stream to large river
Cacti and shrubs (environment found (mositure and temperature), what is special about their leaves)
-dry, seasonally hot/cool (especially hot) -succulent stems and leaves contain water storage tissues
savannas are a result of_(3)
-fires in which increase with the length of dry seasons -large herd herbivores -seasonal flooding
In river continuum concept, feeding styles of organisms also change in response to the difference in food sources: list two and define them (include in what kind of rivers will be found)
-from shredders that tear up and chew leaves(detritus) (in small streams), to collectors that collect fine particles from the water (larger rivers).
Lakes can be formed by _(5)
-glacial processes, from river oxbows (meandering rivers cease to flow through a former channel, leaving a section stranded), in volcanic craters, in tectonic basins, or by damming streams.
what plant growth is well adapted to fire? which are not?
-grasses and sedges are well adapted to fire -trees are not
what biome occur at the base of the mountain? what leads to as you increase in slope?
-grasslands -give way to pine savannas on the initial slopes
what factor(s) might result in grasslands or shrublands "invading" climate space occupied by forest or savanna (3)
-grasslands and shrublands might occur in areas with combinations of precipitation and temperature usually associated with forests or savannas due to disturbances such as fire or deforestation by humans or an outbreak of herbivory. These factors would limit successful establishment of trees, which would normally crowd out grasses and shrubs
tropics are characterized by what temperature and moisture?
-high rainfalls -warm, invariant temperatures
biosphere
-is the zone of life on Earth, where life exists -Living things are found on every part of the Earth, from high mountains to deepest oceans and extreme environments. But most occur within a thin layer of Earth's surface, from the tops of trees to the surface soil layers, and within 200 meters of the surface of the oceans.
how two places that have same amount of precipitation can be quite different regarding the biome located in them?
-it depends on distribution -one might have evenly distributed precipitation while the other may have a dry period (extreme climate) that determines the type of biome found there
why decidious trees shed their leaves?
-it is a solution to seasonal exposure to subfreezing temperatures or extended dry periods
between what two layers the biosphere is found?
-it is sandwiched between litosphere, the earth's surface crust and upper mantle, and the troposphere, the lower layer of the atmosphere
Lakes and still waters (_(term for this)) occur where _
-lentic -depressions in the landscape fill with water.
list the 4 ,from lower to higher, the zones of a mountain
-lower montane zone -montane zone -subalpine zone -alpine zone
list from superficial to deeper the zones of streams and rivers
-main channel -benthic zone -hyporheic zone
grasses, sedges (environment found (moisture and temperature), variation in what, adapted to what, what need to have for them to grow, how grow?)
-moist, seasonally warm/cool, with fire -constant moist, seasonality in temperature -adapted to fire -grasses grow from the base of their leaves
marine biological zones are determined by_(3)
-ocean depth -light availability -stability of the bottom substrate
Boreal Forests: -other name -location -temperature -special phenomena about it and consequences -plant growth form (be specific of names) (2) -special characteristic (think about climate diagram) -contains_
-other name: Taiga -50° to 65°N (Far north of hemisphere) -Long, severe winters -Permafrost (soil that remains frozen year-round) prevents drainage and results in saturated soils (or high water content) -Trees present are conifers—pines, spruces, larches (deciduous needle-leaved trees)—and deciduous birches -we have a great amount of subfreezing temperatures (almost last 6 months) , almost as tundra -fires
how surface area of lake relates to nutrient input in lake?
-surface area of lake is directly proportional to nutrient input in lake -large surface area relative to volume=nutrient rich -small surface area relative to volume= nutrient poor
how temperature between temperate grasslands and tropics compare? (2)
-temperate climates have greater seasonal temperature variation than tropical climates -they have increasing periods of subfreezing temperatures toward the poles
which biomes contain periods of subfreezing average monthly temperatures? (4)(include the 1st and 2nd greatest in this category)
-temperate grasslands -Temperate deciduous forests -Boreal forests (2nd greatest) -Tundra (1st greatest; just 3 months where there is no subfreezing temperatures)
why mountains biological zones work similar to latitude changes?
-the changes in climate associated with changes in elevation alter the composition of the local vegetation
hyporheic zone
-the substratum below and adjacent to the stream. -deeper within the sediments
what is the relation between average annual temperature and average annual precipitation?
-they are indirectly related (negative slope) -the warmer the place, the more precipitation values we have -the colder the place, the less precipitation values we have
why perennial grasses (grasses, sedges) can resists fire? what three hardships they can resist?
-they can grow from the base of their eaves and keep their vegetative and reproductive buds below the soil surface, which facilitates their tolerance of grazing fires, subfreezing temperatures, and dry soils
Biomes are categorized by the most common growth forms of plants distributed across large geographic areas. what this categorization relies?
-this categorization relies on similarities in the morphological responses of organisms to physical environment (not taxonomic relationships)
how is North America in diversity (especially in plains) today vs before?
-today, the Great Plains of North America have very low diversity: -In North America when the last Pleistocene continental glacier receded, the Great Plains supported a diverse megafauna
how is the height of plants in tropical rainforest vs polar regions?
-tropical rainforest: tall -polar regions: short
what water availability and soil temperature determine regarding the soil?
Water availability and soil temperature determine the supply of nutrients in the soil.
what is a key factor that determines vegetation in tropical rainforest?
light -to grow tall or adjust to low light levels
phytoplankton
photosynthetic, restricted to the upper layers where light is available
what biome has a scattered covered of tiny plants clining to the ground, reflecting a harsh climate of high winds, low temperature, and dry soils?
polar regions
Streams tend to form a pattern of _(2), with different biological communities.
riffles and pools
plankton
small, microscopic organisms suspended in the water
in central north america, what kind of biome is found?
temperate grasslands
what biome has multiple verdant layers, high growth rates, and tremendous species diversity?
tropical forest
what region of earth is most probably to found evergreen broad-leaved trees?
tropical regions
here in the phoenix metro, the landscape looks different than natural areas surrounding it. Do we live in the desert in Phoenix?
yes
Explain how the following things change as you increase in elevation in mountain biological zones: a. annual temperature b. annual precipitation
a. Decrease temperature b. Increase precipitation
climate diagram
are graphs of average monthly temperature and precipitation at a location, showing the characteristic seasonal climate pattern.
the distribution of the terrestrial biomes is determined by Earth's_
climate zones
detritus
dead organic matter (ex: leaves that fall on the water)
lake_(2) influence the composition of biological communities
depth and area
when an environment is moist, what two kinds of trees are more likely to be there?
get more trees and evergreen and deciduous
terrestrial biomes are characterized by the _(what is found in biomes)
growth forms of the dominant vegetation
some of the organisms in the benthic zone live in what zone?
hyporheic zone