Download Semester 1: "Know Ten" Group 1

Group 1: 10 Things To Know About…
In pairs, look through your brains, notebooks, notes, etc. to come up with “10 things to know” about each
of the following topics. Be specific, but concise.
Instructions: Pairs will be assigned topics (in bullet points). Under each bullet point, pairs are to come up
with ten key concepts, facts, statistics, etc. that if anything, people should know about these topics.
*Number list the ten things under each topic*
1. The water cycle
Water cycle
1. Powered by energy from the sun which evaporates water into the atmosphere, and then
gravity makes it rain.
2. 84% of water vapor comes from ocean, the rest comes from land
3. Some of freshwater returning to earth surface as precipitation is converted into ice
stored in glaciers, and some infiltrates and percolates through soil and permeable rock
formations to groundwater storage areas called aquifers.
4. Most precipitation falling on terrestrial ecosystem becomes surface runoff
5. Besides replenishing streams and lakes, surface runoff causes natural soil erosion,
which moves soil and rocks fragments from one place to another.
6. Water is the primary sculptor of the Earth’s landscape.
7. Because water dissolves many nutrient compounds, it is a major medium for
transporting nutrients within and between ecosystem.
8. Evaporation and subsequent precipitation act as a natural distillation process that
removes impurities dissolved in water.
9. Water flowing above ground through streams and lakes and below ground in aquifers is
naturally filtered and partially purified by chemicals and biological processes, mostly by
the actions of decomposer bacteria.
10. Only about 0.024 percent of Earth’s vast water supply is available as liquid freshwater in
accessible groundwater and in lakes, rivers and streams.
2. The carbon cycle
1. Based on Carbon Dioxide gas which makes up 0.038 percent of the volume of the
troposphere and is dissolved in water.
2. Carbon Dioxide is a key component in nature’s thermostat.
3. If the carbon cycle releases too much CO2 from the atmosphere, the atmosphere will
cool, vice versa.
4. Terrestrial producers removes CO2 from the atmosphere, aquatic producers removes
it from water. They use photosynthesis to convert CO2 into complex carbohydrates such
as glucose.
5. Decomposers carry out aerobic respiration which is a process that breaks down
glucose and other complex organic compounds and converts the carbon back to CO2 in
the atmosphere or water for reuse by producers.
6. The linkage between photosynthesis in producers and aerobic respiration producers,
consumers, and decomposers circulates carbon in the biosphere.
7. Over millions of years, buried deposit of dead plants matter and bacteria are
compressed between layers of sediments, where they form carbon-containing fossil
fuels such as coal and oil.
8. fossil fuels are not released into the atmosphere CO2 until extracted and burnt, or
until long term geological processes expose these deposits to air.
9. Some of atmosphere’s CO2 dissolves in ocean water and the ocean
photosynthesizing producers remove some. When the ocean warms some of the
dissolved CO2 returns to the atmosphere, just as CO2 fizzes out of carbonated
beverages when it warms. This balances earth’s average temperature.
10. Some ocean organisms build their shells and skeletons by using dissolved CO2
molecules in the sea water to form carbonate compounds such as calcium carbonate.
When they die their shells are buried in sediments for millions of years where under
immense pressure convert into limestone.
3. Nitrogen and phosphorous cycle
1. Nitrogen Cycle- Nitrogen is a crucial component of proteins, many vitamins and many
nucleic acids like DNA.
2. Nitrogen in the atmosphere cannot be absorbed and used directly as a nutrient by
plants or animals.
3. Nitrogen can be fixed through lightning or through nitrogen fixing bacteria.Nitrogen is
fixed to ammonia and then converted to ammonium ions. If the plant does not take
ammonium, it will undergo nitrification. The ammonium is first converted to nitrite, then to
nitrate.
4. When plants and animals die ammonification occurs in which specialized decomposer
bacteria convert this organic material into simpler nitrogen containing inorganic
compounds like NH3 and NH4+. In denitrification, specialized bacteria in waterlogged
soil and bottom sediments of lakes, oceans and swamps convert NH3 and NH4+ back
into nitrite and nitrate ions and then into nitrogen gas and nitrous oxide to repeat the
cycle.
5. Human impact on the nitrogen cycle- burning fuels at high temperatures (causes acid
rain), livestock waste/inorganic fertilizers (warm atmosphere/deplete
ozone/contaminating drinking water),destruction of forests/grasslands/wetlands.
6. Phosphorous Cycle- key component of DNA and energy storage molecules. It is slow
on a human time scale and it runs one way from land to the ocean.
7. Phosphorous is found in terrestrial rock formations and ocean bottom sediments.
Water runoff can take the phosphorus into streams, river and the ocean where it can be
trapped for millions of years as sediment.
8. Plants obtain phosphorus (PO4^3-) directly from water or soil. Animals get
phosphorous from the plants.
9. Phosphorous is often a limiting factor for plant growth on land (unless fertilizers are
used.) It also limits the growth of producer populations in many freshwater streams and
lakes.
10. Human impact on the phosphorous cycle- mining, cutting down areas of tropical
forests (reduce available phosphate in the soil), runoff of animal waste and fertilizers,
runoff from sewage treatment systems.
4. Oceans
1. Ocean has the highest net primary productivity (NPP), which means it has the most
energy available to consumers and most natural capital for humans.
2. Oceans and rocks are the biggest carbon sinks.
3. The coastal zone of the ocean extends out to the continental shelf, and contains many
types of coastal ecosystems with varying tides and high NPP’s. Contains 90% of marine
fisheries though it makes up 10% of the world’s oceans. Coastal zones are the most
threatened area of the ocean due to coastal development, runoff pollution, and
overfishing.
4. Coral reefs make up .1% of the ocean but result in 10% of global fishing yield. In
developing countries, reliance on coral reefs can be as much as 25%. They have high
biodiversity and protect 15% of the world’s coastlines, but are threatened by human
activities. Coral bleaching occurs when the coral becomes stressed by high
temperatures and silt runoff, which causes the zooxanthallae to leave/die.
5. The first level of the ocean is the Euphotic Zone, where most photosynthesis occurs
(70% of ocean’s NPP) and where nekton, phytoplankton, and zooplankton all live. This
layer has a high DOC, warmer waters, and low pressure.
6. The next level is the Bathyal Zone, where the limiting factors include lower levels of
nitrates, phosphate, iron, oxygen, and other nutrients.
7. The lowest level is the Abyssal Zone, where low light and oxygen levels cause
benthos and decomposer species to reproduce slowly and rely on anaerobic respiration
and “marine snow” for nutrients. In this zone, upwellings cause the NPP to temporarily
increase.
8. Ocean and all bodies of water regulate climate and affect wind patterns. Seabreezes
occur because water absorbs heat faster and air tends to flow to low pressure areas
(which are above land during daytime). Wind carries moisture across the windward side
of a mountain where rain occurs, and the leeward side on the opposite is dry and desertlike.
9. Currents affect weather as well as organism distribution. The two types of ocean
currents include surface circulation and deep circulation, and are caused by wind/gravity
and density variation respectively. They flow clockwise in the northern hemisphere and
counterclockwise in the southern hemisphere.
10. Some of the biggest problems for the world’s oceans include pollution from inorganic
fertilizers causing algal blooms, overfishing threatening the sustainability of fisheries,
and climate change which significantly alters ocean temperatures. More sustainable
methods of utilizing oceans include stronger regulation of dumping, better runoff
management, coastal restoration, sustainable fishing practices, etc.
5. Lakes, streams, rivers, and wetlands
1. Lakes- large, natural bodies of standing freshwater formed when precipitation, runoff
and groundwater seepage fill depressions in Earth’s surface.
2. Litoral Zone- lake zone near the shore and consist of the shallow sunlit waters, most
productive zone because of abundance of sunlight and nutrients
3. Limnetic zone- the open sunlit water surface layer away from the shore that extends
to the depth penetrated by sunlight. The main photosynthetic body of the lake, this zone
produces the food and oxygen that supports the lakes consumers.
4.Profundal zone- the deep open water where it is too dark for photosynthesis. Fish
adapted to low oxygen levels, cooler temperatures, and few plants mainly live here
5.Benthic zone- zone that contains mostly decomposers, detritus feeders, and fish that
swim from one zone to the other inhabit this region. Nourished by dead matter that falls from the
littoral and limnetic zones and sediment washing.
Streams and Rivers
1. Surface Water- precipitation that does not sink into the ground or evaporate
2. Runoff-when surface water flows into streams
3. Watershed or drainage basin- land area that delivers runoff, sediment, and dissolved
substances to a stream.
-Areas in a River and Streams
Source Zone- high gradient, high DO
Recharge Zone- smaller gradient, medium
Floodplain Zone- little gradient, slow
River Delta- mixture of salt and fresh, nutrient rich
-Wetlands
Wetland: Land covered with freshwater all or part of the time
Examples: Swamp, Marsh, Prairie Pothole, and Flood Plain
-Absorb and store excess water and provide a variety of wildlife habitats
Services: Filter and degrade toxic waste, reduce flooding and erosion, supply valuable
products, provide recreation for bird watchers, nature photographers
6. Endangered Species
1. Endangered species in the U.S. are protected under the Endangered Species Act,
which is enforced by the National Fish & Wildlife Service.
2. Endangered species can no longer adapt to rapid or gradual environmental changes
(that are outside their range of tolerance) and are more susceptible when they have
specific niches and endemic ranges.
3. Threats to endangered species include naturally introduced invasive species, human
activities (HIPPO [habitat degradation/destruction, deliberately introduced invasive
species, pollution, population growth, overexploitation]), climate change, and .
4. Background extinction is ongoing and due to gradual environmental changes (apprx.
1-5 per million).
5. Mass extinction is when a large group of species is wiped out (25-70%). In the last 5
million years there have been five mass extinctions which have allowed new species to
fill new roles. Mass depletion is when a species has an extinction rate much higher than
other species but it is not severe enough to be mass extinction.
6. Various conservation methods exist, including several land designations that vary in
name by country. National Parks in the U.S. help protect species by setting up areas
open to recreation but not hunting/exploitation.
7. Nature Reserves are most effective when established as large networks with buffer
zones and corridors. Some of the world’s biodiversity “hot spots” are especially protected
because of the large number of threatened/endangered/endemic species.
8. Another solution is community-based conservation where scientists and organizations
work closely with specific circumstances and establish well-planned, well-preserved, and
ecotourism-friendly reserves/wildlife areas.
9. Untouched wilderness is a “biodiversity bank” that provides an “eco-insurance” policy
for human society due to its ecological and economic value, and preservation is
considered by many ecologists to be the most effective/sustainable way to reduce
extinction.
10. Restoration, rehabilitation, and replacement are effective methods of environmental
and species conservation.
7. Ecosystems: Energy flow, trophic roles, productivity
1. Food pyramids show the number of organisms at each trophic level. It is an accurate
indication of how much energy is passed at each level.
2. First law of thermodynamics: Energy cannot be destroyed or created, only
transformed.
3. Second law of thermodynamics: When energy changes, usable energy (heat) is lost.
4. The two types of energy are: kinetic (energy in action or motion) and potential (stored
energy).
5. Energy is extracted from aerobic and anaerobic respiration.
Aerobic respiration- A form of cellular respiration that requires oxygen in order to
generate energy.
Anaerobic respiration-A form of cellular respiration that occurs when oxygen is absent or
scarce.
6. The 3 factors required for life on Earth are: 1) The flow of energy, 2) The cycling of
matter and nutrients, and 3) gravity.
7. 80% of energy that reaches the Earth warms the troposphere and dries the water
cycle, 1% generates winds, .1% photosynthesis.
8. Trophic level energy is stored as biomass. Biomass in each level is lower than the
level below it.
9. Ecological Efficiency: The % of usable energy transferred from each trophic level.
Only 10% is incorporated into biomass of the next trophic level.
10. Trophic levels: Producers/autotrophs (get energy through photosynthesis)
Primary consumers/herbivores
Secondary consumers/carnivores
Tertiary Consumers (decomposers)
Detritavores (dead things)
8. Ecosystems: succession, biodiversity, island biogeography
a. Ecological succession is the observed process of change in the species structure
of an ecological community over time.
b. Every species has a set of environmental conditions under which it will grow and
reproduce most optimally.
c. The species that can grow the most efficiently and produce the most viable
offspring will become the most abundant organisms.
d. Biodiversity simply means the diversity, or variety, of plants and animals and
other living things in a particular area or region.
e. Biodiversity boosts ecosystem productivity where each species all have an
important role to play.
f. Each species plays a part in keeping the biosphere running smoothly.
g. the development of plant and animal life in an area without topsoil; the
development of biotic communities in a previously uninhabited and barren habitat
with little or no soil.
h. Tecological successiononn that occurs on a preexisting soil after the primary
succession has been disrupted or destroyed due to a disturbance that reduced
the population of the initial inhabitants.
i. island biogeography is a field within biogeography that examines the factors that
affect the species richness of isolated natural communities.
j. Island Biogeography examines the richness in biodiversity of islands and
specifically how evolution affects the development of species.
9. Human population growth
1. Human population growth was initially slow, but over the last 20 years it has grown
exponentially (J-curve)
2. The 3 causes for exponential growth: 1) Humans expand into diverse new habitats, 2)
Agriculture in controlling food sources, 3) A decrease in death rate due to technology,
sanitation, and medicine.
3. The rate of growth has slowed down over the years, but the population continues to
grow. Increased life expectancy and reduced death rate are causes of this continual
grow.
4. Effects of continued population growth include: An increase in resource consumption
and an increased environmental degradation and increased ecological footprint.
5. Factors affecting human population sizes: 1) Births 2) Deaths 3) Migration.
Population change = (Births + Immigration) - (Deaths + Emigrations)
6. Crude Birth Rate (CBR) is the amount of babies born per 1,000 women.
China and India have the biggest populations.
7. Fertility = # of children born to a woman during a lifetime.
Replacement level of fertility = # of children a couple must bear to replace themselves
(2.1-2.5)
Total Fertility Rate = Average # of children women typically have during their
reproductive years.
8. Factors that affect fertility and birth rates: 1) Children in labor force, 2) Education and
employment of women, 3) Urbanization, access to family planning, 4) Infant Mortality
Rate, 5) Availability of legal abortions, 6) Birth control.
9. There are 7.1 billion people on the planet
1963: Peak growth rate
10. Factors that affect Death Rate: 1) Increased Food distribution, 2) Better nutrition, 3)
Medical advances, 4) Sanitation, 5) Safer water supplies
10. Agricultural production
1. Croplands provide 77% of the world’s food using 11% of the world’s land.
2. Rangelands and pastures provide 16% of the world’s food using 29% of the world’s
land.
3. Ocean fisheries provide about 7% of the world’s food.
4. High-input agriculture uses large amounts of fossil fuel energy, water, commercial
fertilizers and pesticides to produce single crops (monocultures) and livestock animals
for sale.
5. Plantation agriculture is a form of industrialized agriculture used primarily in tropical
developing countries. It involves growing cash crops on large monoculture plantations,
mostly for sale in developed countries.
6. Feedlots are animal factories that are densely populated industrialized warehouses
where livestock is produced in developed nations.
7. Agribusiness is a collection of giant multinational corporations that control, process,
and distribute food in the global marketplace and in the United States. Agribusiness
accounts for 18% of the US GDP.
8. Traditional agriculture is practiced by 2.7 billion people in developing countries and
provides ⅕ of the world’s food supply on about ¾ of the cultivated land.
9. Interplanting- Growing several crops on the same plot simultaneously.
10. Agroforestry- Crops and trees planted together. The trees are planted to protect the
crops from wind damage.
11. Energy flow
-Energy flow can be seen in an ecosystem in different food chains and food webs
-Energy starts in a food chain or food web (combinations of many food chains) in
the first trophic level that contains producers. Producers are organisms that produce
their own food through means of photosynthesis and provide a food source for primary
consumers.
-The next level in food chains contain primary consumers that are animals that
eat exclusively plants shrubs for their food sources such as rabbits, cows, or horses.
-Moving up the food chain, energy flows to secondary consumers such as
snakes who eats primary consumers such as rabbits.
-The final stage usually in food chains are tertiary consumers such as Hawks
who eat snakes, the secondary consumer. By the time the energy flows to this level
there a good deal of energy has been lost. The amount of energy transferred is
measured in biomass and referred to as ecological efficiency.
-The final part to energy flow are decomposers and detritivores. These
organisms eat dead plant and animal material and put the nutrients back into the soil.
12. Genetic engineering
1. Genetic engineering is changing the genetic material of an organism by adding,
deleting, or changing parts of its DNA in order to produce some desired trait.
2. Recombinant DNA contains DNA from different species and can carry desirable
genes, or be an altered form of a gene.
3. Recombinant DNA can be inserted into an organism to make a transgenic
organism or GMO by using the following techniques:
4. GMO’s are used in…
5. Some controversy surrounding GMO’s...
13. Evolution and Speciation
1. Biological Evolution- The description of how Earth’s life changes over time. Biological
Evolution by natural selection involves the change in populations genetic makeup
through successive generations.
2. Natural Selection is a mechanism for biological evolution of the Earth’s huge variety of
life forms.
3. The idea of natural selection is credited to Charles Darwin.
4. Natural Selection is the ability of individuals to adapt in order to survive. The offspring
of these individuals had similar survival skills. They concluded that these survival traits
will be more prevalent in future populations of these species.
5. An adaptation, or adaptive trait, is any heritable trait that enables an organism to
survive through natural selection and reproduce better under prevailing environmental
conditions.
6. When faced with a change in environmental conditions, a population of a species has
three possibilities: adapt to the new conditions through natural selection, migrate (if
possible) to an area with more favorable conditions, or become extinct.
7. One misconception about natural selection is that “survival of the fittest” means
“survival of the strongest”. To biologists fitness is a measure of reproductive success,
not strength.
8. Natural selection can lead to an entirely new species. This process is called
speciation. Two species arise from one.
9. Generalist species have broad niches. They can live in different places, eat a variety
of foods, and tolerate a wide range of environmental conditions. Ex. rats, cockroaches.
10. Specialist species occupy narrow niches. They may be only able to live in one
habitat, use one or a few types of food, or tolerate a narrow range of environmental
conditions. This makes specialist species more prone to extinction. Ex. panda.
14. Climate and biomes
a. In all other cases, the rays arrive at an angle to the surface and are less intense.
The closer a place is to the poles, the smaller the angle and therefore the less
intense the radiation.
b. The sun's rays hit the equator at a direct angle between 23 ° N and 23 ° S
latitude. Radiation that reaches the atmosphere here is at its most intense.
c. Westerlies blow from the southwest on the Northern Hemisphere and from the
northwest in the Southern Hemisphere. Westerlies steer storms from west to east
across middle latitudes.
d. Our climate system is based on the location of these hot and cold air-mass
regions and the atmospheric circulation created by trade winds and westerlies.
e. stretches from Alaska straight across North America to the Atlantic Ocean and
across Eurasia. The largest stretch of coniferous forest in the world, circling the
earth in the Northern Hemisphere, is called the “taiga.”
f. A desert is an area where little or no life exists because of a lack of water.
Scientists estimate that about one-fifth of the earth's land surface is desert.
g. Mountain biomes are ones in which elevation determines life and climate.
Mountains exist on every continent and have great diversity depending on area
on elevation.
h. Tropical rainforests receive at least 70 inches of rain each year and have more
species of plants and animals than any other biome.They are often found along
the equator.
i. Grasslands are places with hot, dry climates that are perfect for growing food.
This inland biome is made of vast areas of grassy field. It receives so little rain
that very few trees can grow.
j. The deciduous forest biome is in the mild temperate zone of the Northern
Hemisphere. Deciduous trees lose their leaves in fall. The natural decaying of the
fallen leaves enriches the soil and supports all kinds of plant and animal life.
Population ecology
1. Population dynamics - study of how and why populations change in their distribution,
numbers, age, structure, and density
2. Density-dependent population controls - competition, predation, parasitism, infections,
disease
3. Density-independent population controls - natural disasters, changes in climate, and
habitat destruction
4. r-selected species - capacity for high rate of population increase, many small offspring,
little parental care, massive loss of offspring, opportunists, and limited by habitat
5. K-selected species - reproduce later in life, live longer, offspring born more mature,
taken care by parent until reproductive age, low number of offspring, “competitor species” offspring can compete for resources, prone to extinction
6. Age structure - proportion of individuals at various ages, affects how population size
increases or decreases, includes three stages: pre-reproductive, reproductive, post-reproductive
7. Population dispersion - clumped (most common distribution, uneven distribution of
resources, protection from predators, prey, social behaviors/mating/caring for young), uniform
(maximize scarce or evenly spaced resources, interaction of individuals in a population,
territorial behavior), and random (rare because of social interaction and resource availability,
wind dispersion)
8. Biotic potential - populations capacity for growth (r-selected species have higher biotic
potential and K-selected species have lower biotic potential)
9. Intrinsic rate of growth - rate at which population would grow if it had unlimited
resources (per capita rate of increase, max capacity to reproduce), exponential growth = Jcurve, logistic growth = S-curve
10. Environmental resistance - all factors that limit growth (biotical potential +
environmental resistance = carrying capacity: the maximum population of given species that a
particular habitat can sustain indefinitely)
15. Forests and grasslands
1. Tropical forests - high temperatures, high humidity, constant precipitation, near the
equator, highest biodiversity and NPP, low nutrients in the soil
2. Temperate forests - moderate temperatures with changes with seasons, average
precipitation that is spread out over seasons, found past 30 degrees and in the United States
and Europe, has nutrient rich soil, most disturbed by human activities
3. Boreal forests - long cold winters with average summers, snow in winter and rain in
the summer, found just south of Arctic tundra, contains evergreen coniferous trees with nutrient
poor soil
4. Tropical (Savannah) grasslands - warm year round, alternating dry and wet seasons,
found in dry and tropical regions bordering deserts, low vegetating with little trees, fires are likely,
most rapidly growing human population
5. Temperate grasslands - dry and cold winters, hot summers, low precipitation, found in
the interiors of continents, fertile soil due to layers of decaying matter, grasses become resistant
to fires, most used and destroyed by humans for cattle and farmland
6. Polar (tundra) grasslands - very cold year round, low precipitation with snow, found
south of polar ice caps, contains permafrost in soil with grasses, mosses, lichen, low shrubs,
used by humans for oil and military bases.
7. Chaparral grasslands - long warm summers with moderate cool winters, dry in
summer with more precipitation and fogs in winter and spring, found along oceans and deserts,
dense growths of low evergreen shrubs, very prone to wildfires, very popular among humans for
moderate and warm weather near oceans
8. Tropical rain forests cover 2% of the terrestrial surface, but contain half of the world’s
species
9. Overgrazing in grassland biomes can destroy soil and prevent vegetation from
growing
10. Tundra biomes can turn into marshes when permafrost melts in the summer
16. Sustaining biodiversity
1. Effects of Deforestation- decreased soil fertility from erosion, premature extinction of
species with specialized niches, regional climate change from extensive clearing.
2. Solutions for Sustainable Forestry- identify and protect, areas high in biodiversity, stop
clear-cutting on steep slopes, shift government subsidies from harvesting trees to
planting trees.
3. Suggestions for sustaining and expanding national parks- buy private lands inside
parks, increase funds for park maintenance and repairs, increase the numbers and pays
of park rangers.
4. Sustaining Terrestrial Biodiversity- Adopt a forest, recycle paper and buy recycled
paper products, live in town because suburban sprawl reduced biodiversity.
5. Characteristics of Species Prone to Extinction- K-selected, specialized niche, narrow
distribution, feeds at high trophic level, rare, large territories, fixed migratory patterns,
commercially valuable.
6. HIPPOH= Habitat Destruction
I= Invasive Species
P= Population Growth (Human)
P= Pollution
O= Overharvesting/Overexploitation
7. Protecting Wild Species- CITES (Convention on International Trade in Endangered
Species). CBD (Convention on Biological Diversity). ESA (Endagered Species Act).
Wildlife Refuges. Gene Banks and Botanical Gardens. Zoos and Aquariums.
Reconciliation Ecology.
8. Why is it difficult to protect aquatic biodiversity- rapidly increasing human impacts, the
invisibility of problems, citizen unawarenesss, lack of legal jurisdiction
9. Solutions for Protecting Wetlands- legally protect existing wetlands, use midigation
banking only as a last resort, restore degraded wetlands, try to prevent and control
invasions by non native species, require creation and evaluation of a new wetland before
destroying an existing wetland.
10. Ecological Services of Rivers- deliver nutrients to sea to help sustain coastal
fisheries, deposit silt that maintains deltas, purify water, renew and renourish wetlands,
provide habitats for wildlife.