Download Cycles - MrsGorukhomework

Option G
Factors that affect distribution of plants
1. temperature - plants differ in degrees of tolerance to temperature, adaptations
to it.
2. water (review special properties of water) - plants have various degrees of
tolerance to drought, e.g., cactus can withstand a lot, CAM plants and C4 plants,
plants also vary in tolerance to flooding like mangroves. Usually more diversity
with more water
3. Soil
4. pH
5. light - provides the energy that drives most ecosystems, competition for light in
rainforest, intensity and quality also important and make a difference. Will have
different species due to intensity will also affect plant and animal behaviors like
photoperiodisim
6. salinity
7. minerals - nitrates, sulphates, potassium, and iron, some of the basic minerals
needed by plants (review organic) to a lesser extent - wind is one as it causes
heat loss and evaporation (H.L. transpiration) and will affect the physical shape
of the plant.
Also periodic disturbances like volcanoes etc.
Factors that affect distribution of animal species Distribution is the range of
places an animal habits, is linked to abiotic and biotic factors. The main factors
are water and temperature.
1. temperature - endothermic and exothermic
2. water 3. breeding sites
4. food supplies - hibernate
5. territory - elephants need a large territory, competition if crowded
for marine organisms
1. salinity of water
2. wave action
3. temperature of water
4. tidal movements
5. currents
Be able to explain all in detail!!
Note – limiting factor is one that is in the lest supply so it limits
Due to potential crowding of organisms, there will be interactions between
species. They usually fall into one of the following categories – (need 2 specific
examples for each)
1. competition - an interaction that is detrimental to both species
2. predation - adaptations will occur like acute senses, camouflage, mimicry,
agile, fast, poisons or behavioral by birds mobbing, guards like ground hogs and
defense calls, distractive behavior like broken wing.
3. herbivory - where animals eat plants (a form of predation) primary consumer
feeds on producer and either kills whole plant or not (grazers) some adapt with
chemicals like strychnine, morphine, nicotine, digitoxin, and others not harmful to
man like cinnamon cloves, peppermint, animals adapt by not being affected by it
4. parasitism - define, nematode, mosquito, virus - specific names?
5. mutualism - algae on coral, acacia tree and ants
6. commensalism - cattle egrets and cattle as cattle flush up insects, pilot fish
Habitat - address of a species, the environment particular to an organism,
characterized by physical or abiotic factors
Niche - is the profession of a species, includes the behavioral adaptations,
feeding activities and how it interacts with others - is it a predator or prey etc. the
role of the organism. A habitat can be occupied by many species but a niche by
only one.
A species fundamental niche – consists of the full potential range an organism
could use if it could avoid direct competition from other species. (never happens)
To survive and avoid competition, a species usually occupies only part of its
fundamental niche – called its realized niche.
Competitive exclusion - only one species can occupy a niche at one time in one
area. If there is more, competition and the stronger or more adaptive will survive.
Others will die or leave.
Biomass – organic matter produced by plants – total dry weight of all living
organisms in a trophic level.
Note page 329 different methods for calculating biomass – know one!!
Potential Designing lab – page 329 on competitive exclusion/niche or pick an
abiotic factor and its affect on a tree – note see page 330 for leaf area index**
Difficulty in classifying organisms into different trophic levels ?
Gross primary production (GPP) total amount of light energy converted to
chemical energy in a period of time. But need energy to live i.e. cellular
respiration so
GPP – respiration = NPP. (includes energy stored in roots and trunk)
NPP is about 50-90% of GPP, smaller for bigger plants like trees – why?
Tropical rainforest and open oceans have high GPP. Deserts and tundra have
low. (seasons, number of producers)
Be able to calculate values always show units
G.2.5 Construct a pyramid of energy !!! paper two section A and/or section
B question – units are kJ m-2 yr-1 and make the bars and thickness of
proper relative size and width.
Smaller biomass in higher trophic levels → why?
A lot of energy is not passed to herbivores put passed to decomposers and put
into the woody, inedible parts of trees – what you loss when you cut down a
forest
Photosynthetic efficiency – forest more efficient than a desert, desert reflects
light, forest has more plants to absorb light, less extreme climate.
Biomes
- difference between biome and biosphere
Discuss the distribution of tundra in the world today [2]
Tundra is found in northern hemisphere only
At latitudes of around 60º
Size of tundra is changing due to global warming
Species Diversity – species richness and abundance. Related to food web.
Tropical rainforest has the most, desert and tundra have the least. The more
diverse, the more stable the food web. Monoculture?
Argument for maintaining biodiversity for rainforest – G.3.3 DISCUSS means
pros and cons
Pros- contains many species not yet discovered, high biodiversity, soil erosion,
drugs, possible source of ecotourism, ethically not ours to destroy, effect
greenhouse gases as major area of photosynthesis, soil is poor so not good for
agriculture
Cons- have lots of rainforest so can afford to destroy some, already damaged
and can’t repair, need space to grow crops, if allowed to develop could get
money to protect others, possible minerals underneath for money.
Techniques – to measure light intensity done in lux. Two other abiotic factors
could be pH, moisture content, and soil composition. How would you measure,
Wind speed- anemometer
Techniques to calculate population size
- Random sample – involves using a quadrat to compare the population sizes
either thrown randomly, quadrats using used to count plants
- transect – used to show correlation between the distribution of plant/animal
species and an abiotic factor.
Outline a method used to correlate distribution of plant species with an abiotic
factor [2]
 transect used when there is a transition in habitats and populations
description of use of a line or belt transect
height variation/light intensity/salinity/others
along the transect, along with sampling of plant species present
H.L. extra technique- capture-mark – recapture – best to have a large
population, know formula called the Lincoln index. For it to work properly (predict
the size) the population must be; closed, freely mingle, shouldn’t become too
trap-happy (using bait) or trap-shy (painful method), the marks must not effect
them, sufficient time for mingling between first and second capture
Marked unit area
Apply paint spot/tag/radio transmitter to captured animal
Sufficient time elapsed to allow mixing with population to occur
Second capture must be from same marked area
Calculate the Lincoln index where …(formula)
- biomass – for all
- you would count and then do a density or a percentage, know density formula
and how to calculate percent
And once you know how big your populations are, how can you tell if they are
diverse/healthy?
t-test – compares two sets of values or data. A large value indicates little overlap
and a difference between the two sets. A low number indicates an overlap and
probably no difference.
Simpson’s diversity index – calculates index of diversity for a species. A high
value indicates rich diversity, probably clean environment. A low value may
indicate environmental problem like pollution, agricultural use or natural disaster.
S.D. – shows if the differences in the means is significant as just using the mean
may not show it. 1 SD is 68%
Succession
All communities change their structure and composition in response to changing
environmental conditions. The gradual change in species composition of a given
area over time is called ecological succession. During succession, colonizing or
pioneer species arrive first. As the environmental (abiotic) conditions change,
they are replaced by other species and then later by others. Gross production
increases as small plants are replaced by bigger, more stable plants. Until
eventually, the climax species become dominant. They are the stable community
best suited to the abiotic environment.
Two types of succession;
1. Primary succession – no soil or bottom sediment – Mt. Pinatubo, Mt. St.
Helens
Pioneer plants would be lichen, algae, mosses → high tolerance plants, help
establish soil and humus with their dead bodies. Lichen dissolves the rocks,
weathering, organic matter established. Eventually soil which allows seeds to
establish.
Pioneers are poor competitors so will disappear but bigger plants survive →
moss, herbs, small shrubs.
Animals then arrive, help to aerate the soil and more nutrients.
Abiotic environment changing as plants and pioneer animals change the soil and
thereby the water content, more nutrients in soil, holds more water
Species diversity increases with plants and animals
Reach climax community
2. Secondary succession –natural community has been disturbed, removed or
destroyed, has soil, could be due to fire, flood, agriculture, industry, towns,
buildings
Succession can be prevented by removing certain species and maintaining
others – eg. Like in gardens and golf courses
*Affect of living organisms on abiotic environment – question done twice goes
with succession
• amount of organic material – affects soil composition which will affect water
retention and drainage
• roots of plants affect erosion of soil
• mineral content – eg nitrogen
• plants reduce wind erosion an provide shade so effects temperature
• biomass – affect decomposers and recycling of nutrients
• amount of oxygen due to photosynthesis
Human impact
Introduction of exotic species - non-indigenous, know one example, and what it
does to the food chain or web. What happens if you take out an animal?
Need three examples one for biological – toads, one accidental – and
deliberate release – rabbits in Australia
Alien species could have been introduced for biological control, such as
may control pests
economic value eg reforestation to reduce soil erosion
cons are like above question
Biomagnification – asked a lot so far, need named example.
Oxygen – not really a cycle as not always found as O2, is the link between
carbon and water cycles, involves photosynthesis and cellular respiration.
During photosynthesis, light energy is used to hydrolysis water. The oxygen is
thus converted from water to a gas and released. In respiration, the gaseous
oxygen is used to release energy from glucose and then is converted into water
again
Ozone – O3 high levels of ozone in the stratosphere are good as it protects us
from ultraviolet rays. In the lower atmosphere is part of smog, acts as a
greenhouse gas. Dealing with good ozone. Human actins with CFC deplete this
ozone.
1% increase in intensity of UV causes a 2% increase in cancer
1% decrease in ozone can cause a 2% increase in UV that reaches Earth
So we need ozone to protect us from too much UV rays. But what is wrong with
UV? UV is electromagnetic radiation from 200 to 400 nm, can cause mutations
in DNA as it bends or kinks the DNA, UV can damage tissues. Can cause
mutation rate, cause cataracts, skin cancer, reduce photosynthetic rate in algae
which therefore affect food chain.
And how are we destroying CFC – well, first CFC’s are found in refrigerants like
in refrigerators, A/C, propellants in spray cans, some plastics. When released in
the air,
travel up to the stratosphere and the UV light breaks it down releasing Cl. Cl
reacts with ozone O3 + Cl → O2 + ClO And that starts up a chain reaction that
destroys more and more ozone. ClO + O3 → 2O2 + Cl and that Cl goes out and
does anther ozone. Each Cl molecule can catalyze 105 ozone molecules!
What to do?? Montreal Protocol, recycle plastics, regulated disposal of
refrigerators and a/c UV radiation
Tiger book good for data analysis Page 328 – inquiry Page 329 – working with
data page 331 – secondary succession Page 333 – top data, 335, 338
HL
Indicator species – species that ecological requirements are well understood,
need a particular environment and when encountered, indicate something in the
environment so you can construct a biotic index. Biotic index used to monitor
environmental change.
Eg. Of indicator species – stonefly for high oxygen in water, tubifex for low,
crustose lichen for tolerance to air pollution and fruticose lichen for intolerance.
Any change in environment will show in the numbers, used to indicate pollution.
Pollution is seen as an overall decrease in diversity.
Biotic index eg. Lichen community and air pollution. A relative or absolute scale
of numbers or species. Lots of tolerant species will give a low rating, lots of
intolerant species will give a high rating..
(trout and char for high oxygen, leeches and midge larva for low oxygen, perch
for warm water and organic material.
extinction → need named examples FIND
(passenger pigeon due to hunting, dodo due to hunting and destruction of
habitat.
In situ – in their habitat, reserves; advantages – larger areas than zoos, large
populations, already preset, no buildings to build, natural selection can occur,
species already adapted to area, doesn’t disrupt natural behaviour, more
balanced.
Management of nature reserves – often needs intervention like culling(eg too
many elephants) control alien species, predation, restore degraded areas,
promote recovery of threatened species, control human exploitation, control
populations, limit access to sensitive areas, educate local community on
importance, reintroduce extinct species.
Biogeographical features 4.3, 4,4, 4.5, 4.6
Ex situ
*r and K strategies is often used.
r- strategists – usually small animals in unstable environments, little advantage in
competitive adaptations as environment cold change quickly. Environment has
amply food supplies so many offspring can be supported, early maturity due to
climatic factors
capture-mark-recapture method using Lincoln index. Know what each n 1 means
see core notes on techniques.
Fish
Ways to conserve – remove predators, remove for ex situ, national parks,
hunting seasons, legislation for quotas
Action at national level – biodiversity can be conserved by; data collecting to
determine the number of species and whether people following rules, legislation
to making hunting illegal, ensure land is set aside for conservation, captive
breeding used for small populations and those that can’t breed in wild, remove
danger of predators
Importance of environmental monitoring – gives early warning of change, tests
whether species will survive, shows if damage being done BUT can involve
harming animals, disturbing areas, killing for bioassy, money might be better
spent on other management measures.
Environmental impact assessment – pulp mills, power plants
International conservation of fisheries – international limits on size and quotas,
protections of nursery areas, minimum mesh size so don’t catch immature fish,
laws on pollutions, international controls and laws on this