BEE Flashcards
(169 cards)
1
Q
Chemosynthesis
A
Process of producing organic molecules using the oxidation of inorganic molecules, involving in electron donors and water or oxygen molecules
2
Q
Problems of Herbivores
A
- Acquiring lack of protein and acquiring too much-sugar
- Carbon removed via metabolism
- Sugars may also be excreted from the body
3
Q
Ecosystem dynamics
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Changes within a system; infuenced by state factors and interactive controls
4
Q
State factors and Interactive controls
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- State factors: climate, soil/parent material, topography (the altitude of the ecosystem), potential biota (potential maximum growth of population), time; determine biomes in a broad scale
- Interactive controls: resources (energy from sunlight and matter/nutrients and micro-mineral — animals only need a small amount of these, modulators (physical and chemical properties of the ecosystem), human activities, disturbance regime including flood, fire and storm, biotic communities (functional types within a community)
5
Q
Toposequence
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Looking/studying for patterns of organisms living in certain altitudes
6
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Chronosequence
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Looking/studying for patterns of organisms living in different time periods
7
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Ecological succession
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Structure of biological communities over time
8
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Primary succession
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Formation of community from nothing
9
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Secondary succession
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Formation of community after another is destroyed
10
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Rock cycle
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Igneous (from magma), sedimentary rock (small pieces formed from weathering), then Metamorphic rocks (heat and pressure)
11
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Weathering
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Formation of sediments, a key component of soil
12
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Physical Weathering
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Frost wedging/freeze thaw, Thermal expansion or isolation leading to exofoliation
13
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Chemical Weathering
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Oxidation, carbonation, hydrolysis, hydration, solution (Together 5)
14
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Soil profile
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On a deck of Andy’s silty classy mint from Sainsbury, leans an Egg Battered acutely after Castrations
15
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Cation-exchange capacity
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Number of exchangeable cations per dry weight that a soil is capable of holding, at a given pH value, and available for exchange with the soil water solution.
16
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Climate
A
Amount of raindrop + temperature
17
Q
Direct solar radiation/ Diffused solar radiation and their effects on differing latitude
A
- Solar radiation traveling on a straight line from the sun down to the surface of the earth.
- Solar radiation reaching the Earth’s surface after having been scattered from the direct solar beam by molecules or suspensoids in the atmosphere
18
Q
Latitude
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A geographic coordinate that specifies the north–south position of a point on the Earth’s surface
19
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Tilt earth’s influences
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- Seasonality
2. Non-syncing seasonality of north and south hemisphere
20
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Latitudinal atmosphere circulation and biome formation
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- Warm air rises at ITZC via maximum solar input and moist air descends 30 degrees N and S, leading to formation of frequent rain and formation of rainforests
- Formation of desserts with dry wind after the deposition of water it once acquired
21
Q
Formation of tradewinds
A
Earth spins anti-clockwise, and the wind act against the direction
22
Q
Being in high altitude
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- Lower temperature
2. Higher rainfall
23
Q
Land cover’s influence on climate
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- Albedo, fraction of solar energy (shortwave radiation) reflected from the Earth back into space. e.g. Ice, ocean, vegetation
- Evapotranspiration, water is transferred from the land to the atmosphere by evaporation from the soil, other surfaces and by transpiration from plants, to remove heat
24
Q
Causes of long term variation
A
- Milankovitch cycles
Orbital eccentricity: two forms, elliptical and circular orbit, cycle once every 100,000 years
Precession: Earth’s axis itself rotating on another axis; cycle once every 21,000 years (think wobble of Gyro as it is about to stop)
Axial tilt: angle variation Earth’s obliquity oscillates between 22.1 and 24.5 degrees on a 41,000-year cycle - Interannual climate variation
- El-Nino-southern Oscillation: Easterly trade wind does not pushs warm water to the normal direction, leading to drought
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Water budget/balance and it's involving processes/phenomenons
- Relationship between input and output of water through a region
1. Soil moisture recharge: precipitation give off water in a faster rate than transpiration
2. Evapotranspiration
3. Stemflow: interception of water by trunk or stem of plants
4. Soil moisture surplus: soil saturated = no more infiltration occurring (dependent on soil type)
5. Macropores (roots and cracks from organisms such as earthworms)
6. Raindrop impaction of surface layer
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Soil moisture deficit
Water of soil being completely used up
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Causes of water movement
1. Pressure gradient
| 2. Matric forces
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Factors affecting rate of water flow through plants
1. Gradient of water potential
2. Resistance of water movement
3. Pathlength of travelling water
4. Pressure gradients, associated to matric forces
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Matric forces
Cohesion, adhesion, force in the air-water interface due to the polar nature of water) and gravity
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Field Capacity
The amount of soil moisture or water content held in the soil after excess water has drained away.
31
How is water loss from leaves?
Evaporative potential of the air (vapour pressure deficit of the air), depending on the boundary layer resistance (thickness of air around the plant), stomatal opening adjusts flow resistance for appropriate water potential
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Solar radiation budget
Earth receives the same amount of energy via insolation (all forms of electromagnetic radiation) as it emits via atmospheric and terrestrial radiation (shifted to longer electromagnetic wavelengths) to space.
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Nutrient cycling
The movement and exchange of organic and inorganic matter back into the production of living matter.
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Nitrogen Cycle
1. Atmospheric nitrogen >> Ammonium (Nitrogen fixing bacteria in soil) >> Nitrites (Nitrifying bacteria) >> Nitrates (Nitrifying bacteria) >> Atmospheric nitrogen (Denitrifying bacteria) and plants' nitrogen
2. Plants' nitrogen >> Ammonium (decomposers)
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Nutrient Budgets
Insight offering balance between nutrient inputs and outputs (Inputs – Outputs = change in storage); mature forests rarely loses nutrients; disturbance (fires, storms and forest clearance) upset the balance
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Rhizosphere
Narrow region of soil that is directly influenced by root secretions and associated soil microorganisms; may be a presence of Mycorrhizae
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Formation of nutrients
1. Nutrients release with the weathering of rocks
2. Released from the atmosphere (aerosols, dust and trace gas) carried down by wet deposition (acid rains, snow and fog) and dry deposition
3. Areas of floodplain communities, low lands prone to flooding
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Degeneration of nutrients
1. Methanogenesis, reducing C
2. Denitrification in anaerobic environments
3. Dissolving in stream flow
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Mycorrhizae
1. Increase the volume of soil exploited by plants
| 2. Fungi acquires carbohydrates by giving nutrients to plant
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Nutrient use efficiency (NUE)
- Net primary productivity/nutrient uptake
- NUE increases in places with less nutrients
- High concentration of N, P and K in leaves to carry out metabolism
- Wood, on the other hand, is associated with Ca Plant diversity along resource gradients
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Dispersal
Movement of organisms away from each other:
1. Foraging trips — limiting travel distance
2. Migrations — Mass directional movement of large numbers from an location to another
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Reasons for natal dispersal
- AKA, leaving of parental areas
1. Avoid competition with siblings and parents
2. Avoid inbreeding
3. Avoid dominating species
4. Colonizing new areas
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Population
Group of same species found in a particular area in the same time, interacting by means of breeding or reproducing
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Population size
Number of individuals
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Types of Dispersion
1. Clumped
2. Regular
3. Random
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Population density
Number of individuals per unit of area
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Population distribution
Places where individuals of specie are found; determined by abiotic, biotic and historical factors
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Reasons for clump pattern formation
1. Receiving benefits of grouping (Group acquisition of food, Access to mates, Shelter, Protection from predation, Division of labor, Social thermoregulation and Group defense)
2. Resources are patchy
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Reasons for regular pattern formation
1. Antagonistic and repulsion behavior (Individuals defending their own territories)
2. Resources could be used in surrounding area
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Reasons for random pattern formation
1. No attraction and repulsion of individuals
| 2. An area reaching the environmental requirements
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Primary production
Production of organic chemical from inorganic chemical; these processes are photosynthesis and chemosynthesis could be carried by respectively chemotrophs and phototrophs
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What are the factors influencing rate of photosynthesis? How do they influence photosynthesis?
1. Solar radiation - Increase intensity of solar radiation, increases the rate of photosynthesis (however, too much solar radiation reduces the rate of photosynthesis)
2. Minerals (N, P, S, K, Mg, Ca and Fe)
3. Water
4. Inorganic carbon
53
How does soil porosity influence the rate of photosynthesis?
- Loose soil
1. Lack of capillary force >> Less water retained
2. Water are easily absorbed
Hence, roots are thick and does not branch
- Denser soil
1. Water held against gravity, but could not be easily absorbed, leading to roots extensively branching
54
How does solar radiation influence the evolution of leaves?
- Increase intensity of solar radiation, increases the rate of photosynthesis; too high reduces the rate of photosynthesis)
1. Leaves from canopy have thicker but smaller leaves, containing a higher number of chloroplast than leaves of below the canopy
2. Leaves move to track sunlight; hence, able to photosynthesize in low light level and able to avoid direct exposure to strong sunlight
3. May produce wax to limit sun exposure
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Factors influencing carbon dioxide concentration
CO2 concentration depends upon geological time, daily, seasonally and spatially
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Chemosynthesis
Process of producing organic molecules using the oxidation of inorganic molecules, involving in electron donors and water or oxygen molecules
57
Behaviour of Avoiders
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Desert annuals (germination + reproduction within 1 year and dies)
Rainy they spring up and reproduce – and leave their seeds to wait during dry periods
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An example of tolerator
Evergreens keep needles all year long even when water is scarce (frozen)
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Herbivore
An organism that eats tissue or internal fluids of living plants or algae
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A problem that herbivores face and how is it
- Acquiring lack of protein and acquiring too much sugar leading to disease
- Excess carbon are removed via metabolism and sugars may also be excreted from the body
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Frugivores
- Eat fruits, containing rich sugar
- Need large quantity of fruit for suffice nutrients
- Tend to be terrestrial (birds, mammals, turtles and few fishes)
Examples: Red-vented Bulbul (Pychnonotus cafer) and Amazonian tambaqui (Colossoma macropomum)
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Folivores
- Eat leaves & grasses, containing rich carbohydrates and suffice fibre, protein and minerals
- Common among all genus, relatively rare in birds
- Cellulose are, however, hard to digest
- Increases weight, limiting mobility or the ability to fly
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Nectarivores
- Eat nectar, containing rich sugar, high fluid content and some protein
- Excess water is evaporated and excreted
- Long tongue or long proboscis to obtain deeply embedded nectar
Examples: Honey possum (Tarsipes rostratus) andOrnate Day Gecko (Phelsuma ornata)
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Mucivores
- Eat mucus, saps (Pholem or Xylem, liquid flowing inside the plant)
- Xylem: high water content relative to energetic value
- Phloem: Rich in sugars, and have some nitrogen and a bit of minerals
- Excess water is excreted or evaporated
- Tend to be smaller in size
Examples: Cicadas (Cicadidae) and Aphids (Aphidoidea)
1. Content are passively or actively obtained
2. Aphids tap and sap flows out
3, Negative pressure, drawing content to cicadas
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Granivores
- Eat seed, containing rich starch, protein and have some fat, which are usually hard and well defended
- Hard exterior to deal with well protected seeds
- Common for insects, mammals and birds
Example: African bonytongue (Heterotis niloticus)
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Palynivores
Eat pollen, containing high protein, carbohydrate and fat
| Predominately invertebrates, some bats may consume pollen
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-Xylivores
- Eat wood, containing very dense cellulose, hemicellulose and lignina, which are hard to be digested
Examples: termites, wood beetles, beavers
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Algivores
- Eat algae that contains richer protein, minerals, and less cellulose when compared to terrestrial plants
- Algivores are mostly aquatic
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Endophtes
Fungi or Bacteria that live in a plant but do not cause disease
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Adaptations to overcome the indigestible cellulose
- Long digestive tract
- Foregut fermenters (Ruminants, mammals eating plants)
- Four chamber stomach
- Long small and large intestine
- Hindgut fermenter (Non-ruminants)
- Simple stomach and relatively large caecum
- Containing symbiotic bacterias
- Grinding process during or prior to digestion
- Break down plants into smaller pieces, exposing more plant cells to the stomach
- Selective of plant material
- Choosing plants of which that could be digested more easily
- Co-opting bacteria for fermentation
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Coprophagy
Eating herbivores’ semi-digested feces, digesting more food content
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How do herbivores overcome physical defenses and chemical defenses of plants?
1. “Bite and retreat” strategy
2. Excrete toxins
3. Storage/sequestration
4. Detoxification
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Why would herbivores practive geophagy?
1. As a supplement to diet
2. To deal with plant chemicals
3. Provide grit for grinding plant material
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Types of predations
1. Grazers
2. True predators
3. Parasites
4. Parasitoids
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Grazers
- Remove and consume only a part of the prey (mostly plants)
- Predominantly herbivores
Examples: cookie-cutter shark (Isistius brasiliensis) and Phestilla minor
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True predators
- Consume prey in its entirety/prey killed
- Predominately carnivores
Examples: Dusky slug (Arion subfuscus), leopard (Panthera pardus)
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Parasites
- Remove and consume only a part of the prey, rarely resulting in death
- High intimacy with its prey
- Common in plants, animals, fungi and microorganism
Examples: mistletoe and Cymothoa exiaua
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Parasitoids
- Remove and consume only a part of the prey, rarely resulting in death
- Only attacking few organisms in a lifetime
- Organisms that eat already dead organisms are referred to as Detritivores, Saprophages and Decomposer
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Coprophages
Eat their own feces, including flies, fungi and bacteria
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Scavenger
An organism that feed on recently dead organism and /or utilize large portions of dead organism
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Detritivores
May be used to represent smaller animals that ingest macroscopic particles
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Saprophages
May be used to represent ‘true decomposer’
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What are some defensive mechanisms of herbivores?
- Physical: Camouflage, mimicry (mimic predator or something unpleasant to eat), being large and having mobility
- Chemical: toxins or noxious compounds, usually accompanied by warning coloration
- Behavioral: Mobbing, alarms or distraction displays
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Generalist
- Make use of different foods
| - Obtain food fast but may be less nutritious and takes more time to consume
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Specialist
Feed on few types of food
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How does organisms deal with enviromental changes?
1. Avoid
2. Tolerate (where they either conform – coping with internal conditions changing, or regulate – Maintaining internal conditions independently)
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Types of toleration
1. Acclimatisation – Reversible changes that help maintain the functioning of individual organism under changed environmental circumstances
2. Adaptation – A process whereby natural selection adjusts a trait to improve an organism’s fitness under different environmental conditions
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Stress
Condition in which any environmental change results in a decrease in the rate of an important process
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Ways to achieve water balance
1. Iso-osmotic – concentration of water and solute in sea is similar to the their body
2. Hypo-osmotic – concentrations outside the fish are about three times those inside. Evaporation at low tides raises concentration of solutes
3. Hyper-osmotic – no solute in freshwater, so the concentrations inside snails or similar organisms are higher than outside
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Traits of marine vertebrates
1. Hypo-osmotic
2. Drink seawater
3. Actively pumping solutes through gills
4. Secrete other soluttes in isotonic urine
5. Excrete salt from salt glands
6. Excrete hypertonic urine
7. Have less permeable skin
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Traits of invertebrates near Estuary, tidal mouth of large river
1. Hypo-osmotic
2. Impermeable coating (beadles anemone have waxy skin)
3. Burrow or hide
4. Store water (Shore crab)
5. Use amino acids as compensatory osmolytes
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Traits of freshwater
1. Hyper-osmotic
2. Impermeable skin
3. Solutes come from food
4 Active uptake of solutes by gill
5. Excrete excess water using hypo-osmotic urine
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Traits of terrestrial animals
- Little water and no solutes in environment, animals tries to minimize the lose of these to the environment by:
1. Finding damp or humid microclimate, restrict activity to decrease permeability of skin in dry conditions
2. Finding water sources, drinking liquid, eating food, water vapour, osmotic uptake of water in soil or producing water via respiration
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Thermoregulation
- Movement of heat from one object to another
| - Proportional to the difference in heat temperature
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How are heat transferred?
1. Conduction: direct flow of heat between materials through direct contact; rate depends on temperature, area and conductive properties
2. Convection: flow of heat between two materials by mass movement of an intervening fluid; rate depends on area of contact and properties of fluid or gas
3. Radiation: the emission or transimmission of energy in form of waves or particles though space a material medium; rate depends on the temperature and emissivity of the object; rate depends on water vapour density between surface and enviroment
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How do organisms obtain heat?
1. Voluntary activity: heat spread, sweating and dishevelled feather reduces the value of insulation
2. Involuntary muscle movement: shivering, little movement produced, whilst expending energy
3. Non-shivering thermogenesis: brown adipose tissue with high mitochondrial content are burnt for heat
4. Activating endothermic heat generation
5. Muscles around hair follicles contract known as goosebumps for grown hair to trap heat
6. Subcutaneous fat
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How do organisms remove heat?
1. Places with shade and underground
2. Increase sweating and panting for evaporation
- Sweating leads to mineral and water loss, while temperature gradient is reduced, but large surface area is cooled
- Panting leads to increase of ventilation, but skin remains hot, does not reduce temperature gradient and only contributing to water loss
3. Dormancy and migration
4. Heat storage and heat exchanger
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Ethology
Scientific study or animal behaviour
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When do behaviour take place?
When sensory processes recieves information regarding to internal conditions and external environments.
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Sensory processes
1. Chemoreception: receptor capable of detecting and identifying chemical substances
2. Thermoreception: receptor capable of detecting hot and cold temperatures
3. Electromagnetic receptors: receptor capable of detecting electromagnetic radiation
- Ultralight is damaging and thus, it is filtered out by the eyes
4. Electroreception: receptor capable of detecting electromagnetic radiation
- Only possible in water where the weak signals are conducted
5: Nociceptor - pain receptor
6. Mechanoreception: receptor capable of detecting changes in pressure, position or acceleration
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How does animals orientate themselves?
1. Through kinesis: animal responses is proportional to the intensity of stimulus
2. Taxis: animals moves towards towards or away from a stimulus
3. Navigation: animals moves from one place to another in a goal orientated manner
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Types of Navigation
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1. Piltage: navigation using familiar landmarks
Compass orientation (i.e. wasps use pine cones as landmark)
2. Compass orientation: navigation using a particular compass direction (i.e. Indigo bunting uses the pattern of star movement to orientate themselves
3. True navigation: navigation using map references (i.e. matured european starling with experience of migration could get to their goal after being resettled; juveniles could not however)
4. Communication: "actors" use specially designed signals or displayed to modify the behavior of reactors (i.e. bees communicates environmental information through visual means)
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Past Can Truely Confuse
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Why would organisms favor infraspecific interactions?
1. "Many eyes" hypothesis: larger number means greater vigilance, reducing the probablity of an individual being eaten
2. Dilution effect: Individuals are less likely to be picked off
3. Confusion effect: predators have harder time focusing on any one of them
4. More food could be obtained
5. Individuals' chances to find mates
6. Cooperative breeding, raising each other's young
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How does groups of plants differ from each other?
- Bryophytes are gametophyte dominant
- Ferns are sporophyte dominant
- Gymnosperms/ Angiosperms are sporophyte dominant, and they produces macrospores (produces eggs) and microspores (releases sperms)
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Types of asexual reproduction
1. Binary fission
2. Budding
3. Vegetative propagation
4. Fragmentation
5. Parthenogenesis
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Budding
Smaller daughter individuals form on a single mother individual
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Fragmentation
Fragments of parent individual regenerate to form new individuals
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Parthenogenesis
Unfertilised egg develo ped into a daughter individual
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Sexual reproduction
Gametes are reproductive haploid cells that fuse to produce new individuals
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How does Aphids reproduce?
- Spring and summer, they reproduce asexually
- Autumn, they reproduce sexually, laying eggs which could survive through cold winter
- Explosive growth in spring and summer, while also obtaining dispersal and genetic exchange
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Semelparous
- Reproduces young once and die; they invest heavily in their breeding event
- Salmons have semelparity with overlapping generations, spawning adult (smolt and adult)
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Iteroparous
Reproduce young multiple times; reproductive events could occur seasonally or randomly
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Life history theory
Pattern of lifetime growth, development, reproduction and survival (e.g. Pygmy shrew or Sorex minters: 4 g, lives 15 months, 5 littles per year and 2-8)
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Traits for organisms to compete in a stable environment
1. Long life span
2. Delayed maturation
3. Slow reproduction
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How could clutch size be optimized according to Lack?
Optimum clutch size should be an intermediate number of eggs, trading off fecundity (producing young in great numbers) and proportion surviving 自己打個比方
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Shortcomings of Lack's
- He assumed that current reproductive effort does not affect future efforts
- Clutch size only affects offspring viability
- No year to year variation in optimal clutch size
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Population models
Mathematical representations of how populations change over time
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Geometric population growth
Used on organisms with discrete generations (no overlap in reproduction, with mating seasons and stuff, I presume) – e.g. Phlox drummondii
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Exponential population growth
Used when populations reproduce continually
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Logistic growth
- Works well in labs but not in nature
- Evidences are shown by single-cell paramecium and barnacles
1. At low densities, population growth rate is high and population size increases quickly
2. As density increases resources are depleted, population growth rate decreases and eventually stops at the limit that the environment could support, called carrying capacity
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What is BIDE model
B = Births in population, I = Immigration into population, D = Deaths in the population and E = emigration out of the population —> Change in N = B + I - D - E
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Density-independent factors' influence on population
Factors, such as temperature, rainfall and drought, don’t regulate populations but leads to population fluctuations
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Density-dependent factors' influence on population
Factors, such as space, food, parasites, predators and water, regulates population sizes (higher density, lower population size)
- Song sparrows (Melospiza melodia) on Mandarte Island; higher density fewer young survives
- Soybeans’s population growth rate decreases when population density increases
- High density leads to immigration, low density leads to immigration
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What is absolute population size? Why is it used?
Estimate approximates the actual abundance of individuals in the population; time consuming and expensive but more more accurate
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What is relative population size? Why is it used?
Estimate relating to the actual abundance and, allowing comparison between the number of individuals in one place or time relative another; although misleading, it is cheap and quick
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Ways of calculating population size
1. Area-based counts
2. Distance methods
3. Mark and recapture
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What is population viability analysis? Why is it used?
- A mathematical process and a tool set used to estimate probability of population will persist within a certain time period in current conditions and under conservation management; its usages is as follows:
1. Determining required sized for a reserve
2. Deciding number of populations needed for regional persistence
3. Identifying key life stages or demographic processes for conservation or pest control
4. Setting sustainable harvest limits
5. Determining number of individuals to release in an introduction
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Area-based counts
Using counts in a smaller “sample area” (using something like a quadrant) t0 estimate the size of the total population; different dispersions will also need more or less quadrant to get the same degree of accuracy; gets absolute population size estimates on slow moving or sessile animals and plant; gets relative population size estimates on mobile or cryptic animals
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Distance methods
Using the distance organisms’ population size from a point or line is estimated; number and distances of organisms is used to calculate density; detection function can be used to correct estimates and provide absolute population size
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Mark and recapture
Using the proportion of individuals recaptured after initially being captured, marked and released to estimate the population size; particular effective for mobile animals
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What are the assumptions that mark and recapture follow?
1. Population size does not change during the period of sampling
2. Each individual has equal chance of being caught ; some, in reality however, may be more trap prone than others
3. Marking does not affect the on the individual; it may, however, affect the organisms survival, reproduction and reintegration after release
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Sustainable harvests limits
The number of individuals that can be removed without risking the population; e.g 1/2 carrying capacity is the maximum sustainable yield for harvesting: below 1/2 K, new individuals are recruited into the breeding population, above that, new individuals are dying from competition
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What are the two ways of setting limits for harvesting?
1. Fixed quota: remove the same number every year, even slight over harvest could result in extinction
2. Fixed effort: maintain a constant harvest effort; the amount harvested each year will change with the population size; though less risk of extinction, it is harder to enforce
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Life table
A table of values describing important life history variables (e.g. survival) for given ages within a population,
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What does a cohort life table include?
1. Age
2. Number surviving
3. Proportion surviving
4. Survival rate
5. Number of young
6. Young per individual
7. Young per surviving individual
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When are static life table used instead of a cohort life table? How are they used?
- Datas for some organisms are hard to obtain; thus, static life tables are used instead
- Uses data from a certain time period
- To find the number of young, individuals of different age groups are watched to see the number of offsprings they produce; this requires a way of estimating age and the assumption that survival and reproduction are constant
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Alternative life tables
Static life tables but averages data over several time periods
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What are the advantages of alternative life tables compared to static life tables?
1. No need to follow an entire cohort from birth to death 2. Averages of survival and reproduction values are more reliable; but averages hide some interesting fluctuations
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Types of survival and mortality curves
Type 1: Slow decrease of organisms surviving along with time (e.g. human)
Type 2: Moderate decrease of organisms surviving along with time (e.g. songbirds)
Type 3: High decrease of organisms surviving along with time (e.g. frogs)
- These curves varies with population, sexes and cohorts as well
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Types of interactions between cohorts
1. Predation (+ & –)
2. Amensalism ( 0 & – )
3. Competition ( – & – )
4. Neutralism ( 0 & 0 )
5. Commensalism ( + & 0 )
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What are the effects of competition between species?
- Influences individual growth, population growth, reproduction and the longevity
- This is because, resources, such as space, food, water and light, can consumed by organism, can be depleted and influence individuals or populations; lack of these resources limits organisms’ ability to grow, reproduce or survive; important influences such as salinity, temperature and pH level, aren’t consumed or depleted; thus, they are not resources but physical factors
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Exploitation competition
A specie use a resource that would otherwise be used by another; e.g. Synedra, a type of diatom, successfully competes with another diatom, Asterionella, by obtaining more available silica, increasing their population size
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Interference competition
A specie competes directly with another for access to resources that they require; they may occur to plants and stationary animals as well
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Asymmetric competition
When one specie is more harmed by the presence of other than vice versa
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Competition exclusion principles
if two species use the same limiting resources in the same way, then they cannot coexist; if two competing species do exist in the same stable environment, then they do not use the limiting resource in the same way (resource partitioning); the greater the differences between species, the more likely species would coexist; Character displacement, where morphology and/or behaviour diverges to achieve resource partitioning, could occur due to competition exclusion principles.
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Commensalism
An interaction between two species in which one benefits from the other, while other does not benefit and is not harmed
(e g. eastern screech owl brings snakes into owls nest to clear up pest species, but the snakes do no better, nor worse, in the owl’s nest; Barnacles get home sites, transportation and protection from whales and the whales seems unharmed; problem with assuming the interactions of commensalism is 1. Effects unknown may exist although there is an absence of evidence of the effects, 2. effects of a specie to another may depend on their density )
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Mutualism
An interaction between two species in which both organism receives benefit from the presence of each other
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Obligate mutualism
Interactions are species-specific and neither of the two species can survive in the absence of the other
(e.g. leaf cutter ants provide leaves for the fungus to metabolise, tends the fungus in subterranean gardens and fertilise the gardens with their excrement, whilst fungus provides specialised structures that ants feed on, when a virgin queen starts off a new colony, she take some fungi from the birth colony)
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Facultative mutualism
Interactions are not species-specific and both species could survive without the other; e.g. bumblebee consume nectar, whilst goldenrod are pollenated, but they are not dependent on each other
150
Symbiosis mutualism
Mutualism between 2 species that live in close or direct contact physiological contact with each other
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Ephemeral mutualism
Mutualism between 2 species that are loosely associated each other
152
What type of benefits could mutualism provide?
1. trophic benefits
2. defence
3. service benefits
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Trophic benefits
Positive interaction in which one species receives energy or nutrients from the other species; over 80% of plants form mycorrhizal associations: with mycorrhiza plants are able to access and extract water and nutrients from a much larger area, plants gives sugar fungus sugars in return; a type of mycorrhiza, the ectomycorrhizal, associates with trees and shrub, forming sheath around their root, producing above ground fruiting bodies (does not enter plant root cells); another type of mycorrhiza, known as arbuscular mycorrhiza, associates to non-woody plants, growing around and into the root cells (forms arbucules), fewer but larger underground spores; plant draw water from a large radius; plants provides sugar
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Defense benefit
Positive interaction in which one species protects or provides shelter for the other; e.g. pistol shrimp digs and maintains a burrow that watchman goby can use to hide and goby, in return, alerts the nearly blind shrimp of the danger with movement
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Service benefit
Positive interaction in which one specie provides service for the other
(e.g. mullerian mimicry – same colourations of dangerous butterflies of different species lessen the population lost for both species in a long run as the birds are likely to associate both species together after they tried to eat one; this example is a service-service interaction and the interaction is a byproduct of a direct benefit to each species separately and species don’t directly interact; species may have mechanisms to prevent cheating)
156
Give an example where an assumption have led to a wrong conclusion
Widely believed the oxpeckers eat the ticks on rhinos, indicating mutualism; but oxpeckers mostly feed upon the open wounds on rhino
157
Give an example of a mechanism of a mutualistic relationship that prevents cheating
Moths collects pollen from a yucca another, and, in return, yucca moths lay eggs, which then, after developing into moth larvae, also feed off the seeds of the yucca; when there are too many eggs, yucca drops off the eggs, killing the larvae as an result
158
How could community be defined?
1. An assemblage of species populations that occur together at the same place and time
2. An Assemblage of species that interact directly or indirectly
3. Divisible in different ways: e.g. By trophic level, by Guild or by functional group
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Guild
A group of species that share/divide a resource
160
Functional group
Members of a Functional Group play equivalent roles in a community because they feed in a similar way, or share physiological attributes
161
What are the community properties?
1. Species richness
2. Species evens
3. Species diversity
4. Species is highest in tropics
5. Bigger island have more species
6. Equilibrium Theory of Island
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How are community properties defined?
Species richness: total number of species (not number of individual species) in a community; uses specie accumulation curve; it is hard to practice because of taxonomic problems and sampling effort. And it does not take account of the diversity of species
Species evens:
Species diversity: Calculated using Shannon Diversity index, ; uneven distribution of species is much more typical
pi: the proportion of individuals found in the species
S: the number of species in the community
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Food web
- Network formed by trophic (feeding) relationships among species in an ecological community
- Could be broken down into food chain
164
Trophic level
- Position an organism occupies in a food chain (or web)
| - it may be based on feeding relationship, energy flows up the trophic levels
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Trophic efficiency
- How much energy is transferred up the food chain depends upon consumption, assimilation and production
- the amount of energy at one trophic level divided by amount of energy at the trophic level immediate above
166
Indirect effect
Occurs when the influence of one species, the donor is transmitted through a second species, the transmitter, to a third species, the receiver, ; types of indirect interaction
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Types of indirect effects
1. Apparent competition
| 2. Trophic cascade
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Apparent competition
Presence of multiple noncompeting prey species elevates predator abundance, increasing predation pressure
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Trophic cascade
Effects at one trophic level can influence the abundance of species tat another level that is not directly connected to it
(e.g. 1. upland habitat of arctic islands, plants need nutrients brought by birds, but do not due to 2. Venezuelan forests on small lake island, predator release of herbivores, 3. suppression of elk following by the introduction of wolves)
