Topic 3 - Ecology Flashcards
1
Q
Define semelpartiy and iteroparity
A
- Semelparous: individuals breed once in their life. They have one reproductive event and then die
- Iteroparous: individuals can breed multiple times in their life.
2
Q
Define annual and perennial reproduction strategies
A
- Annuals complete their life cycle in one year or less
- Perennials have a repeated breeding season at predictable times each year
3
Q
Define fecundity
A
- An organism’s reproductive capacity (no. offspring it’s capable of producing)
4
Q
Define parental investment
A
- The energetic investment into each offspring
5
Q
Describe early reproduction strategies:
A
- Short-lived, smaller in body size
- Geared towards early energy going toward reproduction instead of growth
- Reduces risk of not reproducing at all
6
Q
Describe late reproduction strategy
A
- Long-lived, larger in body size
- Geared toward putting energy into growth to a larger size where mortality rates are lower, than later in life insetting energy in reproduction
- Higher risk of not reproducing at all or to max capacity if death occurs early.
7
Q
Explain the features of r and k selected species
A
- K selection is the selection for traits that are advantageous in high density populations
- R selected species is the selection for traits that maximise reproductive success in uncrowded or low-density populations
8
Q
Define population ecology
A
- Pop ecology is the study of populations in relation to the environment and resources
- Population: A group of individuals of the same species living in the same location with the individuals relying on the same resources, influenced by similar environmental conditions and interacting with each other.
9
Q
Explain the properties of an ecological population using examples
A
- Boundaries: natural, arbitrary, matches the purpose of the study and the organism
- Size: how many individuals in a population and what changes the number of individuals (births, deaths, immigration, emigration)
- Distribution: the extent to which individuals are spaced in a population
- Structure: the characteristics of the individuals that make up the population (sex ratio, age structure)
10
Q
Explain an application of population ecology
A
- Species management – endangerment
- Pest control
- Disease dynamics
11
Q
Understand how to estimate population size
A
- Full census: counting every individual
- Sampling: estimating
- Imperfect detection: N (abundance) = n (number seen) / P (probability of detection)
12
Q
Describe the limitations and assumptions for different methods
A
- Mark -recapture
- Capture, mark, release, recapture
- Assumptions: marks are durable for length of study, marks don’t decrease survival, probability of recapture remains consistent, closed population (no births, deaths, immigration, emigration)
13
Q
Define demography in your own words
A
- The study of the birth and death rates of populations and how they change over time
14
Q
Identify important aspects of a life history table
A
- Life history is all the events involved in an organism’s survival and reproduction
- Age class (years)
- Number of survivors
- Number of young per year
- Fecundity per surviving individual
15
Q
Explain the three categories of survivorship curves
A
- Type 1: most individuals die later in life (k strategist)
- Type 2: log scale, negative linear relationship between number of survivors and years (uniform rate of decline)
- Type 3: number of survivors rapidly drops and is low in numbers as time progresses (exponential decay) (huge decline in young) (r strategist)
16
Q
Describe the features of a population growth model.
A
- Mathematical models that estimate change in population size over time
- X axis is time
- Y axis is population size
17
Q
Explain an exponential growth model
A
- Populations growing under ideal conditions: unlimited resources and no limiting growth
- Growth rate is constant
- Accelerating growth as individuals increase
- N(t)= N0*ert
- Nt = population size at time t
- N0 is initial population size
- R is intrinsic growth (birth rate minus death rate)
18
Q
Explain a logistic growth model
A
- Starts off exponentially and then growth slows, carrying capacity is reached, and resources limit population
- More realistic
19
Q
Describe density-independent population growth
A
- Often abiotic factors
- Change in the population size regardless of the population density
- Sever events: heat waves, storms, pollution
20
Q
Describe density-dependent population growth
A
- Change in population growth depending on the number of individuals in the population
- Competition for resources
- Predations: attracted to dense population of prey causing large deaths
- Disease: spreads easily in dense populations
21
Q
Explain the effects of environmental and demographic stochasticity of population size
A
- Environmental stochasticity: unpredictable fluctuations in environmental conditions that influence population dynamics by changes in birth and death rates
- Demographic stochasticity: change in birth and deaths of individuals caused by chance
22
Q
Explain the role of source of sink populations in conserving a species from extinction
A
- Source population: support local population growth and can be net exporters of individuals (emigration) to other patches
- Sink population: mortality exceeds births and populations are reliant on immigration to persist
- Metapopulations are groups of isolated populations linked together by dispersal and have patchy distributions. Metapopulations allow individuals to disperse between source (donor) and sink (recipient) populations to reduce extinction probability.
23
Q
Describe the types of strategies predators use to obtain food
A
- Active pursuit
- Stealthy ambusher
24
Q
Describe the types of strategies prey use to avoid being captured
A
- Avoiding detection: camouflage
- Chemical defences: smaller animals
- Warning signals: common in marine systems, used with chemical defences
- Mimicry systems: the mimic closely resembles a dangerous or toxic species
- Behavioural mechanisms: group flocking, alarm vocalisation
25
Compare and contrast the concepts of fundamental niche and realized niche
- Niche: the physical and biological conditions required for growth, reproduction, and survival
- Fundamental niche: a species’ physiological capabilities in ideal conditions
- Realised niche: a species’ physiological capabilities, constrained by interactions with other species such as competition and predation
26
Distinguish between interference competition and exploitation competitions
- Interference competition: occurs when one species directly interferes with or excludes another species’ access to a limiting resource
- Exploitation competition: occurs when a limiting resource is available to all competitors, but the outcome of the interaction depends on the relative efficiency with which each species uses the resource
27
Describe competitive coexistence using a biological example
- Competitive coexistence: the ability of multiple species to live together in the same ecological niche despite competition for the same resources
28
Define dispersal using an example
- Dispersal is the movement from one breeding location to another
- Natal: from birthplace to first breeding place
- Breeding: change of place of breeding
29
Describe the different types of dispersal modes used by animals and plants
- Animals: active (flying, walking, swimming) and passive (currents, floods, attached to animals, vehicles)
- Plants: gravity, wind, water, animals (on or in guts), vehicles/machinery
30
Explain the difference between dispersal and migration
- Dispersal: spreading of individuals away from others and occurs early in life or as adult
- Migration: large-scale movement of members of a species to a different environment
31
Describe types of symbiosis and whether they typically help, harm, or have no effect on the organisms involved.
- Commensalism: one species benefits while the other is unharmed
- Mutualism: both species benefits
- Parasitism: one species benefits while the other is harmed
32
Explain the unique traits and life cycles of parasites, given their habitat is a living host
- Traits:
o Smaller than host
o Live on or in the host for extended periods of time
o Usually don’t kill hosts (but can)
o Hosts can recover
o The hosts of parasites can grow, mount defences against parasites, evolve, and move
- Monoxenic: one host
- Heteroxenic: multiple hosts
33
Describe the abundance, diversity and types of parasites in nature
- Protozoans: single-celled, animals, fungi, plants
- Microparasites: intra-cellular, multiple directly within hosts, numerous, viruses/bacteria
- Macro-parasites: grow on or in hosts but don’t multiple with host, produce infectious stages which they release into the environment to find new host,
- ½ of arthropods are parasitic
- The biomass of parasites (total weight of all individuals in a group) can outweigh a conspicuous animal
34
Explain and give examples of kleptoparasitism
- Parasitism by theft – one animal deliberately taking food from another
- Seabirds: steal fish from each other and chase/harass others until they drop their food
35
Explain the characteristics of mutualistic and commensal relationships with examples
- Pollinations and seed dispersal: mutualistic – reward: pollen and fertilisation for the plant
- Corals are endosymbionts with zooxanthellae – zooxanthellae consume wastes and corals take products of photosynthesis
- Commensalism: epiphytes grow on other plants without disturbing them
36
Explain the concept of animals and plants that are considered pests or weeds
- Organisms with populations that are unnatural or too large meaning they come into conflicts with other interests
- Damaging to agriculture, valued species, environment, and biodiversity
37
Describe the different types of biological control and the considerations needed to make them effective
- Classical biological control: the deliberate importation and release of new species – aims to import natural enemies that are missing
- Augmentative biological control: repeated rearing and release of natural enemies – locally available rather than imported – natural enemies are reared and released into crops
o Inoculative augmentation (long term): control by released enemies and their progeny
o Inundative augmentation (short term): control exclusively by the released enemies
- Conservation biological control: promoting/protecting existing natural enemies – modification of the environment or existing practices to protect and enhance natural enemies to reduce effects of pests
38
Describe the differences between epidemic and endemic diseases, how they affect populations, and how they can be controlled
- Epidemic: increase rapidly in smaller geographic areas
- Endemic: disease is constantly present in a population subset
