ecology

Question 1

what is ecology

Answer 1

• scientific study of interactions that determine the distribution and abundance of organisms, interests with evolutionary physiological and behavioural ecology

Question 2

what is evolution and a prerequisite for it and what is population / speciation

Answer 2

• evolution: change in genetic composition of a population over time, which is reflected in phenotype of individuals
• can not occur at any level lower than the population
• pre-requisite: genetic diversity within the population that accounts for the varied fitness of individuals, diversity arises from generic recombination (crossing over) and mutations
• population: group of inter-breeding individuals of same species in a common place and time
• speciation: evolutionary process in which one species splits into two or more species

Question 3

what is diversity

Answer 3

• size and shape of plants irrespective of species
• lower, middle, upper stories
• foliage cover / height of foliage, age, biomass, and productivity of community
• distance from origin
• canopy dimensions (cardinal point strategy)
• ground to canopy distance

Question 4

what is density

Answer 4

• number of plants in a given area

- PCQM: total plant density = 10,000 / (mean distance)^2

Question 5

what are spatial and temporal scales

Answer 5

• spatial: levels of biological organisation

- temporal: habitat lifespan relative to the generation time of the organism (hours - millions of years)

Question 6

what are abiotic and biotic factors

Answer 6

• A: living things include plants, animals, bacteria, fungi, phytophthora
• B: non living parts of an ecosystem, sunlight, fire, temperature, gases water, soil

Question 7

what are convergent vs divergent species

Answer 7

C: considerable differences, different environments, different characteristics thrive
- homologous structures: indicate common ancestor (wings, arms, fins)
D: clear similarities in ‘unrelated’ species, living in similar environments
- analogous structures: closely related, similar, derived from different evolutionary pathways

Question 8

what is a population / natural selection

Answer 8

• group of individuals of same species that occupy same area

- size: survival of the fittest, beneficial traits thrive, environmental factors (wipe out species / population)

Question 9

what is primary vs secondary succession

Answer 9

• P: form of succession that occurs on land where the soil has not yet developed and no traces of organisms have been recorded while
• S: occurs when a current plant community has been modified or eliminated by disturbances such as the P.cinnamomi / fire infection

Question 10

what is a disturbance opportunist

Answer 10

• thrive in the presence of disturbance
• veldt grass: unstoppable invasive at wireless hill and kings park
• characteristics: drought resistant, high growth rate, rhizomatous, resprout after fire and reproduction is enhanced, modify soil pH and increase soil repellency

Question 11

describe connell’s intermediate disturbance hypothesis

Answer 11

• species diversity is maximised when disturbance is neither too rare or too frequent
• low frequency = low number of species
• moderate frequency = high number of species
• high frequency = very low number of species

Question 12

what is a seeder vs resprouter

Answer 12

• seeder: killed by fire, regenerating from seed

- resprouter: survives, regenerates from protected tissue, alternate strategies are extremes along a continuum