Unit 3 (using Study Buddy) Flashcards
(39 cards)
Define biodiversity
- Describes number and variety of organisms living in geographical area
Define ecosystem
- Communities of organisms interacting with their physical and biological environment
List the measures of biodiversity
- % cover
- % frequency
- species evenness
- species richness
- SDI
Explain species richness
- measure of number of species present in a sampled area
Explain species evenness
- aka relative species abundance
- difference in distribution of total abundance between the species in a community
- distribution and dominance of species within community
Explain % cover
- % of sampled area covered by target species –> used to estimate population of larger area
- often use quadrats
Explain % frequency
- measure of number of times species occurs within sample
- use quadrats
% freq = no. quadrats species is found/total no. quadrats x 100%
Explain Simpson’s Diversity Index
- measure of diversity
- accounts for species richness and evenness
- value between 0 and 1, where 0 indicates no diversity, and 1 is highest diversity
- probability that 2 randomly selected organisms are DIFFERENT species
SDI=1−(Σn(n−1))/(N(N−1))
(where N = total no. organisms of all species, and n = no. organisms of target species)
define intraspecific and interspecific competition
INTRAspecific - competition between 2 or more individuals from SAME species for same resources (eg. food, water, shelter, mates)
INTERspecific - competition between DIFFERENT species for same resources (eg. shelter, food)
describe predation
- one organism (predator) hunts, kills and eats another (prey)
- interaction affects populations and distribution of both species
define symbiosis
- a relationship in which 2 organisms live in close association over a long period of time
list and describe 4 types of symbiotic relationships
- MUTUALISM- both benefit (eg. small fish eat parasites and dead skin from manta rays)
- COMMENSALISM- one benefits, other unaffected (eg. birds nest in tree hollows –> birds get shelter, tree unaffected)
- AMENSALISM- one harmed, other unaffected (eg. cows trample (kill) grass, but cows unaffected)
- PARASITISM - one is host that is negatively affected or killed by parasite, which is adapted to gain requirements for life from host
what are abiotic factors that affect organisms?
climate –> temperature, wind, water
soil characteristics –> pH, nutrient content, composition, salinity
different organisms have different adaptations that give them a certain tolerance range for these abiotic factors
define distribution and describe the different distribution patters
- distribution - regions in which a species is found
- random distribution
- evenly spaced distribution
- clumped distribution
List the 3 biological classification systems
- Linnaean classification
- Reproductive characteristics (sexual or asexual reproduction, K- or r-strategists)
- Cladistics (molecular sequencing)
Explain the Linnaean classification system
- hierarchical classification system based on physical characteristics
- broad to specific (domain, kingdom, phylum, class, order, family, genus, species) –> (Dumb King Phillip Came Over For Good Soup)
Explain biological classification by reproductive characteristics
- asexual reproduction (one parent, identical offspring) vs. sexual reproduction (genetic material from 2 parents, genetically unique offspring)
r-strategists vs. K-strategists:
- R-STRATEGISTS:
- many offspring produced with little investment of energy or parenting
- small size, short gestation period, early reproductive maturity
- opportunistic, thrive in disturbed and temporary habitats
- populations fluctuate greatly, can produce swarms or appear to be absent altogether
- high mortality
- EXAMPLES: insects, bacteria, mice
- K-STRATEGISTS:
- high level of energy invested in growth and care of 1-2 offspring
- large size, long gestation period, slow to reach reproductive maturity
- rely on stable environments and invest in health of offspring to compete for limited resources
- populations fluctuate close to carrying capacity; large inc. or dec. in population threatens species survival
- low infant mortality
- EXAMPLES: humans, polar bears, dolphins, elephants
define ‘cladistics’, ‘cladogram’, ‘phylogenetic tree’, and ‘clade’
- CLADISTICS - classification system grouping organisms according to evolutionary relatedness through common ancestors (usually found through similarity of DNA sequence)
- CLADOGRAM - a branching diagram showing evolutionary relatedness of a number of species (fairly simple, more hypothesis of relationships)
- PHYLOGENETIC TREE - diagram that represents evolutionary relatedness between organisms (more complex, true evolutionary history)
- CLADE - group of organisms that comprise of all evolutionary descendants of a common ancestor
define species and hybrid (and give example of hybrid)
- SPECIES:
- 2 individuals are considered to be same species when they can breed and produce fertile offspring
- HYBRID:
- when 2 closely related species breed and produce offspring –> hybrid
- hybrids are usually infertile and cannot successfully reproduce with species of either parent or another hybrid
- eg. liger = lion + tiger, zebroid = zebra + horse
Explain classification of ecosystems (why it is important and 3 classification systems)
- important to plan decisions about management and conservation
- ecosystems are dynamic, complex structures, so accurate classification can be challenging
Holdridge Life Zone Classification Scheme –> classifies according to climatic conditions (triangle thingo with latitudinal regions, altitudinal belts, annual precipitation, potential evapotranspiration ratio, and humidity provinces)
Specht Classification System –> table with growth of tallest stratum and foliage cover by tallest stratum; usually used in Australia
ANAE Classification System –> Australian National Aquatic Ecosystem, 3 level system using info on climate, landscape, water and soil to classify aquatic ecosystems
Define stratified sampling and describe the purpose/characteristics of stratified sampling
- dividing ecosystem into different layers (strata) to analyse patterns
Purpose:
- POPULATION - assume population of each species in sample is proportional to entire area
- DISTRIBUTION AND DENSITY - eg. clumped, uniform or random distribution
- ENVIRONMENTAL GRADIENTS AND PROFILES - as altitude increases, atmospheric oxygen decreases, possibly out of certain organism’s tolerance range
- ZONATION - discrete zones can be measured and monitored for changes as indicator of changes to abiotic factors and human impact
- STRATIFICATION - rainforests divided into vertical strata to survey variety of organisms with adaptations for unique conditions of each strata
Describe site selection in stratified sampling
- surveys must be undertaken with effort to avoid bias to obtain accurate representation of sample area
- consider participant safety, minimisation of disturbance to community, sample target species, geographical size of area, and time and resources available for sampling
Describe surveying techniques used in stratified sampling
Quadrats:
- may be positioned randomly or at regular intervals along transect
Transects:
- areas selected for sampling as representation of species in community
- line intercept provides sample area along straight line marked with paint/string
- belt transect - 2 parallel lines, counting all species in space between or placing quadrat at regular intervals across area
Explain the transfer and transformation of solar energy into biomass as it flows through biotic components of an ecosystem
Energy transfer - movement of energy from one object to another
Energy transformation - change of energy from one form to another (eg. light into chem)
Energy cycles –> sun provides almost all energy on Earth, light energy transformed to chem energy thru photosynthesis, producer’s energy used and also stored in biomass, producer consumed by primary consumer and therefore transferring (about 10%) chem energy in biomass (continue thru trophic levels)
