biodiversity & classification Flashcards
biodiversity
variety of all living species within an ecosystem
quadrat surveying
using quadrats
identifies distribution & abundance
prone to missing certain areas of the habitat
line surveying
using lines
identifies changes along an environmental gradient
unable to account for abundance
belt surveying
using quadrats & lines
identifies distribution & abundance
identifies changes along an environmental gradient
time-consuming
random sampling
random - through arbitrary pre-determined placement
random number generated quadrats
systematic sampling
ordered - through a transect at intervals
line transect or belt transect
stratified sampling
separate - through zones
zonation (horizontal division) or stratification (vertical division)
species richness
number of species present
percentage cover
proportion of area sampled covered by a species (%)
percentage frequency
number of times a species appears within the quadrats sampled (%)
relative abundance / species evenness
number of individuals of a species in relation to the total number of individuals (%)
simpson’s diversity index
0 - 1 scale
↑SDI = ↑biodiversity
environmental factors’ (biotic & abiotic) limitation on distribution & abundance of species
biotic - prey availability determines where predators are found (distribution) & how many are present (abundance)
abiotic - distribution is an organism’s tolerance range & abundance is an organism’s optimal range
linnaean classification system
morphological features
hierarchical structure
domain, kingdom, phylum, class, order, family, genus, species
binomial nomenclature
r-strategists
high reproductive rate
short lives
quick sexual maturity
short gestation period
minimal off-spring care
unstable habitats
K-strategists
low reproductive rate
long lives
slow sexual maturity
long gestation period
intensive off-spring care
stable habitats
asexual reproduction
one organism involved
mitosis
no sex cells
two or more off-spring
efficient but lack of variation (genetically identical) & ability to adapt
sexual reproduction
two organisms involved
meiosis
sex cells
one or more offspring
inefficient but genetically diverse & able to adapt
interspecies competition
competition between members of different species
intraspecies competition
competition between members of the same species
predation (predator-prey)
one species kills & eats the other species
symbiotic relationship
long-term interspecific interaction where different species live together
parasitism
a relationship where one species is the host (harmed) & the other is the parasite (benefitted)
e.g. ticks & dogs
commensalism
a relationship where one species benefits & the other is unaffected
e.g. remora & sharks
mutualism
a relationship where both species benefit
e.g. flowers & bees
molecular sequences
molecular phylogeny (cladistics)
sequences of molecules to classify organisms
similar sequences show closer evolutionary relationships & more recent common ancestry
more reliable than physical traits
(DNA, RNA, Proteins)
assumptions of cladistics
common ancestor
bifurcation
physical change
clade (monophyletic group)
group of organisms consisting of a common ancestor & all its lineal descendants
biological species concept
a group of organisms which interbreed under natural conditions to produce fertile off-spring
limitations of the biological species concept
fossilized samples cannot reproduce
hybridization between two different species
asexual organisms do not interbreed
interspecific hybrid
when two different species breed together to create offspring
usually infertile; therefore, not considered a species
e.g. mule (male donkey x female horse)
why is classifying ecosystems an important step towards effective ecosystem management ?
classification enables decisions to be made about its management (different ecosystems have different requirements & priorities)
classification allows stakeholders to fulfill a wide range of values (e.g. aesthetic, economic)
classification supports long-term ecosystem resilience (considering unique ecosystem interactions & human impacts)
productive soils characteristics & management techniques
high soil fertility & high water retention
reduce overgrazing & minimize soil erosion
old growth forests characteristics & management techniques
old established trees & few invasive species
back-burning & weed management
coral reefs characteristics & management techniques
shallow water & biologically diverse
reducing carbon emissions & fishing regulations
stratified sampling
purpose : assess vertical vegetation structure by considering the vegetation cover
site selection : sample all strata to represent the vegetative community as a whole
ecological surveying technique : point transect
sampling process : sampling size determined by sampling fraction
minimizing bias : calibration of equipment
data presentation : bar graph with error bars
data analysis : confidence intervals
