IB Biology Option C

limiting factors

affects distribution of a species

biotic limiting factors

interaction between organisms

abiotic limiting factors

environmental conditions

glycophytes

plant species that are not salt tolerant (are stressed by salt water)

halophytes

plant species that are salt tolerant (become stressed in fresh water)

transects

straight line along abiotic gradients from which data is recorded

kite graphs

used to correlate the distribution of a plant or animal species with an abiotic variable

ecological niche

describes the role and position of an organisms in an ecosystem, includes spatial habitat, activity patterns and interactions with other species

fundamental niche

where an organism can live, potential

realized niche

where an organism does live, actual

competitive exclusion

if two species share an identical niche, a species may die out

resource partitioning

if two species share an identical niche, species will segregate

symbiosis

long-term relationship interactions between two species

mutualism

both species benefit from the interaction (clownfish and anemone)

commensalism

one species benefits, other is unaffected (barnacles transported to food by whales)

parasitism

one species benefits at expense of other (ticks and fleas feed on blood of dog hots)

Coral Symbiosis

relationship with zooxanthellae, algae lives within the cells of the coral's endodermis, provided algae with a source of inorganic compound and protective environment, algae provides coral with source of nutrition

keystone species

large impact on an ecosystem relative to its abundance

predatation

keystone species exert pressure on low trophic levels to prevent monopolisation of essential resources (starfish prevents urchin overpopulation)

Mutualistic Species

keystone species may support the life cycle of various species in a community

Engineers

keystone species may refasions the environment in a way that promotes the survival of other organisms

trophic level

position in a feeding sequence

food web

shows all the possible food chains in a community

biomass

the total dry weight of organic matter in organisms or ecosystems

ecological productivity

refers to the rate of generation of biomass in an ecosystem

feed conversion ratio

measures the conversion of food into a desired output

ecosystem

describes a community and its abiotic factors

biomes

geographical areas that have a particular climate and sustain a specific community of plants and animals

tropical rainforest

hot and humid (wet)

taiga

cold and low precipitation (ice not rain)

desert

hot days and cold nights (low rainfall)

climograph

graphical representation of climate patterns for different biomes

energy pyramid

differ between ecosystems die to the effect of climate on the primary productivity of autotrophs

high primary productivity

large bases on energy pyramids because they can support a greater number of trophic levels

gersmehl fiagrams

show differences in nutrient flow and storage between biomes

Tropical rainforest diagram

Taiga diagram

Desert diagram

Tropical Gersmehl

nutrients stored primarily as biomass, warm temperature increases rate of decay and uptake; high rainfall causes increase in transfer rate (runoff, etc.)

Taiga Gersmehl

nutrients stored primarily as litter, cold temperature decreases rate of decay, low rainfall decreases transfer rate

desert gersmehl

nutrients stored primarily as soil, extreme temperatures decrease decay and uptake, low rainfall causes a decrease in transfer rate

primary succession

involves communities developing on entirely new land without any established soil

pioneer species

organisms that initially colonize a region

secondary succession

natural environmental disturbance causes this, starts with pre-existing soil

cane toads

introduced to Australia to limit the spread of crop-eating beetles, lacks a native predator, reproduces rapidly, depleted prey population for native insectivores, has a toxic chemical from its skin that has poisoned species, diseases have been transmitted to native species

invasive species

an alien species that has a detrimental effect on pre-existing food chains

physical control

involves removal or restriction of species by manual or mechanical measures, may include installation of barriers, not usually species specific and impedes native wildlife

chemical control

involves the use of chemical agents to limit the spread, have moderate specificity but often affect local wildlife

biological control

involves using a living organism to control the spread of invasive species, must be monitored to ensure they do not become invasive

biomagnification

process in which chemicals become more concentrated at each trophic level

DDT

chemical which demonstrates biomagnification in high order consumers, fat soluble which means it is retained in the body instead of being excreted

indicator species

sensitive to specific environmental conditions and therefore have a limited range of tolerance

biotic index

compares the relative frequency of indicator species, providing overall environmental assessment

high biotic index

indicates an abundance of indicator species (unpolluted)

low biotic index

indicates an absence of indicator species (polluted environment)

biodiversity

describes the variety of all living organisms in a given ecological area

richness

describes the number of different species present in an area

evenness

describes the relative abundance of given species in an area

simpson's index

determines the relative biodiversity of an ecosystem

high index

indicates a stable site with many niches and low competition (high biodiversity)

low index

indicates a site with few potential niches and where only a few species dominate

island size

larger islands and habitats will promote biodiversity (more niches equals less competition); sustain higher population and have longer, more stable food chains

edge effect

community changes that occur at the boundaries of habitats, ecology will differ from the central areas

In Situ Conservation

preservation of a species within its natural habitat

benefits of in situ

allows species to live in habitats and occupy food chains to which they are adapted, maintains normal animal behavior, provides realistic reintegration conditions for animals produced by breeding programs, provides a place for scientific study and development

disadvantages of in situ

requires active management: maintenance of boundaries to prevent poachers, restoration of degraded habitat areas, facilitating life cycles, recovery of endangered species

Ex Situ Conservation

the preservation of a species away from its natural habitat

benefits of ex situ

allows for control of conditions, can improve chances of successful breeding

disadvantages of ex situ

species raised in captivity are less likely to be successfully reintroduced into wild, does not prevent destruction of natural habitat, increases inbreeding by restricting the gene pool and reduces evolution of natural selection

sustainable yield

level of resource that can be withdrawn from an ecosystem without reducing the base stock

top down control

control applied to higher trophic levels, results in oscillating trophic cascade

bottom up control

control applied to lower trophic levels, results in suppression of higher levels

soil

composed of a mixture of organic matter, mineral particles and rock

nitrogen

key element in plant growth, it is needed for proteins, hormones, and chlorophyll; moves quickly through soils as soluble nitrites, nitrates, and ammonium ions

phosphorus

needed by plants to transfer energy from sunlight; also required for DNA and phospholipids; not typically stored in soil, so sustained crop production requires fertilizers

nitrogen fixation

catalyzed by the enzyme nitrogenase (nitrogen to ammonia)

ammonification

ammonia to ammonium

nitrification

ammonium is converted to nitrites and then converted to nitrates (Require aerated soil)

assimilation

nitrates are converted into amino acids, incorporation of nitrogen into the organic content of a cell

denitrification

nitrates into nitrogen, carried out by denitrifying bacteria (require anaerobic soil, so no oxygen)

waterlogging

occurs when soil becomes inundated with water, impacts the nitrogen cycle by reducing nitrates and nitrites in soil; causes denitrification and leaching

eutrophication

enrichment of an aquatic ecosystem with chemical nutrients