Module 6,7 Flashcards
Ecology
Study of interactions among organisms and environment that determines distribution and abundance
Human influences on biodiversity
- habitat destruction
- invasive species
- climatic change
Biodiversity
Measure of variety of life
3 levels of biodiversity
1) ecosystem diversity
2) species diversity
3) genetic diversity
Ecosystem diversity
Describes variety of habitats present
Species diversity
Measure of # of species and # individuals of each species present
Genetic diversity
Total amount of genetic variability present
Why do we not know exact # species
- biased counts (areas of study)
- habitat type may be difficult
- small size complicates detection
- ambiguities in classification
- discovery new species
Pink land iguana
CONOLOPHUS SUBSCRISTATUS
- remote area
- Unseen until 1986
Species are not equally distributed around the world
True
Ex. # reptile species
Biodiversity hotspots
- Areas rich in endemic species
- significant reservoir under threat from humans
hotspots
- 34
- 2.3% earths surface
- 150,000 endemic plant species
- 5000 species vascular plants
- 1200 species vertebrates
Most species are not found everywhere
True
Ex. Richardsons ground squirrel
UROCITELLUS RICHARDSONII
Terrestrial environment: abiotic factors influencing species distribution…
- temperature
- precipitation
- sunlight
- wind
- latitude
- altitude
- soil
Aquatic environment: abiotic factors influencing species distribution…
- water temp
- light penetration
- dissolved nutrient concentrations
- water currents
- salinity
Species optimal range
Each species functions best over a limited part of full range
Temperature- influence on species distributions
-most important factor due to effects on biological processes and inability of most organisms to regulate body temperature
Endotherm
Organism that generates its own internal heat (mammals and birds)
Ectotherms
Body temperature tends to conform to outside environment in absence of behavioural adaptation (snakes)
Sleepy lizard
TILIQUA RUGOSA
- Australia grasslands
- only active spring/ early summer
- optimal body temp 25-36*
- unable to survive internal temp more than a few degrees above metabolic optimum
Metabolic optimum
Optimum body temp to survive
Coral temperature sensitivity
-sensitive to highs and lows
-shell formation and coral deposition accelerated at high temp but suppressed at low
-
Frost
Limits geographical distribution of tropical and subtropical plants
Ex. Saguaro cacti in Arizona
Saguaro cacti
- distribution limited to areas that do not remain below freezing more than one night
- die if freezing for 36 hrs
- cells rupture if water freezes
Eastern phoebe
SAYORNIS PHOEBE
- breeds in southwestern Yukon, northeastern BC, to Nova Scotia
- further south in winter
- cold temp = high metabolic costs
- below -4 cannot feed fast enough to keep warm
Vampire bats
DESMODUS ROTUNDUS
- central Mexico to northern Argentina
- poor thermoregulation
- limited to areas avg min temp above 10* in January
Coral (cnidarians)
Compact colonies of many individual polyps
Great Barrier Reef
- coral sea of Queensland Australia
- worlds largest coral reef system
- over 2900 reefs and 900 islands
- stretch over 2300 km
- 344,400 km area
- suffering coral bleaching from high ocean temp 2 years after mass bleaching event
Coral bleaching
- when corals are stressed from changes environment conditions
- expel symbiotic algae in tissue = white
