Ecology - Week 12 Flashcards
What is a biome?
classifying communities by dominant vegetation
Where are distinct biomes found?
throughout the world
Do abiotic or biotic factors generally have a greater impact on the distribution of biomes?
abiotic factors
What abiotic factors impact the distribution of biomes?
- precipitation (water)
- topography (landforms and terrain)
- temperature
- sunlight
- wind
- nutrients
What are nutrients influenced by?
both biotic and abiotic factors
What are terrestrial biomes determined by?
climate
What do biomes represent?
different niches
Describe the tropical rainforest.
have to tolerate moisture and heat
Describe the temperate forest.
have to tolerate temperature variation
Describe the temperate rainforest.
have to tolerate temperature variation and moisture
Why are western red cedars well-adapted to the temperature rainforest biome?
they have:
- natural anti-fungal properties (prevents their wood from rotting if it stays wet for a long period of time)
- scaly, needle-like leaves make the trees more tolerant of climates in which temperature, sunlight, moisture and nutrients vary seasonally
What is an essential nutrient?
required for growth and reproduction (usually a limited resource)
(ie. nitrogen)
Where is nitrogen required in the cell?
- nucleotides
- amino acids
- ATP
Why is nitrogen a limiting nutrient in terrestrial ecosystems?
- organisms can only use nitrogen if it’s been “fixed” (converted into a usable form)
- most organisms are incapable of fixing oxygen
What is nitrogen fixation?
nitrogen is fixed = converted into a usable form (N2 → NH3)
What organisms can fix nitrogen?
only prokaryotes can fix atmospheric nitrogen
ie. bacteria in roots, lichen
How does nitrogen circulate within our ecological systems?
through the nitrogen cycle
Nitrogen Cycle - look at diagrams
-
What is nitrogen gas used for in industries?
- liquid nitrogen
- nitrogen gas
- nitroglycerin
- fertilizers
What is liquid nitrogen used for?
- freezing & transportation of food products
- cryopreservation
- coolant for superconductors
What is nitrogen used for?
- scuba diving
- anaesthetic (as NO2)
- to increase engine performance (as NO2)
What is nitroglycerin used for?
dynamite (used in demolition)