15 Flashcards
Most mass of a plant comes from?
CO2 in which carbon gets fixed.
What limits the growth of trees?
Nutrients in the soil that are taken up by plant roots.
!!!Why is the great bear rainforest so productive?
•lots of water
•moderate temperature year rebound
•Ecosystem is nitrogen limited
What type of plant has the lowest biomass?
When more nutrients are depleted and exhausted.
GPP?
Amount energy autotrophs capture by photosynthesis or chemosynthesis per unit time.
Not consumed biomass gets consumed by?
Detritus.
% of energy that gets passed by a 1 higher tropic level?
10%
Why are only 10% of biomass transferred into the next trophic level?
Because not all plants can be edible.
Why is it rare to find an ecosystem with more than four tropic levels?
Not enough primary production to support another level, especially when thinking about the fact that animals need a certain amount of biomass to survive.
NPP increases with? 3•
•temperature
•percipitation
•nutrient availability
What is the biggest effect in NPP over historical time?
Biotic effects as evolution strengthened efficiency.
!!!Important biotic factors that has changed NPP over history?
Aquatic biomass increases/decreases as you move up trophic levels?
Increases.
If aquatic ecosystems have biomass increase over trophic levels, what is similar and different between aquatic and terrestrial ecosystem?
NPP is similar, but higher rate of herbivory.
In aquatic systems, more/less biomass can be consumed and primary producers tend to invest less/more in anti-herbivore defensive structures and more/less structurally complex.
More, less, less.
Does biomass = accessible energy?
No
Aquatic ecosystems are more/less nutritious?
More
In aquatic systems, it is easier/harder to move?
Easier
Ecological stoichiometry?
Assimilation efficiency increases when heterotrophs consume food that are more equal in elemental composition. This implies more nutritious foods.
Terrestrial habitat plants have higher/lower C:N and C:P ratios compared to their herbivores?
Higher
Aquatic habitats plant have higher/lower/more equal C:N and C:P ratios to their herbivores?
More equal
!!!!Bottom up effect?
Bottom trophic levels influence abundance of higher trophic levels.
Top down effect?
Effect from higher tropic levels influence abundance of lower trophic levels.
Trophic cascades?
Indirect, top-down effects of predators on lower trophic levels.
