Ecosystem Ecology Flashcards
the unit composed of all the living things in a single place at a given time, in addition to, the important non-living components of the system.
Ecosystem
encompasses all aspects of a biological community, in addition to factors such as rates of CO2 uptake, rates of nitrogen fixation from the atmosphere, precipitation, seasonal flooding and its effects on nutrients, etc.
Ecosystem
the largest and most encompassing ecosystem we know-it encompasses all the plants and animals on Earth.
Biosphere
Like communities, small ecosystems are “stacked” within larger ones, and the boundaries are sometimes diffuse.
Word!
Much of this discipline concerns itself with the flow of energy and biomass.
Ecoosystems Ecology
These two things are common to all biological communities
Nutrient Cycling and Energy Flow
The complex matrix of interactions among members of a community expends energy, as well as passing it from one member to the next through…
Trophic Interactions
Likewise, biomass is constantly recycled through these 4 things
Production, Predation, Herbivory, and Decomposition
The ultimate energy source for almost every ecosystem on earth.
The sun
These are a partial exception-(they rely on geothermal energy, but still depend upon oxygen fixed by photosynthetic organisms).
Hydrothermal Vent Communities
Energy enters ecosystems via this process
Photosynthesis (or, in a few exotic excosystems, chemosynthesis).
Organisms that bring energy into an ecosystem are called
Producers
Include green plants, algae, cyanobacteria, etc..anything that can make its own energy from nonliving components of the environment.
Producers
All metabolic processes consume energy in some way, and in each reaction, much of it is effectively “wasted”…
Ch’ya
Why are humans homeothermic? (Why do we generate our own heat?)
The wasted heat from metabolic processes, mostly as molecular motion, warms our bodies.
Ultimately, all biological energy radiates into the environment as
Infrared Light
a by-product of respiration
Infrared Light
Much energy is lost every time it passes from one trophic level to the next
True dat!
Does energy recycle on Earth?
No, it is continually replenished from the sun
Recycles through ecosystems
Matter
Atoms of every biologically important element constantly recycle through ecosystems, into the abiotic component of the biosphere, and back into living systems.
Word
How are elements passed from one organism to another?
Trophic Interactions
OR they are taken from the environment
Process that causes nonliving elements to have the potential to re-enter the atmosphere again
Decomposition
The path an element takes as it moves from abiotic systems through producers, consumers, and decomposers and back again
Biogeochemical Cyclye (life-Earth-chemical)
a schematic diagram that describes the trophic interactions in a community and documents energy flow
Food Web
also a trophic interaction that uses up the energy left over in dead bodies of organisms.
Decomposition
one path through a food web, from bottom to top.
Food Chain
Because energy is lost at each step, food chains have a limited number of links.
Yup!
defined as the weight of living matter (usually measured in dry weight per unit area).
Biomass
a figure that quantifies the relative amounts of living biomass found at each trophic level.
Pyramid of Biomass
In most ecosystems, the amount of biomass found in each trophic level increases or decreases progressively as one moves from the bottom to the top of the food chain?
Decreases
The most important producers vary from ecosystem to ecosystem.
OKOK
In cold-water marine systems, for instance, it may be a mixture of photosynthetic haplophytes, diatoms, and dinoflagellates.
Producers vary from ecosystem to ecosystem
Northern coniferous forests typically have a few dominant species of trees, such a pine, spruce, hemlock, cedar.
Tropical rain forests may support hundreds of species of trees.
Producers vary from ecosystem to ecosystem
Producer from ancient ecosystem that is a horsetail which formed colossal forests
Lepidodendron
Producer from ancient ecosystem which is a seed fern that covered vast continents
Glossopteris
Producer from an ancient ecosystem that is an enigmatic seed ferm or gymnosperm that dominated during the breakup of Pangea
Dicrodium
Producers- Spirulinia sp.,
Sea kelp, Ancient trees
Examples of producers
Primary consumers eat..
Producers
Do they possess more or less biomass than producers?
Less
In most ecosystems only a small amount of producer biomass is eaten (plants have evolved numerous mechanisms to protect tissues from consumption)
Cool
Why does a loss of biomass occur between trophic levels?
Digestive inefficiences and the return of CO2 to the atmosphere via cellular respiration
Assimilation efficiencies for most terrestrial herbivores range from
20-60%
These consume primary consumers.
These consume secondary consumers
Secondary Consumers
Tertiary consumers
Who has higher assimilation efficiences, carnivores or herbivores?
Carnivores (50-90 percent)
So why does only a small amount of assimilated energy become biomass in carnivores?
Used towards metabolic energy needs of body maintenance, growth, reproduction, and locomotion