Biology Ecology Ch. 42 Ecosystem
Gross primary production
The total primary production of an ecosystem
Precipitation
the action or process of precipitating a substance from a solution (rain, snow, sleet, or hail that falls to the ground)
Primary production
the amount of chemical energy that autotrophs produce from light energy during a given period of time. Biomass is the dry weight of organic matter produced by primary productivity.
Nitrification
the biological oxidation of ammonia or ammonium to nitrite followed by the oxidation of the nitrite to nitrate.
Nitrogen fixation
the chemical processes by which atmospheric nitrogen is assimilated into organic compounds, especially by certain microorganisms as part of the nitrogen cycle
Condensation
the conversion of a vapor or gas to a liquid
Denitrification
the loss or removal of nitrogen or nitrogen compounds; specifically : reduction of nitrates or nitrites commonly by bacteria (as in soil) that usually results in the escape of nitrogen into the air
Assimilation
the process through which an organism incorporates nutrients from outside its body to the more complex structures needed inside of it
Know the laws of thermodynamics and matter
1. Law of Conservation of Energy: energy cannot be created or destroyed in an isolated system. 2. the entropy of any isolated system always increases. 3. the entropy of a system approaches a constant value as the temperature approaches absolute zero.
Detritivores
A decomposer-A consumer that derives its energy and nutrients from nonliving organic material such as corpses, fallen plant material, and the wastes or living organisms
Eutrophication
A process, by which nutrients, particularly Phosphorous and nitrogen, become highly concentrated in a body of water, leading to increased growth of organisms such as algae or cyanobacteria
Adaptations for plants to acquire limiting nutrients
All plants respond in a qualitatively similar way to low availability of major nutrients by reduced acquisition, lower tissue nutrient concentrations (high efficiency of nutrient use), reduced growth, and effective retranslocation of nutrients from senescing leaves. Such plants maximize their efficiency of nutrient use primarily by prolonging tissue life so that each unit of nutrient provides a maximum return before being lost from the plant.
Ecosystem
All the organisms in a given area as well as the abiotic factors with which they interact (one or more communities and the physical environment around them)
Limiting nutrients
An element that must be added for production to increase in a particular area
Biogeochemical cycles
Any of the various chemical cycles that involve both biotic and abiotic components of the ecosystems
Roles of decomposers in ecosystems and matter cycling
At the end of the food chain, decomposers act as the "clean-up crew" -- they consume dead animal carcasses, decaying plant material and waste products from other members of the ecosystem. Earthworms, for example, take in soil and microorganisms and excrete waste filled with nutrients, which are added to the soil. Fungi absorb nutrients from the plants and animals they consume while releasing enzymes that break down dead organic matter.
Analyze trophic structure and food webs
Autotrophs, the primary producers of the ecosystem, ultimately support all other organisms. Most autotrophs are photosynthetic plants, algae or bacteria that use light energy to synthesize sugars and other organic compounds. Chemosynthetic prokaryotes are the primary producers in deep-sea hydrothermal vents. Heterotrophs are at trophic levels above the primary producers and depend on their photosynthetic output. Herbivores that eat primary producers are called primary consumers. Carnivores that eat herbivores are called secondary consumers. Carnivores that eat secondary producers are called tertiary consumers. Another important group of heterotrophs is the detritivores, or decomposers. They get energy from detritus, nonliving organic material such as the remains of dead organisms, feces, fallen leaves, and wood. Detritivores play an important role in material cycling.
Detritus
Dead organic matter
How much energy is transferred from one trophic level to the next in an ecosystem?
Energy transfer between trophic levels is usually less than 20% (about 10%)
Production limitations in marine environments and terrestrial environments
In aquatic ecosystems, light and nutrients limit primary production. In terrestrial ecosystems, temperature and moisture are the key factors limiting primary production.
What are the typical limiting nutrients for marine and terrestrial ecosystems?
In aquatic ecosystems, light and nutrients limit primary production. In terrestrial ecosystems, temperature and moisture are the key factors limiting primary production.
Primary producers
Make up the trophic level of an ecosystem that ultimately supports all other levels (autotrophs)
Nitrogen cycle
Nitrogen enters ecosystems primarily through bacterial nitrogen fixation. Some nitrogen is fixed by lightning and industrial fertilizer production. Ammonification by bacteria decomposes organic nitrogen. In nitrification, bacteria convert NH4+ to NO3?. In denitrification, bacteria use NO3? for metabolism instead of O2, releasing N2.
Carbon cycle
Photosynthesis by plants and phytoplankton fixes atmospheric CO2. CO2 is added to the atmosphere by cellular respiration of producers and consumers. Volcanoes and the burning of fossil fuels add CO2 to the atmosphere.
Autotrophs
Primary producers
Net primary production
The GPP minus the energy used by the producers for respiration. This is the only available energy for the next trophic level
Trophic efficiency
The Percentage of production transferred from one trophic level to the next
Secondary production
The amount of chemical energy in consumer's food that is converted to their own new biomass
Water cycle
The main processes driving the water cycle are evaporation of liquid water by solar energy, condensation of water vapor into clouds, and precipitation. Transpiration by terrestrial plants moves significant amounts of water. Surface and groundwater flow returns water to the oceans.
Production efficiency
The percentage of energy stored in assimilated food that is not used for respiration or eliminated as waste
Evaporation
The process of a substance in a liquid state changing to a gaseous state due to an increase in temperature and/or pressure
Transpiration
The process when a plant absorbs water in its roots
Effect of location on primary production between different ecosystems
Total primary production in an ecosystem is known as gross primary production (GPP). This is the amount of light energy that is converted into chemical energy per unit time. Overall, terrestrial ecosystems contribute two-thirds of global net primary production, and marine ecosystems contribute approximately one-third. In aquatic ecosystems, light and nutrients limit primary production. Light is a key variable controlling primary production in oceans, since solar radiation can only penetrate to a certain depth known as the photic zone.
Phosphorus cycle
Weathering of rocks gradually adds phosphate to soil. Some phosphate leaches into groundwater and surface water and moves to the sea. Phosphate may be taken up by producers and incorporated into organic material. It is returned to soil or water through decomposition of biomass or excretion by consumers.
Heterotrophs
consumers or organisms
Ammonification
decomposition with production of ammonia or ammonium compounds especially by the action of bacteria on nitrogenous organic matter
The difference between movement of energy and matter through ecosystems
matter is recycled within and between ecosystems. Energy flow is a one-way flow