Sustainable ecosystems endure, and they sustain the organisms that live within them. Matter including nutrients such as nitrogen, are constantly moving through Earth’s spheres.
Human activities that increase the influx of nutrients into a terrestrial or aquatic ecosystem can upset the nutrient balance in the ecosystem. Decisions and actions that are taken to protect the health of ecosystems may involve international agreements and court decisions.
The Mystery of Easter Island Trees were cut to build homes and boats for fishing Cut down trees to clear the land for their crops Burn wood for warmth Easter Island Farming Sustainability
What is an ecosystem? List two examples. An ecosystem is all the interacting parts of a biological community and its environment Examples: –Coral reef, forests, rainforests, ponds, deserts
What is the two part meaning for the word “sustain”? “Sustain” means to endure and support Explain what sustainable ecosystem means. Sustainable ecosystem refers to an ecosystem that is capable of withstanding pressure and giving support to a variety of organisms.
Use the map in Figure 1.2 to explain how ruby-throated hummingbirds are dependent on more than one ecosystem. Ruby-throated hummingbirds live part of the year in a tropical rain forest, and then they stop in many ecosystems along the way as they migrate north in the spring. They spend the summer in meadows and wetlands in Canada.
Do you know any species that depend on more than one ecosystem? Birds fly south during the winter Flowers and plants flourish in the spring and die away as it gets cooler in the fall Any other examples?
What are the two parts of an ecosystem? Define and list four examples for each one. Definition: BIOTIC PARTS – The living parts of an ecosystem Definition: ABIOTIC PARTS – The non-living parts of an ecosystem Examples: Plants, grass, animals, micro-organisms, bacteria, insects Examples: Water, oxygen, light, nutrients, soil
Describe how the three types of biotic interactions work. SYMBIOSISThe interaction between members of two different species that live together in a close association. An example would be a mushroom helping trees absorb water & nutrients from the soil. PREDATIONOne organism consumes another organism for food (predator vs. prey). An example would be the river otter [predator] & fish [prey].
COMPETITIONTwo or more organisms compete for the same resource, such as food, in the same location at the same time. An example would be dandelions competing with grass for the same resources.
Define the following terms: Lithosphere: The hard part of the Earth’s surface Hydrosphere: All the water found on Earth, including lakes, oceans & ground water Atmosphere: The layer of gases above Earth’s surface Biosphere: The regions of Earth where living organisms exist
The Water Cycle As water vapour rises, in the atmosphere, it cools and condenses (evaporation) Clouds form from the condensed water droplets (condensation) Water returns to the lithosphere as precipitation Water returns to the Earth & enters biosphere as it is: –Absorbed by plants & animals –Erodes rock –Consumed by organisms
The Carbon Cycle Carbon is an essential nutrient for all living things CO 2 in the air is used by plants and algae to make sugars (atmosphere biosphere) Organisms break down the sugar to obtain energy for life & growth & CO 2 is released as waste (biosphere atmosphere) Burning fossil fuels releases CO 2 into the atmosphere (biosphere atmosphere) When organisms die, their carbon-containing molecules become part of the soil as they decay releasing CO 2 into the air (biosphere lithosphere) The remains of dead organisms gradually changes to fossil fuels (such as coal, gas, oil) which are carbon rich
The Nitrogen Cycle Involves converting nitrogen into useable forms Nitrogen is needed by plants for photosynthesis Nitrogen Fixation is when nitrogen is converted (by soil bacteria) into ammonium (NH 3 ) or nitrate (NO 3 ) useable forms –It is used by plants and animals and released back into the atmosphere, and the process repeats –Decomposed animals and plants release nurtrients into the soil and through their feces Plants absorb nitrates from the soil most of the time and it is passed on in the food chain as organisms eat one another
Denitrification change nitrate back to nitrogen which can be released into the atmosphere for use again in nitrogen fixation Decomposers break down large nitrogen-containing compounds into smaller ones until they make them into nitrate for the denitrifying bacteria to work on
The Phosphorus Cycle Unlike nitrogen and carbon that’s stored in the atmosphere, phosphorus is stored in the lithosphere When rock is broken down into smaller pieces, phosphorus in the form of phosphate (PO 4 ) is released into the soil PO 4 is then absorbed by plants through their roots PO 4 continues to move through the biosphere as organisms eat one another Bacteria eventually break down dead organisms & waste releasing phosphate back into the soil & the cycle continues. Enters the aquatic ecosystems by leaching or run-off land
List and explain 2 human activities that can throw off the balance in a sustainable ecosystem. Aquatic ecosystems suffer when a run- off has high amounts of agricultural fertilizers Regular constant drilling of the Earth’s lithosphere can deplete resources such as coal, oil and gas
What is eutrophication? Eutrophication is a process which nutrient levels in aquatic ecosystems increase, leading to an increase in the populations of primary producers