LWE: Overview 📖

The Living World - Ecosystems

Introduction

Studying ecosystems is important to environmental science because ecosystems are the basic units of ecological systems and they interact with each other and with their environment in complex ways. By understanding how ecosystems change over time and space, environmental scientists can better predict the effects of human activities and natural disturbances on biodiversity, ecosystem services, and human well-being.

Learning Objectives

In this module, you will learn how to....

  • Explain...
    • how the availability of resources influences species interactions.
    • the steps and reservoir interactions in the carbon cycle.
    • the steps and reservoir interactions in the nitrogen cycle.
    • the steps and reservoir interactions in the phosphorous cycle.
    • the steps and reservoir interactions in the water cycle.
    • how solar energy is acquired and transferred by living organisms.
    • how energy flow and matter cycles through trophic levels and determine how the energy decreases as it flows through ecosystems.
  • Describe...
    • the global distribution and principal environmental aspects of terrestrial biomes.
    • the global distribution and principal aspects of aquatic biomes.
    • food chains and food webs, and their constituent members by trophic level.

 

Module Lessons Preview

In this module, each lesson will focus on teaching you the following topics:

Introduction to Ecosystems (⏳ 6 - 8 mins): Ecosystems are the result of biotic and  abiotic interactions.

Terrestrial Biomes (⏳ 5 - 7 mins): Terrestrial ecosystems are the result of biotic and abiotic interactions.

Aquatic Biomes (⏳ 10 - 12 mins): Aquatic ecosystems are the result of biotic and abiotic interactions.

The Carbon Cycle (⏳ 12 - 14 mins): The carbon cycle regulates the exchange of carbon between the atmosphere, oceans, soil, and living organisms, influencing climate stability and supporting life processes.

The Nitrogen Cycle (⏳ 11 - 13 mins): The nitrogen cycle is essential for sustaining life on Earth as it facilitates the transformation of atmospheric nitrogen into forms that plants can use, contributing to the production of proteins and supporting the entire food web.

The Phosphorous Cycle (⏳ 6 - 8 mins): The phosphorus cycle is vital for ecosystems as it regulates the availability of phosphorus, a critical nutrient for plant growth and development, influencing overall productivity and the functioning of terrestrial and aquatic ecosystems.

The Water Cycle (⏳ 4 - 6 mins): The water cycle regulates the continuous movement of water between the atmosphere, land, and oceans, ensuring a constant supply of freshwater for various biological processes and environmental functions.

Primary Productivity (⏳ 12 - 14 mins): Primary productivity provides the foundation for food chains, energy flow, and supports the overall biodiversity and functioning of ecosystems.

Trophic Levels (⏳ 2 - 4 mins): Energy flow through ecosystems enables the transfer of energy from one trophic level to another, driving biological processes, maintaining ecological balance, and supporting the functions of diverse organisms within the ecosystem.

Energy Flow through Ecosystems (⏳ 7 - 9 mins): Energy flow through ecosystems enables the transfer of energy from one trophic level to another, driving biological processes, maintaining ecological balance, and supporting the functions of diverse organisms within the ecosystem.

Food Chains and Food Webs (⏳ 6 - 8 mins): Food webs and food chains illustrate the interconnected relationships between species, depicting the flow of energy and nutrients, and highlighting the dependence of organisms on each other for sustenance and ecological balance.

 

AP Classroom Connection

This module aligns to Unit 1 in AP Classroom. You can view AP Daily videos, progress checks, and topic questions in AP Classroom. Topic Alignment:

          • Biomes: 1.1 - 1.3
          • Biogeochemical Cycles: 1.4 - 1.7
          • Ecosystem Energy Flow: 1.8 - 1.11

This module is 6-8% of the AP Environmental Science Exam.

 

Textbook Alignment

This module aligns to the following modules/chapters in your AP Environmental Science textbook:

📚 Introduction to Ecosystems (Topic 1.1): Ch. 6, Module 20

📚 Terrestrial Biomes (Topic 1.2): Ch. 4, Modules 12

📚 Aquatic Biomes (Topic 1.3): Ch. 4, Modules 13

📚 The Carbon Cycle (Topic 1.4): Ch. 3, Module 7

📚 The Nitrogen Cycle (Topic 1.5): Ch. 3, Module 7

📚 The Phosphorous Cycle (Topic 1.6): Ch. 3, Module 7

📚 The Water Cycle (Topic 1.7): Ch. 3, Module 7

📚 Primary Productivity (Topic 1.8): Ch. 3, Module 6

📚 Trophic Levels (Topic 1.9): Ch. 2, Module 4-5; Ch. 3, Module 6

📚 Ecosystem Energy Flow (Topic 1.10): Ch. 2, Module 5; Ch. 3, Module 6

📚 Food Chains and Food Webs (Topic 1.11): Ch. 2, Module 5-6; Ch. 6, Module 20

These modules/chapters cover content found in this module and offer practice videos, questions, and flash cards.

 Key Terms (click to reveal)

🖨 Click here to download a PDF of the Living World - Ecosystems Key Terms. Links to an external site.

            • 10% Rule: The ecological principle stating that, on average, only about 10% of the energy from one trophic level is transferred to the next trophic level in a food chain or web.
            • Abiotic: Non-living factors in the environment, such as temperature, sunlight, soil, and water, that influence living organisms.
            • Abyssopelagic Zone: The region of the deep ocean, extending from depths of approximately 4,000 meters to the ocean floor.
            • Adaptations: Characteristics or traits that enhance the survival and reproduction of organisms in their environment.
            • Ammonification: The process in which decomposers convert organic nitrogen into ammonium ions during the decay of organic matter.
            • Aphotic Zone: The portion of a water body, such as oceans or lakes, where light is absent, preventing photosynthesis; typically found in deeper waters.
            • Assimilation: The process by which plants and animals take up nutrients (such as nitrogen) from their environment and incorporate them into their tissues.
            • Autotrophs: Organisms, often plants and algae, that produce their own food through photosynthesis or chemosynthesis.
            • Bathypelagic Zone: The region of the deep ocean, typically found between 1,000 and 4,000 meters below the surface.
            • Biogeochemical Cycles: The pathways through which chemical elements, such as carbon, nitrogen, and phosphorus, move through the Earth's atmosphere, lithosphere, hydrosphere, and biosphere.
            • Bioluminescence: The production and emission of light by living organisms.
            • Biome: A large geographic region characterized by specific climate, soil, and vegetation, supporting particular types of communities.
            • Biosphere: The sum of all ecosystems on Earth, where living organisms interact with the atmosphere, hydrosphere, and lithosphere.
            • Biotic: Living components or factors in an ecosystem, including plants, animals, and microorganisms.
            • Camouflage: A survival strategy where an organism's appearance or behavior allows it to blend in with its surroundings, providing protection from predators.
            • Carbon Cycle: The movement of carbon through various reservoirs, including the atmosphere, oceans, soil, and living organisms.
            • Carnivore: An organism that primarily feeds on other animals.
            • Cellular Respiration: The process by which cells break down organic compounds to release energy for cellular activities, typically using oxygen.
            • Commensalism: A type of symbiotic relationship where one species benefits, and the other is neither harmed nor helped.
            • Community: A group of interacting populations of different species living in the same area.
            • Competition: The interaction between organisms or species that vie for the same resources in an ecosystem.
            • Competitive Exclusion Principle: The ecological principle stating that two species competing for the same resources cannot coexist in the same place for an extended period if other factors remain constant.
            • Cultural Eutrophication: The process by which human activities, such as the input of excess nutrients, lead to accelerated nutrient enrichment in aquatic ecosystems.
            • Decompose: The process of breaking down dead organic matter by decomposer organisms, releasing nutrients back into the ecosystem.
            • Denitrification: The process by which bacteria convert nitrates or nitrites into nitrogen gas or nitrous oxide, releasing nitrogen into the atmosphere.
            • Detritivore: Organisms that feed on dead organic matter and contribute to the decomposition process.
            • Downstream: The direction in which a river or stream flows, typically from higher elevations to lower elevations.
            • Ecology: The study of the interactions among and between organisms and their environment.
            • Ecosystems: Biological communities of interacting organisms and their physical environment.
            • Ecotone: The transitional area between two ecosystems, characterized by a mix of species from both ecosystems.
            • Epipelagic Zone: The surface layer of the ocean where light penetrates, allowing for photosynthesis; also known as the euphotic zone.
            • Evaporation: The process by which water changes from liquid to water vapor, primarily from surfaces of lakes, oceans, and the soil.
            • Evapotranspiration Loop: The combined processes of evaporation from the soil and transpiration from plants, collectively contributing to water vapor in the atmosphere.
            • Food Chain: A linear sequence of trophic levels in an ecosystem that illustrates the transfer of energy from producers to consumers.
            • Food Web: A complex, interconnected model that represents the feeding relationships and energy flow among various species in an ecosystem.
            • Fossil Fuels: Carbon-rich energy resources, such as coal, oil, and natural gas, formed from the remains of ancient plants and animals.
            • Fundamental Niche: The full range of environmental conditions and resources in which a species can potentially exist.
            • Gravitational Water: Water that moves downward through the soil under the influence of gravity.
            • Groundwater: Water stored beneath the Earth's surface in aquifers.
            • Gross Primary Productivity: The total amount of energy captured by autotrophs through photosynthesis.
            • Hadalpelagic Zone: The deepest ocean zone, found in deep ocean trenches.
            • Herbivore: An organism that primarily feeds on plants.
            • Heterotroph: Organism that obtains organic compounds and energy by consuming other organisms.
            • Host: An organism that provides habitat and nourishment for a parasite.
            • Infiltration: The process by which water on the ground surface enters the soil.
            • Infiltration-Runoff Ratio: The proportion of precipitation that infiltrates the soil versus the proportion that becomes surface runoff.
            • Interspecific Competition: Competition for resources between individuals of different species.
            • Intraspecific Competition: Competition for resources between individuals of the same species.
            • Lake: A large, inland body of standing water.
            • Limnetic Zone: The open, sunlit surface waters of a lake, away from the shore.
            • Littoral Zone: The shallow, nearshore area of a lake where light penetrates to the lake bottom.
            • Mesopelagic Zone: The ocean zone found between the epipelagic and bathypelagic zones, characterized by partial sunlight.
            • Moving Water Ecosystem: Ecosystems associated with flowing water, such as rivers and streams.
            • Mutualism: A type of symbiotic relationship where both species benefit.
            • Negative Feedback Loop: A regulatory mechanism that counteracts an initial change, maintaining stability in a system.
            • Net Primary Productivity: The amount of energy captured by autotrophs through photosynthesis, minus the energy lost through respiration.
            • Niche: The role and function of a species in an ecosystem, including its habitat, diet, and interactions with other species.
            • Nitrification: The conversion of ammonium ions into nitrites and then nitrates by bacteria in the soil.
            • Nitrogen Cycle: The movement of nitrogen through various forms and locations in the environment, including the atmosphere, soil, and living organisms.
            • Nitrogen Fixation: The conversion of atmospheric nitrogen gas into ammonia or other nitrogen compounds by certain bacteria.
            • Parasite: An organism that lives in or on another organism (host) and derives nutrients at the host's expense.
            • Parasitism: A symbiotic relationship where one species (parasite) benefits at the expense of another species (host).
            • Phytoplankton: Microscopic, photosynthetic organisms that drift in water and form the base of aquatic food chains.
            • Phosphorus Cycle: The movement of phosphorus through the Earth's lithosphere, hydrosphere, and biosphere.
            • Photic Zone: The upper layer of a water body, where sufficient light penetrates to support photosynthesis.
            • Photosynthesis: The process by which plants and other organisms convert light energy into chemical energy, producing glucose from carbon dioxide and water.
            • Pond: A small, standing water body, typically shallower than a lake.
            • Population: A group of individuals of the same species living in a specific area.
            • Positive Feedback Loop: A mechanism that amplifies an initial change, often leading to further changes in a system.
            • Predator: An organism that hunts, captures, and consumes other organisms (prey).
            • Prey: Organisms that are hunted, captured, and consumed by predators.
            • Primary Consumer: Herbivores that consume producers (plants and algae).
            • Primary Producers: Autotrophs, mainly plants and algae, that capture energy from the sun through photosynthesis.
            • Primary Productivity: The rate at which autotrophs produce organic compounds and capture energy through photosynthesis.
            • Profundal Zone: The deep, dark, open water area in a lake that is too deep for sunlight to penetrate.
            • Realized Niche: The actual range of conditions and resources where a species exists, considering interactions with other species.
            • Resource Partitioning: The division of limited resources among species to avoid direct competition.
            • River: A large, moving body of water flowing in a channel towards the ocean or a lake.
            • Runoff: Water that flows over the surface of the land and is not absorbed by the soil.
            • Secondary Consumer: Carnivores that consume primary consumers.
            • Seep: A location where water emerges from the ground.
            • Spring: A location where groundwater discharges at the Earth's surface.
            • Standing Water Ecosystem: Ecosystems associated with still or standing water, such as lakes and ponds.
            • Symbiosis: A close and long-term interaction between two different species.
            • Tertiary Consumer: Carnivores that consume secondary consumers.
            • Transpiration: The release of water vapor from plant leaves into the atmosphere.
            • Trophic Levels: The hierarchical levels in a food chain or web, including producers and various levels of consumers.
            • Water Cycle: The continuous movement of water through the atmosphere, lithosphere, hydrosphere, and biosphere.
            • Water Vapor: Gaseous water in the atmosphere.
            • Well: A hole drilled into the ground to access groundwater.
            • Wetlands: Ecosystems characterized by periodically or permanently saturated soil, supporting unique plant and animal communities.

 

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