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Unit 1 Overview: The Living World: Ecosystems

2 min read•december 27, 2022

Jenni MacLean

Unit 1 is a foundational unit for Environmental Science because it's going to look at how all of the processes on Earth work. The "building blocks" of the course, so to speak; before we can jump into the fun stuff like , we have to understand the fundamentals of the , for example. Per College Board, the class covers "a wide range of topics, including Earth systems and resources, the living world, population, and land and water use. It also covers environmental issues and the relationship between science and society."

Biomes

When you think of biomes, they come in two major categories: terrestrial and aquatic. Biomes are categorized by the climate (temperature and precipitation) and the biomass (plants and animals) living in them. Due to Earth's tilt, the sun's distribution of energy varies, and this difference is what allows scientists to classify certain regions as biomes. For the major biomes, we classify them based on factors such as yearly rainfall and temperature. AP Environmental Science emphasizes key terms such as environmental conditions, , , and throughout this unit.

Cycles

Every biome relies on natural cycles to move matter from one form to another. The rate and intensity of these processes can help in biome classification. The major cycles we are going to study are the carbon, nitrogen, phosphorus, and hydrologic cycles. Since Earth is a closed system, one which recycles matter rather than losing it, these cycles are essential to understanding our planet. Here are the major topics pertaining to each cycle:

Nitrogen and Phosphorus Cycles: Large Scale Farming, Growth and Development

Water Cycle: ,

Ecosystem Interactions

Ecosystems build food chains and require constant interactivity with other species and surrounding environments. Since resources are limited, adaptation and evolution are required to sustain oneself and survive.

Species Interactions

: 😀-😀

: 😀-😐

: 😀-😟

Predator and Prey: 😀-😟

Trophic levels

In any ecosystem, we can follow the flow of energy from one trophic level to another. Like a tier chart, trophic levels show distribution of consumption similar to a food chain and this corresponding energy output. As a rule, it takes a lot more energy to create an organism in a 3rd or 4th trophic level than something at the bottom. Here is a diagram to help us better visualize the movement of energy.

Image from Wikipedia

In conclusion, Unit One examines the elementary of Earth's functions and how these simple concepts help the planet's natural functions occur properly.

Key Terms to Review (13)

Biodiversity

: Biodiversity refers to the variety of living organisms in a particular ecosystem or on Earth as a whole. It includes diversity within species, between species, and of ecosystems.

Carbon Cycle

: The carbon cycle is the movement of carbon atoms between living organisms (plants and animals), the atmosphere (as carbon dioxide), bodies of water (as dissolved carbon dioxide), and fossil fuels (as stored carbon).

Clean Water Access

: Clean water access refers to the availability of safe and uncontaminated water for human use and consumption. It means having access to water that is free from pollutants, pathogens, and harmful substances.

Climate Change

: Climate change refers to long-term shifts in temperature and weather patterns on a global scale. It is primarily caused by human activities, such as burning fossil fuels and deforestation, leading to an increase in greenhouse gas concentrations in the atmosphere.

Commensalism

: Commensalism is a type of symbiotic relationship between two different species where one organism benefits while the other remains unaffected. The benefiting organism uses the presence of the other for resources like shelter or transportation without causing harm.

Conservation

: Conservation refers to the sustainable management and protection of natural resources, including land, water, plants, animals, and ecosystems. It aims to maintain biodiversity, preserve habitats, and ensure the long-term well-being of both human and non-human species.

Environmental Conditions

: Environmental conditions refer to the physical factors that influence an organism's survival and well-being in its habitat. These factors include temperature, humidity, light levels, soil composition, and availability of food and water.

Hydrologic Cycle

: The hydrologic cycle, also known as the water cycle, refers to the continuous movement of water on, above, and below the Earth's surface. It involves processes such as evaporation, condensation, precipitation, and runoff.

Mutualism

: Mutualism is a type of symbiotic relationship between two different species where both organisms benefit from each other's presence. They rely on each other for resources like food, shelter, protection, or reproduction.

Nitrogen Cycle

: The nitrogen cycle is the process by which nitrogen is converted between its various chemical forms in the environment. It involves nitrogen fixation, nitrification, assimilation, ammonification, and denitrification.

Parasitism

: Parasitism is a type of symbiotic relationship where one organism, called the parasite, benefits at the expense of another organism, called the host. The parasite relies on the host for resources and can harm or weaken it.

Phosphorus Cycle

: The phosphorus cycle involves the movement of phosphorus through rocks, water bodies, soil, and living organisms.

Water pollution

: Water pollution refers to the contamination of water bodies, such as rivers, lakes, and oceans, by harmful substances or pollutants. This can include chemicals, sewage, oil spills, and other waste materials that degrade water quality and harm aquatic life.