AP Environmental Science Unit 1 – The Living World: Ecosystems

Biosphere

It refers to the part of Earth where life exists, including all living organisms and their interactions with each other and the environment.

Commensalistic Relationship

A type of symbiotic relationship where one organism benefits while the other organism is neither harmed nor benefited.

Competition

Occurs when two or more organisms compete for limited resources such as food, water, territory, or mates.

Ecosystem Ecology

Is the study of how living organisms interact with each other and their physical environment within a specific area. It focuses on understanding the flow of energy and nutrients through ecosystems.

Ecosystem Engineers

Organisms that significantly modify their environment, creating new habitats and altering the physical structure of ecosystems. They play a crucial role in shaping and maintaining biodiversity.

Mutualistic relationship

A type of symbiotic relationship where both species involved benefit from their interaction. Each organism provides something the other needs, such as food, shelter, or protection.

Parasitic Relationship

A type of symbiotic relationship where one organism benefits at the expense of another organism, which is harmed in the process.

Predator-Prey Relationship

A dynamic interaction between two organisms, where one organism (the predator) hunts and consumes another organism (the prey) for food.

Resource Partitioning

Refers to the division of limited resources among different species in order to reduce competition. It allows species with similar ecological requirements to coexist by utilizing different parts of the same resource.

Symbiotic Relationship

A close interaction between two different species where at least one organism benefits from the relationship.

Trophic Level

A trophic level refers to the position of an organism in a food chain or food web, determined by its source of energy and how it obtains nutrients. Each level represents a different feeding relationship and energy transfer.

Permafrost

Refers to permanently frozen ground consisting of soil, rock, or sediment that remains below 0°C (32°F) for at least two consecutive years. It is found mainly in polar regions but also exists in some high-altitude areas.

Subtropical Desert

A type of desert that is located in the subtropics, typically between 15 and 30 degrees latitude. It is characterized by hot temperatures, low rainfall, and sparse vegetation.

Taiga

A biome characterized by dense forests of coniferous trees, such as spruce and pine. It is found in cold climates with long winters and short summers.

Temperate Rainforest

Refers to a forest ecosystem characterized by moderate temperatures and high rainfall throughout the year. These forests are typically found along coastal regions with mild winters.

Tropical Rainforest

Refers to a dense forest ecosystem found near the equator that receives high amounts of rainfall throughout the year. It is known for its incredible biodiversity and lush vegetation.

Tropical Seasonal Forest/Savanna

A biome characterized by distinct wet and dry seasons. It consists of scattered trees with grassy areas dominating the landscape during the dry season.

Woodland/Shrubland

Refers to a biome characterized by scattered trees and shrubs, with a mix of grasses and other vegetation. It typically experiences hot, dry summers and mild, wet winters.

Aphotic Zone

Refers to the deeper layer of a body of water that receives little to no sunlight. It is characterized by darkness and low levels of dissolved oxygen.

Benthic Zone

Refers to the lowest level of a body of water, such as a lake or ocean, where organisms live on or in the sediment at the bottom.

Coral Bleaching

Occurs when coral reefs lose their vibrant colors due to stress, such as increased water temperatures or pollution. This can lead to the death of the coral if the stress is prolonged.

Coral Reefs

Diverse underwater ecosystems formed by colonies of tiny animals called coral polyps. They thrive in warm, shallow waters with clear sunlight and provide habitat for numerous marine species.

Eutrophic Lakes

Bodies of water that have high nutrient concentrations, resulting in excessive plant growth (such as algae) and reduced oxygen levels. These lakes often appear greenish or murky due to algal blooms.

Freshwater Wetlands

Land areas saturated with freshwater for at least part of the year, creating unique ecosystems that support diverse plant and animal life.

Intertidal Zones

Refer to the area between high tide and low tide marks on a shoreline. These zones experience regular exposure to both air and water due to tidal fluctuations.

Littoral Zones

Refers to the shallow area of a body of water, such as a lake or pond, where sunlight reaches the bottom and supports plant growth. It is the zone closest to the shore.

Mangrove Swamps

Coastal wetlands characterized by dense growth of mangrove trees, which are salt-tolerant plants that thrive in brackish water. They provide important ecological functions such as protecting coastlines from erosion and serving as nurseries for various marine species.

Mesotrophic Lakes

Bodies of water that have moderate nutrient levels, falling between eutrophic and oligotrophic lakes. They typically support a diverse range of plants and animals.

Ocean Acidification

Occurs when carbon dioxide (CO2) from sources like burning fossil fuels dissolves into seawater and lowers its pH level. This decrease in pH makes seawater more acidic over time, harming marine life such as coral reefs and shellfish.

Oligotrophic Lakes

Bodies of water that have low nutrient concentrations, resulting in clear and oxygen-rich conditions. These lakes typically support a diverse range of aquatic life, including fish species.

Open Ocean

Refers to the vast expanse of seawater that extends beyond coastal areas and continental shelves. It is characterized by deep waters with low nutrient levels and supports a wide range of marine life.

Photic Zone

Refers to the upper layer of a body of water where sunlight can penetrate sufficiently for photosynthesis to occur. It is characterized by high levels of light availability.

Salt Marshes

Coastal wetlands that are regularly flooded by seawater during high tides. They provide critical habitat for many species and help protect coastlines from erosion.

Biogeochemical Cycles

Natural processes that involve the cycling of elements or compounds through living organisms and their environment.

Calcium Carbonate

A chemical compound that is commonly found in rocks, shells, and the skeletons of marine organisms. It is an important component of many natural structures and plays a crucial role in various biological processes.

Carbon Sinks

Natural or artificial reservoirs that absorb and store carbon dioxide from the atmosphere, helping to mitigate climate change.

Cellular Respiration

The process by which cells convert glucose (sugar) into energy (ATP) through a series of chemical reactions. It occurs in both plants and animals and is essential for their survival.

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.

Fossil Fuels

Energy-rich substances formed from ancient organic matter buried deep within the Earth's crust. They include coal, oil, and natural gas. Fossil fuels are burned to release energy but also release carbon dioxide and other pollutants into the atmosphere.

Greenhouse Gas

Gases in the Earth's atmosphere that trap heat from the sun and contribute to the greenhouse effect. They include carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and fluorinated gases.

Photosynthesis

The process through which green plants use sunlight, carbon dioxide, and water to produce glucose (sugar) and oxygen. It is vital for plant growth and releases oxygen into the atmosphere.

Sedimentation

The process by which particles settle out of a fluid (such as water) and accumulate at the bottom over time. It occurs when suspended particles become too heavy to remain in suspension and sink down due to gravity.

Abiotic pathway

Refers to the transfer of energy or materials between non-living components within an ecosystem.

Ammonification

The conversion of organic nitrogen compounds into ammonia (NH3) by decomposer bacteria. It is an important step in the nitrogen cycle, where complex nitrogen-containing molecules are transformed into a form that can be used by plants.

Assimilation

Refers to the process in which plants and animals take up nutrients from their environment and incorporate them into their own tissues for growth and development.

Biotic pathway

Refers to the transfer of energy or materials between living organisms within an ecosystem.

Denitrification

A natural process in which certain bacteria convert nitrates (NO3-) into nitrogen gas (N2), releasing it back into the atmosphere. It occurs primarily in oxygen-depleted environments, such as wetlands and soil.

Fertilizers

Substances that are added to soil or plants to provide essential nutrients for growth. They typically contain nitrogen, phosphorus, and potassium, which help promote healthy plant development.

Limiting Nutrient

An essential nutrient that is in short supply relative to its demand by organisms in an ecosystem. Its scarcity can restrict the growth and productivity of organisms within that ecosystem.

Mineralization

The process by which organic matter, such as dead plants and animals, is broken down into inorganic substances like minerals. This releases nutrients back into the soil or water for use by other organisms.

Nitrate (NO3)

A compound made up of nitrogen and oxygen. It is an essential nutrient for plants and is often found in fertilizers.

Nitrification

The process by which ammonia (NH3) is converted into nitrite (NO2-) and then into nitrate (NO3-), primarily carried out by bacteria.

Nitrogen Cycle

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

Aquatic functions

Refer to the various roles and processes performed by aquatic ecosystems, including freshwater and marine environments. These functions include water purification, nutrient cycling, habitat provision, flood control, and climate regulation.

Biomolecules

Organic molecules that are essential for life processes, such as carbohydrates, lipids, proteins, and nucleic acids. They provide structure and function to cells and organisms.

Decomposition

The process by which organic matter breaks down into simpler substances through the action of decomposers like bacteria and fungi. It plays an important role in nutrient cycling by releasing nutrients back into the environment.

DNA

A molecule that carries the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms. It consists of two long strands twisted into a double helix structure.

Geologic Uplift

Refers to the process by which Earth's crust is raised, resulting in the elevation of landforms such as mountains and plateaus.

Groundwater

Refers to the water present beneath Earth's surface in saturated zones called aquifers. It is an important source of drinking water and supports ecosystems.

Human Impacts on the Phosphorus Cycle

Refer to the activities and actions of humans that disrupt or alter the natural flow of phosphorus in ecosystems. These impacts can include excessive use of fertilizers, deforestation, and pollution from industrial processes.

Limiting Nutrient

An essential nutrient that is in short supply relative to its demand by organisms in an ecosystem. Its scarcity can restrict the growth and productivity of organisms within that ecosystem.

Organic phosphorus

Refers to phosphorus compounds found in living organisms or organic matter. It plays a crucial role in biological processes such as DNA synthesis, energy transfer, and cell membrane formation.

Phosphate Rocks

Sedimentary rocks containing high concentrations of phosphate minerals. They are primarily used as a source of phosphorus for fertilizers in agriculture.

Phosphorus Cycle

Involves the movement of phosphorus through rocks, water bodies, soil, and living organisms.

Runoff

Refers to the movement of water, such as rainwater or melted snow, over the land surface and into bodies of water. It occurs when the ground is unable to absorb all the water, leading to excess water flowing over the surface.

Sedimentation

The process by which particles settle out of a fluid (such as water) and accumulate at the bottom over time. It occurs when suspended particles become too heavy to remain in suspension and sink down due to gravity.

Synthetic fertilizers

Man-made substances that contain essential nutrients for plant growth, such as nitrogen, phosphorus, and potassium. They are commonly used in agriculture to increase crop yields.

Weathering

The process by which rocks, minerals, and other materials on Earth's surface are broken down into smaller pieces or chemically altered. It can be caused by physical forces like wind and water, as well as chemical reactions.

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.

Groundwater

Refers to the water present beneath Earth's surface in saturated zones called aquifers. It is an important source of drinking water and supports ecosystems.

Hydrologic 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.

Percolation

Refers to the process of water seeping through soil or rock layers and moving downward into the ground.

Photosynthesis

The process through which green plants use sunlight, carbon dioxide, and water to produce glucose (sugar) and oxygen. It is vital for plant growth and releases oxygen into the atmosphere.

Plant Uptake

Refers to the process by which plants absorb water and nutrients from the soil through their roots, allowing them to grow and thrive.

Precipitation

Refers to any form of moisture that falls from the atmosphere onto Earth's surface. This can include rain, snow, sleet, or hail.

Soil erosion

The process by which soil is moved or displaced from one location to another, usually due to natural forces like wind and water. It can lead to the loss of fertile topsoil, making it difficult for plants to grow.

Surface Runoff

Refers to water that flows over the land surface rather than infiltrating into the ground. It occurs when rainfall or snowmelt exceeds the soil's ability to absorb it or when the ground is already saturated.

Transpiration

The process by which plants release water vapor into the atmosphere through their leaves. It helps to cool down the plant and also plays a role in transporting nutrients from the roots to other parts of the plant.

Gross Primary Productivity (GPP)

Refers to the total amount of energy that is captured by plants through photosynthesis in a given area or ecosystem.

Net Primary Productivity (NPP)

Refers to the amount of energy that remains after plants have used some of their captured energy for their own respiration.

Photosynthesis

The process through which green plants use sunlight, carbon dioxide, and water to produce glucose (sugar) and oxygen. It is vital for plant growth and releases oxygen into the atmosphere.

Respiration

Refers to the process by which living organisms, including plants, release stored energy from organic compounds to carry out life functions.

Species Diversity

Refers to the variety of different species present in a particular ecosystem or on Earth. It includes both the number of species present and their relative abundance.

Trophic Levels

Refer to the different levels in a food chain or food web where organisms obtain energy. Each level represents a different position in the transfer of energy, with producers at the bottom and top predators at the highest level.

Commensalism

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.

Community Ecology

The study of how different species interact with each other within a particular habitat or ecosystem.

Consumers

Organisms that obtain energy by consuming other organisms. They cannot produce their own food and rely on the energy stored in other living things.

Decomposers

Organisms that break down dead organic matter into simpler substances, such as nutrients, through the process of decomposition.

Detritivores

Organisms that consume detritus, which is dead organic matter like fallen leaves or animal waste. They help break down this material into smaller particles for decomposition.

Food Web

A complex network of interconnected food chains within an ecosystem. It represents multiple feeding relationships and interactions among various organisms.

Law of Thermodynamics

Refers to a set of principles that describe the behavior and transfer of energy in systems. It states that energy cannot be created or destroyed, only transferred or transformed.

Mutualism

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.

Natural Selection

The process by which certain traits or characteristics become more or less common in a population over time due to their impact on survival and reproduction.

Niche

Refers to the specific role or position that an organism occupies within its ecosystem, including its interactions with other organisms and its use of resources.

Predator-Prey Relationship

A predator-prey relationship is a dynamic interaction between two organisms, where one organism (the predator) hunts and consumes another organism (the prey) for food.

Scavengers

Organisms that feed on dead animals or decaying organic matter. They play an important role in recycling nutrients back into ecosystems.

Secondary Consumers

Organisms that feed on primary consumers. They occupy the third trophic level in a food chain or web.

Tertiary Consumers

Organisms that feed on secondary consumers. They occupy the fourth trophic level in a food chain or web.

Trophic Levels

Refer to the different levels in a food chain or food web where organisms obtain energy. Each level represents a different position in the transfer of energy, with producers at the bottom and top predators at the highest level.