Learn: SUNY ESF - EFB 320, Exam 1

Ecology

The scientific study of the abundance and distribution of organisms in relation to other organisms and environmental conditions.

Biotic

Living

Abiotic

Nonliving

Ecological Systems

Entities that have their own internal processes and interact with their external surroundings.

Individual

A living being; the most fundamental unit of ecology.

Adaptation

A characteristic of an organism that makes it well suited to its environment.

Population

The individuals of the same species living in a particular area.

Species

Historically defined as a group of organisms that can naturally interbreed with each other and produce fertile offspring. Current research demonstrates that no single definition can be applied to all organisms.

Community

All populations of species living together in a particular area.

Ecosystem

One or more communities of living organisms interacting with their nonliving physical and chemical environments.

Landscape

Two or more ecosystems connected by the movement of individuals, populations, matter, and energy.

Biosphere

All the ecosystems on Earth.

Law of Conservation of Matter

Matter cannot be created or destroyed; it can only change form.

Law of Conservation of Energy

Energy cannot be created or destroyed; it can only change form.

Dynamic Steady State

When the gains and losses of ecological systems are in balance.

Phenotype

An attribute of an organism, such as its behavior, morphology, or physiology.

Genotype

The set of genes an organism carries.

Evolution

Change in the genetic composition of a population over time.

Natural Selection

Change in the frequency of genes in a population through differential survival and reproduction of individuals that possess certain phenotypes.

Fitness

The survival and reproduction of an individual.

Producer (Autotroph)

An organism that uses photosynthesis to convert solar energy into organic compounds or uses chemosynthesis to convert chemical energy into organic compounds.

Consumer (Heterotroph)

An organism that obtains its energy from other organisms.

Mixotroph

An organism that obtains its energy from more than one source.

Predator

An organism that kills and partially or entirely consumes another individual.

Parasitoid

An organism that lives within and consumes the tissues of a living host, eventually killing it.

Parasite

An organism that lives in or on another organism, but rarely kills it.

Pathogen

A parasite that causes disease in its host.

Herbivore

An organism that consumes producers such as plants and algae.

Competition

An interaction resulting in negative effects between two species that depend on the same limiting resource to survive, grow, and reproduce.

Mutualism

An interaction between two species in which each species receives benefits from the other.

Commensalism

An interaction in which two species live in close association and one species receives a benefit, while the other experiences neither a benefit nor a cost.

Symbiotic Relationship

When two different types of organisms live in a close physical relationship.

Scavenger

An organism that consumes dead animals.

Detritivore

An organism that feeds on dead organic matter and waste products that are collectively known as detritus

Decomposer

Organisms that break down dead organic material into simpler elements and compounds that can be recycled through the ecosystem.

Habitat

The place, or physical setting, in which an organism lives.

Niche

The range of abiotic and biotic conditions that an organism can tolerate.

Manipulative Experiment

A process by which a hypothesis is tested by altering a factor that is hypothesized to be an underlying cause of the phenomenon.

Manipulation (Treatment)

The factor that we want to vary in an experiment.

Control

A manipulation that includes all aspects of an experiment except the factor of interest.

Experimental Unit

The object to which we apply an experimental manipulation.

Replication

Being able to produce a similar outcome multiple times.

Randomization

An aspect of experiment design in which every experimental unit has an equal chance of being assigned to a particular manipulation.

Microcosm

A simplified ecological system that attempts to replicate the essential features of an ecological system in a laboratory or field setting.

Observation (Data)

Information, including measurements, that is collected from organisms or the environment.

Natural Experiment

An approach to hypothesis testing that relies on natural variation in the environment.

Mathematical Model

A representation of a system with a set of equations that correspond to hypothesized relationships among the system's components.

Global Warming

The increase in the average temperature of the planet due to an increased concentration of greenhouse gases in the atmosphere.

Greenhouse Gases

Compounds in the atmosphere that absorb the infrared heat energy emitted by Earth and then emit some of the energy back toward Earth.

Variance of the Mean

A measurement that indicates the spread of data around the mean of a population when every member of the population has been measured.

Sample Variance

A measurement that indicates the spread of data around the mean of a population when only a sample of the population has been measured.

Ecotone

A boundary created by sharp changes in environmental conditions over a relatively short distance, accompanied by a major change in the composition of species.

Interdependent Communities

Communities in which species depend on each other to exist.

Independent Communities

Communities in which species do not depend on each other to exist.

Species Richness

The number of species in a community.

Log-Normal Distribution

A normal, or bell-shaped, distribution that uses a logarithmic scale on the x-axis.

Simpson's Index

D = ∑ni​(ni​−1)​ / N(N−1)

Shannon-Wiener Index (H')

H = −∑(pi) ∗ ln(pi)

Rank-Abundance Curve

A curve that plots the relative abundance of each species in a community in rank order from the most abundant species to the least abundant species.

Species Evenness

A comparison of the relative abundance of each species in a community.

Keystone Species

A species that substantially affects the structure of communities despite the fact that individuals of the species might not be particularly numerous.

Intermediate Disturbance Hypothesis

The hypothesis that more species are present in a community that occasionally experiences disturbances than in a community that experiences frequent or rare disturbances.

Food Chain

A linear representation of how different species in a community feed on each other.

Food Web

A complex and realistic representation of how species feed on each other in a community.

Trophic Level

A level in a food chain or food web of an ecosystem.

Primary Consumer

A species that eats producers.

Secondary Consumer

A species that eats primary consumers.

Tertiary Consumer

A species that eats secondary consumers.

Omnivore

A species that feeds at several trophic levels.

Guild

Within a given trophic level, a group of species that feeds on similar items.

Direct Effect

An interaction between two species that does not involve other species.

Indirect Effect

An interaction between two species that involves one or more intermediate species.

Trophic Cascade

Indirect effects in a community that are initiated by a predator.

Density-Mediated Indirect Effect

An indirect effect caused by changes in the density of an intermediate species.

Trait-Mediated Indirect Effect

An indirect effect caused by changes in the traits of an intermediate species.

Bottom-Up Control

When the abundances of trophic groups in nature are determined by the amount of energy available from the producers in a community.

Top-Down Control

When the abundance of trophic groups is determined by the existence of predators at the top of the food web.

Soil

The layer of chemically and biologically altered material that overlies bedrock or other unaltered material at Earth's surface.

Parent Material

The layer of bedrock that underlies soil and plays a major role in determining the type of soil that will form above it.

Horizon

A distinct layer of soil.

Leaching

A process in which groundwater removes some substances by dissolving them and moving them down through the soil to lower layers.

Weathering

The physical and chemical alteration of rock material near Earth's surface.

Water Potential

A measure of water's potential energy, which indicates its tendency to move from one area to another.

Matric (Matrix) Potential

The potential energy generated by the attractive forces between water molecules and soil particles.

Wilting Point

The water potential at which most plants can no longer retrieve water from the soil.

Cation Exchange Capacity

The ability of a soil to retain cations.

Soil Salinization

The process of repeated irrigation, which causes increased soil salinity.

Cohesion

The mutual attraction among water molecules.

Transpiration

The process by which leaves can generate water potential as water evaporates from the surfaces of leaf-cells ito the air spaces within the leaves.

Cohesion-Tension Theory

The mechanism of water movement from roots to leaves due to water cohesion and water tension.

Stomata

Small openings on the surface of leaves, which serve as the points of entry for and exit points for water vapor.

RuBP Carboxylase-Oxidase (Rubisco)

An enzyme involved in photosynthesis that catalyzes the reaction of RuBP and carbon dioxide (CO2) to form two molecules of glyceraldehyde 3-phosphate (G3P)

C3 Photosynthesis

The most common photosynthetic pathway, in which carbon diozide (CO2) is initially assimilated into a three-carbon compound, glyceraldehyde 3-phosphate (G3P).

Photorespiration

The oxidation of carbohydrates to carbon dioxide (CO2) and water (H2O) by rubisco, which reverses the light reactions of photosynthesis.

C4 Photosynthesis

A photosynthetic pathway in which carbon dioxide (CO2) is initially assimilated into a four-carbon compound, oxaloacetic acid (OAA).

Crassulacean Acid Metabolism (CAM)

A photosynthetic pathway in which the initial assimilation of carbon into a four-carbon compound occurs at night.

Negative Feedbacks

The action of internal response mechanisms that restores a system to a desired state, or set point, when the system deviates from that state.

Independent Variable

A factor that causes other variables to change.

Dependent Variable

A factor that is being changed.

Continuous Variable

A variable that can take on any numeric value, including values that are not whole numbers.