People and Earth's Ecosystem: Comprehensive Ecology Review

Vocabulary practice flashcards covering levels of biological organization, history of ecological science, Barry Commoner's Four Laws of Ecology, symbiotic relationships, and major Earth biomes.

Levels of Organization

The structures in nature that are defined by part-whole relationships, with things at higher levels being composed of things at the next lower level.

Atom

The smallest unit of matter that cannot be broken down into anything simpler by chemical means.

Molecule

The smallest units of most compounds formed by the chemical bonding of atoms.

Organelle

Specialized structures that perform important cellular functions within cells, such as the nucleus, mitochondria, and chloroplasts.

Cell

The smallest unit of life, defined as collections of living matter enclosed by a barrier that separates them from their surroundings.

Tissue

Groups of similar cells that perform a particular function.

Organ

Groups of tissues that work together to perform closely related functions, such as the heart, brain, skin, eyes, and teeth.

Organ System

Groups of organs that work together to perform closely related functions, such as the nervous system.

Organism

An individual living entity that can carry out all basic life processes, which may be single-celled or multicellular.

Population

Groups of individuals of the same species that live in the same area.

Community

Groups of different species that live together in a defined area.

Ecosystem

Groups of all the organisms that live in a particular place, together with their nonliving physical environment.

Biome

A region of the Earth where climate and geography determine its flora and fauna, composed of groups of ecosystems sharing the same climate and similar dominant communities.

Biosphere

The part of the Earth in which life exists, including land, water, air, and the atmosphere.

Ecology

The study of the relationships between organisms and their biotic or abiotic environment; the term was coined in $1869$ by German zoologist Ernst Haeckel from the Greek word "oikos".

Great Chain of Beings (Scala Naturae)

A hierarchical concept of nature proposed by Aristotle in the $4^{\text{th}}$ Century B.C.E. structured as: God > Angels & Spirits > Humans > Animals > Plants > Minerals.

Theophrastus

Considered the 'Father of Botany', he classified plants by habitat (soil type, climate, moisture) in works like 'Historia Plantarum' and investigated the role of climate in plant life cycles.

Arcadian Ecology

An early $18^{\text{th}}$ century ecological school of thought advocating for a simple, humble life for man and a harmonious relationship between man and nature.

Imperial Ecology

An early $18^{\text{th}}$ century ecological school of thought that believes in establishing man's dominance over nature through the exercise of reason and hard work.

Taxonomy

The science of naming and classifying organisms pioneered by Carolus Linnaeus in $1758$ within his work 'Systema Naturae'.

Alexander von Humboldt

Referred to as the 'Father of Ecology', he published 'Idea for Plant Geography' in $1804$, describing species distribution alongside geographic and geological data.

Theory of Evolution and Adaptation

A biological framework proposed in $1859$ by Charles Darwin describing natural selection and the 'survival of the fittest', where inherited traits improve an organism's survival and reproduction.

Biogeography

The discipline introduced in $1895$ by Eugenius Warming dedicated to studying the geographic distribution of living organisms in relation to abiotic factors like wind, fire, and temperature.

Vladimir I. Vernadsky

Scientist who published 'The Biosphere' in $1926$, redefining the biosphere as the global ecological system integrating all living beings and their interactions with elements of nature.

Gaia Hypothesis

An ecological concept introduced by James Lovelock in $1970$ proposing that Earth is a single living entity capable of ensuring its own survival even if humans destroy themselves.

Barry Commoner

Biologist and author of 'The Closing Circle' who summarized the fundamental principles of ecology into the Four Laws of Ecology.

First Law of Ecology

"Everything is connected to everything else" — posits that there is one ecosphere for all living organisms, meaning what affects one affects all.

Food Chain

The specific path by which energy passes from producers receiving sunlight to various levels of consumers and decomposers.

Food Web

A network of several linked food chains representing complex feeding relationships where a predator in one chain may be linked to prey in another.

Intraspecific Competition

Competition that occurs between members of the same species competing for identical resources such as food, water, shelter, mates, or den sites.

Interspecific Competition

Competition that takes place between populations of different species competing for the same shared resources, such as food or territory.

Predator Pressure

A measurement of predator population density and its relationship to feeding behavior, where higher pressure leads to decreased prey survival.

Second Law of Ecology

"Everything has to go somewhere or there is no such place as away" — restates the laws of thermodynamics in ecology, indicating that matter and energy are preserved and recycled without final waste.

Sublimation

The phase change in the water cycle where snow and ice transform directly into water vapor in the air without melting into liquid water first.

Transpiration

The process where water absorbed by plant roots is utilized in leaves and excess moisture is released as water vapor into the atmosphere through stomata.

Infiltration

The process of water entering and seeping into the soil through the Earth's surface, replenishing the drinkable groundwater table.

Nutrient Cycle

The continuous cyclic movement of essential minerals and elements (such as phosphorus, nitrogen, potassium, and calcium) through soil, water, air, and living tissues.

Third Law of Ecology

"Everything is always changing (Nature knows best)" — states that natural systems evolve continuously and human-made technological interventions are often detrimental to systemic balance.

Ecological Succession

The natural process by which the structure and species composition of a biological community evolve and change over time.

Primary Succession

Ecological succession that occurs when living organisms colonize a completely barren, lifeless habitat devoid of soil for the very first time.

Secondary Succession

The re-colonization process of an ecological community following a disturbance in an area that was previously occupied by plants and animals.

Pioneer Species

Small, hardy, fast-spreading species that colonize bare, un-inhabited terrain first, frequently producing large amounts of seasonal seeds.

Climax Community

A relatively stable community of prominent species that emerges at the mature culmination of succession, though it remains non-permanent.

Fourth Law of Ecology

"There is no such thing as a free lunch" — establishes that any exploitation or extraction of natural resources incurs an unavoidable ecological cost and potential degradation.

Symbiosis

Any sustained biological interaction between two different species, derived from the Greek words "sym" (together) and "bios" (life).

Mutualism

A symbiotic relationship in which both interacting organisms derive a mutual benefit and neither organism suffers harm.

Obligate Mutualism

A type of mutualism where neither of the participating species can survive without the presence of the other.

Facultative Mutualism

A mutualistic interaction where participating species benefit from each other but are fully capable of surviving independently.

Trophic Mutualism

A mutualistic partnership structured specifically around the complementary transfer and exchange of energy and nutrients between two species.

Defensive Mutualism

A mutualistic relationship wherein one species receives food and shelter in return for defending the partner species against predators or parasites.

Dispersive Mutualism

A mutualism in which an animal obtains nectar or nutrition from a flower while simultaneously dispersing its pollen throughout the surrounding environment.

Parasitism

A symbiotic interaction in which one organism (the parasite) obtains physiological benefits at the direct physical expense or harm of the host.

Endoparasitism

A form of parasitism where parasites reside internally within the tissues or cavities of the host's body, such as tapeworms or flukes.

Ectoparasitism

A form of parasitism where parasites live externally on the outer surface or skin of the host organism, such as ticks, fleas, and lice.

Commensalism

A symbiotic interaction where one organism benefits while the other organism is neither helped nor harmed.

Inquilinism

A commensal relationship where one species utilizes the body or a body cavity of another living organism strictly as physical shelter or housing.

Phoresy

A form of commensalism where an organism (phoront) temporarily attaches to a host animal strictly for transportation without extracting nutrients or causing parasitism.

Metabiosis

A commensal association where one species unintentionally creates or prepares a suitable living habitat for another organism, such as hermit crabs inhabiting abandoned shells.

Desert Biome

The driest biome on Earth, receiving precipitation of $< 200\,\text{mm/yr}$ with temperatures ranging from $38\,^{\circ}\text{C}$ to $-3.9\,^{\circ}\text{C}$ on sandy, gravelly, or stony soil.

Shrubland Biome

A biome characterized by chaparral, woodland, or savanna with hot, dry summers and cool, moist winters, receiving $200\text{--}1000\,\text{mm/yr}$ of precipitation on acidic, sandy soils.

Grassland Biome

An open and continuous biome dominated by grasses measuring between $0.2\,\text{m}$ and $2.1\,\text{m}$, with $500\text{--}900\,\text{mm/yr}$ of rainfall and loam or silt soils.

Tropical Rainforest Biome

The oldest and most biodiverse terrestrial biome, receiving heavy precipitation of $1800\text{--}2500\,\text{mm/yr}$ with temperatures of $30\,^{\circ}\text{C}$ to $18\,^{\circ}\text{C}$ on weathered clay soils.

Temperate Deciduous Forest Biome

A four-season forest biome dominated by broadleaf deciduous trees, supported by $750\text{--}1500\,\text{mm/yr}$ of precipitation and loam or silt loam soils.

Coniferous Forest (Taiga) Biome

A high-latitude biome situated between $50^{\circ}\text{N}$ and $60^{\circ}\text{N}$ dominated by evergreen conifers, experiencing temperatures from $20\,^{\circ}\text{C}$ to $-40\,^{\circ}\text{C}$ on acidic, sandy loam soils.

Tundra Biome

The coldest biome, found above $60^{\circ}\text{N}$, with temperatures below $0\,^{\circ}\text{C}$, precipitation under $250\,\text{mm/yr}$, treeless vegetation, and permafrost silt soil.

Aquatic Biome

The global biome covering $75\%$ of the Earth's surface, comprised of both freshwater ecosystems (rivers, lakes, streams, wetlands) and marine environments.