Ecology 1 - Glossary

Biodiversity

Refers to the variety of all living things on Earth—plants, animals, fungi, and microorganisms—along with the genetic differences within them and the complex ecosystems they form.

Resilience

The capacity of an ecosystem to absorb disturbances, adapt to changing conditions, and reorganize while still maintaining its essential structures and functions.

Psammosere

Sub-type of Xerosere, it is a succession on sand dunes; typ. along coastal— exposed to salt spray.

Xerosere

Succession in a dry, arid environment.

Hydrosere

Succession that begins in a body of water, like a newly formed pond transitioning into land.

Lithosere

Succession that begins on bare, lifeless rock.

Pioneer Stage

The initial phase of ecological succession, where hardy, fast-growing organisms first colonize barren environments or disrupted ecosystems.

Climax Community

The final, stable stage of ecological succession. In this state, a balanced ecosystem of plants, animals, and fungi reaches equilibrium and adapts optimally to the region's climate.

Seral Community (Sere)

The entire sequence of intermediate communities that develop in an area during ecological succession. It represents the evolutionary stages of an ecosystem, starting from pioneer species until it reaches a stable, mature "climax community".

Dynamic Equilibrium

The state of dynamic stability between living organisms and their environment. It means that despite constant fluctuations and natural disturbances, an ecosystem's species populations and resources remain in a balanced, sustainable state through continuous adaptation and nutrient cycling.

Succession

The process where a biological community's species composition changes over time.

Keystone Species

An organism that holds an ecosystem together. While not always the largest or most abundant, it has a disproportionately large impact on its environment. If removed, the ecosystem can drastically change or collapse.

Trophic Cascade

An ecological phenomenon where changing the population of a top predator triggers a chain reaction of indirect effects that ripple down the food web, dramatically altering the entire ecosystem.

Resource Partitioning

An evolutionary adaptation where competing species use limited resources in different ways, at different times, or in different places. This mechanism minimizes direct competition, allowing similar species to coexist in the same habitat without one driving the others to extinction.

The competitive exclusion principle (Gause's Law)

It states that two related, competing species cannot stably coexist in the exact same ecological niche if resources are strictly limited. The superior competitor will monopolize the resources, eventually driving the other species to local extinction

Generalist Species

An organism that can thrive in a wide variety of environmental conditions and utilize a diverse array of resources, such as food and shelter.

Specialist Species

An organism that thrives only in a narrow range of environmental conditions or has a very limited diet. Because they rely on specific resources or precise habitats, they are highly adapted to their specific ecosystems but are extremely vulnerable to extinction when their environment changes.

Intraspecific Competition

A biological interaction where members of the same species compete for limited resources.

Interspecific Competition

The struggle between individuals of different species for limited shared resources in an ecosystem (like food, water, or territory).

Population Density

The concentration of individuals within a specific geographic area, calculated by dividing the total population by the total land area.

Community

The study of how different species interact and coexist within a defined area. It analyzes biodiversity, population structures, and dynamic relationships like competition, predation, and mutualism to understand how these factors shape the abundance and distribution of life in an ecosystem

Ruderal Species

These are hardy trailblazers that are the first to colonize land disturbed by natural disasters or human activity.

R Selected Species

These are organisms that prioritize high reproduction rates, rapid maturation, and exponential population growth to quickly colonize unstable or disturbed environments.

K Selected Species

These are organisms that thrive in stable environments and live at or near their ecosystem's carrying capacity. They typically exhibit large body sizes, long life spans, and slow maturation.

Carrying Capacity

The maximum population size an ecosystem or environment can support sustainably over time. It is dictated by limiting factors like food, water, habitat, and space.

Metapopulation

A "population of populations"—a group of spatially separated groups of the same species that interact at some level. Helps lessen effect of local extinction through rescuing/repopulation nearby habitats.

Evolution

HAppening on the population level, the scientific theory that populations of living organisms change over successive generations through the alteration of their heritable traits.

Natural Selection

The primary mechanism of evolution, where organisms better adapted to their environment are more likely to survive, reproduce, and pass on their advantageous traits.

Species

Largest group of organisms that can reproduce.

Ecological resilience

the capacity of an ecosystem to cope with disturbance or stress and return to a stable state.

Exosphere

Being the topmost layer of Earth's atmosphere, it acts as a transition zone between the atmosphere and interplanetary space.

Aggradation

The natural process of the build up of a riverbed or surrounding land through the deposition of stream-borne sediments.

Biosphere

Refers to the thin film on Earth's surface in which all life exists, the sum of all ecosystems on Earth.

Dioxin

Highly toxic, persistent organic pollutants (POPs) that bioaccumulate in fatty tissues and biomagnify through the food chain. They are unintentional byproducts of industrial combustion and chemical processes, accumulating in soil and sediment.

The Great Pacific Garbage Patch

The world's largest accumulation of ocean plastic, located in the North Pacific Ocean between Hawaii and California.

Desertification

The persistent degradation of dryland ecosystems—arid, semi-arid, and dry sub-humid areas—into desert-like landscapes, driven primarily by human activities and climate change

Troposphere

One of the major atmospheric zone that is directly above the earth's surface and extends up to a height of 20 kilometers above the equator and 8 kilometers over the poles.

Heterotrophs

Organisms that cannot produce its own food; thus, needing to consume other organisms for energy

Lithosphere

It is the solid, rigid outer shell of the Earth, encompassing the crust and the uppermost part of the mantle that acts as the foundational platform for terrestrial life

Organic Matter

It makes up 5% of soil composition.

Ecology

The scientific study of the relationships between living organisms (including humans) and their physical environment. It examines how biotic (living) and abiotic (non-living) components interact to influence the distribution, abundance, and adaptation of life, ranging from microscopic bacteria to global ecosystems.

Exchange or Cycling Pool

A smaller but more active portion (often biotic) that moves materials in nutrient cycling.

Ecosystem

An ecological system which involves a unit that includes a community of organisms in a given area, interacting with the physical environment so that the flow of energy leads to clearly defined trophic structure, biotic diversity, and material cycles.

Hydrosphere

It is the total amount of water on a planet, encompassing all liquid, frozen, and gaseous water found on, under, and above its surface

Thermosphere

Located above the mesosphere, this atmospheric zone is about 80 to 90 kilometers thick and it is characterized by extremely low density but very high temperatures due to absorption of intense solar radiation. Despite high temperatures, the air is so thin (near-vacuum) that there are not enough molecules to transfer heat, meaning it would feel freezing cold.

Population

Ecological scale/levels: Studies groups of the same species living in the same area, examining population dynamics, density, and structure (e.g., penguin population size and growth).

Scouring

A specific form of accelerated surface erosion where fast-moving water removes sediment, soil, and gravel from around riverbeds, coastlines, or infrastructure foundations

Abrasion

A primary process of physical erosion where transported materials—such as sand, pebbles, or ice—wear away at a surface over time through friction, grinding, and scraping.

Nutrient Cycling / Ecological Recycling / Biogeochemical Cycle

It is the continuous movement and exchange of organic and inorganic matter back into the production of living matter.

Autotrophs (Producers)

Organisms that produce their own food from simple inorganic materials such as plants and algae.

Ecosystem

The smallest/basic functional unit of ecology that can sustain life in isolation from all but atmospheric surroundings.

Reservoir Pool

The large, slow-moving, generally non-biological component of nutrient cycling that holds nutrients for long periods of time.

Atmosphere

The gaseous, protective envelope surrounding Earth that acts as a vital, active component of the biosphere

Water and Air

These two make up 50% of soil composition in equal percentage (25%).

Decomposers (Microconsumers/ Saprotrophs/Osmotrophs)

Organisms that converts materials released by plants and consumers to their original elements (C, O, H, N, S, P).

Biogenic

Collective term for substances, structures, or processes directly produced, created, or maintained by living organisms

Primary Consumers

Heterotrophic organisms that directly consumes producers/autotrophs to obtain energy and nourishment. They are also called herbivores.

Global Warming

The long-term rise in Earth's average temperature, driven primarily by human activities—specifically the burning of fossil fuels (coal, oil, and natural gas)—which release heat-trapping greenhouse gases into the atmosphere.

Community

Ecological scale/level: Focuses on interactions between different populations of different species, such as predation, competition, and symbiosis in a specific area.

Deforestation

The permanent, human-led removal or thinning of forest cover to repurpose land for agriculture, logging, or urbanization, resulting in severe, long-term ecological imbalances

Ecosystem

Ecological scale/level: Examines the community of living organisms (biotic) interacting with their non-living (abiotic) environment, including energy flow and nutrient cycling.

Carbonates

Oceans dissolve and store carbon dioxide from the atmosphere in forms of __________ for marine life (shells), acting as a massive carbon sink.

Sulfur Cycle

A hybrid (has gaseous and sedimentary phase) biogeochemical cycle where sulfur moves between rocks, waterways, the atmosphere and living systems.

Phosphorous Cycle

A slow sedimentary type of biogeochemical cycle that moves phosphorous through lithosphere, hydrosphere, and biosphere.

Greenhouse Effect

A natural phenomenon where gases in Earth's atmosphere trap heat from the sun, preventing it from escaping into space and keeping the planet warm enough to sustain life

Climate Change

This refers to long-term, significant shifts in global or regional weather patterns and average temperatures, primarily driven since the 1800s by human activities like burning fossil fuels.

Minerals

It makes up the 45% of soil composition.

Enhanced Greenhouse Effect

It is the accelerated warming of Earth's atmosphere caused by human activities; therefore surpassing the normal heat limit caused by normal green house effect.

Siltation

The pollution of water bodies by fine mineral particles—primarily silt, clay, or sand—leading to increased sediment concentration in water and accumulation on the bottom

Carbon Dioxide Cycle

A gaseous biogeochemical cycle of continuous, natural movement of carbon atoms between the atmosphere, oceans, soil, and living organisms.

Secondary Consumers

Heterotrophic organisms that feed on primary consumers (herbivores) to obtain energy; These consumers can be carnivores (meat-eaters) or omnivores (animals that eat both plants and meat)

COHNSP

The six most important elements that constitutes 95% of all living organisms.

Persistent Organic Pollutants (POPs)

These are toxic, carbon-based chemical substances that resist environmental degradation, bioaccumulate in human and wildlife fatty tissues, and are transported long distances through air and water.

Nitrogen Cycle

A very complex gaseous type of biogeochemical cycle that breaks down the nitrogen from organic to inorganic form.

Syncecology

Subdivision of ecology that studies groups of organisms which are associated together as a unit.

Ablation

The removal of material from an object's surface through sublimation, melting, vaporization, or chipping caused by intense heat, high-speed fluid/gas, or laser energy

Biomes

Refers to large scale areas of similar vegetation and climate.

Brown Belt

Heterotrophic metabolism occurs in the lower ___________ stratum in which organic matter accumulates in the soils and sediments.

Environment

The sum total of all surrounding conditions, influences, and resources—natural or human-made—that affect the life, development, and survival of organisms

Eco-feminism

A social and political movement and theory that connects the exploitation of nature with the oppression of women, arguing that both are devalued by patriarchal, hierarchical systems.

Sedimentation

The physical process where suspended particles (such as sand, soil, or organic matter) settle out of a fluid—typically water or air—and deposit at the bottom due to gravity or centrifugal force

Sun

The ultimate source of energy of living organisms.

Cultural Ecology

The anthropological study of how human societies adapt to their physical environments, focusing on the relationship between cultural practices, resource utilization, and environmental conditions

Autoecology

Subdivision of ecology that studies the individual organism/specie, with emphasis on life histories and behavior as a means of adaptation to the environment

Green Belt

Autotrophic metabolism occurs in the upper __________ stratum in which light energy is available.

Decomposers

Organisms, typically micro-organisms such as fungi, bacteria, worms, or insects that relies on dead organisms for sustenance.

Stratosphere

Located above the troposphere, this atmospheric zone is about 30 kilometers in thickness and contains the ozone layer.

Mesosphere

Located above the stratosphere, this atmospheric zone is about 40 kilometers in thickness and it is characterized by gradual decline in temperature, making it the coldest part of the atmosphere. This is also where meteors burn up, creating a shooting star.

Tertiary Consumers

Heterotrophic organisms that primarily feed on secondary consumers to obtain energy. They are also called the top carnivores or apex predators.

Trophic Levels

It is a structural levels in ecosystem that defines an organism's position in a food chain based on how it obtains energy.

Provisioning

Ecological Services— Tangible resources extracted directly from nature. This includes agricultural crops, drinking water, lumber for building, medicinal plants, and fuel.

Regulating

Ecological Services— Natural processes that moderate the environment and protect human well-being. Examples include forests and oceans absorbing carbon dioxide to stabilize the climate, wetlands acting as natural flood barriers, and insects pollinating crops.

Cultural

Ecological Services— Non-material benefits that contribute to human mental and physical health. This includes the enjoyment of outdoor recreation, tourism, aesthetic appreciation, and spiritual enrichment.

Supporting

Ecological Services— The fundamental ecosystem processes that make all other services possible. These include the water cycle, nutrient cycling, photosynthesis, and soil formation.

Tropical Rainforest

A warm and humid biome near the equator with high rainfall throughout the year, dense layered vegetation, and the greatest biodiversity among terrestrial ecosystems.

Tropical Grasslands (Savanna)

A warm biome with grasses as the dominant vegetation, scattered trees, seasonal rainfall, and distinct wet and dry periods often shaped by fire and grazing.

Temperate Rainforest

A cool, moist forest biome with high rainfall, dense vegetation, large trees, and abundant mosses, ferns, and fungi.

Temperate Grasslands

A biome dominated by grasses with few trees, moderate rainfall, fertile soils, and seasonal temperature changes including hot summers and cold winters.

Desert

A dry biome characterized by very low rainfall, extreme temperature variations, and plants and animals adapted to water scarcity.

Taiga (Boreal Forest)

A cold forest biome dominated by coniferous trees such as spruce, pine, and fir, with long winters and short growing seasons.