Introduction to Ecology and Ecological Factors

Flashcards covering the inter-relation between the living world and the environment, focusing on biotic and abiotic factors, soil formation, ecological laws, and atmospheric layers.

Interdependence

The relationship where living beings continuously interact with the environment and each other to grow, reproduce, and survive.

Biomes

Large-scale ecological areas like grasslands, rainforests, and deserts that exist based on factors like annual rainfall, average temperature, and the earth's position relative to the sun.

Ecotypes

Variations evolved by widely distributed species to adapt to specific habitat conditions.

Carrying capacity

The potential of every habitat to support a certain number of organisms; knowledge of this is essential for habitat management.

Limiting factors

Abiotic components that determine and restrict the population growth, number, and diversity of biotic factors in an ecosystem.

Producers

Autotrophs, such as plants and green algae, that use light energy to synthesize their own food.

Consumers

Heterotrophs that directly or indirectly depend on producers for their food, categorized as herbivores, carnivores, omnivores, and parasites.

Decomposers

Saprophytes that act on dead matter and decay it for their nutrition.

Mutualism

A symbiotic relationship between two different organisms in which each partner benefits.

Parasitism

A symbiotic relationship where one partner (the parasite) benefits by living on or in another organism (the host) while harming it.

Commensalism

A symbiotic relationship where one partner benefits while the other neither benefits nor is harmed.

Ecology

The scientific study of the interactions among organisms and their environment, encompassing levels from individuals to the biosphere.

Species

The most basic unit of classification, defined as a group of similar individuals capable of interbreeding or exchanging genes.

Population

A group of individuals of the same species living and interbreeding within a given area.

Community

A diverse group of organisms that interact in a common location, such as a forest inhabited by various animals, plants, bacteria, and fungi.

Ecosystem

A community of lifeforms in concurrence with non-living components, first coined by English botanist A.G. Tansley in 1935.

Biosphere

A narrow zone on the Earth's surface where soil, water, and air (Lithosphere, Hydrosphere, and Atmosphere) combine to sustain life.

Pedogenesis

The complex process of soil development through interaction between biological, topographic, and climatic effects.

Physical weathering

The mechanical breakdown of rocks through processes such as wetting-drying, heating-cooling, freezing-thawing, glaciation, and sand blast.

Hydration

A type of chemical weathering where water is absorbed by minerals, causing them to swell, such as anhydrous anhydrite ($CaSO_4$) forming gypsum ($CaSO_4 \cdot 2H_2O$).

Hydrolysis

Chemical weathering where minerals react with water to form new minerals, such as the change of orthoclase ($K_2Al_2Si_6O_{16}$) to kaolinite ($Al_2O_3 \cdot 2SiO_2 \cdot 2H_2O$).

Chelation

The dissolution of rock minerals by organic acids produced through the biochemical activity of microorganisms like lichens and bacteria.

Soil profile

The seen sequence of layers or horizons in fully developed soil, including the $O, A, B, C,$ and $R$ horizons.

Humus

Amorphous, finely divided organic matter found in the $A_1$ (melanized) region of the soil horizon.

Zone of leaching

Also known as the $A_2$ region or eluvial zone, where minerals and organic chemicals are rapidly lost downwards by heavy rainfall.

Zone of illuviation

The $B$ horizon, where chemicals leached from the upper layers are collected; it is typically dark-colored and coarse-textured.

Solum

The collective term for the $A_1, A_2,$ and $B$ horizons, representing the mineral soil.

Convectional precipitation

Precipitation caused by the strong heating of the Earth's surface, making warm moist air rise vertically, cool, and condense, often resulting in afternoon thunderstorms.

Orographic precipitation

Relief precipitation occurring when moist air is forced to rise over mountains, resulting in a wet windward side and a dry rain shadow region.

Cyclonic precipitation

Widespread rainfall occurring when two different air masses (one warm and one cold) meet, force-rising the warm air over the cold air.

Sleet

Small, hard ice pellets that form when raindrops pass through a cold layer of air near the ground and freeze; indicates a temperature inversion.

Ecological amplitude

The range of environmental conditions (temperature, pH, salinity, etc.) within which a species can survive and reproduce.

Eurytopic species

Organisms that can tolerate wide variations in environmental conditions, such as Eurythermal or Euryhaline species.

Stenotopic species

Organisms with a narrow ecological amplitude, such as Stenothermal Antarctic fishes that only survive in near-freezing waters.

Liebig's law of the minimum

The principle stating that growth is determined by the scarcest limiting factor rather than the total resources available.

Optimal zone

The most favorable range within the zone of tolerance that supports maximum growth and development for an organism according to Shelford's law.

Thermal stratification

The arrangement of water layers in lakes based on temperature: Epilimnion (top), Metalimnion (middle thermocline), and Hypolimnion (bottom).

Spring overturn

A phenomenon where strong spring winds cause complete mixing of water, dissolved oxygen, and nutrients in a lake as it reaches an isothermal temperature of $4^\circ C$.

Poikilothermic animals

Cold-blooded animals or ectotherms whose body temperature changes according to environmental fluctuations.

Homeothermic animals

Warm-blooded animals or endotherms (birds and mammals) that maintain a constant body temperature through metabolic activities.

Bergman’s Rule

The observation that mammals in colder areas are larger in size than their counterparts in warmer climates.

Allen’s Rule

The observation that extremities like tails, snouts, ears, and legs of mammals are relatively shorter in colder regions.

Gloger’s Rule

The rule stating that animals in the tropics are darker and more heavily pigmented than those in colder, dry regions.

Vernalisation

A cold treatment process required by certain seeds to ensure they do not germinate until after winter.

Normal lapse rate

The rate in the Troposphere where temperature decreases by $1^\circ C$ for every $165\,m$ of height.

Tropopause

The transitional zone that separates the Troposphere and the Stratosphere.

Stratosphere

The atmospheric layer extending from the troposphere up to $50\,km$; it contains the ozone layer and is ideal for flying aircraft.

Ionosphere

The lower Thermosphere located between $80$ and $400\,km$ that consists of electrically charged particles used for reflecting radio waves.

Compensation intensity

The light intensity at which a plant's photosynthesis exactly balances its respiration.

Phototropism

The movement of plants in response to light, where stems move toward light (positive) and roots move away (negative).

Long Day Plants (L.D.P.)

Plants that bloom when the light duration is more than $12$ hours per day, such as radish or spinach.

Photo kinesis

The process in some lower animals where light intensity controls the speed of locomotion.

Anemophily

The term for wind-mediated pollination, accounting for approximately $18\%$ of total pollination worldwide.

Abrasion

A component of weathering where sand particles carried by high-speed wind collide with rocks or leaf surfaces, causing physical damage.