ecological system (G3 REPORT)

ecological system

a community of living organisms interacting with each other and with their physical environment.

• freshwater environments

• marine ecosystems

• terrestrial ecosystems

types of ecological ecosystems

freshwater environment

These ecosystems are essential for sustaining life because they provide drinking water, irrigation, fisheries, and habitat for diverse plant and animal species.

• lentic ecosystem

• lotic ecosystem

• wetlands

• groundwater

types of freshwater environment

lentic ecosystems

include still or standing bodies of water such as lakes, ponds, and bogs. These systems support diverse aquatic life and may develop temperature layering that affects oxygen distribution.

lotic ecosystems

consist of flowing water systems such as rivers and streams. They are usually well-oxygenated and support organisms adapted to continuous water movement.

wetlands

are areas with high soil moisture where land is saturated or flooded either permanently or seasonally, including swamps and marshes. They function as natural water filters and help control flooding.

groundwater

refers to water stored beneath the Earth’s surface in underground aquifers. It serves as a major source of freshwater for domestic, agricultural, and industrial use.

• natural disturbances

• human-induced disturbances

types of disturbance

• floods

• drought

• typhoons and storms

• earthquakes

• volcanic eruptions

types of natural disturbances

• deforestation

• urbanization

• agriculture

• mining

• industrial activities

• overfishing

• dam construction

type of human-induced disturbances

• chemical pollution

• biological pollution

• physical pollution

• thermal pollution

• nutrient pollution

• oil pollution

types of pollution

chemical pollution

harmful substances dissolved in water

• fertilizers

• pesticides and herbicides

• industrial chemicals

• heavy metals

biological pollution

involves living organisms or organic waste that contaminate water:

• sewage and human waste

• harmful bacteria

• invasive species

physical pollution

s refers to solid materials that pollute water:

• plastic waste

• garbage and solid waste

• sediments

thermal pollution

Hot water released from factories or power plants increases water temperature, which lowers oxygen levels and affects aquatic organisms.

Nutrient Pollution (Eutrophication)

Excess nutrients from fertilizers cause rapid growth of algae (algal blooms). These blooms reduce oxygen levels in water and can lead to fish kills

Oil Pollution

Oil from boats or industrial spills can form a layer on the water surface, blocking oxygen and harming aquatic life.

marine ecosystem

a large, complex ecological system composed of saltwater environments such as oceans, seas, coral reefs, estuaries, and coastal areas.

• intertidal zone

• continental shelf

• pelagic realm

• benthic realm

• photic zone

• twilight zone (mesopelagic)

• aphotic zone

oceanic zones

intertidal zone

The area between high and low tide, exposed to air at times and submerged at others. Organisms here must withstand changing conditions like waves, drying, and salinity shifts.

continental shelf

The shallow, gently sloping extension of land under the ocean. It receives sunlight, making it rich in nutrients and home to diverse marine life such as plankton and corals.

pelagic realm

The open water column away from the shore and bottom. It supports free-swimming species like fish, turtles, and whales.

benthic realm

The ocean floor, ranging from shallow coastal areas to deep trenches. It hosts bottom-dwelling organisms such as sponges, sea cucumbers, and brittle stars.

photic zone

The sunlit upper layer of the ocean (to about 200 m). Photosynthesis occurs here, supporting phytoplankton and the majority of marine biodiversity.

twilight zone (mesopelagic)

Extends from 200 m to 1,000 m. Light is dim, limiting photosynthesis. Many organisms here are adapted to low light and pressure.

aphotic zone

Depths below 1,000 m where no sunlight penetrates. Life relies on adaptations like bioluminescence and feeding on detritus or other organisms.

• open ocean (pelagic zone)

• coral reefs

• estuaries

• mangrove forest

• intertidal zone

types of marine ecosystems

Open Ocean (Pelagic Zone)

Refers to the vast body of saltwater that extends beyond coastal areas. It is divided based on depth and light penetration.

• Deepest and largest marine system

• Limited nutrients in surface waters

• Supports plankton, fish, whales, and large predators

coral reefs

Coral reefs are underwater ecosystems built by colonies of tiny animals called coral polyps that secrete calcium carbonate.

• Found in shallow, warm waters

• Highly biodiverse

• Sensitive to temperature changes

estuaries

A coastal area where freshwater from rivers mixes with seawater.

• High nutrient levels

• Nursery grounds for fish and shellfis

• Highly productive ecosystems

mangrove forests

Mangroves are salt-tolerant trees and shrubs that grow along tropical coastlines.

• Protect coastlines from erosion

• Provide habitat for marine species

• Trap sediments and pollutants

intertidal zones

The area between high tide and low tide levels.

• Organisms must tolerate changing conditions

• Exposed to air during low tide

• Home to crabs, barnacles, sea stars

disturbance

is any temporary or permanent change in environmental conditions that disrupts ecosystem structure, function, or species composition.

• tropical storms and typhoons

• tsunamis

• volcanic activity

• climate variability

natural marine disturbances

• pollution

• overfishing

• coastal development

• climate change

human-induced marine disturbances

terrestrial ecosystem

essential for maintaining life on Earth, as they provide food, shelter, and regulate climate.

• forest

• grasslands

• tundra

• desert

types of terrestrial ecosystems

forest

They serve as a natural habitat for a vast range of living species and also comprise the highest species diversity.

grassland

the most dominant type of vegetation and these types of environments occur naturally in several parts of the world. These types of terrestrial ecosystems serve as a home for a wide diversity of animal species, such as elephants, giraffes, hyenas, jackrabbits, lions, rhinos, warthogs and zebras.

• tropical grasslands

• temperate grasslands

types of grasslands

tundra

which are characterized by harsh environmental conditions similar to deserts and are usually windswept, snow-covered and treeless.

desert

barren region of the landscape, which has extremely high or low temperatures and has scarce vegetation.