Ecosystem Ecology: Biotic and Abiotic Factors

Ecosystems

• An ecosystem involves the interaction of biotic organisms and abiotic components.

Biotic and Abiotic Factors

• Biotic Factors include living components; plants, animals, and microorganisms.
• Abiotic Factors include non-living components; sunlight, water, soil, and temperature.

Overview of Ecosystem Ecology

• Ecology is the study of organisms and their relationships with the environment.
• Ecosystem ecology studies interactions among living and non-living things in an ecosystem.

Aspects of the Ecosystem

• Structural aspects concern the arrangement, species types, and life histories.
• Functional aspects cover energy flow and material cycling.

Characteristics of an Ecosystem

• A major structural and functional unit of ecology.
• The structure directly relates to species diversity.
• Energy requirements depend on the ecosystem's structure.
• Energy flow and material cycling dictate the ecosystem's function.
• Ecosystems develop to be more complex over time.
• Environmental factors and energy fixation face limitations.
• Organisms are required to adapt to alterations in their environments.

Components of an Ecosystem

• Solar Energy acts as the main source of energy.
• Producers transform energy into food, like plants.
• Consumers ingest either producers or other consumers.
• Decomposers break down organic material from dead organisms.
• Nutrients are key in life cycles.

Relationships Among Organisms

• Competition is a key relationships among organisms.
• Neutralism is a key relationships among organisms.
• Protocooperation & mutualism are also relationships among organisms.

Levels of Ecological Organization

• The levels of organization include; Organism, Population, Community, Ecosystem, and Biosphere.

Ecosystem Structure and Functioning

• Ecological processes are regulated and provided with stability.
• Nutrients are put through cycles between biotic and abiotic components.
• A balance is maintained among trophic levels.
• Minerals go through cycles throughout the biosphere.
• Abiotic components assist with organic synthesis.

Types of Ecosystems

• Forests and grasslands are examples of terrestrial ecosystems.
• Freshwater and marine are examples of aquatic ecosystems.

Ecosystem Disturbances & Change

• Ecosystem disturbances are events that disrupt ecosystems.
• Ecosystem change involves altering the structure and function of an ecosystem.

Earth's Formation

• Earth was formed 4.6 billion years ago from dust and gas around the Sun.
• A distant star's explosion and collapse prompted Earth's formation.
• Earth is the 3rd planet from the sun in the solar system.
• Earth is noted as one of the four terrestrial planets, alongside Mercury, Venus, and Mars.
• Earth cooled for millions of years, allowing oceans to form after an initial unrecognizable and hot state.

Accretion

• During Earth's early formation, a protoplanet collided with it.
• Asteroids bombarded the planet, influencing its current structure.

Geocentric Theory (Ptolemy, 150 CE)

• Claudius Ptolemy proposed the geocentric theory.
• Earth is the universe's center, according to this theory.
• The Sun, Moon, stars, and planets travel in circular paths around Earth.
• This was the main belief for about 1,400 years.

Heliocentric Theory (Copernicus, 1543)

• Nicolaus Copernicus proposed the heliocentric theory.
• The Sun is at the center of the solar system, as per this theory.
• All planets, including Earth, orbit the Sun.
• Planetary motion was explained better in this model compared to the geocentric one.

Big Bang Theory

• The Big Bang Theory is the most accepted theory for the universe's origin.
• The universe came into being 13.7 billion years ago from a hot, dense point.
• Since its formation, the universe has been constantly expanding.

Earth's Atmosphere Layers

• Troposphere: Contains weather and greenhouse gases, nearest layer to Earth.
• Stratosphere: Contains the ozone layer.
• Mesosphere: Meteors burn up in this layer.
• Thermosphere: Auroras take place here.
• Exosphere: Outermost layer that fades into space.

Earth's Hydrosphere: Types of Water

• Oceans are the largest water bodies.
• Freshwater is found in lakes, rivers, and streams.
• Groundwater is water stored underground.
• Glacial water is ice from melting glaciers.
• Atmospheric Water Vapor is water in the air.

Continents

• Asia is the largest continent and home to Mount Everest.
• Africa contains the Sahara Desert and the Nile River.
• North America includes the Rocky Mountains.
• South America is home to the Amazon Rainforest and Andes Mountains.
• Antarctica is the coldest and driest continent.
• Europe is surrounded by water on three sides.
• Australia is the smallest and driest continent.

Major Oceans

• The Pacific Ocean is the largest and deepest.
• The Atlantic Ocean is the second largest and rich in marine life.
• The Indian Ocean is the warmest ocean basin.
• The Southern Ocean surrounds Antarctica.
• The Arctic Ocean is the smallest and coldest.

Continental Drift and Pangaea

• Alfred Wegener proposed the Continental Drift Theory in 1912.
• All continents were once a single landmass named Pangaea.
• Pangaea divided into Laurasia (North) and Gondwana (South) over time.
• Continents are still moving because of plate tectonics.

Evidence of Continental Drift

• Continents seem to fit together like puzzle pieces.
• Similar species fossils exist across different continents.
• Comparable rock formations and mountain ranges occur across continents.

Plate Tectonics

• Plate tectonics explains the lithosphere as broken into tectonic plates moving over the asthenosphere.
• Plates are enabled to float and glide due to convection currents in the mantle.

Seafloor Spreading Hypothesis (Harry Hess, 1960s)

• New ocean floor is created where plates separate at mid-ocean ridges.
• Mid-ocean ridges consist of underwater mountain chains where magma cools and forms new crust.

Types of Plate Boundaries

• Convergent boundaries happen where plates collide, resulting in subduction and mountain formation.
• Divergent boundaries occur where plates separate, creating mid-ocean ridges and rift valleys.
• Transform boundaries are where plates slide past each other, forming faults and causing earthquakes.

Earth's Heat Engine

• Earth accumulates heat from its core and radioactive decay.
• Convection in the mantle is driven by heat, thus moving tectonic plates.

Mantle Plumes & Hotspots

• A mantle plume is a column of hot magma rising from deep within the mantle.
• A hotspot results as a surface area above a mantle plume where volcanic activity is present.

Earthquakes

• Tectonic earthquakes result from quick plate movements.
• Volcanic earthquakes are caused by magma movement.

Earthquake Terms

• Hypocenter: The underground origin of an earthquake.
• Epicenter: The surface location directly above the hypocenter.
• Foreshock: Minor tremors before a major earthquake.
• Mainshock: The most powerful earthquake in a series.
• Aftershock: Smaller earthquakes are known as smaller tremors that follow the main event.

Volcanoes

• A volcano is a mountain or hill made from lava, ash, and rock fragments from a volcanic vent.

Types of Eruptions

• Effusive eruptions mean lava flows steadily.
• Explosive eruptions include volcanoes that throw ash, gas, and rock.

Types of Volcanoes

• Active volcanoes have erupted or are erupting.
• Dormant volcanoes are inactive but may erupt again.
• Extinct volcanoes are not expected to erupt again.

Mountain Formation

• Orogeny is the process of mountain formation led by tectonic movements.
• Mountain Range are groups of mountains with similar structure.
• Mountain System is a collection of multiple mountain ranges.