Aquatic Biomes, Lakes, Rivers, and Atmosphere: Key Concepts for Ecology

What are the main components of aquatic biomes?

Antarctic, marine, lakes, wetlands, and rivers and streams.

How do aquatic organisms obtain nutrients?

From water.

What is the primary source of most of the world's rainfall?

Evaporation of seawater.

What percentage of Earth's surface do oceans cover?

Approximately 75%.

What is the salt concentration of oceans?

About 3%.

What is the role of marine algae and photosynthetic bacteria in oceans?

They absorb carbon dioxide and produce oxygen.

What are lakes primarily formed by?

Precipitation, runoff, or groundwater seepage filling depressions.

What are the four processes that can form lakes?

Glacial activity, volcanic craters, erosion in river valleys, and tectonic uplift.

What is the Benthic Zone of a lake?

The bottom of the lake, where organisms tolerate cool temperatures and low oxygen.

What characterizes the Limnetic Zone of a lake?

A well-lit, open surface water area occupied by phytoplankton and zooplankton.

What is the difference between Oligotrophic, Mesotrophic, and Eutrophic lakes?

Oligotrophic lakes are nutrient-poor; Mesotrophic lakes have moderate nutrients; Eutrophic lakes are nutrient-rich.

What is Eutrophication?

The process where nutrient runoff causes excessive algae growth, leading to low oxygen levels.

What causes thermal stratification in lakes?

Density changes due to temperature shifts, leading to distinct layers of water.

What is the hypolimnion in a lake?

The lower layer of water that is cool, dense, and insulated from the sun.

What is the epilimnion in a lake?

The surface layer of water that is warmed by the sun and less dense.

What factors determine the nutrient content of rivers and streams?

Terrain, vegetation, adjacent vegetation, weathering of rocks, and soil erosion.

What is Nitrogen Fixation?

The conversion of atmospheric nitrogen into ammonia or nitrate ions, usable by plants.

What is the role of legumes in the nitrogen cycle?

They are key participants in nitrogen fixation.

What is the 10% Rule in ecological pyramids?

Only about 10% of energy is transferred from one trophic level to the next.

What is productivity in an ecosystem?

The rate of generation of biomass, expressed in mass per unit area per unit time.

What happens to the majority of solar energy that reaches Earth?

35% heats water, land, and evaporates water; 15% is reflected back into space.

What is the significance of the stratification of water in lakes?

It affects temperature, oxygen levels, and the types of organisms that can thrive.

What are artificial lakes constructed for?

Hydroelectric power, recreation, industrial use, and domestic water supply.

What is the profundal zone in a lake?

Deep, no-light regions too dark for photosynthesis, inhabited by fish adapted to cool waters.

What is the Littoral Zone of a lake?

Shallow areas close to shore where rooted and floating plants flourish.

What is the primary role of decomposing bacteria in the nitrogen cycle?

To convert dead organisms and wastes back into ammonia and ammonium ions.

What is denitrification?

The process by which anaerobic bacteria convert ammonia into nitrogen gas and nitrous oxide.

How does burning fossil fuels reduce biodiversity?

It produces acid rain that alters the pH of water habitats, making them uninhabitable for many species.

What are some remediation strategies for the impact of burning fossil fuels?

Enact carbon taxes, require scrubbers for industries, provide tax incentives for renewable energy, and promote the use of renewable energy sources.

How does deforestation affect biodiversity?

It reduces the quality and quantity of suitable habitats for many species of flora and fauna.

What can be done to remediate the effects of deforestation?

Replanting trees and using selective cutting methods.

What is the impact of modern industrial agriculture on biodiversity?

It involves monoculture, which reduces genetic diversity and habitat quality.

How can modern industrial agriculture be remediated?

Implement crop rotation, intercropping, organic farming, polyculture, and polyvarietal cultivation.

What are the consequences of overfishing on biodiversity?

It threatens keystone species and can lead to the extinction of endangered species.

What measures can be taken to combat overfishing?

Enforce international treaties, establish fishing quotas, and tighten enforcement of the Endangered Species Act.

How do pesticides affect biodiversity?

They kill both pests and beneficial organisms indiscriminately.

What remediation techniques can be used regarding pesticide use?

Require integrated pest management techniques.

What is the impact of genetically modified organisms (GMOs) on biodiversity?

GMOs decrease genetic variation necessary for species to adapt to environmental changes.

What regulations can be implemented for GMOs?

Require labeling, sterile GMO crops, and rigorous testing before approval.

How does water pollution affect biodiversity?

It can lead to high nutrient levels or low dissolved oxygen levels, which can be lethal to aquatic species.

What remediation methods can be used to address water pollution?

Require secondary and tertiary treatment methods for water treatment plants and promote the use of recycled water.

What does the Theory of Island Biogeography propose?

The number of species on an island is determined by immigration and extinction rates of isolated populations.

What factors influence Island Biogeography?

Degree of isolation, habitat fragmentation, habitat suitability, climate, initial species composition, and human activity.

What are generalist species?

Species that can live in various environments and have varied diets, such as raccoons.

What are specialist species?

Species that require unique resources and have a limited diet, like the giant panda which primarily eats bamboo.

What are r-selected species?

Species that produce many offspring, have low parental care, and mature rapidly, often found in unstable environments.

What are K-selected species?

Species that have few offspring, high parental care, and mature slowly, typically found in stable environments.

What is carrying capacity (K)?

The maximum number of individuals that an environment can sustainably support, which can change over time.

What are regulating factors that maintain population sizes at carrying capacity?

Sunlight availability, food availability, nutrient levels, oxygen content, and space.

What does a pyramid-shaped age-structure diagram indicate?

High birth rates with a majority of the population in the reproductive age group.

What does a bell-shaped age-structure diagram indicate?

Pre-reproductive and reproductive age groups are nearly equal, characteristic of stable populations.

What does an urn-shaped age-structure diagram indicate?

The post-reproductive group is largest and the pre-reproductive group is smallest, indicating declining populations.

What is demographic transition?

The shift from high birth and death rates to lower rates as a country develops from pre-industrial to industrialized.

What characterizes Stage 1 of demographic transition?

High birth and death rates due to poor living conditions and scarce food, resulting in low population growth.

What characterizes Stage 2 of demographic transition?

Rapid population increase due to lower death rates from improved hygiene, medical advances, and sanitation.

What characterizes Stage 3 of demographic transition?

Urbanization and economic pressures reduce birth rates, leading to population stabilization.

What characterizes Stage 4 of demographic transition?

Population growth is zero as birth and death rates equalize, with a high standard of living.

What characterizes Stage 5 of demographic transition?

Death rates exceed birth rates, leading to population decline, common in some European and East Asian countries.

What does the plate tectonic theory state?

Earth's lithosphere is divided into plates that float on the mantle, with seismic activity occurring at their boundaries.

What is a subduction zone?

A region where one tectonic plate moves underneath another.

What forms when a denser oceanic plate subducts a less dense continental plate?

An oceanic trench on the ocean side and a mountain range on the continental side.

What is a divergent boundary?

A boundary where two tectonic plates slide apart from each other, creating fault zones and oceanic earthquakes.

Give an example of an oceanic divergent boundary.

Mid-Atlantic Ridge.

What occurs when two oceanic plates converge?

An island arc is formed, which is a curved chain of volcanic islands.

What is a transform boundary?

A boundary where tectonic plates slide past each other, often causing earthquakes.

Provide an example of a transform boundary.

The San Andreas Fault.

What are the three main ingredients of soil?

Minerals, open spaces for air or water, and organic materials.

What is the surface litter in soil?

Leaves and partially decomposed organic debris.

What is topsoil?

The upper layer of soil rich in organic matter, living organisms, and inorganic materials.

What happens in the zone of leaching?

Dissolved and suspended materials move downward through the soil.

What is subsoil characterized by?

A yellowish color due to accumulated iron, aluminum, and clay.

What is soil erosion?

The movement of weathered rock and soil components caused by water, wind, and human activity.

What are some poor agricultural techniques that lead to soil erosion?

Improper plowing, monoculture, overgrazing, and removing crop wastes.

What is loam?

A soil mixture of clay, sand, silt, and humus, rich in nutrients and good for water retention.

What is humus?

The dark organic material in soil formed from decayed plant and animal matter.

What role do earthworms play in soil?

They help mix humus with minerals, improving soil structure and nutrient availability.

What is nitrogen's role in living organisms?

It is a fundamental nutrient found in amino acids and nucleic acids, making up about 3% of the human body.

What is the troposphere?

The lowest layer of Earth's atmosphere, where weather occurs and most of the atmosphere's mass is found.

What is the stratosphere known for?

It contains the ozone layer, which absorbs ultraviolet radiation from the sun.

What is the mesosphere?

The third layer of the atmosphere, known as the coldest layer where many meteoroids burn up.

What happens in the thermosphere?

It is extremely hot and contains the ionosphere, where satellites orbit due to low air density.

What is the exosphere?

The outermost layer of Earth's atmosphere, where atmospheric particles are extremely sparse.