APES U4

Carbon Cycle

Photosynthesis

Respiration

Decomposition

Long-term storage

Combustion

Ocean exchange

Nitrogen Cycle

Nitrogen fixation – Atmospheric N₂ is converted into ammonia (NH₃) or similar usable forms by bacteria or lightning.

Nitrification – Ammonia is converted to nitrites (NO₂⁻) and then to nitrates (NO₃⁻) by soil bacteria.

Assimilation – Plants absorb nitrates and build organic nitrogen; animals get it by eating plants.

Ammonification (decomposition) – Decomposers turn organic nitrogen from dead matter/waste back into ammonia.

Denitrification – Specialized bacteria convert nitrates back into N₂ gas, returning it to the atmosphere.

Phosphorus Cycle

Weathering of rocks

Uptake by plants

Animals get phosphorus by eating plants or other animals.

Decomposition – decomposers return phosphate to the soil or water.

Runoff & sedimentation

Water Cycle

Evaporation

Transpiration – Plants release water vapor from leaves.

Condensation

Precipitation – Water returns to Earth as rain/snow.

Infiltration/Runoff – Water soaks into ground (groundwater) or runs over land into bodies of water.

carbon sources and sinks

Carbon sources: respiration, decomposition, combustion

Carbon sinks: photosynthesis, ocean uptake, fossil fuels

Nitrogen sources and sinks

Nitrogen sources: nitrogen fixation, lightning, fertilizer production, decomposition

Nitrogen sinks:, soil organic matter, denitrification

Phosphorous sources and sinks

Phosphorus sources: rock weathering, decomposition, fertilizer runoff

Phosphorus sinks: plant uptake, soil storage, sediments, rock formation

Water sources and sinks

Water sources: evaporation, transpiration

Water sinks: oceans, glaciers, groundwater, lakes, soil

Population vs. Community

Pop - Group of individuals of same species at same time and place

Community - All the different pops of different species

Biotic vs Abiotic Factors

Abiotic - Nonliving factors that influence living organisms

Biotic - All the living organisms in an ecosystem that interact with one another

Range of tolerance

Range of conditions within which a species can survive grow and reproduce

Limiting Factors

Any biotic or abiotic factor that restricts growth of a pop

Food Chain

A linear sequence showing how energy and nutrients pass from one organism to another in an ecosystem

Food Web

A complex network of interconnected food chains showing all feeding relationships in an ecosystem

Energy Flow

The one-way movement of energy through an ecosystem from producers to consumers and decomposers

Tropic Levels

producers → primary consumers → secondary consumers → tertiary consumers → decomposers

Producer example

Grass, algae

Primary Consumer example

Grasshoppers, rabbits

Secondary Consunmer example

Frogs, small fish

Tertiary Consumer example

Hawks, lions

Decomposers example

Fungi

Ecological efficiency

percentage of energy transferred from one trophic level to the next

10% Rule

only 10% of energy is avalible to the next tropic level

10% rule formula

Ecological Efficiency: \frac{Energy_{}athigherlevel}{Energyatlowerlevel}\cdot100

GPP

Total energy captured by producers, represents all energy produced

NPP

Energy remaining after producers use some for respiration (R)

NPP = GPP-R

C and E of EL Nino

Causes: Weakened trade winds, pressure changes

Effects: Lower fish pops, reduced amounts of nutrient rich water, crop failures, increased risk of disease outbreaks

Genetic Biodiversity

Variation of genes within a species

Species Biodiversity

Variety of species in a particular ecosystem or globally

Ecosystem Diversity

Variety of ecosystems in a region or the planet

Species Richness

The number of different species present in a given area or ecosystem

Demographic Bottleneck

A sharp reduction in the population size of a species due to environmental events or human activities, leading to reduced genetic diversity

Island Biogeography

Larger island - more species, lower extinction rates

Islands closer to mainland - more species

Species Equlibrium - Species richness reaches a equlibrium, immigration rate - extinction rate

Symbiosis Types

• Mutualism: +/+

• Commensalism: +/0

• Parasitism: +/–

• Amensalism: –/0

• Neutralism: 0/0

Resource Partitioning

similar species coexist in the same habitat by dividing resources so they don’t directly compete

Describe Competitive Exclusion Principle

two species competing for the same limited resource cannot coexist indefinitely in the same niche

Identify types of Survivorship curves

Calculate change in Population Growth

change in pop = (#BIRTHS-#DEATHS)+(#IMMIGRANTS-#EMIGRANTS)

Keystone Species

A species that has a large effect on its ecosystem, disproportionate to its abundance

Indicator Species

A species sensitive to environmental changes, signaling ecosystem health

R-selected Species

Species that reproduce quickly, have many offspring, and little parental care

K-selected Species

Species that reproduce slowly, have few offspring, and high parental care

Characteristics of Successful Invasive Species

rapid repro, broad diet, tolerance to wide env conditions. areas w/low biodiversity more prone

Describe characteristics of species prone to extinction

Small pop size, small geographic area, specialized

Describe solutions to Endangered Species

Control of invasive species, habitat protection, captive breeding