APES Midterm Review

Unit 1: The Living World: Ecosystems

1. Ecological Relationships and Competition

   • Symbiosis: A close, long-term interaction between two different species (Mutualism, Commensalism, Parasitism).

   • Competition: Struggle between organisms for resources.

     • Interspecific: Between different species.

     • Intraspecific: Between individuals of the same species.

   • Resource Partitioning: Process where species utilize different portions of a resource to reduce competition and allow coexistence.

   • Predation: Interaction where a predator kills and eats prey.

2. Trophic Levels and Functional Roles

   • Autotrophs: Produce food via photosynthesis or chemosynthesis.

   • Carnivores: Consume other animals.

   • Detritivores: Feed on dead organic material (nutrient cycling).

   • Scavengers: Consume decaying biomass.

   • Generalists vs. Specialists: Generalists have varied diets; specialists have specific niches.

3. Biomes and Cycles

   • Biomes: Large ecological areas defined by flora, fauna, and distinct rainfall/temperature patterns aligned with latitudinal bands.

   • Freshwater vs. Marine: Distinctions based on salinity, biodiversity, and habitat.

   • Biogeochemical Cycles:

     • Carbon Cycle: Exchange between biosphere, geosphere, hydrosphere, and atmosphere (photosynthesis, respiration, combustion).

     • Phosphorus Cycle: Movement through lithosphere and hydrosphere via weathering; no atmospheric phase.

     • Nitrogen Cycle: Fixation, nitrification, assimilation, ammonification, and denitrification.

Unit 2: The Living World: Biodiversity

1. Biodiversity Metrics

   • Levels: Genetic, Species, and Ecosystem diversity.

   • Species Evenness: Distribution of species in a community.

   • Species Richness: Total number of species; indicates stable ecosystems.

2. Ecosystem Services

   • Provisioning: Products like food and water.

   • Regulating: Climate and waste regulation.

   • Cultural: Recreational or spiritual benefits.

   • Supporting: Basic processes like nutrient cycling.

3. Island Biogeography

   • Theory: Predicts species richness based on island size (area) and distance from the mainland (isolation).

Unit 3: Populations

1. Population Dynamics

   • Survivorship Curves:

     • Type I: High survival until old age.

     • Type II: Constant mortality.

     • Type III: High early mortality.

   • Carrying Capacity ($K$): Maximum population size an environment can sustain; identified as the plateau phase in logistic growth.

   • Malthusian Theory: Population grows exponentially while resources grow arithmetically, leading to scarcity.

2. Human Population and Demographics

   • Age Structure Diagrams: Shapes include Pyramidal (rapid growth), Columnar (stable), and Inverted Pyramid (declining).

   • Demographic Transition Model:

     • Stage 1: High birth/death rates.

     • Stage 2: Death rates fall (growth).

     • Stage 3: Birth rates fall.

     • Stage 4: Low birth/death rates (stable/declining).

   • Replacement Fertility: Level to replace a generation; approximately $2.1$ in developed nations.

Unit 4: Earth Systems and Resources

1. Atmospheric and Solar Patterns

   • Earth's Tilt: Responsible for seasons based on the angle of direct sun rays.

   • El Niño and La Niña: Oscillations in Pacific ocean temperatures affecting global weather.

   • Orographic Effect: Rainshadow effect where windward sides of mountains get rain and leeward sides remain dry.

2. Soil and Water

   • Soil Classification: Uses the Soil Triangle (sand, silt, clay percentages).

   • Properties: Retention, drainage, and waterlogging potential.

   • Freshwater Reserves: Stored in ice (majority), groundwater, lakes/rivers, and the atmosphere.

Unit 5: Land and Water Use

1. Resource Management

   • Tragedy of the Commons: Overexploitation of shared resources (e.g., overfishing, deforestation).

   • Clear Cutting: Increases soil erosion and sedimentation in water.

   • Soil Erosion: Linked to plant removal; leads to fertility loss.

2. Agriculture

   • Tilling: Traditional vs. No-Till impacts on soil health and moisture.

   • Fertilizers: Synthetic (fast, high runoff) vs. Organic (slow, improves soil structure).

Unit 8: Aquatic and Terrestrial Pollution

1. Cultural Eutrophication

   • Process: Excess nutrients (fertilizer runoff) lead to algal blooms, hypoxia, and "dead zones" (e.g., Gulf of Mexico).

Unit 9: Global Change

1. Conservation and Protection

   • Ozone Layer: Located in the stratosphere; protects from UV radiation.

   • Invasive Species: Traits include fast growth, high reproduction, and lack of natural predators.

   • CITES Treaty: Regulates international trade of endangered species.

   • Conservation Landscaping: Use of native plants and xeriscaping to support local ecosystems.

Scientific Foundations

1. Experimental Design

   • Components: Control groups, independent variables, and dependent variables.

   • Data Interpretation: Understanding correlation vs. causation in graphs/tables.