APES Midterm Study Guide

APES First Semester Final Concept Guide

Environmental Science Overview

  • Abiotic Factors: Non-living components of ecosystems (e.g., water, temperature, soil).

  • Biotic Factors: Living organisms and their interactions in ecosystems (e.g., plants, animals).

  • Sustainability: The ability to meet the needs of the present without compromising future generations.

  • Biodiversity: The variety of life in the world or in a particular habitat.

Population Dynamics

  • Anthropogenic: Refers to environmental changes caused or influenced by human activities.

  • Scientific Method: A systematic approach for investigating phenomena, acquiring new knowledge, or correcting and integrating previous knowledge.

  • Systems Approach: A way of understanding complex environmental issues by considering interactions within and between components.

Environmental Science Principles

  • Radioisotopes: Isotopes that emit radiation and are used in various applications, including medical and environmental studies.

  • pH: Measure of acidity or alkalinity of a solution, on a scale from 0-14.

  • Ocean Acidification: Caused by increased CO₂ absorption by seawater, leading to harmful effects on marine life.

  • Positive Feedbacks: Processes that amplify the effects of a change (e.g., melting ice reducing albedo).

  • Negative Feedbacks: Processes that counteract a change, leading to stability (e.g., body temperature regulation).

Energy Principles

  • 1st Law of Thermodynamics: Energy cannot be created or destroyed, only transformed.

  • 2nd Law of Thermodynamics: In any energy transfer, energy becomes more disordered (increased entropy).

  • Calculating Energy Efficiency: Formula can include the input/output ratio of energy.

  • Entropy: A measure of disorder; systems tend toward increased entropy over time.

Ecology and Energy Flow

  • Trophic Levels: Hierarchical levels in an ecosystem, comprised of producers, primary consumers, secondary consumers, etc.

  • Gross Primary Productivity (GPP): The total amount of energy captured by photosynthesis in an ecosystem.

  • 10% Rule: Only about 10% of the energy from one trophic level is available to the next level.

Key Processes in Ecology

  • Cell Respiration: The process by which organisms convert glucose and oxygen into energy.

  • Photosynthesis: The process by which plants use sunlight to synthesize foods from carbon dioxide and water.

  • Hydrological Cycle: The continuous movement of water on, above, and below the surface of the Earth.

  • Carbon Cycle: The cycle through which carbon is exchanged among the biosphere, atmosphere, oceans, and geosphere.

  • Nitrogen Cycle: The series of processes by which nitrogen and its compounds are interconverted in the environment and in living organisms.

  • Phosphorus Cycle: The movement of phosphorus through the lithosphere, hydrosphere, and biosphere.

  • Eutrophication: Nutrient enrichment of water bodies, leading to excessive growth of algae and subsequent oxygen depletion.

  • Sulfur's Role: Involved in acid rain and the formation of sulfates that affect air quality and ecosystems.

Watersheds and Disturbance

  • Watersheds: An area of land that drains into a river or lake.

  • Intermediate Disturbance Hypothesis: Biodiversity is maximized when ecological disturbances occur at a moderate frequency and intensity.

  • Layers of the Atmosphere: Includes the troposphere, stratosphere, mesosphere, thermosphere, and exosphere based on temperature gradients.

  • Albedo Effect: The reflection of solar radiation by the surface of the Earth; changes can affect climate.

  • Factors Determining Climate:

    • Temperature

    • Precipitation

Climate and Ecosystems

  • Adiabatic Cooling/Heating: The change in temperature of air when it expands or is compressed without heat exchange.

  • Rain Shadow Effect: A region having little rainfall because it is sheltered from prevailing rain-bearing winds by hills.

  • Species Richness: The number of different species in a given area.

  • Species Evenness: The relative abundance of different species in a given area.

Genetic Variation in Populations

  • Founders Effect: Reduced genetic diversity that occurs when a new population is established by a small number of individuals.

  • Genetic Drift: Random fluctuations in allele frequencies in a small population.

  • Bottleneck Effect: A sharp reduction in the size of a population due to environmental events.

  • Artificial Selection: The intentional breeding of organisms for desired traits.

  • Mutations: Changes in genetic material that can lead to new traits.

  • Adaptations: Traits that improve an organism's ability to survive and reproduce in a particular environment.

  • Allopatric Speciation: The evolution of species due to geographic isolation.

  • Sympatric Speciation: Speciation that occurs without physical separation.

  • Niche Specialist: A species that has a narrow ecological niche.

  • Niche Generalist: A species that can thrive in a wide variety of environmental conditions.

Resource Management and Population Studies

  • Resource Partitioning: Different species utilizing the same resource in different ways to reduce competition.

  • Density-Dependent Factors: Factors that increase in intensity as population density increases (e.g., competition).

  • Density-Independent Factors: Factors that affect population size regardless of density (e.g., natural disasters).

  • Population Growth Rate: The rate at which the number of individuals in a population increases in a given time.

  • Rule of 70: A mathematical formula used to estimate the doubling time of a population (doubling time in years = 70/growth rate).

  • Carrying Capacity: The maximum population size that an environment can sustain indefinitely.

  • Logistic Growth Curve: A model of population growth that describes slow growth when a population size is small, rapid growth when the population size is moderate, and level-off as the population approaches carrying capacity.

  • Exponential Growth Curve: A model where the growth rate of a population accelerates over time in ideal conditions.

  • Survivorship Curves: Graphs depicting the number of survivors over time for a given species, indicating mortality rate.

  • r/K Selected Species: Differentiation between species that reproduce quickly in unstable environments (r) and those that reproduce slowly and are more stable (K).

Interactions and Community Ecology

  • Types of Symbiosis:

    • Mutualism: Both species benefit.

    • Commensalism: One species benefits while the other is unaffected.

    • Parasitism: One species benefits at the expense of the other.

  • Keystone Species: A species that has a disproportionately large impact on its environment relative to its abundance.

  • Succession: The process of change in the species structure of an ecological community over time.

  • Total Fertility Rate (TFR): The average number of children born to a woman over her lifetime.

  • Replacement Level Fertility: The level of fertility at which a population exactly replaces itself from one generation to the next.

Migration and Demographics

  • Immigration/Emigration: The movement of individuals into or out of a population.

  • Age Structure Diagrams: Graphs that show the distribution of various age groups in a population.

  • Population Momentum: The tendency for a population to continue to grow after a fertility decline.

  • Demographic Transition: The transition from high birth and death rates to lower birth and death rates as a country develops.

Geological and Soil Science

  • Rock Cycle: The series of processes that change rocks from one type to another through melting, cooling, erosion, and pressure.

  • Plate Tectonic Theory: The theory that the Earth's lithosphere is divided into tectonic plates that move on the asthenosphere.

  • Divergent Boundaries: Areas where tectonic plates move apart, leading to the creation of new crust.

  • Convergent Boundaries: Areas where tectonic plates collide, leading to subduction or mountain building.

  • Soil Texture Chart: A tool used to assess the texture of soil based on the proportion of sand, silt, and clay.

  • Soil Erosion: The wearing away of the topsoil due to factors like water, wind, and human activity.

  • Soil Horizons: Layers of soil that differ in composition, texture, and color.

  • Soil Particle Size: Classifications of soil particles into sand, silt, and clay based on size.

Environmental Issues

  • Acid Mine Drainage: Water pollution caused when sulfuric acid and dissolved iron from mining operations flow into nearby waterways.

  • Surface Mining Reclamation Act: Legislation requiring the restoration of land disturbed by mining.

  • Water Table: The level below which the ground is saturated with water.

  • Ogallala Aquifer Issues: Over-extraction and depletion of this crucial water resource affecting agriculture and communities.

  • Levees vs Dikes: Structures built to control water flow; levees are often built alongside rivers while dikes protect land against flooding from the ocean.

  • Water Diversion: The process of redirecting water from one location to another, often for agricultural, industrial, or urban use.

  • Domestic Water Use: The consumption of water by households for cooking, cleaning, bathing, and irrigation.

  • Klamath River Issues: Conflicts over water use impacting agriculture, fish populations, and indigenous communities.