SCX 010: Environmental Science Module 9 Quiz & Flashcards

Study Notes

Biotic: Includes producers (plants), consumers (animals), and decomposers (bacteria, yeast, fungi).
Abiotic: Physical and chemical factors that influence biotic components.

Producers (Autotrophs): Capture solar energy to produce food from organic and inorganic materials.
Consumers (Heterotrophs): Rely on autotrophs for food; categorized into:
- Herbivores: Plant eaters.
- Carnivores: Flesh eaters.
- Omnivores: Eat both plants and animals.
Decomposers: Break down dead matter, recycling nutrients back into the ecosystem.

Ecosystems are organized into biomes, large ecological zones defined by dominant vegetation and climate.
Types of Biomes:
- Tundra: Characterized by long winters and short summers.
- Taiga: Features poor soil and a short growing season.
- Temperate Deciduous Forest: Hot summers, cold winters, and rich soil.
- Tropical Rainforest: Warm temperatures and abundant moisture.
- Grassland: Suitable for crops with distinct seasonal temperature changes.
- Desert: Dry climate with minimal plant life.

Freshwater: Includes standing (lentic) and flowing (lotic) water.
Marine: Consists of oceanic environments with zones defined by depth (e.g., benthic zones).

Producers (Base): Fundamental organisms like plants and algae that perform photosynthesis.
Primary Consumers (Second Level): Herbivores like rabbits and deer that consume producers.
Secondary Consumers (Third Level): Carnivores that feed on primary consumers (e.g., foxes).
Tertiary Consumers (Fourth Level): Top carnivores preying on secondary consumers (e.g., hawks).
Terminal Consumers (Top Level): Apex predators, facing minimal natural threats.

Energy Loss: Approximately 90% of energy is lost at each trophic level due to metabolic processes.
Decreasing Biomass: Relative living matter diminishes as one ascends the pyramid.
Limited Levels: Typically, ecosystems sustain only 4-5 trophic levels due to energy loss constraints.

Linear Pathway for Energy Flow: Shows direct energy movement from producers to consumers.
Example: Grass → Grasshopper → Frog → Snake → Hawk.
Food Webs: Complex interconnections of food chains that represent true energy dynamics in ecosystems.

Grazing Food Chain:
- Begins with producers and progresses to herbivores and then carnivores (e.g., corn → caterpillar → chicken).
Detrital Food Chain:
- Starts with decomposed organic material and includes detritivores (e.g., dead leaves → earthworms → chicken).
Food Web Organizations:
- Grazing Web: Initiates with photosynthetic organisms.
- Detrital Web: Commences from organic detritus.

Hierarchical levels based on feeding relationships:
- First Level: Primary producers (plants).
- Second Level: Herbivores (primary consumers).
- Third Level: Carnivores (secondary consumers).
- Fourth Level: Tertiary consumers feeding on other carnivores.
Decomposers: Recycle nutrients based on the type of organic material encountered.