Overview
This lecture introduces the basics of ecology, including key definitions, ecological terms, abiotic and biotic factors, soil types, organism adaptations, and factors affecting species distribution.
Recap: Classification Basics
- Classification is the process of grouping organisms; types include artificial, natural, and phylogenetic.
- Artificial classification may lead to inaccuracies (e.g., dolphins and sharks grouped by appearance).
- Hierarchy: Kingdom, Phylum, Class, Order, Family, Genus, Species (mnemonic: "King Philip Came Over For Good Soup").
- Scientific names use genus and species for universal identification.
- Five kingdoms: Plantae, Animalia, Fungi, Protista, Monera (viruses are not a kingdom).
Introduction to Ecology
- Ecology is the study of interactions between living organisms and their physical environment.
- Key aims: Define ecology, distinguish population/community and niche/habitat, list and explain abiotic/biotic factors.
Fundamental Ecological Terms
- Population: All members of one species in a specific area.
- Community: Different populations living together in an area.
- Species: Group able to interbreed and produce fertile offspring.
- Niche: The role or job of an organism in its ecosystem.
- Habitat: The place where an organism lives.
- Biosphere: Regions of Earth where life exists.
- Environment: All surroundings, including living (biotic) and non-living (abiotic) components.
- Ecosystem: Interaction between biotic and abiotic components.
Abiotic Factors Affecting Ecosystems
- Abiotic factors are non-living physical/chemical factors like light, temperature, moisture, soil, minerals, gases, and pH.
- These are also called limiting factors as they determine which organisms can survive in an area.
- Examples: Water availability and soil fertility influence plant diversity; extreme temperatures, oxygen levels, and dryness limit organism presence.
Soil Types and Their Impact
- Sandy soil: Large particles, low water/nutrient retention, not very fertile.
- Silt: Moderate particles, more fertile, good for crops.
- Clay: Tiny particles, holds water, prone to waterlogging.
- Loam: Mix of sand, silt, clay; very fertile and ideal for agriculture.
- Soil components: Organic matter (humus), minerals, living organisms, water, and air.
Plant and Animal Adaptations
- Xerophytes: Plants adapted to dry conditions (e.g., deserts).
- Halophytes: Plants adapted to salty soils (e.g., mangroves).
- Hydrophytes: Water plants.
- Mesophytes: Plants in moderate conditions.
- Mangroves: Prop roots for anchorage, breathing roots for oxygen, salt glands and sacrificial leaves for salt management.
- Freshwater fish excrete dilute urine; saltwater fish drink and excrete salt via gills and concentrated urine.
Biotic Factors Affecting Ecosystems
- Biotic factors are living components: food availability, competition, diseases, decomposers, predation.
- Competition affects access to resources and can cause migration.
- Decomposers recycle nutrients, supporting ecosystem fertility.
- Predation influences species diversity and population sizes.
Key Terms & Definitions
- Ecology — study of how organisms interact with each other and their environment.
- Population — all individuals of one species in a given area.
- Community — multiple populations living in the same area.
- Niche — role/job of an organism in its environment.
- Habitat — the physical place where an organism lives.
- Abiotic factors — non-living environmental factors.
- Biotic factors — living components of the environment.
- Mangroves — halophyte plants adapted to saline, waterlogged environments.
Action Items / Next Steps
- List three methods used by ecologists to trap organisms for study.
- List two sampling methods for distribution of organisms.
- State two pros and cons for one sampling method.
- Review and study all terms and concepts from this session.