Ecology: Biosphere and Biomes Overview

Biosphere and Distribution of Life on Earth

• The biosphere is the thin outer layer of the Earth.
• The lithosphere is the rocky part of the Earth's surface.
• The hydrosphere is the water part of the Earth's surface.
• The atmosphere is the gaseous component of the Earth's surface.

Biome

• A biome is a geographic area notable for the species living there.
• A biome can be made up of many ecosystems.

Major Terrestrial Biomes

• Deciduous forests
• Coniferous forests
• Tropical rainforests
• Grasslands
• Tundra
• Deserts

Major Aquatic Biomes

• Deserts
• Fresh waters
• Marine waters
• Estuaries and Mangroves

Animal Distribution

• Animals have two primary ways to be distributed on Earth:
  • Dispersal: Population movement from one location to another
  • Vicariance: Separation of populations due to environmental and climate changes

Levels of Ecological Organization

• Ecosystem
• Community
  • Population
    • Organism

Ecology

• Ecology is the study of the relationship between organisms (plants and animals) in relation to their environment.
• The environment is the immediate surroundings of an organism.

Ecosystem Components

• The abiotic component of an ecosystem is characterized by its physical parameters.
• Abiotic components establish the basic nature of an ecosystem.

Abiotic Components

• Inorganic and organic compounds (e.g., water, nitrogen, and carbon cycles; carbohydrates, lipids, and proteins)
• Temperature
• Light
• Moisture
• Altitude

Biogeochemical Cycles

• Matter moves between ecosystems, biotic and abiotic environments, and organisms.
• Biogeochemical cycling involves biological, geologic, and chemical interactions.
• The five major biogeochemical cycles are those of Carbon, Nitrogen, Phosphorus, Sulfur and Water (Hydrologic).

Water Cycle

• The water cycle collects, purifies, and distributes water.
• Processes include: Evaporation, transpiration, condensation, precipitation, infiltration, and runoff.

Carbon Cycle

• Carbon is a basic constituent of organic compounds (carbohydrates, fats, proteins, and nucleic acids).
• Living organisms require carbon for respiration, assimilation, and photosynthesis.

Nitrogen Cycle

• Nitrogen accounts for almost 78% of the atmosphere.
• Nitrogen is essential for living organisms, particularly for proteins and nucleic acids.

Biotic Components

• Biotic components are the living parts of an ecosystem.
• Examples include: Cabbage, pepper, roly polys, spiders, crickets, worms, and bacteria.

Producers

• Producers are autotrophs, such as algae and green plants.
• They use sunlight for photosynthesis to create their own energy.

Consumers

• Consumers, also known as heterotrophs, get their energy from producers.
• Major consumer classes include herbivores, carnivores, omnivores, and detritivores.

Herbivores

• Herbivores are primarily consumers or plant-eaters.
• Examples include pandas, rabbits, deer, and grasshoppers.

Carnivores

• Carnivores are secondary consumers that feed directly on animals.
• Examples include bull sharks, Nile crocodiles, Gila monsters, and piranhas.

Omnivores

• Omnivores are tertiary-level consumers that feed on herbivores and carnivores.
• Examples include pigs and raccoons.

Detritivores

• Detritivores eat dead plants and animals (decomposers).
• Examples include worms, beetles, bacteria, and fungi.

Energy

• Energy flows into ecosystems as sunlight.
• Almost all life depends on the conversion of energy into organic compounds.

Production, Food Chain, Food Web and Trophic Level

• Production is the energy accumulated by plants during photosynthesis.
• Primary productivity is the rate of energy storage by plants.
• Gross productivity is the total rate of energy storage.
• Plant growth results in biomass accumulation (standing crop).

Food Chain

• A food chain describes how energy flows through an ecosystem.
• Plants are eaten by consumers, who are then eaten by other consumers.

Food Web

• A food web shows the interconnected relationships among various food chains.

Trophic Level

• Trophic level is a step in a food chain.
• It represents the organism's feeding level in a food chain.

Community

• A community is the biotic portion of an ecosystem.
• It consists of populations of interbreeding organisms of the same species.

Ecological Dominance

• A community is usually dominated by a single group of species.
• Dominant species greatly affect the nature of the environment, occupying space that would otherwise be occupied by other species.

Ecological Niche

• A niche is an organism's role in the biotic environment.
• It includes interactions, relationships, and food needs.

Population

• A population is a group of organisms belonging to the same species.
• They share a specific area and share unique attributes.

Species Interaction

• Competition: When two or more species in the same ecosystem use the same niche.
• Predator-prey relationship: Individuals of a predator population kill and eat individuals of a prey population.
• Parasite-host relationship: Parasites feed at the expense of their host, often being smaller.
• Commensalism: A type of symbiotic relationship where one organism benefits from the relationship without harming the host.
• Mutualism: An interaction between species where both species benefit.
• Protocooperation: A mutually beneficial interaction, but not essential for survival.

Population Growth

• Unrestricted growth occurs when there's ample resources and no competition.
• Exponential growth happens when limitations like food and space aren't factors, and the ecosystem approaches its carrying capacity.
• The maximum density the environment can support is called its carrying capacity.

Density-Dependent Factors

• Density-dependent factors controlling population include overcrowding, limitations on food and space, disease, predation, and stress.

Density-Independent Factors

• Density-independent factors include extreme weather, abrupt environmental changes, and hazards of varying severities.

Land

• Land supports life, providing habitats and resources like nutrients, water, and food.
• Humans depend on land for resources and sustenance.

Types of Land

• Agricultural land—Land dedicated to agricultural activities.
• Forest land—Land supporting forest ecosystems.
• Urban land—Land developed for human settlements.
  • These examples contain data like hectares of land use, conversion rates, and forms of degradation of each specific type of land mentioned.