Ecosystems and Energy Flow

Definition: A community of living organisms (biotic factors) and non-living components (abiotic factors) interacting with each other in a specific environment.
Key components:
- Producers (plants, algae): make own food through photosynthesis
- Consumers (herbivores, carnivores, omnivores): obtain energy by consuming other organisms
- Decomposers (bacteria, fungi): break down dead organic matter
Energy flow:
- From producers to consumers through food chains
- Energy lost at each trophic level (10% rule)
Nutrient cycling:
- Nutrients recycled between biotic and abiotic factors

Definition: Variety of species, genes, and ecosystems in an environment
Types of biodiversity:
- Species diversity: number of different species
- Genetic diversity: variation within a species
- Ecosystem diversity: variety of ecosystems
Importance of biodiversity:
- Maintains ecosystem services (e.g., pollination, pest control)
- Supports food security and medicine
- Enhances ecosystem resilience

Processes:
- Nitrogen fixation: conversion of atmospheric nitrogen (N2) to ammonia (NH3) by bacteria
- Ammonification: conversion of ammonia to ammonium ions (NH4+)
- Nitrification: conversion of ammonium ions to nitrate ions (NO3-)
- Denitrification: conversion of nitrate ions back to atmospheric nitrogen
Human impact:
- Overuse of fertilizers leads to eutrophication
- Nitrogen oxides (NOx) contribute to air pollution

Processes:
- Photosynthesis: conversion of CO2 to organic compounds by plants
- Respiration: release of CO2 from cells during energy production
- Decomposition: breakdown of organic matter, releasing CO2
- Fossil fuel formation: long-term storage of carbon in fossil fuels
Human impact:
- Burning fossil fuels releases CO2, contributing to climate change
- Deforestation reduces carbon sequestration

Processes:
- Evaporation: water vapor formation from oceans, lakes, and rivers
- Condensation: water vapor conversion to liquid water
- Precipitation: water falling to the ground as rain, snow, or hail
- Infiltration: water absorption into soil
- Runoff: water flowing over land into bodies of water
Human impact:
- Over-extraction of groundwater leads to water scarcity
- Pollution of water sources affects human health and ecosystems

Definition: Selecting a subset of individuals or data from a larger population
Types of sampling:
- Random sampling: every individual has an equal chance of selection
- Systematic sampling: selecting individuals at regular intervals
- Stratified sampling: dividing the population into subgroups and sampling from each
Importance of sampling:
- Allows for representative data collection
- Reduces costs and time required for data collection
- Enables generalization of results to the larger population

Ecosystems consist of biotic factors (living organisms) and abiotic factors (non-living components) interacting in a specific environment.
Producers (plants, algae) make their own food through photosynthesis.
Consumers (herbivores, carnivores, omnivores) obtain energy by consuming other organisms.
Decomposers (bacteria, fungi) break down dead organic matter.
Energy flows from producers to consumers through food chains, with a 10% energy loss at each trophic level.
Nutrients are recycled between biotic and abiotic factors.

Biodiversity is the variety of species, genes, and ecosystems in an environment.
Species diversity refers to the number of different species.
Genetic diversity refers to the variation within a species.
Ecosystem diversity refers to the variety of ecosystems.
Biodiversity maintains ecosystem services, supports food security and medicine, and enhances ecosystem resilience.

Nitrogen fixation converts atmospheric nitrogen (N2) to ammonia (NH3) by bacteria.
Ammonification converts ammonia to ammonium ions (NH4+).
Nitrification converts ammonium ions to nitrate ions (NO3-).
Denitrification converts nitrate ions back to atmospheric nitrogen.
Overuse of fertilizers leads to eutrophication, and nitrogen oxides (NOx) contribute to air pollution.

Evaporation forms water vapor from oceans, lakes, and rivers.
Condensation converts water vapor to liquid water.
Precipitation involves water falling to the ground as rain, snow, or hail.
Infiltration absorbs water into soil.
Runoff involves water flowing over land into bodies of water.
Over-extraction of groundwater leads to water scarcity, and pollution of water sources affects human health and ecosystems.

Sampling involves selecting a subset of individuals or data from a larger population.
Random sampling gives every individual an equal chance of selection.
Systematic sampling involves selecting individuals at regular intervals.
Stratified sampling divides the population into subgroups and samples from each.
Sampling allows for representative data collection, reduces costs and time, and enables generalization of results to the larger population.