Essential Concepts in Ecology and Environmental Science

Fundamental Ecological and Biological Concepts

Biodiversity: The Variety of Life

Biodiversity refers to the varying or different life forms found on Earth. It encompasses several types:

• Genetic Diversity: The variety of genetic materials within a species or a population.
• Species Diversity: The number and abundance of species present in different communities.
• Functional Diversity: The biological and chemical processes, such as energy flow and matter recycling, needed for the survival of species, communities, and ecosystems.
• Ecological Diversity: The variety of terrestrial and aquatic ecosystems found in an area or on the Earth.

Evolution: Changes in Organism Genetic Makeup

Evolution refers to the changes in a population of organisms' genetic makeup over generations.

Mutation: Gene Changes and Adaptation

A mutation is a change in the genes of a single organism. The process of adaptation through mutation involves:

1. Organisms possess specific traits.
2. Environmental changes occur.
3. Survival traits become active or are selected for.
4. Over years, a population evolves, becoming better adapted to survive and reproduce under these new conditions.

Speciation and Extinction: Shaping Biodiversity

Speciation: The formation of new species, often resulting from processes like geographical isolation or reproductive barriers.

Extinction: The dying out of a species.

• Background Extinction Rate: The natural, slow rate of species extinction.
• Mass Extinction: A significant event that results in the greatest loss of species over a relatively short geological period.

Genetic Engineering: Modifying Organisms

Genetic engineering involves the direct manipulation of an organism's genes. Key aspects include:

1. The splicing of genes from organisms.
2. Transfer of genes between different organisms.
3. Transfer of genes between organisms that would never normally breed.
4. Intermingling of plant and animal genes.
5. Introducing bacteria into plants and animals.

Endemic Species: Unique to One Area

An endemic species is a species that can only be found in one specific area, for example, the Panda Bear.

Biomes: Large Ecological Regions

Biomes are large ecological regions characterized by specific types of natural vegetation and climate.

Climate (specifically precipitation and temperature) is the most important factor that determines the type of biome. Examples of major biomes include grasslands, deserts, forests, and mountains.

Wetlands: Vital Ecosystem Services

Wetlands provide crucial ecosystem services:

1. They filter and detoxify water runoff before it enters waterways and oceans.
2. They provide food and habitat for wildlife.
3. They reduce storm damages and coastal erosion.

Important Factors in Aquatic Environments

Key factors influencing aquatic ecosystems include:

• Water temperature
• Dissolved oxygen content
• Food availability
• Available light for photosynthesis

Ocean Zones and Biodiversity

Ocean zones vary in biodiversity. The most biodiverse areas are the coastal zone and the open sea, followed by the ocean floor.

Major Vertical Ocean Zones

The major vertical zones of the ocean include:

• Epipelagic (Sunlight/Euphotic Zone)
• Mesopelagic (Twilight/Disphotic Zone)
• Bathypelagic (Midnight Zone)
• Abyssalpelagic (Abyssal Zone)
• Hadalpelagic (Hadal Zone)

Lake Zones

The distinct zones within a lake are:

• Littoral Zone
• Limnetic Zone
• Profundal Zone
• Benthic Zone

Lentic vs. Lotic Water Systems

• Lentic: Refers to standing water bodies (e.g., lakes, ponds).
• Lotic: Refers to flowing water bodies (e.g., rivers, streams).

Trophic States of Lakes

Lakes are classified by their nutrient levels:

• Oligotrophic: Low nutrient levels.
• Mesotrophic: Moderate nutrient levels.
• Eutrophic: High nutrient levels.
• Hypereutrophic: Excessive nutrient levels.

Surface Water

Surface water is water found on top of the land, such as in rivers, lakes, and oceans.

Runoff

Runoff is the water that, after precipitation, moves downslope and across the land and streets, eventually entering waterways.

Watershed

A watershed is the area of land that collects and delivers runoff to waterways.