Ecology: Ecosystems, Biotic and Abiotic Factors

Ecology Introduction

• Focus shifts from microscopic organisms to studying nature and life with the naked eye.
• The discussion transitions to ecology, ecosystems, biotopes, and biocommunities.

Biotic vs. Abiotic Factors

• Biotic factors are living organisms in an environment (animals, plants).
• Abiotic factors are non-living elements (temperature, humidity, sunlight, rainfall).

Defining Ecology

• Ecology studies the relationships between organisms, their environment's abiotic factors, and other organisms within the same or different species.
• Examines how organisms adapt to their environment based on abiotic factors like humidity and temperature.
• Studies interactions and relationships between organisms adapted to a specific environment.
• Ecology studies organisms, their adaptation to the environment based on abiotic factors and their interactions.

Ecosystems Explained

• An ecosystem is a study system, such as a forest, lake, or marine area.
• Can range in size, even encompassing the entire Earth, as defined by the researcher.
• Includes the biotic factors, abiotic factors, and their interactions within a specific area.
• For a forest ecosystem, this includes the animals, plants, sunlight, temperature, humidity, and interactions between these components.

Abiotic and Biotic Factors in Ecosystems

• Abiotic factors are non-living elements such as sunlight, temperature, humidity, and cloud cover.
• Biotic factors are living organisms such as trees, animals and bushes

Ecosystem Structure

• Ecosystems have a common structure regardless of whether it's a forest, lake, or sea.
• At the base of the ecosystem are producers.
• Producers are organisms that photosynthesize.
• They can capture solar energy and produce glucose (food) through photosynthesis.
• Plants use inorganic molecules from the soil, water, sunlight, and carbon dioxide to produce glucose.
• Producers are also called autotrophs.
• They make their own food.
• Other organisms consume plants, then other organisms consume those organisms, etc..

Consumers in the Ecosystem

• Beyond producers, there are consumers.
• Consumers eat other consumers, and can consume other organisms.
• Ecosystems contain producers that perform photosynthesis and capture solar energy from inorganic molecules to produce glucose.
• These producers are also called autotrophs because they secure their energy and the food they need to survive.

Decomposers

• Every ecosystems include decomposers
• Decomposers include bacteria and fungi in the soil.
• Decomposers feed on dead organic matter (leaves, fruit, dead organisms).
• Decomposers clean the ecosystem by feeding on dead organisms.
• For instance, an apple falling from a tree decomposes due to decomposers in action, same with dead animals.
• Mushrooms are decomposers
• They have a root system that excretes chemicals, kills and consumes insects.
• Decomposers turn organic matter into inorganic.
• Decomposers are nature's cleansers in the ecosystem.

Ecosystem Recap

• An ecosystem consists of autotrophs (producers).
• Autotrophs produce oxygen by taking carbon dioxide and water with sunlight, and then also create glucose and energy.
• Examples are plants, seaweeds, algae.
• Consumers eat the food created by autotrophs.
• When something dies, decomposers feed on them to clean up and continue the cycle.

Populations

• An ecosystem will not have just a single organism, like a flamingo you could have hundreds.
• When you have a grouping of a single species in an ecosystem, they're known as a population.
• Population is organisms within an ecosystem and belonging to the same species.

Biotic and Abiotic factors

• Biotic factors include any living organism within the ecosystem.
• Abiotic factors include any non-living factor, like rain, sunlight, water etc..

Biotope and Biocommunity

• A biotope is the area where a population lives.
• A biocommunity is all organisms that live inside a biotope
• Can be defined as a collection of the different population living in an environment in contact with each other.

Abiotic Factors Influence Variety of Organisms

• Abiotic factor directly dictate what kind of organism will be present and thrive in an environment Eg in the desert it is very hot and there is little rain, meaning there will be very few animals compared to a forest which is far more populated.

Autotrophic and Heterotrophic Ecosystems

• An autotrophic system is an ecosystem which produces its own energy and food.
• Autotrophic systems are usually populated by plants which produce glucose by photosynthesis.
• In contrast heterotrophic systems rely on another source to get energy
• Cities require the import of food and energy to thrive
• Because of this, they are unstable

Ecosystems and Balance

• The balance in the ecosystem is beautiful
• The ecosystems can function so well independently with such order because of the balance
• Here's an example of how to explain how organisms survive and stay balanced.
• A certain ecosystem contains a certain plant, that serves as the only food for small mice.
• All the mice enjoy the food and proceed to reproduce.
• They reproduce until they overpopulate and over consume their source of food.
• When the source of food is gone, many mice start to die out since there's nothing to eat.
• However with many mice dying out, the plants can now grow out again.
• So as the plants start to regrow, the mice population also starts to grow again.

Variety Leads to Stability

• Variety is an important measure to determine how stable an ecosystem is.
• More variety, the more stable
• So in an ecosystem, you might only have mice and grass, but if you take out the grass, the ecosystem will collapse.
• In contrast, in a more complex system where there is a complex food web and a diverse number of species, if a species goes extinct, the ecosystem will remain stable.
• That's why scientists try and protect the bio diversity of an environment.