Unit 1 Yr 2 - Ecology A: Human Impact and Conservation

What is an ecosystem

Biological communities of interacting organisms and their physical environment

What are components of an ecosystem

Biotic and Abiotic factor

What are some biotic factors of an ecosystem

• Producers/Autotrophs

• Consumers/Heterotrophs

• Decomposers

What are some abiotic factors of an ecosystem

• Sunlight

• Temperature

• Water

What is a stable ecosystem

An ecosystem that is usually stable without human activity, and it has existed for millions of years

What are some examples of stable ecosystem

• Tropical rainforests like the Amazon

• Desert ecosystems like the Kalahari Desert

What are the requirements for stability in ecosystems

• Supply of energy

• Genetic diversity

• Recycling of nutrients

• Climatic variables remaining in tolerance levels

What is an example of a supplier of energy for stability in ecosystems

The sun

What is an example of a recycler of nutrients for stability in ecosystems

Decomposers like fungi and scavengers.

Why is genetic diversity for stability in ecosystems important

It needs to have genetic diversity to protect populations from changes in the environment

Why is the fact that climatic variables need to stay within tolerance levels for stability in ecosystems important

To make sure it is supporting the population’s needs within that environmentand to prevent stress on the ecosystem

What is a tipping point

A critical threshold that, when crossed, leads to large and often irreversible changes in the climate system

What is the main example of a tipping point

The main example is the Brazilian tropical rainforest, the Amazon

Explain how the Amazon is reaching its tipping point

Up to 20% of the Amazon has been deforested since the 1970s. There is an uncertainty over the minimum area of rainforest that is sufficient to maintain these processes. However, the ongoing deforestation of the Amazon is a concern, as it may be reaching a climate change tipping point

What is the formula for Percentage Change

Percent change = Final-Initial/Initial x 100

What is a mesocosm

Any indoor experimental system that examines the natural environment under controlled conditions

What advantage do mesocosms provide for investigating ecosystems

Mesocosms allow scientists to control and manipulate variables while investigating ecosystems

How can harvesting of crops and fish be sustainable

If the rate of harvesting is lower than the rate of replacement

Define and describe sustainable fishing

• Harvesting fish at a sustainable rate

• Where the fish population doesn’t decline over time because of fishing

• Uses selective methods to maximize fish capture without causing fish populations to decrease

What does sustainable fishing depend on

The rate of harvesting to be lower than the rate of replacement

Define maximum sustainable yield

The largest catch of fish that can be sustained over time without causing the fish stocks to decrease

Explain how Pacific Cod are an example of a sustainable harvesting of fish

• Pacific Cod in Alaska are managed sustainably because strict catch limits keep harvest rates below reproduction time capacity

• Gear rules and seasonal closures protect habitats and lower bycatch

• Scientists monitor this through stock assessments, catch limits, data collection, and adaptive management

How do locals harvest Silver Top Palms in a sustainable way

They don’t harvest the regenerative heart, they harvest the part of the palm that grows, as harvesting the heart kills the plant as a whole

What is sustainable agriculture

The methods of agricultural production that meet the current needs of food production while preserving the natural environment and farmland for future generations

What are the factors that affect sustainable agriculture

• Soil erosion

• Leaching of nutrients

• Supply of fertilizers and other inputs

• Pollution

• Carbon footprint

Describe how soil erosion affects sustainable agriculture

Many agricultural practices erode the soil which reduces the