Interactions in the Environment: Unit Review

Organism, population, community, ecosystem.

It includes the non-living parts (water, mud, sunlight, oxygen) and all the interactions among living and non-living parts.

For example: tree roots hold soil; deep snow makes it hard for deer to find food; sunlight lets plants make food.

Biotic: fallen log, bacteria, moss. Abiotic: snow, sunlight, sand.

Warm water holds less dissolved oxygen, and brook trout need cold, oxygen-rich water.

Independent: amount of salt. Dependent: number of seeds that sprout.

For example: earthworms loosen soil, trees shade the ground, beavers raise water levels.

carbon dioxide + water → (light energy) → glucose + oxygen

Cellular respiration (glucose + oxygen → carbon dioxide + water + energy).

Secondary consumer.

A scavenger is an animal that eats dead animals (a raven). A decomposer (fungi, bacteria) breaks dead matter into nutrients that return to the soil.

600 kJ. 60 000 → 6 000 → 600.

It is used for life processes and lost as heat (some is also not eaten or not digested).

Only a small amount of energy reaches the top of the pyramid, so it can support only a few animals.

Without otters, urchins increased and ate the kelp. When otters returned, urchins decreased and kelp grew back.

Biomagnification: the walleye is higher in the food chain and eats many smaller fish, keeping the mercury from all of them, and it has lived longer.

70 kJ. 70 000 → 7 000 → 700 → 70.

Energy flows one way (lost as heat); matter cycles and is reused.

For example: cellular respiration, decomposition, burning fossil fuels or wood.

Bacteria in their root nodules fix nitrogen from the air into a form plants can use.

It returns nutrients to the soil for new plants instead of burying them in a landfill where they make methane.

Primary (no soil).

Secondary (soil and seeds are there).

They release weak acids that break down rock and their remains help form soil.

Soil, seeds and roots are already present.

Biotic: food, wolves, disease, parasites. Abiotic: deep snow, cold, water, shelter.

The largest population an ecosystem can support over a long time.

Density-independent. It affects the population no matter how crowded.

8 animals (24 ÷ 3).

For example: cover crops, crop rotation, buffer strips, no-till, soil testing before fertilizing.

Overfishing caused the cod population to collapse.

Taking less than the population can replace, so there will be enough in the future.

Raw materials, making, transporting and using, disposal.

Positive: electricity with no air pollution while running. Negative: some birds and bats are killed; needs land and materials.

Helps: identifying species in trail-camera photos or sound recordings. Cost: data centres use lots of electricity (and water).

Most of Ontario's electricity comes from nuclear and hydro, which release very little carbon dioxide.

Using the strengths of Indigenous knowledge with one eye and Western science with the other, together, for the benefit of all (shared by Mi'kmaw Elders Albert Marshall and Murdena Marshall).

For example: Indigenous Guardians, fire stewardship at Walpole Island First Nation, co-management in Nunavut, manoomin harvesting, Métis Captains of the Hunt, Thaidene Nëné.

Knowledge is tied to specific peoples and places; naming the nation is accurate and respectful.

For example: evidence it works, size of effect, cost, how long it lasts, side effects, fairness.

Birds fly around it through the open glass. Markings must be close together (about 5 cm or less).

A result that was not planned, such as planting one tree species everywhere and losing biodiversity, or paper bags using lots of water and energy to make.

To see if it really works (for example, trees surviving, not just planted) and to fix problems early.