Forests, Cities (urban ecosystems), & Farms (agro ecosystems)

Wood  We use forests for wood and other products, like paper  Trees are cut (“harvested”) in one of three ways:  Clear-cutting  Shelterwood cutting  Selective cutting

Clear-Cutting Characteristics Cut all or most of the trees down Similar to what happens after a forest fire Large areas are cleared New trees are planted so that they are all the same age Most common method Advantages Economical (saves money) Efficient (quick)

Shelterwood Cutting Characteristics Older (“mature”) trees are cut Long stripes are cut Advantages New trees are planted and protected by the existing trees Disadvantages Costs more than clear cutting Less efficient

Selective Cutting Characteristics Only certain trees are cut Done in parks where people want the forest to look nice Advantages Very little harm to the ecosystem Disadvantages Costs more than clear cutting and shelterwood cutting

Forest Fires  Forest fires are a natural part of a forest ecosystem and are useful to some organisms  Humans don’t like forest fires because they want to cut down the trees and sell them  Humans try to stop and prevent forest fires which can harm the ecosystem

Stewardship  As humans, it is our responsibility to take care of the earth, it’s plants, animals, and other organisms.

Cities  Cities cause lots of pollution  Air pollution  Cars, burning fossil fuels (coal, oil, gas), factory pollution  Water pollution  Companies dump pollutants and garbage

City vs. Natural Ecosystem FeatureCityNatural Ecosystem Main partsBuildings, roadsPlants Few; Grass, flowersLots; Diversity of plants Animals (other than us)Few; dogs, cats, mice, birds Lots: diversity of animlas Water cycleUse sewers and drains because most of the ground is covered in asphalt/concrete Water moves through soil into ground water; ponds, streams, rivers Nutrients and wasteWaste is collected and disposed of Natural cycling and decomposition FoodComes from farmsNatural food webs SustainabilityNeeds constant managing Sustainable without any help

Greener Cities  How to make cities less harmful to the environment and more sustainable  Reduce, reuse, recycle  Compost  Shop locally  Use public transit  Plant more trees and grass  Have stacked housing (apartments, condos)  Live close to amenities (stores, etc.)

Food for Cities Comes from Farms  We get our food from farms  Farms are not natural – we make them  Most of the food that we grow/make in Canada originally came from other countries  Vegetables and fruit are grown in large gardens  Corn, wheat, potatoes, etc.  Usually only one type of plant is grown in a garden “ monoculture ”  Meat comes from livestock (animals that are born and raised on a farm)  Cows, pigs, chickens, etc.