The Urban Ecosystem Chapter 4.7

Cities  Cities cause a lot of air and water pollution  Air pollutions comes from car exhaust, burning fuels, and gases from industries  Water pollution comes from biological, commercial and industrial waste

 People who live in cities rely on:  Forestry and mining for a variety of materials (ie. Lumber for furniture)  Agroecosysems for food (ie. Farm land crops)  Natural ecosystems for recreation (ie. A park)

Urban vs. Natural Ecosystems FeatureUrbanNatural

FeatureUrbanNatural -surface features -buildings, roadways, parking lots -dominated by plants

FeatureUrbanNatural -plant species -not common -non-native species like grass, small flowers -highly dense and diverse

FeatureUrbanNatural -common animal species -low diversity/low abundance -dogs, cats, mice, pigeons, etc -high density, highly diverse

Feature UrbanNatural -water cycle -surface waters goes into drains/sewers -surfaces are impenetrable to water -humans consume lots of water -waste water returns to surface -surface water goes to streams/lakes -rainfall is absorbed at surface -water drains through soil to groundwater

FeatureUrbanNatural -flow of materials -influx of material goods to support humans -human body waste collected, treated and disposed in environment -household/commercial waste disposed in environment -minimal recycling -natural nutrient cycles take place in ecosystems

FeatureUrbanNatural -food webs-dependent on importing food from outside -complex natural food webs

FeatureUrbanNatural -sustainability-cannot be sustained without inputs from other ecosystems -independently sustainable

We Need Nature  Humans cannot survive in an isolated urban environment. We rely on outside natural ecosystems.  City planners and politicians have had to start thinking about “greener cities”; they must consider the impact of human actions on ecosystems  Ie. Banning plastic bags

What can we do? ActionBenefit -composting programs -reduces landfills, provides fertilizer -use LED traffic lights -reduces energy consumption -promote public transit-reduce pollution - promote green roofs-improves air quality