Human Impact on Ecosystems: Human Impact on Ecosystems:

Land DevelopmentLand DevelopmentSVN3ESVN3E

Habitat LossHabitat LossThe biggest impact on wildlife from The biggest impact on wildlife from

land development is land development is habitat losshabitat loss..

HabitatHabitat: the natural home or : the natural home or environment of an animal or plantenvironment of an animal or plant

Habitat FragmentationHabitat Fragmentation

Also significant is the Also significant is the fragmentationfragmentation (breaking apart into small areas) of (breaking apart into small areas) of habitat.habitat.

Habitat FragmentationHabitat Fragmentation

Habitat fragmentation affects the ability Habitat fragmentation affects the ability of animals to move to find food and of animals to move to find food and shelter and mates and the ability of shelter and mates and the ability of plants to reproduce by seeds.plants to reproduce by seeds.

MicroclimatesMicroclimates

Land development Land development can also create can also create microclimatesmicroclimates (e.g. asphalt will (e.g. asphalt will heat up more than heat up more than grass).grass).

microclimatemicroclimate: the : the climate of a small climate of a small areaarea

Changing ProducersChanging Producers

How humans use land also changes How humans use land also changes the balance of species by adding the balance of species by adding specific producers to the developed specific producers to the developed land.land.

E.g. more lawns means that we have E.g. more lawns means that we have more grasses and animals that prefer more grasses and animals that prefer grasses (such as Canada geese)grasses (such as Canada geese)

Changing PredatorsChanging Predators

Humans will also remove predators, Humans will also remove predators, which can have ripple effects, which can have ripple effects, altering the landscape.altering the landscape.

E.g. the removal of wolves has led to E.g. the removal of wolves has led to an overpopulation of deer, which eat an overpopulation of deer, which eat tree bark and saplings, destroying tree bark and saplings, destroying forest growth.forest growth.

Other DisruptionsOther Disruptions

Changes can also be more subtle, Changes can also be more subtle, disrupting the flow of an ecosystem, disrupting the flow of an ecosystem, especially the flow of water.especially the flow of water.

A concrete-lined drainage ditch

WetlandsWetlands

Very vulnerable to disruption of flow Very vulnerable to disruption of flow are are wetlandswetlands, lowland marshes or , lowland marshes or swamps that are saturated with swamps that are saturated with water (holding as much as possible).water (holding as much as possible).

WetlandsWetlands

Wetlands capture, store, and slowly Wetlands capture, store, and slowly release (cleaner) water to release (cleaner) water to surrounding areas.surrounding areas.

WetlandsWetlands

When wetlands are filled in, When wetlands are filled in, surrounding areas can get surrounding areas can get floodingflooding (excess water) or (excess water) or droughtdrought (not (not enough water).enough water).

Flooding on the Red Hill Expressway