Transcript Habitat Loss

How Humans
Influence Ecosystem
• Wetlands are special ecosystems
– high biodiversity
– filter many impurities out of the water that slowly flows through them
• sometimes called the “kidneys” of the Earth
– their water-logged soil hold large amounts of water, which can help
prevent flooding
• Up to 70% of the wetlands in the lower Fraser Valley have been lost
• Up to 85% of the wetlands in the South Okanagan have been lost.
• Land use is how humans use land around us for urban development,
agriculture industry, mining and forestry
• Resource use refers to the ways we obtain and use naturally occurring materials
(BC -sulfur/coal/lumber)
•
Land and Resource Use has been the cause many BC wetlands to disappear
Habitat Encroachment
Two Terms:
• Habitat loss refers to loss of habitats due to human activities.
• Habitat fragmentation is the splitting of large habitats into many smaller
ones, resulting in disrupted natural activities for plants and animals.
Agriculture
•
can remove entire ecosystems and leaves the area exposed to
wind/water (erosion, affecting healthy topsoil)
•
agricultural usually only plants 1 species (monoculture)
- This reduces biodiversity, and leaves the crop vulnerable
to pests or disease
- Polycultures, of many plant species, are more
economically and biologically diverse (sustainable)
•
the soil compaction happens due to farm animals and vehicle
–
With no room for water to enter the soil it then runs off and increased erosion
can occur
– Aeration = remove small plugs of soil
•
Addition of farm fertilizers and pesticides to the area has adverse
effects on the ecosystem
Deforestation
• the clearing or logging of forests such that the land is
never reclaimed or replanted
– Leading to soil degradation, where wind and water
erode topsoil and leave bare unfertile land
Resource Exploitation
• Humans depend on resource exploitation for jobs, materials, food,
shelter and energy
• Resource collecting can lead to habitat loss, soil degradation and
contamination of water supplies
– Overexploitation is the extraction of resources until they are gone
• This can result in extinction, such as with the passenger pigeon
• Many mining and resource exploitations require reclamation efforts
– reduces environmental impacts of exploitation, and tries to restore
the original (or at least functional) habitats
Sustainability
•
Two ways:
1. The ability for an ecosystem to
sustain ecological processes
- continued biodiversity and
healthy ecosystem
2. People using an ecosystem to
meet their needs today without
reducing the function or health
of the ecosystem in the future
Example:
Returning young coho salmon to rivers near
Port Alice can help maintain sustainability
With sustainability can bring:
• Economic opportunity
• biodiversity
• healthy ecosystem