Threats and solutions

There are 5 main causes for species extinction: - Habitat loss (85%) - Exotic species (50%) - Pollution (24%) - Overexploitation (17%) - Disease (3%)

Habitat loss has occurred in all ecosystems; human disruption is the greatest factor.
Habitats may be destroyed or fragmented, both of which cause substantial harm: - Fragmentation: Divides habitats into smaller pieces, limiting access to resources. - Consequences of Fragmentation: - Reduction in resources available to organisms. - Allopatric speciation can occur as populations become isolated. - Loss of access to critical areas like breeding sites. - Smaller habitats may not provide large enough territories for organisms to support themselves and their offspring.

Habitat destruction primarily occurs to create farms: - Current agricultural practices produce enough food to provide a healthy diet of 2,500 calories per day for everyone on Earth. - Despite production, one-sixth of the world’s population is considered malnourished. - Misallocation: Grain is often used to feed livestock instead of humans. - Consequences of Farming on Biodiversity: - Large-scale land destruction for crops or livestock reduces biodiversity by encouraging monoculture. - Monoculture: the cultivation of a single crop species, leading to a destroyed food web. - Usage of fertilizers and pesticides can lead to the elimination of organisms and create resistance in pests.

Maintaining Soils:
- Keep crop waste and root systems on fields to preserve moisture and prevent erosion. - Prevent overgrazing or trampling of pastures.
- Employ crop rotation to replenish nutrients.
Employing Polyculture:
- Plant companion crops together to increase biodiversity and benefits such as providing shade and nutrients, and protection from pests.
Minimizing Pesticide Use:
- GMOs may assist in reducing pesticide dependency. - Avoid applications before rainfall to minimize runoff into ponds and lakes, which can cause eutrophication. - Use beneficial organisms, like ladybugs or spiders, to control pests. - Grow organically and rotate crops to maintain soil health.

Habitat destruction results from building houses and industry: - Destruction of habitats to create buildings, roads, and parking lots. - Preferences for homes versus apartments increase urban sprawl, extending suburbs and consuming more land.

Urban development often blocks rainwater percolation into the soil, causing excess runoff.
Contaminants may be washed into storm drains rather than replenishing groundwater.
Communities may not support pollinators or biodiversity in their gardens due to plant choices.
Increased pollution arises from traffic, light, noise, and household or industrial wastes.

Encourage apartment living to utilize vertical space.
Preserve sensitive areas and greenspace, promoting walking trails and neighborhood appeal.
Develop stormwater ponds to collect runoff and create new wildlife habitats.
Ensure efficient public transit to mitigate pollution impacts.
Promote gardens that are friendly to bird and insect populations and respect natural areas.

Invasive species, also referred to as exotic, alien, or introduced species, do not have co-evolutionary relationships with the native community. They tend to: - Exhibit high biotic potential (i.e., reproduce quickly). - Be effective resource exploiters. - Be resistant to predators or not have natural predators. - Cause harm to native species within ecosystems.

Aggressive species are native and can cause ecosystem harm by outcompeting others, while invasive species are non-native and disrupt existing balances. - Example: Virginia Creeper, native to Ontario, can harm non-native vegetation by engulfing trees.

Introduced to Guam in the late 1940s after WWII, likely via military cargo, the Brown Tree Snake originated in the South Pacific.
Lacking natural predators on Guam, its population surged, reaching densities of 5,000 snakes per square kilometer, creating ecological disruptions: - Extinction of 10 out of 12 native forest bird species due to predation, leading to a trophic cascade. - The absence of birds resulted in increased spider populations and diminished seed dispersal of native trees.

Avoid importing potentially invasive plants, seeds, or pets.
Remove invasive plants or animals where legally supported (e.g., lionfish hunting).
Alert local environmental agencies about dangerous invasives (e.g., giant hogweed).
Refrain from releasing pets into the wild.