HIPPCO

• Habitat Fragmentation/Loss

  • Deforestation (lumber, cities, roads)

  • Wetland draining (ag, urbanization)

  • River wtaer level decreased by dams

• Invasive Species 

  • Invasives such as z. Mussel and kudzu vine outcompete native species for food/space, lowering populations

• Population Growth

  • Human pop. growth drives hab. Loss 

  • Urbanization, ag. Expansion to feed more people remove/fragment hab. 

• Pollution (Pollutants)

  • Oil spills reduce marine org. Pop. sizes 

  • Pesticides (glyphosate, atrazine) kill non-target species

• Climate Change

  • Shift biomes & therefore species habitat ranges, can change temp. & precip. Patterns too rapidly for a species to adapt or migrate, causing pop. decline or extinction 

• Over Exploitation

  • Excessive hunting or poaching (faster than reproductive rate) leads to pop. decline 

Habitat Fragmentation 

• Roads & Pipelines

  • Roads & oil/gas pipelines fragment habitats; disrupt movement & lead to fatal collisions with vehicles

• Agricultural & Urban Land Use

  • Clearing forest/grassland for ag. Fields or urbanization fragments those habitats

• Logging

  • Both removal of trees & construction of logging roads to transport lumber fragment forest ecosystems

Metapopulations

• Some species are more disrupted by fragmentation than others

  • Large predators needing large hunting space

  • Smaller populations of large k-selected

• Habitat Fragmentation creates smaller, isolated subpopulations

  • Smaller sps have less genetic diversity are more prone to inbreeding depression, and are less resilient to env. Disturbance or disesase

  • Metapopulations are mostly isolated, sps connected by habitat corridors; this can allow some gene flow (mating between populations) and improve genetic diversity

Edge Effect

• “Edge habitat” where two ecosystems such as forest-grassland or ocean-river (estuaries) meet have diff. Characteristics than the middle of each ecosystem

  • Some species thrive in the edge habitat & biodiversity is often higher in edge habitats due to diversity of food, shelter, and nutrient resources

  • Edge habitats can expand range of potentially disruptive species (ex: brown headed cowbird) that thrive in grassland-forest edge

    • Brood parasite that leaves its eggs in the nests of songbirds for them to raise, unknowingly

Climate Change

• Temperature change

  • Warming temp. Can shift biomes

    • Boreal forest & temperature coniferous forests may shift northward; tundra may decrease

• Precipitation change

  • Warming global temperature will decrease precipitation in some areas, leading to soil desiccastion and desertification 

    • Will increase in some areas, expanding tropical ecosystems

• Sea level rise

  • Estuary habitats (salt marshes, mangroves) become fully submerged & more saline; coastal ecosystems become flooded

Biodiversity & Domestication

• Crops

  • Fewer plant species are grown as selective breeding and GM results in only the highest yield species

  • GM use and selective breeding also lead to less genetic diversity in crops, making them more vulnerable to disease or environmental disruptions

• Livestock

  • Historically there have been over 8000 breeds of the 11 species most commonly eaten by humans

    • Breeds were uniquely adapted to local climate

    • Many breeds are now extinct, or at risk due to selection for only highest productivity

Mitigating Biodiversity Loss

• Protecting & Connecting Habitats

  • Protecting important habitats by creating national parks, nature preserves, or preventing them from being developed

  • Connecting fragmented habitats with wildlife corridors enables movement/breeding

• Sustainable Land Use

  • Urban growth boundaries, infill, and building up (not out) to reduce urban sprawl can preserve existing habitats

  • Expanding parks, urban gardens, green roofs can provide habitat for many species

  • Sustainable agriculture, lowering meat consumption can reduce ag. Land needs, preventing hab. Loss

• Restoring Lost Habitats

  • Replanting clear-cut forests

  • Reestablishing praries on old