Biodiversity

Cards (60)

  • There are currently 1.75 million described species, but there are probably 13-14 million species in total, with most undiscovered species being invertebrates
  • Coral reefs, tropical forests, and the deep ocean are the main sources of biodiversity
  • Greater species diversity leads to a healthier ecosystem
  • Ecosystem services (cultural, regulatory, or supportive) are only possible if biodiversity is maintained
  • Organisms do not exist in isolation, and symbiotic relationships (e.g., insects & flowers) and predator-prey relationships (e.g., sea otters & urchins) contribute to ecosystem stability
  • Each population has a role (niche) in an ecosystem, contributing to biogeochemical cycles and acting as bio-filters
  • Genetic diversity is important because each species has a unique set of genes that code for proteins, control behaviors, and provide solutions to environmental changes
  • Species diversity equals genetic diversity, and diverse ecosystems have a greater diversity of gene pools, making them more stable and adaptable to environmental changes
  • High genetic diversity is important for the survival of coniferous forests and other ecosystems in the face of diseases and fungal infestations
  • Monocultures with low genetic diversity are vulnerable to pests and diseases
  • Genetic diversity is scientifically important for gene transfer to improve crops and cure diseases
  • Biodiversity provides benefits such as food sources, raw material for genetic engineering, and the basis for drugs and medicines
  • Organisms have aesthetic, ethical, and religious value, contributing to recreation, ecotourism, and religious practices
  • Natural disturbances to biodiversity include background extinction, volcanic eruptions, ecological succession, and mass extinction events
  • Mass extinction events are caused by factors like asteroid impacts, climate change, ocean acidification, and potentially anthropogenic activities
  • Endangered species are those with so few individuals that they may become extinct soon, while threatened species have declining numbers and are likely to become extinct
  • Characteristics of endangered or threatened species include extremely localized range, low reproductive success, endemism, and low adaptability or extreme specialization
  • Direct causes of habitat loss and fragmentation, invasive species, hunting, poaching, capture and sale of exotics, overfishing, predator and pest control, and climate change impact biodiversity
  • Habitat fragmentation leads to barriers to dispersal, genetic isolation, inbreeding, and edge effects like pesticides, diseases, and predation by domestic animals
  • Wildlife corridors are important for connecting habitat fragments and maintaining biodiversity, although they are expensive to establish and maintain
  • Invasive species pose a significant threat to biodiversity by out-competing native species and lacking natural predators
  • Island biogeography explains how species colonize islands, leading to unique endemic species with specialized adaptations and low genetic diversity
  • The Brown Tree Snake in Guam is an example of an invasive species that disrupted the island's ecosystem, leading to the extinction of several endemic species
  • Conservation efforts include human population control, protection of remaining habitats, and the establishment of wildlife corridors to maintain biodiversity
  • Hot spots are areas with high endemism and significant habitat loss, requiring conservation efforts to protect endemic plant species and their habitats
  • Conservation strategies involve protecting habitats through national parks, sanctuaries, refuges, and forests, with varying levels of protection
  • The Endangered Species Act prohibits the trade of products from endangered species and requires the development of recovery plans based on biological considerations
  • International policies like CITES aim to regulate the trade of endangered species and their products to prevent further decline in biodiversity
  • The earth's biodiversity refers to all the plants and animals in the biosphere, also known as species diversity or species richness of an ecosystem
  • Three objectives of studying biodiversity:
    • Understand the value of species
    • Explore human impacts of species diversity
    • Explore how to protect species richness in ecosystems
  • Biodiversity is a non-renewable natural resource, and if species go extinct, they are lost forever
  • Ecological impacts of removing species from an ecosystem:
    • Insects pollinators eliminated by pesticide use disrupt pollination
    • Removal of nitrogen-fixing bacteria affects soil fertility
    • Bivalves like clams and mussels removal impacts water filtration
    • Gray wolves removal disrupts predator-prey balance
  • Connection between species diversity and ecosystem services:
    • Species diversity loss leads to the loss of ecosystem services provided by the system
  • High species diversity leads to high genetic diversity, increasing ecosystem stability and adaptability to environmental changes
  • Predictions for forest scenarios:
    • Forest with high species diversity may suffer from bark beetle infestation affecting susceptible species like white pines
    • Forest with low species diversity (clear-cut and replanted with only white pines) may face severe consequences if invaded by bark beetles
  • Importance of genetic diversity:
    • Genetic diversity ensures species can adapt to environmental changes
    • Genetic diversity increases the stability of ecosystems
  • Biodiversity is key to the ecotourism industry worldwide
  • Difference between biological extinction and commercial extinction:
    • Biological extinction means complete loss of a species
    • Commercial extinction refers to the inability to find a species in the market
  • Background extinction occurs naturally due to competition and environmental changes
  • Mass extinctions differ from background extinctions by being rare, punctuated events triggered by external factors like asteroid impacts or climate change