They are species that balance the ecosystem. Various ways in which they do that are in 5 ways

• keystone predators

  • If removed from ecosystem prey will increase = imbalance in ecosystem
  • Examples: Purple sea star, american alligator (specific to ecosystem)

• Modifiers

  • It’s a species that brings positive change in the environment in which they are living, benefiting the ecosystems they live in
  • Example: Black tailed prairie dog. The prairie dogs are an important food for animals in that species of that ecosystem. More importantly the prairie dogs dig burrows soil which allows water to penetrate, and also gives shelter to other organisms

• Prey

  • It’s a keystone organism that causes fluctuations in the number of predators - so basically it helps maintain the number of predators in an ecosystem and maintains the balance in the density/biodiversity of that ecosystem
  • Example: Chinook Salmon (juvenile), Sockeye Salmon, both of these salmon act as prey, and food for birds, mammals and reptiles. Salamanders are also keystone prey (food)

• Mutualists

  • These species participate in mutually beneficial interactions
  • Example: Hummingbirds (There are plants that have adapted to pollination only by humming birds)

• Hosts

  • They create shelter and homes for organisms
  • Example: Quaking aspen - It creates shelter for many insects, and birds.

  

  This is an image of quaking aspen - its a tree

  Good parasites

  Helminth therapy  involves giving a person helminth parasites, such as hookworm, that will live in their body. This type of therapy may help treat certain health conditions, such as Crohn's disease, allergies, and ASD