Megafauna
Megafauna is any animal more than or equal to 100 pounds (45 kilograms).
Megafauna is any animal more than or equal to 100 pounds (45 kilograms).
Keystone species
Gray wolf
A keystone species is a species that has a greater effect than the population would suggest on other species found in the ecosystem. Eliminating a keystone species may dramatically alter the structure and function of a community. Keystone species can be categorized as habitat engineers changing the environment from one form to another. For instance, the beaver engineers a moving river into a pool by building a dam. A specific keystone species is a top predator because top predators regulate prey populations. Loss of one species may lead to the exponetial growth of a population resulting in a population crash and/or extinction of a species. For instance, the gray wolf, or timber wolf, was eradicated from the United States during the 20th century. Gray wolves are considered a keystone predator species. The recent reintroduction of gray wolves to Yellowstone National Park has revitalized the ecosystem. The wolf has altered the behavior and abundance of elk, the major prey of the gray wolf. The management of the elk population by the wolves has caused an increase in the willow tree population, food source of the elk. Sea otters are another example of a keystone species. Sea otters regulate sea urchin populations. Over abundance of sea urchin can destroy kelp forests turning a luscious underground forest into a desert. Kelp provide nutrients and shelter to many marine and avian species. Kelp also serves as a nursery for various species like crustaceans, jellyfish, and mammals. Due to the signifcant changes keystone species have upon ecosystems they are carefully managed and observed.
Environmental Science by G.Tyler Miller and Scott Spoolman
Environmental Science by G.Tyler Miller and Scott Spoolman
Metapopulation
Types of Metapopulation
Metapopulation is described as a population that is made up of distinct subpopulations that live in unconnected habitats. The separation of the habitats occur because the area is not suitable due to human or environmental influence. However, species within the population may migrate among the habitats. The interactions between the subpopulations must occur for the population to be deemed a metapopulation. Individuals move between habitats at a rate that maintains interaction among the subpopulations without losing distinction. Most habitats in nature are broken into patches; these patches allow populations to persist even when subpopulations go extinct. http://crssa.rutgers.edu/courses/lse/Web_Patch/final/Tanya/Rohrbach_Final.htm