The more commonly used light-year is also presently defined to be equal to precisely 7007315576000000000â 31557600 light-seconds, since the definition of a year is based on a Julian year (not Gregorian year) of exactly 365.25 days, each of exactly 7004864000000000000â 86400 SI seconds.
Keystone resource a component of the environment utilized by individuals in the ecological community without which the individuals would not thrive or without which the ecological community structure would be negatively effected. Kin selection
The jaguar is at the top of the food chain so is an apex predator. It is also a keystone species, one of those organisms which have a major role in maintaining the status quo of an ecosystem. It feeds on a vast range of prey and regulates the populations of these native animals, creating a balanced environment.s well as being a keystone species, the jaguar is an 'umbrella species' meaning that if it is protected, its broad home range and habitat needs will automatically ensure the protection of other species which share that range and those habitats. The jaguar is the national animal of Guyana and Brazil. Advertisement.