immigrating species, however the matrix is far more varied. By imagining how different types of isolated ecosystems, for example a pond that is surrounded by land, are similar to an island ecosystems it can be understood how theories and phenomena that are true of island ecosystems can be applied to ILS. However, the overall immigration and extinction patterns that are outlined in the theory of island biogeography as they play out on islands, also play out between ecosystems on the mainland. The concepts of area of an island and the level of isolation from a mainland as presented in the theory of island biogeography, apply to ILS. The main difference is in the dynamics of area and isolation. For example, an ILS may have a changing area because of seasons, which may impact its degree of isolation. Resource availability plays an important role in the conditions that an island is under. This is another factor that changes in ILS in comparison to real islands, since generally there is a greater resource availability in some ILS than true islands. Species-area relationships, as described above, can be applied to Island Like Systems (ILS) as well. It is typically observed that as the area of an ecosystem increases, the species richness is directly proportional. One major difference is that -values are generally lower for ILSs than true islands. Furthermore, values also vary between true islands and ILS, and within types of ILS. Applications in conservation biology Within a few years of the publishing of the theory, its potential application to the field of conservation biology had been realised and was being vigorously debated in ecological circles. The idea that reserves and national parks formed islands inside human-altered landscapes (habitat fragmentation), and that these reserves could lose species as they 'relaxed towards equilibrium' (that is they would lose species as they achieved their new equilibrium number, known as ecosystem decay) caused a great deal of concern. This is particularly true when conserving larger species which tend to have larger ranges. A study by William Newmark, published in the journal Nature and reported in The New York Times, showed a strong correlation between the size of a protected U.S. National Park and the number of species of mammals. This led to the debate known as single large or several small (SLOSS), described by writer David Quammen in The Song of the Dodo as "ecology's own