Land Usage
The lower elevations on several of the islands have been cleared for housing and farming. The upper elevations are still largely forested. Types of plants farmed in the islands include vanilla, coconuts, sweet potatoes, and cinnamon. While farming is important the main source of revenue for the islands is the tourist sector.
Damage
Damage to the Seychelles islands is a huge issue to the anthropogenic disturbance of native habitats. Human disturbance is a major part of this issue through land clearing, and the introduction of nonnative species poses a serious threat. Alien species now compromise 57% of the total flora of the Seychelles, and this percentage is estimated to increase over time. (Procter 1984). Humans introduced goats, pigs, and cattle inhibit regeneration of native forests, while introducing cats, dogs, common mynah (Acridotheres tristis) and tenrecs prey upon native species, such as birds, lizards, caecilians and invertebrates. Nonnative species compete with the native species and provide inadequate habitats for the native animals. Besides land clearing and invasive species, a main conservation concern of the Seychelles Islands is the vulnerability of small populations within restricted ranges. Many native species have most likely had a small population, while the majority of them were spread over several islands. After human disturbance, species has decreased to one or two relict populations. The endemic land birds exemplify this by occupying a mere fraction of their historic range, due to these small populations in single locations are especially vulnerable to stochastic events and have a high probability of extinction. Some trans-location efforts have been made to help mitigate the risks inherent in having spatially restricted populations, but not without their own risks. The Seychelles government, in cooperation with international agencies, is doing their job in protecting the unique biological heritage of the islands. Even with the governments help, the long-term survival of many species and habitats are still far from certain.
Stable Night Light Detection: 1992 to 2009The National Oceanic and Atmospheric Association's (NOAA) Defense Meteorlogical Satellite Program (DMSP) has compiled a global nighttime light time series from 1992 to 2009. This satellite system is thus capable of global observation of the location of form and density of development within human settlements at moderate spatial resolution. This information can be incredibly useful for understanding where humans are developing settlements, and how it has changed over a 19 year time span. In the case of the Seychelles it is clear there has been encroachment upon most of the protected areas of the largest Island, Mahe as well as the island group of Praslin. However, there has been a noticeable decline in human settlement on the island of Silhouette, which is surrounded by a protected area.
For more information in regards to night light detection please use the link provided: http://www.ngdc.noaa.gov/dmsp/gcv4_readme.txt |
References:
http://www.worldwildlife.org/wildworld/profiles/terrestrial/at/at0113_full.html
Stable Night Lights: NOAA's National Geophysical Data Center. DMSP data collected by US Air Force Weather Agency
http://www.worldwildlife.org/wildworld/profiles/terrestrial/at/at0113_full.html
Stable Night Lights: NOAA's National Geophysical Data Center. DMSP data collected by US Air Force Weather Agency