Less than 21 percent of Earth contains all of its large mammalsDecember 24th, 2007 - 1:18 pm ICT by admin
Washington, Dec 24 (ANI): A new research has established that less than 21 percent of the Earths terrestrial surface contains all of the large mammals it once held around 500 years back.
For the study, researchers compared historical (AD 1500) range maps of large mammals with their current distributions.
They found out that though large mammals often play critical roles within ecosystems by affecting either prey populations or the structure and species composition of vegetation, they are highly vulnerable to extermination by humans.
In fact, human activities like habitat alteration and direct exploitation or persecution have greatly reduced the extents of the geographic ranges of individual species.
According to a report published in the Journal of Mammalogy, large species are particularly prone to local extermination because they are differentially hunted for the flourishing trade in wild meat, controlled as competitors, or otherwise persecuted. Severe habitat fragmentation within species ranges also results in increasingly rare intact large mammal faunas.
The objectives of the study were to indicate where historical human impacts occurred and to show where the remaining intact large mammal assemblages are found, how they are distributed, and their level of protection.
But, the results vary widely by geography.
Although less than 21 percent of the earths terrestrial surfaces still contain the large mammal faunas that were once there, the proportions varied between 68 percent in Australasia to only 1 percent in Indomalaya.
The research has availed a number of positives from the findings.
For example, the researchers said that areas that contain complete large mammal groupings merit conservation attention because only 8 percent of that land area is well protected.
They also said that modern methods for designing reserves can incorporate a wide variety of data layers, and even proposed that the results of their analysis be another layer to consider.
Already, large international conservation organizations have used this development to prioritize their global actions.
Additionally, support for long-term conservation should be directed toward intact assemblages that are small and intensively managed as well as to faunas of remote and inhospitable areas, the research suggested. (ANI)
Tags: assemblages, conservation attention, critical roles, data layers, dec 24, extents, extermination, geographic ranges, groupings, habitat alteration, habitat fragmentation, mammal, mammals, range maps, species composition, species ranges, study researchers, terrestrial surface, terrestrial surfaces, wild meat