Biogeosystems and Biodiversity – The Network of Biotic Diversity on Earth
Diversity is not a new management method, but an old and elementary principle of nature. Biodiversity is the basis of all life and biotic evolution. Apart from species diversity, it refers to the genetic diversity within a population and the diversity of natural biotopes and habitats, especially the diversity of ecosystems. Genetic diversity is the prerequisite of the evolution in all geological eras of earth. The development of ecosystems is the multilayered and more differentiated the larger their species diversity. In this context, their stability depends on their individual structure and species diversity, as living beings have always been dependent on each other via food chains and symbioses. What do the Bengal tiger (Panthera tigris tigris), the Red Panda (Ailurus fulgens), the Seychelles nut (Lodoicea maldivica) and the Nebrodi fir (Abies nebrodensis) have in common? They are all included in the IUCN-Red Lists of highly endangered species. Natural biodiversity worldwide is continuously decreasing at present. According to estimates, approximately 130 species become extinct every day. Over the past 50 years, global species diversity has thus decreased by approximately 40 % which can geologically be compared with the consequences of past natural disasters; only today, human being is considered the main culprit for the current mass extinction. The main causes of what is currently happening are exploitation of natural resources, habitat destruction, soil sealing and over fertilisation leading to the current so-called 6th mass extinction on earth. The United Nations declared the year 2010 the “International Year of Biological Diversity” in order to call attention to the imminent serious loss of biotic diversity of both animals and plants worldwide. The aim is to make everybody fully aware of the significance of biological diversity as well as of the consequences of its loss to global economic and human-political development. Examples are given from Germany and Europe. Today, no exact data are available to confirm how many species are currently living on earth. Estimates reckon with approximately 15 million. Approximately 1.7 million species are denominated and described, but only 40,000 species have been studied with regard to their endangering. There may be, for example, much fewer plant species on earth than it has been assumed so far. It is true that approximately 1 million names have been allocated, for example, to plant species; however, the existence of only 280,000 species has been proven. After conducting comparisons for years, a large number turned out to be only synonyms or even variations of already known or described plants.