Incredible differences in biodiversity

(translated from Dutch internet article at www.kennislink.nl "Knowledgelink")

Incredible Wealth

Impressive examples of the enormous biodiversity found in tropical rain forests can be provided. Terry Erwin an American entomologist (insect expert =), sprayed in the tropical rain forest of Panama the crowns of large trees of 19 tree species with the same insecticide. Under the trees he collected the dead insects on large sheets. The result stunned the world: it appeared that 1,200 different species of beetles alone had fallen from the tops of which more than 90% were unkown to science. The same technique was used by an ant specialist with a tree crown in Peru and that experiment produced 54 different kinds of ants, more species than are known in the Netherlands, Belgium and Luxembourg (BENELUX) together.

These results led to a drastic revision of the estimate of the number of insect species that inhabited the earth: probably more than 8 million (some say more than 30 million) - compare with article on biodiversity - . Despite the fact that the wealth of plant species is not as extreme as that of insects, which is astonishing richness, it is still much higher in tropical climates than for example in temperate regions like Europe and North America.

The Englishman Peter Ashton's inventory of about 100 hectares (1 km2) rain forest in Borneo (Indonesia) revealed 3,200 different tree species. In the Netherlands (33,939 km2) there are 1,300 known plant species, of which about 50 tree species. Even more astonishing are the results of the inventory of the Dutchman Jan Reitsma in Gabon (Central Africa) on a 10 × 10 meters block of tropical rainforest with 130 different species of plants! The ultimate claim is perhaps the One hundred thousand species of insects on a single hectare of the Yasuni National Park, by some selected as the most diverse area in South America (and possibly in the World)

 

The History of biodiversity

Biodiversity is increasing on our planet considering a timeframe of 4 billion years as is illustrated by the graph. So far five major extinctions are dinstinguished indicated by the yellow arrows. The treasure of evolutionary biodiversity which we are slowly unraveling during the last centuries has mainly been developed since the last 250 million years when biodiversity was at is lowest after the permium mass extinction. Looking at numbers of biodiversity it is important to realize that biodiversity can be expressed in number of species or genera like in the first graph or families (second graph) which are the three lowest ranks of the tree of life on earth. 300px-Phanerozoic_Biodiversity

The impact on biodiversity of the present ongoing man-made Holocene Extinction will according to some exceed the impacts of the previous five mass extinctions. The slowing down of the loss of biodiversity in some developed countries1, is responsible for increased loss in other areas while the resources for continued growth have to come from somewhere. Continued growth of the demand for limited natural resources will (eventually) not destroy Nature but just make the planet uninhabitable for "homo sapiens". Nature will recover even from a manmade dip in the blue curve line of extinction like it recovered from the previous extinctions shown in the second graph. A dip or extinction whether man made or not could be fatal for homo sapiens but have no more impact on the planet than all previous dips or mass extinctions.

The slowgun "Save the Planet" is therefor not accurate and should rather be "Save the homo sapiens"

1) though often at the expense of the biodiversity in others through "ecological footprints" 

family_extinction_rates_biodiversity