Conditions that promote karst development are well-jointed, dense limestone near the surface; a moderate to heavy rainfall; and good groundwater circulation. Limestone (calcium carbonate) dissolves relatively easily in slightly acidic water, which occurs widely in nature.
Crowther said first he had to figure out how many trees are on Earth and that number was far more than anyone expected: 3.04 trillion trees, according to a study published Wednesday in the journal Nature. 14 Photos Trees Around The World.
How many animal species are there on earth? Here's a rough count, and a brief explanation of how scientists arrive at the numbers. How many animal species are there on earth? Here's a rough count, and a brief explanation of how scientists arrive at the numbers. How Many Animal Species Are There? Retrieved from https://www.thoughtco.com/how-many-animal-species-on-planet-130923 Strauss, Bob.