Biotic diversity and energy flow. Forcing from man and nature
1993
Margalef, R. (Barcelona Univ. (Spain). Facultat de Biologia. Dept. Ecologia)
Biotic diversity (species richness) is understood and measured as if it were a static property and it is apparently accepted that the major problems concern statistics (diversity indices). Actually, diversity is an expression of dynamics, being the expression of the combined results of two feedback loops that operate, respectively, on the total biomass or number of individuals, and on the genetic differentiation of the whole biomass. Diversification can increase with stable and even shrinking biomass, but not if the system is subjected to repeated disturbances or increased turnover (increased production/biomass ratio). Examples of the opposite situations are: 1) A chemostat or flow culture, and 2) the fictitious but meaningful examples of a museum display case or of Noah's ark. Mankind accelerates turnover in all the rest of the biosphere, through exploitation, transportation and energy forcing, and the only reasonable prediction is unfortunately that the present loss of natural diversity shall continue.
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