Tardigrades, Density, Diversity, Effects of DDT
Twenty lichen-bearing tree bark samples were collected from DDT sprayed American elm trees (Ulmus Americana L.) in central Iowa. Twenty comparable samples were collected from an adjacent nontreated habitat. A tardigrade density of 4 individuals collected from the treated habitat was found to differ significantly (P < .01) from a density of 97 individuals collected from the non-treated area. Margalef's diversity index (D=S-1/1n N) determinations were found to be 0.00 and 0.44 for the treated and non-treated habitats, respectively. Tardigrade species organization within the nontreated habitat did not differ significantly from that as predicted by MacArthur's broken-stick model, suggesting that tardigrade species occupy contiguous, non-overlapping niches within a lichen-bearing tree bark ecosystem. It is suggested that measurements depicting microfauna-lichen-tree bark relationships might serve as useful criteria in evaluating pesticide stress effects on total forest ecosystems.
Proceedings of the Iowa Academy of Science
© Copyright 1972 by the Iowa Academy of Science, Inc.
Barrett, Gary W. and Kimmel, Ronald G.
"Effects of DDT on the Density and Diversity of Tardigrades,"
Proceedings of the Iowa Academy of Science: Vol. 78:
, Article 3.
Available at: http://scholarworks.uni.edu/pias/vol78/iss3/3