Colonization of chemical factory wastes by soil nematodes

Abstract

Soil nematodes were studied in 39- and 49-year-old “red” dumps mainly composed of Fe 2O 3 waste pyrite remnants from production of sulphuric and other acids, and in a 84-year-old “white” dump mainly composed of CaCO 3 material from soda production. The youngest stage of spontaneous biological succession contained moss–lichen patches which were mainly inhabited by bacterivorous nematodes ( Acrobeloides nanus, Panagrolaimus rigidus, Rhabditis terricola, Bursilla monhystera) in very low abundance (about 50×10 3 ind m −2). Invasion of grass resulted in increase of bacterivorous nematodes up to several millions ind m −2 but with considerable seasonal fluctuations. Nematode assemblages diversified in sites colonized by various deciduous trees and Paratylenchus straeleni was the dominant plant parasitic nematode. In site with stabilized grass carpet on the “white” dump dominant nematodes were Geocenamus quadrifer and Pungentus engadinensis. Eudorylaimus spp. first appeared in 49-year-old dump but their populations remained very low (1–9×10 3 ind m −2). Some species found in control deciduous forests on natural soils (e.g. Xenocriconemella macrodora, Cephalenchus hexalineatus, Tylolaimophorus minor, Ogma menzeli, Hoplotylus femina) did not colonize deposits. Natural succession of nematodes on chemical waste materials was very slow and even after about 80 years their communities under deciduous trees showed many differences from those in nearby semi-natural mixed forests.