PARENT SESSION
Contributed Oral Session 166: Soil Communities and Plant-Root Interactions
Friday, August 12, 8:00 AM - 11:30 AM, Meeting Room 522 A, Level 5, Palais des congrès de Montréal
Ecosystem development in various scales: Interaction between vegetation, soil fauna and soil micro-flora during primary succession in post mining sites.
Frouz, Jan*,1, Prach, Karel2, Pizl, Vaclav1, Hanel, Ladislav1, Elhottova, Dana1, Tajovsky, Karel1, 1 Institute of Soil Biology AS CR, Ceske Budejovice, Czech Republic2 Sourh Bohemian University, Ceske Budejovice, Czech Republic
ABSTRACT- Community structure of vegetation, soil micro-flora and fauna and their effect and soil changes were studied in a chronosequence of 27 post mining sites (1-41 years old) located near Sokolov (Czech Republic). A clay alkaline substrate (pH 8) was dumped in heaps; its pH and available calcium and sodium decreased during the succession, while total carbon and nitrogen, available potassium increased. TWINSPAN distinguished two clearly separated clusters of plots based on composition of the plant community. The first cluster included plots 1-23 years old dominated by euritopic and ruderal plants. These plants colonised sites early after heaping and increased their cover from sparse vegetation in initial stages to dense shrubs. The second cluster covered sites 24-41 years old; forest and meadow species became more frequent in the woodland type plant community. The humus layer, which appeared in latter succession stages, was selected by a discriminant analysis as the strongest predictor of the second cluster. Microstructure analysis indicated that earthworm activity, namely the mixing of organic and mineral layers, played a principal role in humus layer formation. Changes in the structure of topsoil affected soil biota as well. Microbial respiration and biomass as well as density of soil fauna groups (pauropods and testate amoebae) peaked in shrub-dominated stages with thick fermentation layer. Bacterial community was the most diverse in early stages latter decreased perhaps as a result of fungal competition. Macrosaprophagous soil fauna and earthworms appear in the shrub stage but their density peaked in latter stages. Earthworm mediated soil mixing decreased microbial biomass and respiration and increased proportion of micro-flora capable to decompose complex substances. The result indicated that plants play a principal role in soil biota succession (both fauna and micro-flora), but, on the other hand, changes in the topsoil mediated by soil fauna played an important role for vegetation and micro-flora succession and as well.
Key words: succession, restoration, diverstity, soil formation