Spontaneous regeneration of Collembola assemblages in a raised bog after human-induced disturbance

Abstract

Peatlands in anthropogenically transformed landscapes play an important role in biodiversity conservation. Most Baltic raised bogs have been completely destroyed by drainage and peat extraction. Collembolan and plant assemblages from an old peat mine (post-excavation pits and dykes overgrown by pine trees) were compared to those of intact ombrotrophic raised bog habitats (open bog and bog-pine forest) 70 years after excavation cessation. The plant cover and collembolan structure in regenerating pits were similar to those of the assemblages in natural open raised bogs. Rare tyrphobiont and tyrphofilous Collembola species occurred in both habitats. The assemblages in open bog habitats differed significantly from those in natural pine bog forest and dykes overgrown by pine trees. The assemblages of the natural open raised bog and pine bog forest were the most diverse and included numerous highly specialized Collembola species. The assemblages occurring on wooded dykes were significantly different from those at other peatland sites and were more similar to those of upland pine forests. The analysis of environmental factors (determined by moss Ellenberg numbers) showed that moisture was the most important factor affecting Collembola occurrence in natural and disturbed habitats. The occurrence of moss species also had a significant influence on the species composition of the collembolan assemblages. Our study revealed that seventy years of spontaneous ecosystem regeneration after peat excavation have led to habitat restoration for peat bog mesofauna. These results have important implications for conservation and restoration planning in disturbed peatlands.