Vegetation succession in restoration of disturbed sites in Central Europe: the direction of succession and species richness across 19 seres

Abstract

Questions (1) How do seres differ with respect to vegetation changes? (2) What are the directions of succession? (3) How do species numbers change? (4) How do target species, i.e. those typical of natural and semi‐natural vegetation, participate in succession? (5) Are spontaneously developed successional stages acceptable from the point of view of ecosystem restoration? Location Extracted peatlands, bulldozed sites in forests destroyed by air pollution, an emerged bottom of a water reservoir, corridors of former Iron Curtain, artificial fishpond islands and barriers, sedimentary basins, spoil heaps from mining, stone quarries, forest clearings, road verges, sand and gravel‐sand pits, ruderal urban sites, river gravel bars and abandoned arable fields, located in various parts of the Czech Republic in Central Europe. Methods Phytosociological relevés were recorded in 10–25 m2 plots located in the centre of representative successional stages defined by their age, ranging from 1 to 100 yrs. In total, we obtained 2392 vegetation samples containing 951 species. We performed DCA ordination to compare 19 seres. Desirable target species were considered as those representing (semi)‐natural vegetation and all Red List species. Results The seres studied are more similar in their species composition in the initial and early stages, in which synathropic species prevail, than in the later stages when the vegetation differentiates. This divergence is driven mainly by local moisture conditions. In most cases, succession led to woodland, which usually established after ca. 20 yrs. In very dry or wet places (with limited presence of woody species) open vegetation developed, often highly valuable from the restoration and conservation point of view. The total number of species and the number of target species increased in the majority of seres with successional age. Conclusions The vegetation in the sites studied formed a continuum along a moisture gradient and by successional age. The individual seres largely overlapped in their species composition; the sere identity was not significant. Spontaneous succession usually proceeded towards woodland, except at very dry or wet sites, and generally appeared to be an ecologically suitable way of ecosystem restoration of disturbed sites because target species became dominant over time.

Participation of the Czech flora in succession at disturbed sites

“…It should be mentioned that the "tolerance" of species to successional age is summarized here across all the seres, disregarding sere identity. This is justified by our earlier finding (Prach et al 2014) that sere identity is not a statistically significant factor determining the species composition of seral stages; successions over a large geographical area and across environmental factors form a continuum in space. This validates our decision to consider all the seral stages together and disregard their identity.…”

“…We also extracted some data from published and unpublished records (see Prach et al 2014). We considered all seres, which we identified in a sufficient number of representative successional stages in the Czech Republic over the past four decades .…”

“…The seres included successional stages on various spoil heaps from brown coal, black coal and uranium mining, sand and sand-gravel pits, limestone quarries, acidic rock quarries, basalt quarries, extracted peatlands, road verges, ploughed and then abandoned strips along the state border (the former "iron curtain"), river gravel bars, artificial islands and barriers in fishponds, the bottom of a former water reservoir, sedimentary basins, ruderal urban sites, abandoned fields, bulldozed sites of forests damaged by air pollution, forest clearings and burnt forests. Most of the seres are described in separate studies or summarized in papers (Prach et al 2013(Prach et al , 2014(Prach et al , 2016. In these references, there are details of the seres, including determination of successional age, which was based on rather precise records provided by mining companies, land owners and our own observations.…”

“…The particular seres differed in number of samples, number of sites, location and successional age, but they were all sampled in a comparable way (Prach et al 2014). All but one of the seres (river gravel bars) were initiated by human activity.…”

“…1). This data set (Database of Successional Series -DaSS; Prach et al 2014Prach et al , 2016 includes nearly 3000 phytosociological relevés from seral stages aged 1 to > 150 years, for a high number of successional series (hereafter seres), both primary and secondary, and in terms of the encountered species it includes more than half of the Czech flora (Prach et al 2014(Prach et al , 2016.This extensive material therefore is sufficiently representative and suitable for evaluating the ability of the Czech flora to colonize disturbed sites, based on real quantitative data.…”