Mowing may bring about vegetation change, but its effect is strongly modified by hydrological factors

Aleksander Kołos,Piotr Banaszuk

doi:10.1007/s11273-018-9615-x

Aleksander Kołos, Piotr Banaszuk

Open Access

https://doi.org/10.1007/s11273-018-9615-x

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Abstract

We assessed the effect of long-term (11 years) mowing with a hand scythe on the distributions of plant species and species turnover within meadow communities dominated by Carex acutiformis and C. acuta in a small lowland river valley subjected to annual flooding. We hypothesized that mowing would trigger the process of species exchange toward multispecies communities according to the abiotic environmental gradients, as has been reported for traditionally used wet meadows. We found that mowing had a much greater impact on the increase in plant species abundance in wetter, subjected to deeper and longer flooding, zone of the valley than in its drier part. The treatment and hydrology had no substantial effect on the sedges and cryptogams while the graminoids and the forbs were the least stable components of the plant communities. We found that annual management was conducive to the appearance of numerous seedlings of Alnus glutinosa in the part of wetland situated close to the valley edge. Surface flooding was found to be a driving force modifying the impact of mowing on sedge meadows. This “hydrological resetting impulse” created a specific floristic reset of the community, bringing it to the more simplified forms. Mowing every 4–5 years at the beginning of August is advisable to protect sedge meadows distributed in flooded small lowland river valleys.

Highlights

Valley wetlands and wet meadows are essential elements of the agricultural landscape in Europe, where for hundreds of years they have been continuously managed as a source of fodder
In some regions this impact can be exacerbated by future climate change, which can affect the hydrology of wetlands and wet meadows in some unpredicted way (Thuiller et al 2005)
Significant (p \ 0.05) upward trends have been observed for the average air temperatures of the winter and spring months, February-April, and summer months, July and August, the observed pattern of variability was different for those two periods (Fig. 2A, B)

Summary

Introduction

Valley wetlands and wet meadows are essential elements of the agricultural landscape in Europe, where for hundreds of years they have been continuously managed as a source of fodder. Semi-natural open ecosystems, dominated by sedges or grasses, developed due to the deforestation of the floodplains Their strong feature is the relatively high level of groundwater and the variably intense surface floods that occur most years (Marcinkowski and Grygoruk 2017). Environmental determinants could be of paramount importance in determining the species pool of meadow communities, and the richness of vascular plants within mown meadows can be explained by abiotic factors, primarily by hydrology (Leyer 2005; Kołos and Banaszuk 2013). In some regions this impact can be exacerbated by future climate change, which can affect the hydrology of wetlands and wet meadows in some unpredicted way (Thuiller et al 2005)

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