The influence of historical management on the vegetation and habitat properties of semi-dry grassland

Abstract

We assessed the effect of historical management on the vegetation and habitat properties of semi-dry grasslands on a regional scale in the Swabian Alb (South Germany). Grasslands were categorized into ancient, old, young and recent sites according to the management over the last 200 years. With around two species, diversity of vascular plants was moderately higher in grasslands with at least six decades of continuous management, which was supported by the GLM. With seven and ten species, diversity of cryptogams and threatened plants significantly increased from recent to ancient grasslands. Short-term managed grasslands exhibited a strong similarity in species composition along increased proportions of species from cultivated grasslands with high forage values, different from most long-term management grasslands. The shift in species composition from mainly typical semi-dry grassland plants for long-term management towards ubiquitous plants from cultivated grasslands was emphasized by a set of indicator species for each time span. The effect of fertilizing in the arable field use was still lingering in recent grasslands, reflected in higher levels of nutrients. Plant available phosphorous was even three times higher with averagely 37 mg/kg soil. Long-term managed grasslands are relicts of pasturing for centuries in the traditional or improved three field rotation systems and harbour a higher diversity, whereas recent grasslands are marked by the shift to modern agriculture and provide a higher fodder quality. Our results suggest that different managements are required to maintain the grassland’s quality depending on the time span of establishment. Particularly short-term managed grasslands may need more intensive grazing to re-develop them into the direction of long-term grasslands.