Regional seed mixtures for the re-creation of species-rich meadows in the White Carpathian Mountains: results of a 10-yr experiment
How does sowing a regional seed mix compare with a commercial grass mix and natural regeneration for re-creating species-rich hay meadow vegetation? What is the trajectory of vegetation change of these treatments over 10 yr compared with ancient meadow vegetation on a nearby nature reserve? What factors indicate successful restoration on ex-arable land?
White Carpathian (Bílé Karpaty) Mountains, Czech Republic.
In 1999 an experiment was set up to investigate methods of re-establishing species-rich meadow vegetation on ex-arable land. Large plots sown with a regional seed mixture (RSM) were compared with three other ‘lower cost’ treatments – sowing narrow 2.5-m wide strips of the RSM into a matrix of commercial grasses (RCG), sowing strips of RSM into a matrix of natural regeneration (RNR) and natural regeneration alone (NR). Results are presented for years 2000, 2004 and 2009.
Regional grass species established and persisted in cover and species number, regional herb species established and persisted in number but declined in cover. Perennial weeds increased in years 2000–2004 but had declined by 2009. The vegetation showed a gradual convergence in the direction of the ancient meadow vegetation and the vegetation was species-rich but a long way from the ancient meadow composition.
The experiment demonstrated lasting benefits of regional seed mixtures, including rapid establishment of meadow species with no perennial weed stage, producing vegetation suitable for haymaking. However, sowing regional seed mixtures is the most expensive method and colonization of these plots by unsown target species was slow. Satisfactory results were achieved by the cheaper method of sowing strips of regional seed mixture in a matrix of natural regeneration or natural regeneration alone, and colonization by unsown target species was the more successful here, although some of this was due to colonization (cross-contamination) from adjacent plots. The poorest results were in the commercial grass treatments due to strong competition from sown commercial grasses. Overall, to achieve biodiversity goals in grassland restoration it is essential to use seeds of regional provenance.