Csontos & Kalapos (2012) Grass and Forage Science

Csontos, P. & Kalapos, T. (2013): More lightweight and isodiametric seeds for C4 than for C3 grasses are associated with preference for open habitats of C4 grasses in a temperate flora. Grass and Forage Science 68: 408-417. DOI: 10.1111/gfs.12003

Abstract

Seed mass and shape of grasses were analysed in a temperate flora containing 178 and 26 species belonging to C3 and C4 photosynthetic types respectively. The weedy character and the annual or perennial status were also considered. On the basis of the seed traits studied, three groups were distinguished: C4 grasses, annual C3 grasses of weedy character and perennial non-weedy C3 grasses. The C4 group had more isodiametric (same diameter in all directions) seed shape and lower average seed mass than the C3 group. To our knowledge, this has not yet been described for temperate C4 grasses and is certainly associated with their preference for open habitats where competition for light is small. Weedy annual C3 grasses had heavier and less isodiametric seeds than C4 grasses did. These species are mostly specialized to establish in the dense cover of perennial vegetation, and this ability distinguishes them from the C4 group. Non-weedy perennial C3 species possessed less isodiametric seeds than did C4 grasses, but did not differ from weedy annual C3 grasses. As most alien C4 grasses naturalized in Hungary are annuals with small, isodiametric seeds, these traits are good candidates to be included in screening for potential future invasives in open habitats.

Keywords

C4 grasses, photosynthetic types, seed ecology, seed slenderness, thousand-seed weight, weeds

Török et al. (2012) Ecological Engineering

Péter Török, Tamás Miglécz, Orsolya Valkó, András Kelemen, Katalin Tóth, Szabolcs Lengyel, Béla Tóthmérész (2012): Fast restoration of grassland vegetation by a combination of seed mixture sowing and low-diversity hay transfer. Ecological Engineering 44: 133-138.

Abstract

Technical reclamation of grasslands is a powerful tool for conserving biodiversity in fragmented landscapes. Plant material transfer and sowing seeds of local provenance are used most frequently to recover grassland vegetation in former croplands. The joint application of these methods is rarely used, although it has the potential to gain a predictable and directed vegetation development with effective early weed suppression. We studied the effectiveness of combining low diversity seed sowing and hay-transfer in weed suppression and recovery of perennial grassland vegetation in Hortobágy Puszta, Central-Europe, by testing the following hypotheses: (i) lower weed cover and biomass is expected in vegetation recovered by the joint method of sowing and hay transfer than by seed sowing only. (ii) With sowing and additional hay transfer a higher rate of establishment of Festuca species is expected than with sowing only. Our results supported both hypotheses. We found that the additional application of hay significantly accelerated the development of perennial grassland vegetation and provided a higher weed suppression rate in the first year and onwards in most plots than seed sowing only. A higher establishment rate was detected both in the cover and the biomass of perennial grasses including Festuca species in all plots with hay addition than with sowing only. Our results suggest that a combination of hay transfer and low diversity sowing may provide a cost-effective alternative to the more costly high-density sowing and if proper sources for high-diversity hay are available, it may replace high-diversity seed mixtures.

Keywords

Grassland restoration; Festuca; Biomass; Litter; Weeds; Mulch; Species richness