High-diversity sowing in establishment gaps: A promising new tool for enhancing grassland biodiversity

TY - JOUR

T1 - High-diversity sowing in establishment gaps

T2 - A promising new tool for enhancing grassland biodiversity

AU - Valkó, Orsolya

AU - Deák, Balázs

AU - Török, Péter

AU - Kirmer, Anita

AU - Tischew, Sabine

AU - Kelemen, András

AU - Tóth, Katalin

AU - Miglécz, Tamás

AU - Radócz, Szilvia

AU - Sonkoly, Judit

AU - Tóth, Edina

AU - Kiss, Réka

AU - Kapocsi, István

AU - Tóthmérész, B.

PY - 2016/1/1

Y1 - 2016/1/1

N2 - Halting the loss of grassland biodiversity and restoring degraded ecosystems are high priority tasks in the EU Biodiversity Strategy. Sowing low-diversity seed mixtures is widely used in grassland resto-ration because of its high predictability and fast, promising results. Generally, the sown perennial grass-es establish within a few years and form a dense sward, which effectively suppresses weeds. Unfortu-nately, these grasslands are often species-poor because the sown grasses hamper the colonisation of target grassland forbs. Our aim was to test a novel approach to increase the diversity of species-poor grasslands. We selected eight 8-year-old grasslands restored by low-diversity seed sowing where we created 32 establishment gaps by breaking up the grass sward and sowing a high-diversity seed mixture (35 native species). Altogether, we established three grazed gaps (1 m × 1 m, 2 m × 2 m and 4 m × 4 m) and one fenced gap (4 m × 4 m) per site and monitored the presence and abundance of sown and non-sown species within a time frame of two years. We asked the following questions: (1) Which target species establish most successfully? (2) What is the effect of establishment gap size on the establish-ment success of target species and weeds? (3) What is the effect of management (grazed versus not managed) on the species composition of the establishment gaps? Our results showed that by creating establishment gaps and sowing diverse seed mixtures, we were able to overcome microsite and propa-gule limitation, successfully introducing target species into the species-poor grasslands. We found that all sown species established in the gaps, and the majority of the species maintained or even increased their first-year cover in the second year. Smaller gaps were characterised by lower cover of sown spe-cies and a quite stochastic development compared to the larger ones. Weed cover was moderate in the first year and decreased significantly in the second year, regardless of gap size. Therefore, in restoration practice, the use of larger establishment gaps is recommended. We found that the cover of sown species and weeds were similar in the grazed and unmanaged gaps during our study. However, management by extensive grazing might be crucial in the long-term because livestock can disperse target species propa-gules and create microsites. Our study shows that establishment gaps can serve as biodiversity hotspots. Further studies need to clarify to what extent they can improve the restoration success across the entire grassland.

AB - Halting the loss of grassland biodiversity and restoring degraded ecosystems are high priority tasks in the EU Biodiversity Strategy. Sowing low-diversity seed mixtures is widely used in grassland resto-ration because of its high predictability and fast, promising results. Generally, the sown perennial grass-es establish within a few years and form a dense sward, which effectively suppresses weeds. Unfortu-nately, these grasslands are often species-poor because the sown grasses hamper the colonisation of target grassland forbs. Our aim was to test a novel approach to increase the diversity of species-poor grasslands. We selected eight 8-year-old grasslands restored by low-diversity seed sowing where we created 32 establishment gaps by breaking up the grass sward and sowing a high-diversity seed mixture (35 native species). Altogether, we established three grazed gaps (1 m × 1 m, 2 m × 2 m and 4 m × 4 m) and one fenced gap (4 m × 4 m) per site and monitored the presence and abundance of sown and non-sown species within a time frame of two years. We asked the following questions: (1) Which target species establish most successfully? (2) What is the effect of establishment gap size on the establish-ment success of target species and weeds? (3) What is the effect of management (grazed versus not managed) on the species composition of the establishment gaps? Our results showed that by creating establishment gaps and sowing diverse seed mixtures, we were able to overcome microsite and propa-gule limitation, successfully introducing target species into the species-poor grasslands. We found that all sown species established in the gaps, and the majority of the species maintained or even increased their first-year cover in the second year. Smaller gaps were characterised by lower cover of sown spe-cies and a quite stochastic development compared to the larger ones. Weed cover was moderate in the first year and decreased significantly in the second year, regardless of gap size. Therefore, in restoration practice, the use of larger establishment gaps is recommended. We found that the cover of sown species and weeds were similar in the grazed and unmanaged gaps during our study. However, management by extensive grazing might be crucial in the long-term because livestock can disperse target species propa-gules and create microsites. Our study shows that establishment gaps can serve as biodiversity hotspots. Further studies need to clarify to what extent they can improve the restoration success across the entire grassland.

KW - Alkali grassland

KW - Grazing

KW - Loess grassland

KW - Seed mixture

KW - Species establishment

KW - Weed control

UR - http://www.scopus.com/inward/record.url?scp=85029921163&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85029921163&partnerID=8YFLogxK

U2 - 10.14471/2016.36.020

DO - 10.14471/2016.36.020

M3 - Article

AN - SCOPUS:85029921163

VL - 36

SP - 359

EP - 378

JO - Tuexenia

JF - Tuexenia

SN - 0722-494X

ER -