Zoochory on and off: A field experiment for trait‐based analysis of establishment success of grassland species

Abstract

Aims We tested the establishment success of grassland species in the presence or absence of zoochory by livestock and identified the traits associated with successful establishment. Location Hortobágy National Park, Hungary. Methods In six restored species‐poor grasslands we established two species‐rich 4 m × 4 m source plots per site in 2013. One source plot was managed by extensive cattle grazing (“zoochory on”), the other one was fenced and protected from grazers (“zoochory off”). We monitored the vegetation development in the source plots (2014–2018), and the establishment success of sown species (2016–2018) in adjacent dispersal plots in four, 20‐m‐long strips per source plot in a total of 960 dispersal plots. We calculated community‐weighted means of thirteen plant traits related to regeneration and competitive ability. The effect of grazing, year, distance from source plots, grazing–year and grazing–distance interactions on population and trait dynamics in the source and dispersal plots were analysed with generalized linear mixed‐effect models. Results Although grazing reduced the cover and flowering success of sown species in the source plots, the number of successful establishment events was higher in dispersal plots next to grazed source plots. The sown species were the most abundant in plots adjacent to source plots, but occurred at all monitored distances. Zoochory favoured perennial plants with high specific leaf area (SLA), low leaf dry matter content (LDMC), short stature, light seeds, early flowering period, high clonal index and anemochory index. Conclusions We showed that species that can colonize the matrix with and without zoochory have contrasting trait syndromes. In grazing‐adapted ecosystems, fencing source populations of target species does not always seem to be a good option. It was a good tool for increasing the cover and flowering success of the sown species in the short run, but it significantly decreased their chance to colonize the surrounding area in the long run.

Reversing expansion of Calamagrostis epigejos in Carpathian mountain grasslands by mowing and application of hemiparasitic Rhinanthus alectorolophus

“…Grazing may be introduced in late summer or early autumn. This late‐season grazing is generally recognized as a measure of promoting biodiversity by facilitating seed dispersal and creating regeneration gaps crucial for seedling recruitment (Kleinebecker et al., 2011; Davis et al., 2014; Kiss et al., 2021). However, grazing should be combined with prior cutting and biomass removal after a good establishment of R. alectorolophus .…”

Vegetation Cover Management and Landscape Plant Species Composition Influence the Chrysopidae Community in the Olive Agroecosystem

“…Our results showed greater plant cover values in zoochoric plant species in grazed olive farms. Previous studies of zoochory have concluded that perennial plant species, with large leaf areas and low leaf dry-matter content, are selected over small plant species with light seeds and early flowering periods [ 50 ]. Good examples of this case from our study are M. minima and M. rigidula , both creeping therophytes with legume sizes of 2.5–3.5(4) mm in the former and 4.5–7 × 6.5–7.5 mm in the latter [ 51 ].…”

Co-seeding grasses and forbs supports restoration of species-rich grasslands and improves weed control in ex-arable land

“…To create and maintain a high diversity grassland, forbs, especially rare and weak competitors, should be sown as soon as possible, as even so there is high chance for some of them to perish over the years 33,38 . Besides, further interventions (harrowing, grazing) may also be needed to create suitable microhabitats for later-arriving species 35,36 . www.nature.com/scientificreports/ Not only grass sowing, but also weed encroachment in fallow plots delayed sown forbs establishment.…”

“…Grass sowing is widely used approach in large-scale restoration projects, but it should be considered that the developed closed sward not only suppresses weeds but also hampers the establishment of late-successional target grassland forbs 24,29,33 . Application of diverse seed mixtures by overseeding the grass matrix 34,35 or sowing into gaps with bare soil 24,36 is used mainly to increase species richness of species-poor restored grasslands.…”