The effect of different combination of livestock grazing on herbage production in permanent dry grasslands
Rangelands are multifunctional natural non-arable land, covered by different types of vegetation, including herbaceous and woody plants. Dry grasslands occupy areas that have relatively dry and nutrient-poor soils and they are mainly used for livestock grazing. Grazing is recognized as an important ecological factor in grassland ecosystems, which has affected the structure, the composition and the characteristics of vegetation. The aim of this paper was to study the effect of different combination of livestock grazing on the production in two dry grasslands. The study area was located near the lakes Zazari and Chimaditida, in Florina region, western Macedonia, Greece. The grasslands in Zazari were used by small ruminants and cattle of the nearby village, while the grasslands in Chimaditida were used mainly by sheep and very few goats. The herbage production in both grasslands was measured in 2008. It was found significantly lower in the grasslands of Zazari than in the grasslands of Chimaditida. The grazing by different kind of animals has created a different plant structure and composition in the grasslands.
Plant diversity of grazed and reforested Mediterranean rangelands
Rangelands cover a large area in the Mediterranean region but are largely degraded due to their improper grazing management. The aim of this study was to investigate the effect of various management practices applied for restoration of degraded Mediterranean rangelands on plant diversity. The research was conducted in rangelands of Lagadas county, in North Greece, dominated by evergreen shrublands. The management practices studied were: moderate grazing, overgrazing, control (banning of grazing), partial and full reforestation with pines (Pinus pinaster). Three transects were established on each management practice. Plant cover was recorded along each transect using the line-point method and species composition was calculated. Additionally, species presence /absence was measured using 10 quadrats per transect. The recorded species were classified into five a priori groups (trees, shrubs, grasses, legumes, forbs). Furthermore, three plant diversity indices (Shannon-Wiener, evenness and species richness) were calculated for each transect. The five management practices had high plant cover, with the exception of the overgrazed one. The composition of the vegetation however differed in terms of the dominant plant group in each practice. As far as plant diversity is concerned, the moderately grazed practice had the highest values followed by the control while the full reforestation had the lowest. It is concluded that the various management practices for restoration of degraded Mediterranean rangelands affect differently plant species composition and diversity. However moderate grazing can contribute to restoration of plant diversity without resorting to other management practices such as pine plantations.
Late Holocene changes in the high-altitude vegetation of mountainous areas of north-central Greece and the role of grazing
Palynological studies have been carried out in the Lailias, Belles, Voras and Pieria (Flambouro) mountains which are located in north- central Greece. The four mountainous sites share some common geological and vegetation features. All sites have crystalline bedrocks and the high altitude forest vegetation is dominated by beech and/or pine forests though there are differences among these areas regarding the extent of these forest types, their location in relation to the coring sites etc. A distinct subalpine zone is present in all sites except Lailias and is dominated by Juniperus communis ssp. nana, ericaceous dwarf shrubs and extended grasslands. A comparative palynological study of the changes in the high-altitude vegetation of the four sites is attempted covering the Late Holocene. Pollen types related with human induced disturbance (e.g. forest clearings, animal husbandry) are compared up against pollen types of major forest vegetation units. Signs of local grazing pressure can be traced in various time periods in the diagrams of Beles, Lailias and Pieria. Though traceable in the Voras diagram, grazing pressure seems to have no major impact on the forest vegetation.
The short-term impacts of cessation of grazing on plants and land snails in grasslands in the west of Ireland
The Burren in western Ireland is famous for its biodiversity. It is well accepted that the high biodiversity of the region is linked strongly to its agricultural traditions. However, there are significant changes happening in the landscape including a major expansion of hazel scrub into grazing land. This is due, at least in part, to changes which have occurred in farming in recent decades. To provide some evidence-based insight into this issue, this study investigated the effects that the complete cessation of grazing in Burren grasslands would have on biodiversity – with the focus on vascular plant and land snail communities. Large changes were recorded from within fenced grassland exclosures (with more mixed pictures emerging for scrub and woodland). A significant decrease was seen in both species richness and diversity for the plants in the grasslands, along with a significant increase in the amount of litter present. In the case of the snails, however, abundance increased significantly inside the fenced plots, while there was only a very small change in the controls. Shifts in community structure were also evident. It is likely that the molluscs benefitted from the higher vegetation and denser litter, providing them with food, shelter and moisture.
Grazing effects on floristic diversity of a juniper-oak rangeland
The aim of the present study was to investigate the effects of grazing intensity on plant cover and floristic diversity of a juniper – oak rangeland ecosystem in the Mediterranean region. The research was conducted in an area, which is grazed mainly by goats, at Megalo Dereio in Evros region, northeastern Greece. Three experimental plots were selected in a rangeland dominated by Juniperus oxycedrus with the spontaneous presence of Quercus frainetto: 1) a lightly grazed plot, 2) a moderately grazed plot and 3) a heavily grazed plot. An area of 25 m2 in each plot was fenced in autumn 2008, in order to be protected from grazing. The plant cover, the species composition and the herbage production were measured in June 2010 and ecological diversity indices as well as the forage utilization percent were determined. The plant cover was significantly reduced by heavy grazing. The floristic diversity was not affected by the different grazing intensities. There was however, a significant reduction of it where protection from grazing was applied.
