Effects of grazing and fires on biodiversity of oak forest rangeland in W. Lesvos.
The abandonment of oak forests from rural populations because of the great decrease of economic value of their products leave the forest to fires, to illegally woodcutting, to clearcutting and to overgrazing. In west Lesvos there is an oak forest Quercus ithaburensis subsp. macrolepis of 5.000 h. Although numerous studies have been devoted to the impact of livestock on vegetation, information about effects of grazing on oak forest is still scarce. The aim of the present study is to analyse the biodiversity of plant communities in two different ecosystems of valonia oak which differ on management a) grazing “Filia” area b) grazing and fires “Antissa” area. The density of oaks was 41 trees/ 0,1 h in “Filia” and 18 trees/0,1 h in “Antissa”. The grazing pressure was bigger in ‘Filia’ area. The biomass of herbaceous plants was 824 kg/h in “Filia” and 420,6 kg/h in ‘Antissa”. The structure of ecosystems of the middlestory and understory was degraded with the dominance of undesirable vegetation for livestock mainly in “Antissa” area. The soil properties were better in “Filia” area but the differences were not significant. The richness and biodiversity indices increase in ‘Antissa” area mainly because of fire and the successional stage of ecosystem.
Εffect of abiotic factors on grasslands diversity
Grasslands diversity is the expression of the interaction of abiotic factors, as they differentiated along altitude gradient and the biotic ones (plants). The aim of this research was to study the effect of abiotic factors on grassland diversity. The research was conducted on Othrys mountain grasslands in central Greece at altitude range between 800 – 1500 m. The abiotic parameters which are related with plant’s growth, as soil nitrogen and organic matter content and phosphorus concentration were measured from soil samples that were taken in depth of 0-20 cm from soil surface. Also the topographic parameters of experimental areas as altitude, inclination and exposition were measured. The plants’ diversity index of Shannon – Weiner and Equitability were calculated from plants’ density measurement. The results showed that diversity increased in grasslands with altitude >1200 m. Also it was found that the interaction of the topographic (altitude, inclination) and soil (nitrogen, phosphorus) variables contributed to the increase of perennial grass and legume species and so to these grasslands diversity.
The effects of grazing on terraced agro-ecosystems of Lesvos Island (Greece)
We used GIS mapping to study the spatial distribution of the terraced areas on the island of Lesvos, in particular those used today as pastures and related to husbandry. In addition we investigated the effects of husbandry activities (grazing, stabling etc.) on the status of conservation of the supporting walls of these terraces. The evaluation of the mapping results has shown that the west and northwest part of the island suffers the highest terrace abandonment, which goes hand-in-hand with the development of goat and sheep keeping. Despite of the fact that such abandonment is evident in other parts of the island, we expect that the aforementioned areas are more severely and immanently threatened compared to the rest of the island. This is due to the present land use and grazing pressure (high in the W and NW) and the geological substrate (volcanic rock used to build the supporting walls in the W and NW).
Contribution of snow on the development and maintenance of mountainous grasslands in the arid environments of Crete
Even though the mean annual rainfall of Crete (Pm= 870 mm) is higher than that of the rest of Greece (Pm= 630 mm), Crete is considered as an extremely arid area exhibiting a desertification tendency. This phenomenon is due to a) the concentration of the highest quantity of precipitation from November to March and the almost total lack of rainfall at the rest of the year and b) the geological substrate of the mountains of Crete that consist of intensely weathered – eroded penetrable carbonate formations. In this study snow and snowpack conditions at typical mountainous areas of Crete were studied and their contribution to the maintenance of grasslands at these sites was evaluated. The data suggest that, in order to confront desertification phenomena in Crete, it is important to conserve grassland ecosystems, which comprise the only ecosystems that can exist at the mountainous parts of the island. Furthermore, grasslands of mountainous areas with high quantity of snowfall and satisfying snowpack maintenance are found to possess a high floristic diversity.
Presentation of Forest Service’s actions in the framework of the Life-project: “Conservation actions for Gypaetus barbatus and biodiversity in Crete”.
This paper presents the actions that were implemented by the Forest Service of Crete’s Region and the Forest Service Departments of Herakleion, Chania, Rethymnon, and Lasithi prefectures under the framework of the LIFE02NAT/GR/8492 project: «Conservation Actions for Gypaetus barbatus and the Biodiversity in Crete». It refers to the following activities and works: 1.Management Plans for agro-pastoral extensification at the two project sites of Agios Dikaios and Asteroussia mts. 2.Construction of a bird observatory at Asteroussia mts., 3.Construction of two small ponds for wildlife-use at the two project sites, 4.Construction of livestock water-troughs, 5.Fencing of sensitive areas (vulture feeding station, priority habitat of Phoenix theophrastii at Asteroussia mts. and site of pilot habitat restoration), 6.Construction and distribution of one thousand wasp traps to local beekeepers, 7.Construction of the necessary infrastructure for the production of chukar partridges of local genetic origin to be released at the two project sites, 8. Pilot habitat restoration measures at Asteroussia area, 9.Control of access at certain track roads, 10.Operation of vulture feeding stations, 11.Restoration of foraging habitat quality by game management, 12.Patrolling and warding at all project sites, 13.Organization of nature festivals at the two project sites, 14.Construction of interpretative nature trails at Asteroussia mts.
