Plant diversity of grassland ecotopes in the Pieria mountain of Greece
In order to understand and apply sustainable management on mountain grassland ecosystems, it is necessary to record their flora and vegetation diversity. This is particularly important for the grassland ecosystems of the NATURA 2000 Network, because they are special habitats for conservation purposes. The study area included two grassland habitats located at about 910 m and 1860 m a.s.l. of the Pieria mountain in Macedonia, Greece. According to NATURA 2000 nomenclature, two habitats were identified: the speciesrich Nardus grasslands on siliceous substrates in mountain areas (and submountain areas in continental Europe) (code number 6230); and the semi-natural dry grasslands and shrubland facies on calcareous substrates (code number 6211). Richness and abundance data were collected and analyzed with the use of the indices Shannon-Weaver and species richness. Diversity indices were found higher in the lower than in the higher ecological zone. The same results were found for the diversity of annuals. The diversity of the most important floristic families was also recorded.
Plant injurious and predatory mites on Quercus spp. in Greece
The study deals with the plant injurious and predatory mites found on Quercus spp. in Greece. The examination of a large number of samples from Quercus spp. revealed the presence of 12 species of plant injurious mites belonging to the families: Eriophyidae (10 species) and Diptilomiopidae (2 species).Three species of the family Tarsonemidae were also found. The species of the family Eriophyidae belong to 8 genera: Cecidophyes (2 species), Aceria (2 species), Bariella (1 species), Achaetocoptes (1 species), Acaricalus (1 species), Acarelliptus (1 species), Caliphytoptus (1 species) and Glyptacus (1 species). The species of the family Diptilomiopidae belong to 2 genera: Diptacus (1 species) and Rhyncapytoptus (1 species). While the species of the family Tarsonemidae belong to the genera: Tarsonemus (2 species) and Dendroptus (1 species). Along with the above mentioned mites, 19 species of predatory ones were found belonging to 3 families: Phytoseiidae (14 species), Stigmaeidae (3 species) and Cunaxidae (2 species). The species of the family Phytoseiidae belong to 2 genera: Typhlodromus (12 species) and Amblyseius (2 species). The species of the family Stigmaeidae belong to 3 genera: Stigmaeus (1 species), Storchia (1 species) and Zetzelia (1 species). While the species of the family Cunaxidae belong to the genera: Cunaxa (1 species) and Cunaxoides (1 species). All eriophyoid mites found and two of the three species of the family Tarsonemidae are recorded for the first time in Greece. For each species data are provided about its distribution to various Quercus species as well as its global distribution.
The structure of plant community in Phlomis fruticosa L. ecosystem
The structure of the plant community in a Phlometum ecosystem was analyzed from data collected from four different sites in western Epirus during the years of 1993 and 1995. To determine the floristic composition, measurements of vegetation, were used in order to estimate its composition, while for the determination of the soil characteristics nine profiles have been studied until the parent material was found. According to the data of taxa, biotic and ecological forms were determined. From the analysis it was found that therophytes were the dominant plants (41.18%) due to the arid and warm climate prevailed, while the dominance of the perennial herbaceous species (50%) shows their ability to survive in the xerothermic conditions.
The soil seed bank in range ecosystems of Psilorites mountain in Crete
The soil seed bank is considered as a genetic reserve of the populations, which helps them to recover after a disturbance (e.g. fire, erosion) or after the cessation of a pressure such a grazing. In this research, the soil seed bank of 30 sites with different fire and grazing histories was measured. From each of the 30 study sites, 20 soil cores of 5 cm deep and 5.7 cm wide (about 127 cm3) were taken. Of those 10 cores were taken under phrygana and 10 away from phrygana. In the laboratory, they were air dried for 2-4 weeks, sieved with a 4mm wire mesh; subsequently they were put in plastic containers in the greenhouse, where they were irrigated with a mist system every 2-4 days. The seedlings were counted and removed when they were identifiable or transplanted to other containers in order to be identified later. The number of seeds recorded varied from 509 seeds/m2 in a grazed forested rangeland to 47.339 seeds/m2 in a grazed grassland site. The number of seeds was significantly higher away from phryganic species than under their canopy. In burned and grazed phryganic sites, the number of seeds in the soil was significantly lower than in unburned and grazed phryganic sites for all plant categories except phrygana. In grasslands, the number of seeds was higher in grazed than in ungrazed sites. It is concluded that the soil seed bank was richer in overgrazed sites indicating a resilience of the studied ecosystems to the action of animals, while the combination of overgrazing and wildfires significantly reduced the soil seed bank.
Temporal changes analysis of landscapes with the use of Geographic Informational Systems (GIS)
Main reasons for degradation of traditional landscapes of continental Greece are the temporal changes of management practices. Portaikos valley and Pertouli land were chosen as a study area. The landscape of the study area is made up of natural and cultural features and artifacts and represents a typical traditional landscape of mountainous Greece. The possibilities of Geographic Informational Systems (GIS) have been exploited in order to achieve proper photointerpretation techniques in detection and mapping of land cover/use changes in airphotographs. Changes in the study area mainly concern management practices (changes in traditional pastoral systems), but also demographic and socioeconomic changes and they lead to homogeneous landscapes. Landscape changes mostly concern the decline of grasslands, agricultural lands and shrublands by 31.77%, 46.72% and 10.47 respectively between 1945 and 1992 while forest lands increased by 14.68% and 21.31% (conifers and broadleaves respectively) during the same period. Main
feature of forest change has been a shift between sparser to denser forests that in some cases was up to 57.7% (increase of dense coniferous forests).
