Eleni Eleftheriadou

Estimation of Reference Potential Evapotranspiration with Focus on Vegetation Science—the EmPEst Software

Owing to the difficulties in measuring daily reference potential evapotranspiration, its estimation by means of the ASCE Penman-Monteith approach and various other empirical equations that are less demanding in terms of input data is favoured for various applications in vegetation science and climatology. This study presents the development of a Visual Basic software that can be used for the estimation of the daily PETref by means of the standardized ASCE Penman-Monteith equation for both short (clipped grass) and tall (full-cover alfalfa) crops and thirteen additional empirical equations. Statistical measures of goodness of fit are also calculated to make it easier for users to compare and detect the empirical equations that have the minimum bias of estimation against the ASCE Penman-Monteith equation.

Micromorphological traits and essential oil contents of Micromeria kerneri Murb. and M. juliana (L.) Benth. (Lamiaceae)

The chemical composition of the essential oil (analysed by GC and GC-MS), the types and distribution of trichomes and pollen morphology (analysed by scanning electron microscopy) were investigated in two closely related species, Micromeria kerneri Murb. and Micromeria juliana (L.) Benth. (Lamiaceae) from Southeast Europe as a contribution to their taxonomy. The essential oil of M. kerneri was characterized by a high concentration of oxygenated sesquiterpenes, with caryophyllene-oxide as the major compound. Caryophyllene-oxide was also the major component of the essential oil of M. juliana from all localities, except from Mt Krivošije (Montenegro), where piperitone oxide was the major constituent. Non-glandular trichomes, peltate trichomes, and two types of capitate trichomes (type 1 composed of one basal epidermal cell, and one head cell with subcuticular space; type 2 composed of one basal epidermal cell, two stalk cells, and one head cell with subcuticular space) were observed on leaves, the calyx and on the stem. Pollen of both species had six apertures (hexacolpate) set in the equatorial pollen belt (zonocolpate) and showed medium reticulate ornamentation. Multivariate analysis (PCA and UPGMA) of essential oil components clearly separated the investigated M. kerneri and M. juliana populations, and confirmed the opinion that they are different taxa. On the other hand, micromorphological traits between these species were the same. Nevertheless, definitive conclusions about the taxonomic relationships among these species will require genetic analysis.

Three new Hieracium taxa (Asteraceae, Cichorieae) from Mt Cholomon, Chalkidiki, Central Makedonia, Greece

Abstract Gottschlich G., Melikoki K., Eleftheriadou E. & Theodoropoulos K.: Three new Hieracium taxa (Asteraceae, Cichorieae) from Mt Cholomon, Chalkidiki, Central Makedonia, Greece. — Willdenowia 43: 59–64. June 2013. — Online ISSN 1868-6397;

On the occurrence of Salix appendiculata (Salicaceae) in Greece

Abstract Kailis N. & Eleftheriadou E.: On the occurrence of Salix appendiculata (Salicaceae) in Greece. — Willdenowia 43: 257–261. December 2013. — ISSN 0511-9618;

Monitoring of Modern Pollen Deposition by Means of Pollen Traps in the Pieria Mountains, Greece: Preliminary Results

A modern pollen deposition monitoring program has been initiated in Greece for the first time. For this purpose six modified Tauber traps (Hicks and Hyvarinen, 1986), were placed on a transect from black pine (Pinus nigra) forest to the tree-line of Scots pine (Pinus sylvestris) in the Pieria mountains.