Ábrahám Levente (szerk.): Válogatott tanulmányok VIII. - Natura Somogyiensis 23. (Kaposvár, 2013)

Salamon-Albert É.: Climatic conditions and habitats in Belső-Somogy, Külső-Somogy and Zselic as vegetation-based landscape regions IV. Precipitation envelopes of mesic deciduous woodlands

Salamon-Albert, E.: Climatic conditions and habitats

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m a.s.l.), the average is 161 m a.s.l. 30 year annual temperature varies between 9,8 °C and 11,3 °C, the average is 10,8 °C (Salamon-Albert et al. 2011). Studied regions are positioned in the intersection of three macro-climatic zone: from west the atlantié, from east the continental and from south the mediterranean one, that can highly influence the climatic surface. According to the newest climatic map of Europe constructed by the categories of Köppen-Geiger climate classification system (Peel et al. 2007) there is a humid cold continental climate in the region on global scale. Regarding to a district scale climate classification (Péczely 1963, 2006, www.met.hu/) moderately warm - moderately dry and moderately warm - moderately wet climate types dominate and furtherly, six ones occur in the region among twelve regional climate types of Hungary configuring a climatically diversed sample area for a high resoluted climate based landscape ecological investigation. Regarding to the large scale climate classification mid-latitude grasslands, broadleaf deciduous forests and woodlands but rarely some mixed evergreen and broadleaf forests can be dominated in the vegetation potentially fitted into the zone of submontaneous oak-hornbeam woodlands as mesic woody habitats and thermophilous oak woodlands with open steppe oak woodlands and riparian vegetation at European scale (Ozenda and Borel 2000).

BIOCLIM variables

Yearly, quarterly and monthly sum or deviation in precipitation as bioclimatic variables [from BIOCLIM 12 to 19] were used calculated from meteorological data measured by the local weather stations of the Hungarian Meteorological Service (http://vissycd. glia.hu/atlasz.html, Mersich et al. 2001). They are also integrated into the WorldClim database for further applications (http://www.worldclim.org). Spatially interpolated variables are applied recalculated for the regional surface at fine resoluted hexagon scale of META database by the Institute of Ecology of the Hungarian Academy of Sciences (Czúcz et al. 2007). Bioclimatic variables are developed in order to generate more biologically meaningful ecological predictors and are often used in ecological niche computation as bioclimate envelope model.

Precipitation variables for the analyses are BIOCLIM-12 the mean annual sum, BIOCLIM-13 the mean sum of wettest month, BIOCLIM-14 the sum of driest month, BIOCLIM-15 the annual seasonality calculated as standard deviation of monthly means, BIOCLIM-16 the sum of wettest quarter, BIOCLIM-17 the sum of driest quarter, BIOCLIM-18 the sum of warmest quarter and BIOCLIM-19 the sum of coldest quarter. Annual data refer to monthly averages from January to De-cember, wettest quarter refers means from June to August, driest quarter refer means from January to March, warmest quarter refer means from June to August, coldest quarter refer means from December to February as the periods of three months, % of a year.

Habitats of mesic deciduous woodlands

META habitat and mapping project (2002-2006) was a systematic survey of the Hungarian semi-natural vegetation on landscape scale connected with spatial and geographical information (Bölöni et al 2007, Molnár et al 2007, Horváth et al. 2008). Data collecting in the field were carried out at high resoluted hexagon scale (35 ha) as basic units, and they were integrated into quadrats for landscape mapping (35 km2), both were added to the so called MÉTA database (Horváth and Polgár 2008). In our study mesic woody habitats connected with precipitation variables from BIOCLIM series were assigned for 16300 hexagons of 163 MÉTA quadrats of the three landscape regions.

Totally, 5 MÉTA habitat types of mesic woodlands in the associated habitat group (K) were identified in South Transdanubia, including Kla the lowland pedunculate oak-