Many of the climate change researchers believe that in this century the average temperature is expected to rise apart from the climate becoming more extreme (Solomon et al., 2007). These weather anomalies can significantly influence the living beings, including the range limits of plants. This could seriously effect our indigenous tree species,
... some prognoses assume that the 82-100 % of the zonal spread of the sessile oak will have fallen outside the optimum climate area in tthe Carpathian Basin by 2050 (Czúcz et al., 2013). Such and similar forecast make the climate tolerance and health condition examinations of the sessile oak stands particularly important, so that we can measure the changes in plant communities. We have examined the health conditions of two elderly - over the age of 100 years - stands with the FAKOPP +D Acoustic Tomograph. One of the stands can be found in the Börzsöny Mountain, s while the other one in the Gödöllő Hills.
Coenological based diversity examinai ons were carried out in the Börzsöny off set on the sessile oak dominated stands. To reveal the sylviculture’s eff ects on the biodiversity, in 6 forest stands, characterised by same standard parameters were carried. The Shannon- and Simpson- diversity indices were used for comparison of biodiversity va
...lues of diff erent age-groups. Altogether 88 vascular plant species (15 trees, 11 shrubs, 62 herbaceous taxa) were ideni fi ed in the stands of sessile oak woodlands. The diversity of the canopy level was the highest at the 19 year-old stand, and the lowest at the oldest, 92 year-old stand. The diversity of the shrub layer was the highest at the 61 year-old and lowest at the 2 year-old stand. In case of the ground level increasing diversity values were noi ced between the 2 and 61 years old groups, then the diversity values decreased at the stands which are older than 61.