The flora mapping activity covered Hungary’s whole area. The work was performed according to the Central-European flora mapping methodology, and its grid map system leans on the graticule. The main fields have a distorted trapezoid shape, size of which is 10 minutes of longitude and 6 minutes of latitude, namely approximately 12.5 km times 11.1 km. Grid units were created by quartering of the main fields, so the main field quarters’ (quadrates’) size is 5 minutes of longitude and 3 minutes of latitude, namely 6.25 km times 5.55 km. Hungary’s area is covered by 2832 quadrates, from which 2474 with their whole surface, while 358 just partially, are crossed by the border.
Most of the occurrence data derive from field surveys of the period between 2002 and 2014.The database was completed by the literature data, which had been published after 1990, and had a quadrate identifier, or identification could be clearly performed. (Unfortunately several valuable floristic data had to be ignored due to lack of spatial identifyableness.)
Estimating changes of potential natural forest community composition
Climate change is expected to affect the compositional and structural attributes of forest vegetation in the Carpathian Basin. Forest dynamics is closely related to climate trends, soil features and surplus water. The aim of the investigation was to determine the distribution of potential natural forest community (PNF) categories according to past, present and future climate. Potential natural forest communities (PNF) are the forest vegetation that would be expected under given site factors (e.g. climate, geomorphology, geology, soil, hydrology) without human intervention or hazard event. Potential vegetation can differ appreciably from the original natural and actual vegetation. PNF shifts were estimated mainly from climate trends (indicated by the change of the Forestry Aridity Index) using meteorological observations from the past and based on regional climate change scenarios until 2100.