Cryptogamic Biomass in Pannonic Acidic Sand Steppes Subject to Changing Land-Use.

Cryptogams, often neglected in vegetation dynamics studies, compose a large part of biomass and contribute to the biodiversity of sandy grasslands. Since the work of Verseghy (1970s), their productivity has not been analyzed in Hungary. We studied the lichen and bryophyte dynamics (hereinafter called cryptogams) at two Eastern Hungarian dry sandy grassland sites. The sites of Corynephorus canescens and of Festuca vaginata dominance, respectively, belonging to the community Festuco vaginatae-Corynephoretum have been monitored. We aimed at (1) quantifying the diversity and biomass of the cryptogamic communities; (2) exploring the cryptogamic response to management changes; and (3) studying the effect of experimental management (fencing) on the cryptogamic assemblages. The sites have been compared in 2013 and 2018, respectively. Forty microplots per site per management have been analyzed in both years. Samples of lichens and bryophytes were hand-sorted, dried and then measured. Fencing has led to increased biomass of cryptogams within a few years. Lichens in general benefited comparatively more from exclosure than bryophytes. The increase in lichen biomass (especially that of Cladonia rangiformis) is clearly due to the over 10-year absence of grazing. The only lichen favored by moderate grazing is the legally protected C. magyarica. Short spells of low-intensity grazing can promote the species richness of cryptogams in the community.

Cryptogamic communities on flatroofs in the city of Debrecen (East Hungary).

Cryptogams of ten urban flatroofs, contrasting in their age and size, were studied between 2016 and 2018. Siliceous (bituminous felt, gravel, brick) and calcareous (concrete) substrata occurred at each site. Microclimate (T, RH) at two sites of contrasting shading was monitored from September 2016 to January 2017. Biomass of two differently aged, exposed flatroofs was sampled in October 2018. Taxa of Cladonia and Xanthoparmelia have been identified by spot tests and HPTLC. A total of 61 taxa (25 bryophytes, 36 lichens), mostly widespread synanthropic species, have been detected with an explicit difference of species composition between shaded and exposed sites. Floristically interesting species included acidophilous bryophytes (Hedwigia ciliata, Racomitrium canescens) and lichens (Xanthoparmelia conspersa, Stereocaulon tomentosum) of montane character. The most widespread lichen is Cladonia rei which accounted for a significant part of the biomass at selected sites. Species-area curves for bryophytes at exposed sites have become saturated at 100-150 m2. In contrast, saturation of lichen diversity has not been reached even at the largest sites. Flatroofs with traditional roofing techniques can harbour relatively diverse microhabitats and species-rich synanthropic vegetation. It is urgent to study these sites before renovation with modern roofing techniques eliminates them. Diversification of urban surroundings is possible in the future via application of various substrats in renovated and newly constructed roofs.