2015. augusztus 10., hétfő

Deák et al. (2015) Ecological Complexity

  • We tested the effects of winter cutting versus abandonment on wetland diversity.
  • Winter cutting decreased habitat diversity and structural heterogeneity.
  • Unmanaged wetlands harboured high amount of biomass in heterogeneous distribution.
  • Diversity of vegetation types correlated positively with all biomass fractions.
  • Intensive reed cut decreases wetland diversity by overriding edaphic conditions.

There is a conflict between nature conservation and thatching industry regarding the management of reedbeds. On one hand, reedbeds are of an economical importance by providing thatching material, on the other hand, they harbour several endangered species. Reedbeds are typically managed by winter cutting, but its impacts on biodiversity are poorly understood. Our aim was to study the effects of winter cutting on the habitat diversity and structural heterogeneity of wetlands in a lowland alkali landscape (East-Hungary). We tested the following hypotheses: (i) Both diversity of plant species and habitat diversity are lower in winter cut wetlands compared to unmanaged stands. (ii) The distribution of biomass (green biomass, litter and standing dead biomass) is more homogeneous in winter cut wetlands compared to unmanaged ones. We found that winter cutting decreased habitat diversity and structural heterogeneity at multiple scales. Number of plant species and all measures of habitat diversity (number of patches, vegetation types and the length of vegetation margins) had lower scores in cut wetlands than in unmanaged ones. We found that unmanaged wetlands harboured high amount of accumulated biomass and they also maintained high habitat diversity likely due to the heterogeneous distribution of the biomass. In unmanaged wetlands, biomass accumulation did not decrease habitat diversity and also contributed to a higher structural heterogeneity. In cut wetlands, expansion of reed was an important driver of the decrease in habitat diversity and structural heterogeneity. Reed expansion likely overrode fine-scale edaphic conditions (hydrology and salinity) in shaping vegetation patterns; thus we suggest to avoid intensive winter cutting.

Biomass, Landscape, Management, Margin, Marsh, Phragmites

Löki et al. (2015) Willdenowia

Löki V., Tökölyi J., Süveges K., Lovas-Kiss Á., Hürkan K., Sramkó G. & Molnár V. A. (2015): The orchid flora of Turkish graveyards: a comprehensive survey. Willdenowia 45(2): 231–243.

Graveyards are widely known among orchidologists as finding places of several orchid species in Turkey, including some very rare and localised ones. Graveyards provide places that are less strongly affected by landscape-altering human activities than other habitats because of their special cultural roles and religious privileges. In this study we performed a comprehensive survey of Turkish graveyards as orchid habitats. In total, 300 graveyards were studied in 30 provinces of Turkey in 2014. 84 orchid taxa (almost half of the known Turkish orchid flora) were found in 208 graveyards. From the studied provinces two south-southwestern provinces (Muğla, Antalya) emerged as peaks of species richness. This finding is in accordance with the overall biogeographical pattern of orchid diversity in Turkey. Our survey also contributes new floristic data to the orchid flora of Turkey. We documented salep collection in 10 graveyards from six provinces involving nine species. Altogether, we found orchids in 69% of the inspected graveyards, allowing us to conclude that the occurrence of orchids in Turkish graveyards is not a rare phenomenon. Thus, graveyards can be important refuges for orchids in the changing economical and agricultural circumstances of Turkey.

Asia minor, cemetery, flora of Turkey, Near East, Orchidaceae, salep, SW Asia

E. Vojtkó et al. (2015) Acta Biologica Hungarica

E. Vojtkó A., Sonkoly J., Lukács B. A. & Molnár V. A. (2015): Factors affecting reproductive success in three entomophilous orchid species in Hungary. Acta Biologica Hungarica 66(2): 231–241.

The reproductive success of orchids is traditionally estimated by determining the fruit-set of individuals. Here, we investigated both the fruit and the seed production of three orchid species and the factors that may affect individual fruit-set, like pollination strategy, individual traits or the annual amount of precipitation. The species (Dactylorhiza sambucina (L.) Soó, Dactylorhiza majalis (Rchb.) P. F. Hunt & Summerhayes and Platanthera bifolia (L.) L. C. M. Richard) were studied in three consecutive years (2010–2012) in the Bükk Mountains, Hungary. All the three species were proved to be non-autogamous by a bagging experiment. Data analyses showed significant differences between seed numbers but not between fruit-sets of species. There was no statistical difference in individual reproductive success between wet and dry years however, the effect of the annual amount of precipitation is significant on the population level. Comparison of published fruit-set data revealed accordance with our results in P. bifolia, but not in D. sambucina and D. majalis. We assume that the surprisingly high fruit-set values of the two Dactylorhiza species may be due to the fact that the pollination crisis reported from Western European countries may not be an actual problem in the Bükk Mountains, Hungary.

Dactylorhiza majalis, Dactylorhiza sambucina, fruit-set, Platanthera bifolia, pollination crisis

Molnár V. et al. (2015) Applied Ecology and Environmental Research

Molnár V. A., Löki V., Takács A., Schmidt J., Tökölyi J., Bódis J. & Sramkó G. (2015): No evidence for historical declines in pollination success in Hungarian orchids. Applied Ecology and Environmental Research 13(4): 1097–1183.

Pollination crisis (the decline of pollinator populations) is a global phenomenon which threatens biodiversity, human welfare and economy. The degree to which different plant populations/species are affected by pollination crisis is still unclear. In this study, long-term herbarium dataset was used to quantify the reproduction rate of Hungarian orchids between 1853 and 2008. We quantified fruit-set rate of 663 specimens belonging to 27 species. Data were available from an average of 10.3±9.3 localities, 76.5±43.2 years, and 23.4±25.6 specimens per species. Herbarium data were validated with field-observed data in case of the different pollination strategies. According to our results, the reproductive success of the vast majority of orchid species has not changed during time and pollination crisis is not apparent in Hungary at least until the end of the 20th century.

herbaria, natural history collections, Orchidaceae, pollination crisis, pollination mode

Boda et al. (2015) Journal of Insect Conservation

Réka Boda, Csaba Bereczki, Adrienne Ortmann-Ajkai, Péter Mauchart, Bálint Pernecker, Zoltán Csabai (2015): Emergence behaviour of the red listed Balkan Goldenring (Cordulegaster heros Theischinger, 1979) in Hungarian upstreams: vegetation structure affects the last steps of the larvae. Journal of Insect Conservation 19(3): 547-557.

In odonates, the emergence behaviour and finding suitable substrates for successful molting may influence the next generation and ultimately can determine the survival of the entire population. Understanding emergence behavior of endangered species and those granted special conservation status is particularly important. Despite this, little is known about the life history and emergence behaviour of Cordulegaster heros, a characteristic inhabitant of headwater streams. We hypothesised that the taxonomic composition and structure of the vegetation significantly affect the travel distance to the emergence site and the substrate choice. Two stream sections with different riparian zone vegetation were surveyed for exuviae in the emergence periods in two consecutive years, supported with detailed vegetation mapping. Significant differences were found between the vegetation characteristics at the two sites and differences were also found between emergences in edge zones within a site, indicating that the importance of vegetation structure operates within the scale of sites as well as between sites. At the site with more diverse vegetation, smaller horizontal but higher vertical travel distances and more varied emergence substrate choice were found. Habitat composition and complexity appears to determine the emergence behaviour of C. heros, so for the successful conservation of this species we recommend choosing appropriate forest management regimes and even maintaining riparian forests in near-pristine condition.

Odonata, Exuviae, Travel distances, Emergence-site selection and preference, Vegetation grid mapping

Boda et al. (2015) Hydrobiologia

Réka Boda, Csaba Bereczki, Bálint Pernecker, Péter Mauchart, Zoltán Csabai (2015): Life history and multiscale habitat preferences of the red-listed Balkan Goldenring, Cordulegaster heros Theischinger, 1979 (Insecta, Odonata), in South-Hungarian headwaters: does the species have mesohabitat-mediated microdistribution? Hydrobiologia, DOI: 10.1007/s10750-015-2317-y

Life cycle and microdistribution patterns of Cordulegaster heros, a charismatic species for nature conservation, are poorly known. Life history characteristics and multiscale habitat preferences of the larvae were followed for one year in monthly intervals by systematic samplings in eight headwaters, which resulted in data on 2562 individuals. We hypothesized that meso- and microhabitat complexity play an important role in forming the population structure and microdistribution of the species. Based on the distribution of the consecutive larval instars, duration of later stages and time of molt and emergence, the larval development of C. heros in the Mecsek Mountains lasts for at least three, but with a maximum of four years. All three levels of the multi-habitat structure [habitat (sites), and meso- (riffle/pool sequence) and microhabitats (biotic and different particle-sized abiotic types)] have significant effects on the spatial distribution of the larvae. Densities and population structures vary among the sites, but mesohabitat type and microhabitat diversity (heterogeneity within a pool or riffle) govern the microdistribution. C. heros prefers pools with small or medium microhabitat heterogeneity and higher proportion of small particle-sized substrates, especially in younger stages. Older larvae are less sensitive for these effects.

Odonata, Larvae, Life cycle, Spatial microdistribution, Meso- and microhabitat preference