2014. május 14., szerda

Török et al. (2014) PLoS ONE

Török P, Valkó O, Deák B, Kelemen A, Tóthmérész B (2014) Traditional Cattle Grazing in a Mosaic Alkali Landscape: Effects on Grassland Biodiversity along a Moisture Gradient. PLoS ONE 9(5): e97095. doi: 10.1371/journal.pone.0097095

Extensively managed pastures are of crucial importance in sustaining biodiversity both in local- and landscape-level. Thus, re-introduction of traditional grazing management is a crucial issue in grassland conservation actions worldwide. Traditional grazing with robust cattle breeds in low stocking rates is considered to be especially useful to mimic natural grazing regimes, but well documented case-studies are surprisingly rare on this topic. Our goal was to evaluate the effectiveness of traditional Hungarian Grey cattle grazing as a conservation action in a mosaic alkali landscape. We asked the following questions: (i) How does cattle grazing affect species composition and diversity of the grasslands? (ii) What are the effects of grazing on short-lived and perennial noxious species? (iii) Are there distinct effects of grazing in dry-, mesophilous- and wet grassland types? Vegetation of fenced and grazed plots in a 200-ha sized habitat complex (secondary dry grasslands and pristine mesophilous- and wet alkali grasslands) was sampled from 2006–2009 in East-Hungary. We found higher diversity scores in grazed plots compared to fenced ones in mesophilous- and wet grasslands. Higher cover of noxious species was typical in fenced plots compared to their grazed counterparts in the last year in every studied grassland type. We found an increasing effect of grazing from the dry- towards the wet grassland types. The year-to-year differences also followed similar pattern: the site-dependent effects were the lowest in the dry grassland and an increasing effect was detected along the moisture gradient. We found that extensive Hungarian Grey cattle grazing is an effective tool to suppress noxious species and to create a mosaic vegetation structure, which enables to maintain high species richness in the landscape. Hungarian Grey cattle can feed in open habitats along long moisture gradient, thus in highly mosaic landscapes this breed can be the most suitable livestock type.

Biodiversity, Cattle, Conservation science, Ecosystems, Grasslands, Grazing, Shannon index, Species diversity

2014. május 3., szombat

Tökölyi et al. (2014) Biological Journal of the Linnaean Society

Tökölyi, J., Schmidt, J. and Barta, Z. (2014), Climate and mammalian life histories. Biological Journal of the Linnean Society, 111: 719–736. doi: 10.1111/bij.12238

Mammals display considerable geographical variation in life history traits. To understand how climatic factors might influence this variation, we analysed the relationship between life history traits – adult body size, litter size, number of litters per year, gestation length, neonate body mass, weaning age and age at sexual maturity – and several environmental variables quantifying the seasonality and predictability of temperature and precipitation across the distribution range of five terrestrial mammal groups. Environmental factors correlated strongly with each other; therefore, we used principal components analysis to obtain orthogonal climatic predictors that could be used in multivariate models. We found that in bats, primates and even-toed ungulates adult body size tends to be larger in species inhabiting cold, dry, seasonal environments, whereas in carnivores and rodents a smaller body size is characteristic of warm, dry environments, suggesting that low food availability might limit adult size. Species inhabiting cold, dry, seasonal habitats have fewer, larger litters and shorter gestation periods; however, annual fecundity in these species is not higher, implying that the large litter size of mammals living at high latitudes is probably a consequence of time constraints imposed by strong seasonality. On the other hand, the number of litters per year and annual fecundity were greater in species inhabiting environments with higher seasonality in precipitation. Lastly, we found little evidence for specific effects of environmental variability. Our results highlight the complex effects of environmental factors in the evolution of life history traits in mammals.

body size, comparative analysis, macroecology, predictability, reproductive traits, seasonality

Molnár V. et al. (2014) Plant Biosystems

Molnár V. A., Popiela A., Lukács B. A. (2014): Elatine gussonei (Sommier) Brullo et al. (Elatinaceae) in Sicily. – Plant Biosystems 148: 27-30. DOI: 10.1080/11263504.2013.788099

This study reports the Sicilian occurrence of Elatine gussonei (Sommier) Brullo et al., a rare and endangered species previously known only from Lampedusa, Malta and Gozo. The species was found on three localities near settlements Modica and Ispica (south-eastern Sicily).

Distribution, Mediterranean temporary ponds, section Elatinella, seed morphology, wetland ephemerophyte