"Folia Geobotanica"

Fernández-Pascual, Eduardo;Jiménez-Alfaro, Borja;Hájek, Michal;Díaz, Tomás E.;Pritchard, Hugh W.

doi: 10.1007/s12224-015-9223-ypmid: N/A

Abstract Calcareous fens are azonal habitats permanently saturated by groundwater. This is expected to have a buffer effect on soil temperature, alleviating climate changes and allowing plant communities to occupy diverse climatic regions. We analysed the extent of such buffering and its relation with a relevant plant trait, the seed germination niche breadth, along altitudinal gradients in fens of the Cantabrian Mountains (Spain) and the Western Carpathians (Slovakia). In each fen we recorded soil temperature for several years and compared it with WorldClim predictions for air temperature. We also collected seeds from five Cyperaceae fen specialists to evaluate the influence of soil temperature on germination. Although the soil temperatures and WorldClim predictions were strongly correlated, their absolute values differed substantially, showing a narrower thermal amplitude and warmer minimum winter temperature in the soil. The greatest differences in soil temperature and germination niche breadth were those between mountain regions. Narrower germination niches correlated with the colder Slovak winter. Our results suggest that the soil thermal buffer allows species to escape frost temperatures in winter, but also high summer temperatures in warm regions, explaining their wide distribution ranges. The warm regeneration niche does not match the cooler soils, but shows variability and potential for adaptation. While these findings support resilience to climate warming, changes in precipitation rather than temperature seem to be the main threat for fen persistence.

Seer, Franziska K.;Irmler, Ulrich;Schrautzer, Joachim

doi: 10.1007/s12224-015-9230-zpmid: N/A

Abstract In the last century, increases in human population and beach tourism have affected coastlines worldwide. Resulting pressures on beach ecological systems demand research concerning tolerance of beach plants to disturbance by humans. At three different Baltic Sea beaches, Atriplex prostrata, Honckenya peploides and Crambe maritima were planted and observed while subjected to trampling stress intensities of 0, 1 and 2 footsteps·m−2·d−1. Plant height, leaf growth, number of leaves, chlorophyll content of leaves and fitness of photosystem II were measured at monthly intervals. Survival of plants was documented until the following summer. Linear mixed effect models fit the effects of trampling intensity, time and species on growth, photosynthetic productivity and reproduction of plants. Survival was fitted using general linear mixed models for binomial data. The results indicated that the annual species A. prostrata showed an initial decrease in growth at the first trampling treatment, but no effects on seed weight due to trampling pressure. Honckenya peploides was not affected by trampling. Crambe maritima showed a reduction in growth and survival under any level of trampling pressure. Experimental trampling pressure was compared to observed trampling intensities at beaches with low visitor frequency, which was ascertained to be between 3 and 8 footsteps·m−2·d−1. Because of the greater potential of endangerment for C. maritima, we suggest that nature conservation focus on reducing human trampling on the upper beach area, e.g. by closing this area. This practice would allow tourists continued recreational access to the water as well as to the lower beach area.

Kapusta, Paweł;Szarek-Łukaszewska, Grażyna;Jędrzejczyk-Korycińska, Monika;Zagórna, Monika

doi: 10.1007/s12224-015-9232-xpmid: N/A

Abstract The highly specialized flora of localities affected by former metal ore mining and metallurgy is endangered by succession or intentional afforestation all over Europe. Its last remnants therefore deserve our attention. We examined whether Scots pine encroaching on a heavy-metal grassland (Olkusz Zn-Pb mining area, S Poland) is outcompeting specialized herbaceous species, as has been observed elsewhere. Plant species composition and richness sampled at 124 plots were analysed in relation to pine stand parameters (canopy cover, stand age, stand basal area), abiotic environmental factors (e.g. soil properties) and spatial variables (e.g. plot coordinates). Plots were divided into three shading categories and compared in terms of vegetation and habitat parameters. Scots pine outcompeted several light-demanding species, leading to a decrease of total species richness and cover. Characteristic species of this grassland (Biscutella laevigata, Silene vulgaris) and some metal-tolerant plants were clearly insensitive to shading. For these early successional species, more important was the availability of microsites with shallow skeletal soil or bare subsoil. Tree stand parameters differently affected grassland vegetation: canopy cover caused primarily a compositional shift in the community, while stand age was the principal agent of decline in species richness. Scots pine increased the soil concentrations of available Ca and Mg, and negatively affected soil development (organic matter and mineral particle accumulation), which might be beneficial to some shade-tolerant grassland species. Maintaining the studied grassland’s present species richness and composition would require cutting woody plants less frequently than recommended for dry grasslands of non-metalliferous sites, and disturbing the soil surface.

Mizuno, Taiki;Momohara, Arata;Okitsu, Susumu

doi: 10.1007/s12224-015-9229-5pmid: N/A

Abstract Ferns typically grow in soil that has sufficient moisture to enable the germination, fertilization and growth of gametophytes. However, the epiphytic fern, Lepisorus thunbergianus grows on tree trunks often in urban areas, where its gametophytes are susceptible to desiccation and its spores are easily washed off by rainwater. To understand how these ferns become established and survive in such challenging conditions, we conducted a quadrat survey on trunks of Prunus mume (which has cracked bark) and Ilex integra (which has smooth bark), focusing on the presence of bryophyte communities, which are known to facilitate seed establishment. Regardless of bark roughness, fern gametophytes occurred more frequently in the communities of small-leaved and short-bodied liverworts, and young fern sporophytes occurred more frequently in the communities of tall-bodied mosses. As the gametophytes of L. thunbergianus are taller than the liverworts, they are able to grow in the presence of liverworts without experiencing shading effects. However, sites with liverworts were unsuitable for fertilization of fern gametophytes because they were more desiccative environments than the sites where tall mosses grew. In habitats where tall mosses grow, fern gametophytes tended to be affected by competition from the bryophytes, whereas once fern gametophytes had established and matured, it was easy for them to generate young sporophytes because tall mosses retain sufficient moisture for the ferns’ fertilization. In summary, the presence of a moss community is an important factor aiding the establishment of this epiphytic fern in desiccated urban areas.

Mártonfiová, Lenka

doi: 10.1007/s12224-015-9231-ypmid: N/A

Abstract In agamic complexes, the ‘minority cytotype exclusion principle’ can be modified to the ‘sexual cytotype exclusion principle’: Apomicts produce polyploid progeny of maternal genotype without the need for pollination, but still produce pollen. Outcrossing sexuals thus suffer from unsuccessful hybridizations – they produce reduced amounts of progeny. This causes a decrease in the relative frequency of sexuals and later leads to their exclusion from the population. However, in the agamic complex Taraxacum sect. Taraxacum, diploid sexuals coexist with triploid apomicts in stabilized mixed populations. This paper deals with hybridizations in natural populations, the possibilities of new triploid apomicts originating and investigates why the 'sexual cytotype exclusion principle' does not work in Taraxacum sect. Taraxacum. The progeny of diploids from natural populations screened by the flow-cytometric seed screening method consisted only of diploids. Different simulations of natural pollinations were carried experimentally. When the flowers of a diploid received different mixtures of pollen of surrounding diploids and triploids, pollination was successful and only diploid progeny was produced, probably due to the preference of high-quality compatible pollen of diploids by diploid maternal plants. Therefore, the 'sexual cytotype exclusion principle' cannot work in Taraxacum sect. Taraxacum, and diploids and triploids can coexist in common populations. Polyploid progeny was produced by a diploid plant surrounded only by triploid apomicts to a certain distance. This suggests that new polyploid apomicts can be produced only in places where isolated diploids can occur among triploids. Newly formed apomicts further spread their progeny to both areas of apomicts and areas of mixed populations.

de Bello, Francesco;Berg, Matty P.;Dias, André T. C.;Diniz-Filho, Jose Alexandre F.;Götzenberger, Lars;Hortal, Joaquín;Ladle, Richard J.;Lepš, Jan

doi: 10.1007/s12224-015-9228-6pmid: N/A

Abstract There is considerable uncertainty about if, and when, phylogenetic information is needed to answer various ecological questions about trait-based ecological studies. It has been recommended that both functional and phylogenetic information should be combined, and some researchers have even suggested that functional information for species should be ‘corrected’ because species are not phylogenetically independent. Here, we address these issues by identifying key types of questions in functional trait-based ecology and discussing the utility of phylogenetic information for answering them, either as a correction or in combination with functional traits. Phylogenetic analyses are identified as essential to answer questions related to the evolution of adaptations to abiotic and biotic conditions. However, we argue that phylogenetic information is not always relevant for functional trait studies, and should not be incorporated into ecological analyses without clear justification. Phylogenetic relatedness between species should not be considered a bias to be corrected, but rather an evolutionary signal that allows results to be interpreted at different evolutionary scales. Furthermore, if traits are conserved, phylogeny can be used as a proxy for missing information on traits and functional trait diversity. We conclude by providing guidelines on when to apply, and how to interpret, results obtained using phylogenetic information for a variety of ecological questions linked to functional traits.