Diversity, Ecology and Phytogeography of Bryophytes across Temperate Forest Communities-Insight from Mt. Papuk (Croatia, SE Europe).

It has been widely documented that the complex structure of forest ecosystems supports considerable bryophyte species and functional diversity. In this study, we assessed the diversity, distribution and ecological and phytogeographical features of bryophytes across a gradient of temperate forest types on Mt. Papuk. This is the largest and highest mountain in the lowland, Pannonian part of Croatia, with high geological diversity and various temperate forests covering 95% of the mountain. According to the predominant tree species (oak vs. beech), geological bedrock (calcareous vs. siliceous) and soil reaction (alkaline vs. acidic), 21 study plots were classified into four distinct forest types. In all, 184 bryophyte species (35 liverworts and 149 mosses) were recorded. Although the forest types investigated did not differ significantly with respect to species richness, each was characterized by a considerable number of diagnostic bryophyte species. According to our results, one of the main ecological factors determining the variability of the forest bryophyte composition was geological bedrock and the associated soil reaction. Basiphilous forests developed on carbonate bedrock harbored more thermophilous and nitrophilous bryophytes and were characterized by southern-temperate and Mediterranean-Atlantic biogeographic elements. In contrast, acidophilous forests growing on silicate bedrock were characterized by wide-boreal and boreo-arctic-montane elements, i.e., bryophytes indicating cooler habitats and nitrogen-deficient soils. Based on the results, we hypothesized that the main latitudinal biogeographic distinction between southern and northern biogeographic elements is driven more by geological substrate than by the main tree species in forest communities. The present study confirmed previous findings that bryophytes are good and specific habitat indicators and show associations with different forest types, which can help to understand the complexity, ecological microconditions and biogeographic characteristics of forest communities.

In vitro micropropagation of rare and endangered moss Entosthodon hungaricus (Funariaceae) / Micropropagação in vitro do musgo raro Entosthodon hungaricus, ameaçado de extinção (Funariaceae)

The moss Entosthodon hungaricus (Boros) Loeske is an European endemic species typical of dry and saline soils extending from the Iberian Peninsula to Aral-Caspian steppes, similarly to some other xerothermic bryophytes. However, the distribution range is fragmented and localities are quite scattered and the species is considered as rare and vulnerable because of its ephemeral characteristics and specialized ecology. With the aim to develop an active protection plan for this species, the ex situ conservation requirements of E. hungaricus were developed. The axenic culture in in vitro conditions were established, and the optimal growth parameters were adjusted to achieve fully developed gametophytes ready to be reintroduced to its native range and other potentially native areas, where this species was once reported but has not been collected in recent times, suggesting its local extinction (i.e. some areas in Vojvodina, N. Serbia). Starting materials were derived from recent herbarium specimens and from fresh materials collected from Hungarian populations. Several means for sterilization of stating material and growing nutritive media were assayed in different regimes of light and temperature. Here we describe the conditions to achieve full plant development and for its micropropagation. Such materials are adequate for ex situ conservation purposes and for experimental introductions in native and potentially native areas. The first axenical culture of E. hungaricus was successfully established, and the first in vitro micropropagation of this rare and endangered species was achieved. Our study contributes to the conservation biology as well as for the potential use of this moss species in biotechnological research.

O musgo Entosthodon hungaricus (Boros) Loeske é uma espécie endêmica Européia típica de solos secos e salinos que se estendem da Península Ibérica até as estepes Aral-Cáspias, similar a outras briófitas de clima seco. Entretanto, a distribuição é bastante dispersa e fragmentada e a espécie é considerada muito rara e vulnerável devido às suas características efêmeras e ecologia especializada. Com o intuito de desenvolver um plano de proteção a essa espécie, foram elaborados os requisitos de preservação ex situ das E. hungaricus. As condições para a cultura axênica in vitro foram estabelecidas e os parâmetros ideais de crescimento foram atingidos para conseguir gametófitos completamente desenvolvidos, prontos para serem reintroduzidos em suas áreas nativas e em outras áreas potencialmente nativas, onde essa espécie já foi relatada. Porém, não houve coleta da mesma nos últimos anos, o que sugere uma extinção local (por exemplo, algumas áreas em Voivodina, Norte da Sérvia). Os materiais iniciais foram derivados de espécies recentes de herbários e de materiais frescos coletados de populações Húngaras. Várias formas de assepsia do material inicial e dos meios de crescimento nutritivo foram ensaiadas em diferentes regimes de luz e temperatura. No trabalho descrevemos as condições para obter desenvolvimento completo da planta e sua micropropagação. Os materiais são adequados para os fins de conservação ex situ e para as introduções experimentais em áreas nativas e/ou potencialmente nativas. O estudo contribui para a conservação biológica bem como para o potencial uso dessa espécie de musgo em pesquisas biotecnológicas.

How do temperate bryophytes face the challenge of a changing environment? Lessons from the past and predictions for the future.

Bryophytes are a group of early land plants, whose specific ecophysiological and biological features, including poikilohydry, sensitivity to moderately high temperature and high dispersal ability, make them ideal candidates for investigating the impact of climate changes. Employing a combined approach of species distribution modelling (SDM) and molecular phylogeography in the temperate moss Homalothecium sericeum, we explore the significance of the Mediterranean refugia, contrasting the southern and northern refugia hypotheses, determine the extent to which recolonization of previously glaciated areas has been facilitated by the high dispersal ability of the species and make predictions on the extent to which it will be impacted by ongoing climate change. The Mediterranean areas exhibit the highest nucleotidic diversities and host a mixture of ancestral, endemic and more recently derived haplotypes. Extra-Mediterranean areas exhibit low genetic diversities and Euro-Siberian populations display a significant signal of expansion that is identified to be of Euro-Siberian origin, pointing to the northern refugia hypothesis. The SDMs predict a global net increase in range size owing to ongoing climate change, but substantial range reductions in southern areas. Presence of a significant phylogeographical signal at different spatial scales suggests, however, that dispersal limitations might constitute, as opposed to the traditional view of spore-producing plants as efficient dispersers, a constraint for migration. This casts doubts about the ability of the species to face the massive extinctions predicted in the southern areas, threatening their status of reservoir of genetic diversity.