Tagged: Mediterranean




2nd course: Cereals, nettles and conifers (and fish…) ****

Famously, humans will have a go at eating anything, which is why they’re considered to be omnivores, and they are therefore omnivorous *. However, information concerning how such dietary preferences came to be, and when – and where – in the course of human evolution is not complete. One source of evidence that’s been exploited by Emanuela Cristiani et al. is ‘dental calculus’ . Alternatively known as tartar (“the mineralised biofilm of dental plaque adhering to the tooth enamel”), this material can give an indication of materials – such as food – taken into the mouth. The particular plaque examined...

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Spanish scrubland.

Non-structural carbohydrate dynamics in shrubland under drought-induced die-off

The relationship between plant carbon economy and drought responses of co-occurring woody species can be assessed by comparing carbohydrate (C) dynamics following drought and rain periods, relating these dynamics to species’ functional traits. Lloret et al. studied nine woody species coexisting in a continental Mediterranean shrubland that experienced severe drought effects followed by rain. The authors measured total non-structural carbohydrates (NSC) and soluble sugars (SS) in roots and stems during drought and after an autumn rain pulse in plants exhibiting leaf loss and in undefoliated ones. Lloret and colleagues note that previous authors have said stored non-structural carbohydrates are never...

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Quercus ilex

Trading food for water – trees exude more carbon under drought stress

Plants secrete carbon compounds into soils through their roots, affecting microbes in such a way that nutrient availability in the soil can increase. This root exudation can cost over 10% of the carbon fixed through photosynthesis, but this cost is thought to be largely offset by the benefits of altering soil microbial activity. Given the amount of carbon that plants can release into soils, root exudation is an important link between the above- and belowground carbon cycling. Despite the importance and magnitude of this process, our understanding of how stresses such as drought affect the amount of exuded carbon is...

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Bee Orchid

RAD-seq and morphology clarify evolutionary relationships in Eurasian bee orchids

Eurasian bee orchids (Ophrys, Orchidaceae) have become the most popular model system for studying reproduction via insect-mediated pseudo-copulation and for exploring the consequent, putatively adaptive, evolutionary radiations. However, despite intensive past research, both the phylogenetic structure and species diversity within the genus remain highly contentious. Bateman et al. combine next-generation DNA sequencing with morphological cladistic analysis to clarify phylogenetic structure and character evolution within the genus. The morphological data proved unusually homoplastic and poorly congruent with the molecular data, which resolved three major groups; this strongly supported the monophyly of nine out of ten ‘macrospecies’ previously circumscribed using candidate-gene approaches.

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Anthoxanthum

The Mediterranean cradle of Anthoxanthum diploid diversity

The Mediterranean region has cradled the evolution of many European plant taxa, including grass genera. Chumová et al. use a multidisciplinary approach combining sequence data, rDNA FISH, climatic niche characterization and spatio-temporal modelling to investigate the evolutionary relationships of diploid Anthoxanthum (Poaceae) members. The Balkans and Apennines are identified as the source area of diploid diversity, with climatic changes starting in the Miocene acting as the main factors promote taxa differentiation. A. gracile and A. alpinum were the only well-differentiated lineages. The taxonomically uncertain ‘Mediterranean diploid’ is a possible relic of the most recent common ancestor of the other diploid...

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Orchid

Temporal dynamics of Corsican orchid communities

Orchids are particularly sensitive to environmental changes due to their narrow ranges in secondary-successional habitats, and partially cryptic which impede the observation during monitoring. Here Vogt-Schilb et al. investigated how habitat change can impact orchid spatio-temporal distributions in Corsica, while taking into account imperfect detection. Two field surveys conducted 27 years apart (1982–1984 vs. 2009–2011) at the same 45 sites in Corsica show contrasting patterns in orchid dynamics at different spatial scales; while marked turnover of species composition was revealed locally, the regional species pool was maintained despite an overall increase in woody plant cover. The existing landscape mosaics of...

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Phylogeography of a widespread species: Pre-glacial vicariance, refugia, occasional blocking straits and long-distance migration

Phylogeographic studies give us the opportunity to reconstruct the historical migrations of species and link them with climatic and geographic variation. They are, therefore, a key tool to understanding the relationships among biology, geology and history. One of the most interesting biogeographical areas of the world is the Mediterranean region. However, in this area, the description of concordant phylogeographic patterns is quite scarce, which limits the understanding of evolutionary patterns related to climate. Species with one-dimensional distribution ranges, such as the strawberry tree (Arbutus unedo) are particularly useful to unravel these patterns. In a new study published in AoB PLANTS,...

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Investigating the impacts of recycled water on a long-lived conifer

Recycled wastewater is a popular alternative water resource. Although typical salt contents in recycled water are low (< 2.0 dS m-1), levels may still be harmful to salt-sensitive plants. The results of a new study published in AoB PLANTS by Nackley et al. have direct implications for public and private institutions seeking to conserve water by irrigating landscapes with recycled (a.k.a. reclaimed) water. The authors discovered that salt accumulation in soils would negatively impact coast redwoods (Sequoia sempervirens) when recycled water salinity exceeds 1.0 dS m-1. This is the first paper reporting the impacts of salinity on the growth of...

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Pollen receipt and quality in endemic-rich communities

Pollen receipt and quality in endemic-rich communities

The magnitude of pollen limitation is highly variable among habitats, species and differing plant communities. Alonso et al. analyse natural variability in pollen receipt and tube formation, and compare pollen quality and quantity between co-flowering endemics and non-endemics at three biodiversity hotspots in Andalusia, California and Yucatan. They find that only a combination of abundant and good quality pollen and a low number of ovules per flower can confer relief from pre-zygotic pollen limitation. Endemics are not always disadvantaged: the relative pollination success of endemic and non-endemic species, and its quantity and quality components, are community dependent.

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