Changes in the spectral composition of light under the snowpack may help plants perceive the onset of spring and physiologically prepare for exposure to the full sunlight and cold temperatures they will experience once they emerge.
We spent the last two weeks of May 2019 at the Station Alpin du Lautaret in the French Alps, which has been designated a Research Platform for long-term ecological studies under the framework of Horizon 2020 Transnational Access – who funded our research visit through the French National Centre for Scientific Research, CNRS.
Our team of researchers, collaborating with José Ignacio García Plazaola and Beatriz Fernandez-Marin from the University of the Basque-Country, to study how plants response to the steep increases in UV radiation that they receive on emergence from under snow cover in spring.
By characterising the patterns of response to UV radiation in terms of the photoprotection and UV-screening of plants across a diversity of species, we hope to better understand how and why these response evolved and what environmental cues underpin their induction.
In Arctic and alpine environments warming temperatures are expected to result in longer growing seasons and to encourage growth, but snow will melt faster and more will fall as rain. This means that the protective winter blanket of snow cover may no longer be present to hide plants from the extremes of cold that periodically occur. Whether plants can overcome this paradox to benefit from the increased sunlight and warmth above the snow, while resisting the greater fluctuations in temperature, will depend on their physiological capacity to cope with the changing conditions.
We focus on the role played by UV-absorbing compounds in protection against high light and low temperature combinations as shoots emerge from under snow in the early spring.
Solanki T. et al., 2018 UV-screening and springtime recovery of photosynthetic capacity in leaves of Vaccinium vitis-idaea above and below the snow packPlant Physiology and Biochemistry. https://doi.org/10.1016/j.plaphy.2018.09.003
Complex trade-offs in allocation to growth can determine the success of oak species where their ranges overlap.
This is highlighted by our paper Ramírez-Valiente et al., (2018), where higher root investment under seasonal drought by cork oak gave it an advantage over Holm oak, despite our prior expectations that the latter species is more drought tolerant.
José-Alberto Ramírez-Valiente, Ismael Aranda, David Sanchéz-Gómez, Jesús Rodríguez-Calcerrada, Fernando Valladares, T Matthew Robson; Increased root investment can explain the higher survival of seedlings of ‘mesic’ Quercus suber than ‘xeric’ Quercus ilex in sandy soils during a summer drought, Tree Physiology, , tpy084, https://doi.org/10.1093/treephys/tpy084
Following on from the publication of our database on the network of European beech trials in Scientific Dataearlier this month, I spent last week with Marta Benito-Garzon & Santa Neimane in one UK trial testing a new approach to monitoring beechnut production.
The prototypes will be deployed over this autumn and then optimized to register only falling seeds, not leaves or other objects, by validating the beechnut counts against the number of seeds caught in the bags beneath.
Once perfected the electronic monitoring system, designed by Marta Benito-Garzon (INRA Bordeaux) will allow researchers to follow the timing of autumn seed dispersal in real time from the comfort of their offices!
We’ve just returned from a 10-day field trip to Japan where our collaborators Qingwei Wang and Hiroko Kurakawa are studying the effects of shortwave solar radiation on the growth and subsequent decomposition of leaves from shade tolerant and light demanding plant species in controlled experiments under low and high light conditions.
This visit included a fascinating trip to a beech forest in central Japan to an experiment where the rate of leaf litter decomposition is being compared over 1-year on the forest floor and in an open area under filters screening out various parts of the solar spectrum, in an attempt to estimate the role that photodegradation plays in the decomposition from leaves of different functional types of forest plant in open and shaded environments.
A complimentary experiment at the Forestry and Forest Products Research Institute in Tsukuba City is testing how these species grow under waveband-selective filters, and whether generalisations between plant life forms can be made about the role of these different wavebands in growth and physiology as well as decomposition.
We recently traveled to Austria to help set-up our collaborators’ experiments monitoring the effects of UV-B radiation exposure on Pinus cembra pollen in the mountains above Innsbruck. If we can understand how exposure to UV radiation affects the accumulation of UV-absorbing compounds in pollen today, we may be able to calibrate the concentrations of these compounds found in ice- and sediment cores used in climatic reconstructions. This information potentially will allow palyontologists to understand how UV radiation changed over geological time and what the implications of these changes might have been for the Earth’s ecosystems. By better understanding past climate we will be better prepared to forecast how modern-day changes in UV radiation might affect the Earth’s ecosystems.
Here we take parallel measurements with broadband UV-B sensors and a spectroradiometer next to a specimen pine tree during the period before flowering.
Saara Hartikainen and Matthew Robson recently headed to Lammi Biological Station to “star” in some short films explaining the educational research activities that we designed for the Lammi Research Natural Trail.
We hope to encourage the public to have a go at estimating Leaf Area Index in the young silver birch stand using the canopy scope activity, and to help in assessing leaf, flower, and fruit development in plants growing in quadrats on the forest floor.
The data that we collect from the public will be used to help us estimate phenological development, and will eventually be compared with data from different sites to improve our understanding of the controls on the length of the growing season and forest canopy cover.
Here are some shots from the film-makers in action!
After his internship with Charlie Warren in Sydney last winter, David will be looking to compare notes with some of the leading researchers in IRGA techniques for measuring the conductance of carbon dioxide and water from leaves.