Long-Term Ecological Research into plant UV adaptation high in the French Alps

Santa Neimane and Twinkle Solanki recording diurnal patterns in leaf optical properties of alpine plants under UV filters

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.

 

Pedro J Aphalo measures solar radiation; to better understand how reflection from the snow pack affects exposure of plants in the environment.

 

 

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.

Springtime recovery of Vaccinium vitis-idaea leaves above and below the snow pack

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.

Is the paper, Solanki et al., 2018, published in a special issue of Plant Physiology and Biochemistry on UV-cross protection, we explore the ecophysiological response of Vaccinium hummocks to snow cover over the course of a year in central Finland.

Twinkle Solanki taking Dualex measurements in central Finland

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 pack Plant Physiology and Biochemistryhttps://doi.org/10.1016/j.plaphy.2018.09.003

Allocation to root growth can determine the survival of Mediterranean oaks during seasonal drought

The range of Holm oak (Quercus ilex), green; cork oak (Q. suber), purple; and their overlap, brown. Circle sample site, and triangle the field experiment.

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.

Acorns germinating under controlled conditions prior to planting in the experimental plot

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

Remotely monitoring seed fall in beech stands

Following on from the publication of our database on the network of European beech trials in Scientific Data earlier this month, I spent last week with Marta Benito-Garzon & Santa Neimane in one UK trial testing a new approach to monitoring beechnut production.

A seed trap installed in Little Wittenham trial, Oxfordshire. Seeds falling through the tube are automatically recorded and the information relayed back to a central computer

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!

Is photodegradation an important process in forest understoreys?

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.

Marta Pieriste takes hemispherical photos amongst litter sachets on the beech forest floor
Qingwei Wang checks his filter experiment testing understorey plant response to removal of UV-B, UV-A, blue and green sunligh

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.

Understanding contemporary UV effects on pollen to reconstruct UV exposure over geological time

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.

Find up more in last years UNEP update.

Filming for the Lammi Nature Trail

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.

You can watch the canopy scope video here in English and in Finnish; and the quadrat phenology video here in English and in Finnish.

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!

Quadratvideo2NatureTrailMovie

Learning Advanced Practical Ecophysiology in Portugal

David Israel and Craig Brelsford will follow the example of Saara Hartikainen two years ago, and participate in a BES Plant Environmental Physiology Group advanced practical course in techniques for plant ecophysiology near Lisbon in Portugal (12th-16th September).

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.