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,

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!

How does plant photoprotection respond UV-A radiation?

Short wavelengths within the UV-A region of the solar spectrum fall between the known action spectra of the UV-B photoreceptor, UVR8, and the photoreceptors CRYPTOCHROME and PHOTOTROPIN which are predominantly blue light and long-wave UV-A photoreceptors.  Our new paper, out in Physiologia Plantarum today questions the roles played by these photoreceptors in response to UV-A and whether radiation in the blue and UV-A regions can help prime plant photoprotection for subsequent high irradiance.

Craig Brelsford and Matt Robson take leaf chlorophyll fluorescence measurements under high irradiance.

Find the paper here: Brelsford et al., (2018) Do UV‐A radiation and blue light during growth prime leaves to cope with acute high light in photoreceptor mutants of Arabidopsis thaliana?

Quantifying the phenotypic and genotypic variation among European beech populations

Craig Brelsford of the University of Helsinki, (CanSEE group) scores spring phenology in the CostE52 European beech provenance trial in La Rioja Spain.

The culmination of more than 10 years of data collection and analysis, a database of beech traits from over half a million trees planted in a common-garden experiment covering the whole of Europe is out today in Scientific Data.

This resource should help researchers better assess the impacts of climate change on species ranges. The most comprehensive dataset of its kind, it promotes beech as a model species on which to test ideas about the relative importance of intra-specific plasticity and genetic variability in helping populations cope with a changing climate.

You can find the paper here: Robson T.M., Benito Garzon M., BeechCoste52 database consortium (2018) Phenotypic trait variation measured on European genetic trials of Fagus sylvatica L. SCIENTIFIC DATA | 5:180149 | DOI: 10.1038/sdata.2018.149

Here is a press release  from INRA in France, and other press releases from the resilience blog of the European Forestry Institute and its sister institute EFIMED.

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.

Effect of horticultural shade screens and nets on spectral quality

Shade screen and net are used to control the environment of plants growing in polytunnels and greenhouses but they have some unintended consequences in modifying the spectrum of light that plants receive.

Titta Kotilainen has a new article out describing these effects and what they imply for the use and selection of these products. Check it out in PLOS one – HERE!

We recently spent the week at GreenTech Expo in Amsterdam finding out more about innovations in LED lighting and spectral manipulation of the light used in plant production scenarios. In response we are preparing an extended a continuation of our research into spectral quality with an extended dataset of screen and net assessments.

Finnish Growers’ Association highlight our research into the greenhouse light environment


Some results from our Academy of Finland Key Funding project were recently presented by Titta Kotilainen in the Finnish Growers’ Association “Puutarha & Kauppa” magazine. Climate screens that are typically used inside greenhouses to manage humidity and temperature alter light transmission, resulting in large differences in both the fraction of irradiance attenuated and spectral ratios received underneath.

Different climate-control screens, that are superficially very similar in terms of their appearance and texture, have very different effects on the light environment, which would go unnoticed without this sort of measurement. Spectral characterization of this nature is required to interpret the results of studies examining plant responses to different greenhouse screens. Material manufacturers, growers, and horticultural consultants can all benefit from these data aiding the selection of material to better match the desired end-results.

Herlin Foundation Funding for Twinkle Solanki

Congratulations to Twinkle Solanki who has received a year’s grant from the Herlin Foundation to continue her PhD “Improving estimates of carbon assimilation and light use by forests by scaling processes from the leaf to canopy levels”.

Pictorial representation of measurements of irradiance and leaf optical properties at vertical gradients of the forest canopy

This means that all of our CanSEE PhD students have obtained competitive funding now for their doctoral work: Saara Hartikainen (Academy of Finland); Craig Brelsford (Doctoral Programme in Plant Sciences of the University of Helsinki); Marta Pieriste (Region of Normandy); David Israel (Finnish Cultural Foundation) and Twinkle Solanki (Herlin Foundation), as well as post doc Titta Kotilainen (Academy of Finland, Key Funding).

Blue light advances bud burst in branches of three deciduous tree species under short-day conditions

Congratulations to Craig Brelsford on the acceptance of the first publication towards his PhD, which will shortly be published in Trees: Structure and Function.  But in particular, a big thank you to the two reviewers for this article for Trees who gave us particularly thoughtful and constructive feedback and wrote really well-considered and knowledgeable reviews to help us improve the paper.

Dormant Twigs Receiving Spectra with and without blue light