The sheep are now back next to the PaNDiv field site, which means two things: winter is coming, and after a season outside the fieldwork is over!
Maintaining the experiment has already kept us quite busy over the last months: weeding three times the whole field to always have the same diversity in the plots, spraying fungicide for the pathogen exclusion treatment and fertilizing to study the effects of Nitrogen addition.
On top of that, we harvested this year again a lot of data. For all our species, we quantified fungal pathogen infection, looked at herbivory damage and measured classic functional traits (height, SLA, LDMC, etc). We assessed the percentage cover of all plant species growing on the field, and collected over 3000 biomass samples and 30 000 insects. This year we had a closer look at the belowground compartment, measuring soil respiration regularly and collecting more than 1000 soil samples.
We also welcomed researchers from other universities to collaborate on the PaNDiv project. Rodrigo Granjel (1), PhD student from Sevilla, Spain collected data to study coexistence mechanisms. Bjarke Madsen and Urs Treier (2) from Aarhus, Denmark, flew their drones over the field, to link ground measurements with remote sensing data.
In our greenhouses facility, we grew the 20 PaNDiv species and the most common weeds invading the plots with an N addition treatment, to get an array of functional traits in controlled conditions. We also used this opportunity to explore the variability and the response of morphological traits, for instance related to vegetative propagation, together with Mathieu Millan, a researcher in plant architecture from Montpellier, France
We couldn’t do that much without a dedicated team of PhD, Master students and technicians, and all our hard working field helpers. More than 50 different people came to work with us between April and November, thank you!
Now it’s time to process all these samples, analyse the data … and get ready for next fieldwork season!
(1) http://www.oscargodoy.com/
(2) https://twitter.com/UAS4Ecology
March, a cold start of the fieldwork season
In June the plants have grown big
Spraying fungicide to study the effects of pathogen removal
July, second weeding of the whole field
Biomass cutting (photo Beatrice Schranz)
Collecting insects with suction sampling
Graphosoma italicum, one of the many insects found on the field (photo Tosca Mannall)
Autumn soil sampling
After 840 litter bags sewed, 2.5 months of decomposition, 4 years of experiment running and more than a 100 helpers helping, we are happy to announce that we submitted last week the first results of the PaNDiv Experiment. This paper looks at the response of decomposition to direct and indirect effects of nitrogen enrichment, with a fancy structural equation model testing the relative importance of litter quality and soil biotic and abiotic conditions.
