School children become researchers

The geobotanist Prof. Dr. Michael Scherer-Lorenzen of the University of Freiburg is recruiting schoolchildren for a citizen-science project due start in the spring of 2018. The researchers are enlisting school pupils from eight European countries to help hide hundreds of caterpillars made of modeling clay in oak trees. The children will also be asked to collect leaves and analyze them. The aim of their mission is to investigate insect pests – for example the caterpillars which develop into gypsy and processionary moths – and their predators. Traces left by the beaks, teeth or mandibles of predators such as birds, spiders or mammals, reflect their activity with respect to climatic conditions.

A team of researchers from eight countries led by Dr. Bastien Castagneyrol of the French National Institute for Agricultural Research (INRA) is starting a project to document predator consumption and the oaks’ defenses in all of Europe’s climate zones. The school pupils’ assignment is to make caterpillars out of modeling clay and wire. Then, in the spring of 2018, they will then attach the fake caterpillars to a common oak (Quercus robur) in their vicinity. The predators will try to eat this bait as as they would genuine prey and leave behind evidence of their efforts as they do it. The traces will be counted and photographed after two weeks and one month. What is more, the school pupils are being asked to send a few leaves to the project director in France for analysis of the degree of defoliation and the leaves’ chemical composition.

In Europe, the common oak is a species of tree that accommodates a broad range of diverse, insect herbivores. While these pests consume only a small portion of the leaves, taken in total, they can nevertheless weaken a tree and slow its growth. If the pests develop en masse, then they may even kill the tree if this comes in conjunction with sickness or other stress factors, such as drought, for example, that has been caused by climate change. Yet the oaks are not defenseless. They produce repellent or even toxic substances in their leaves. Furthermore, the insect herbivores are nutritional prey for many predators. The trees are protected from their foes in this way, which is called a trophic cascade.

Many researchers are investigating how climate change is affecting trophic cascades. It has long been known that insect herbivores do more damage in warmer regions than colder ones. As temperatures rise, insects become active earlier in spring and summer and survive further into autumn. This could weaken the oaks in southern as well as northern Europe – unless they invest more in mounting defenses. The help of school pupils in different countries will make it possible to compare the chemical defenses, insect damage, and predator attacks with respect to climate.

The oaks selected for this process can be found more easily and reliably in autumn before the leaves fall, than in the spring, so teachers who would like their pupils to take part in this project should contact Michael Scherer-Lorenzen as soon as possible.

For more information and a contact form for instructors
https://sites.google.com/view/aboutoaks/accueil/deutsch

For more information for partner schools
https://drive.google.com/file/d/0Bzm5qFwPGZfYZFd6cWZ1UkhRTFE/view