We try to give some answers to the most frequently asked questions here. If your question is not answered or is still unclear, please do not hesitate to contact us or attend one of our regular virtual BugNet coffee breaks where we will be happy to discuss your questions.
Starting the experimental study
How do I start the experimental BugNet study?
- Select a site – a wide range of different sites are possible. Sites could contain woody species but they should be evenly distributed across the plots. Write us if you have questions regarding site selection! Most BugNet sites are grasslands.
- Measure out your plots and mark them.
- If possible collect baseline soil (see protocol, this is not mandatory)
- If possible, collect baseline plant cover (also not mandatory)
- START TREATMENTS
- Assess plant biomass and plant cover annually at peak biomass
- Maintain the land use of your site and apply the treatments regularly. If your site has been mown just continue mowing. If you site is slightly grazed just let it be grazed in the future, too. If you fence your site (which might be necessary sometimes) consider mowing it from time to time to avoid succession. Let us know if you have questions!
What is the leeway for acceptable heterogeneity among subplots?
That’s a tricky question and not easy to answer. Some heterogeneity is unavoidable, but the more homogeneous your plots are the more likely we will find treatment effects.
How should I time the baseline measurements and the start of treatment?
If you can collect baseline soil in your plots without delaying the start of your treatments then it would be great if you could do so (however, baseline soil per plot is not mandatory). The same refers to the plant cover baseline data (nice to have but not crucial). If collecting baseline cover would delay your treatments then we prefer that you start your treatments as soon as possible and simply assess cover and biomass at peak vegetation.
Maintenance of plots
What should I do if my site gets destroyed by fire, flood or if it has been very dry?
Continue with the treatments and measurements, and record where and when the disturbance/drought has taken place. This can be very interesting, e.g. molluscs might have stronger effects on recovery after a drought than under normal conditions.
Should I mow my site? How should I handle succession?
- Yes, if the site has been mown before. You should maintain the land-use and avoid succession taking place. If you mow, don’t forget to adjust the biomass and cover sampling according to the mowing regime (e.g. shortly before the mowing).
- Maybe, if you site has been grazed and is now fenced. If the vegetation gets shrubby due to absence of large herbivores, mowing might be good to avoid transition into forest. Alternatively, you can remove woody species (we don’t want successional stages).
Should I fence my site?
- If your area is only lightly grazed, this is fine and can remain so.
- If your area is heavily grazed, this is not ideal as we will not be able to detect any effects of the pesticides on plant biomass. In such a case, fencing is a viable option, but you would need to mow your site from time to time to prevent it from entering a successional stage.
- Sometimes fencing is necessary (e.g., in our alpine site cows are not allowed to get in touch with pesticides). In such a case you can fence your site and you might consider mowing it from time to time.
What is meant with treatment add-ons?
In every site there is “room” for at least two treatment add-ons. These are totally voluntary, and no one needs to do an add-on. However, they might be a nice opportunity. We talked a bit about potential treatment add-ons and two seem to perceive a lot of interest. One is a warming add-on with open top chambers, the other one is to use a “mycorrhizal killer”, to better understand the importance of mutualists for plant communities. We will soon prepare protocols for these two add-ons, and will send them around to give you the opportunity to comment on them. However, also other add-ons received interest, and we will make another poll soon, now that we have more collaborators.
What to do with really big shrubs? Should we use allometry to assess their biomass like in the comparative part?
We will add a protocol on how to assess shrub biomass soon.
When should I assess damage?
First, assessing damage is not required currently (this was part of the comparative part). However, it would be great if you could assess plant damage in your third year of treatment application. Some collaborators have assessed damage to test the efficiency of the treatments and whether there are interacting effects, and if you want to assess damage this is very welcome. We usually assess damage before the biomass harvest or also later in the season, as pathogens accumulate in late summer. We avoid leaves that are clearly senescing (dying), as we cannot distinguish between pathogen infection and senescing. You can find information on how to assess damage here.
What about sites that don’t conform to an annual growing season?
We assume that the growing season in your site depends on rainfall. In such a case you can adjust the data collection and treatment application to your growing season.
How do I protect myself during pesticide application?
You can find information on how to protect yourself while handling pesticides here and in the safety information sheets of the respective pesticides.
Where should I send my samples and how should I prepare them?
Please send your soil and biomass samples from the experimental BugNet study to Anne Kempel in Switzerland. You can find detailed information on how to prepare, label and ship your samples here.
Treatment efficiency and timing
Can I increase the dosage of the molluscicide? I have the feeling it is not effective.
Yes, in very productive sites with many slugs it makes sense to increase the dosage. In Bern we have also doubled the dosage. Make sure to report this in your data sheet.
My grassland is very productive, I have the feeling that Karate Zeon has a very low efficacy reducing insects in the plots. Should I increase the dosage?
Increasing the dosage could indeed be an option. Make sure that all the vegetation is covered by the pesticide when spraying; in very productive sites you might indeed need a larger quantity of pesticide then in very unproductive systems. Some very productive sites have also increased the dosage of molluscicide, and you can do this is you have the feeling it is not efficient (please note it down in your data sheet).
Molluscicide might have a fertilization effect. What to do about this?
That is an important point, and we should think about addressing this in greenhouse studies. We should certainly quantify any potential fertilizing effect.