Our county will be starting a pilot to phase out glyphosate based weed-killer this year and promote biodiversity-friendly growing policies. 50% of selected areas will be treated as normal, cut frequently and sprayed with glyphosate to control weeds. The other half of each area will be left untreated and allowed to grow. We as a community are interested in studying the difference in plant (and potentially insects) species between both areas over the course of the summer. My question is, has a similar study already been done and could someone point us to it? Thank you very much.
My first question here would be is glyphosate actually being used appropriately in the first place? It is a broad spectrum systemic herbicide but it is not residual herbicide so if you want to keep weeds down for longer periods then you would use something else.
Have you set up a properly replicated controlled trial so you can be sure of the results?
Many Councils have used glyphosate to prepare new flower beds & for dealing with weeds in pavements. Bristol C C carried out some trials. https://democracy.bristol.gov.uk/documents/s13382/Glyphosate%20final%20report%20main%20appendix%20April%202017_final.pdf
However there’s no mention of monitoring for biological diversity…
As Miked says, setting up a monitoring exercise whose results are reliable requires a lot of planning. If you already have data from previous years that would be useful, because the background level of variabilty in both plants & invertebrates over one summer will make drawing valid conclusions difficult. Will Replicated Controlled Trials be possible?
Perhaps others will come here with some suggestions. However, it’s never to late to start general monitoring. Knowing what you’ve got In the two areas this year and collecting data as the trials continue can be very satisfying.
I recall reading that reduction of mowing of rural verges (as a cost saving measure) has had a negative effect on botanical diversity - wildflower rich verges becoming overgrown by brambles and coarse grasses.
Mowing and spraying with glyphosate don’t seem to fit together. Mowing implies that the site is meant to have a vegetation cover, but glyphosate is a broad spectrum herbicide which kills most plants. (Waxy-leaved plants escape by not absorbing the glyphosate (it’s not very effective on ivy), some plants with extensive root systems can regrow (which is why it takes multiple applications to kill off Fallopia japonica), and a few species have evolved resistant genotypes.)