The worldwide decline of insects is one of the major challenges for humankind. One of its main drivers is intensive farming, which reduces habitats and food resources for insect populations and ...causes direct mortality by pesticides. In addition, mowing of grassland poses another threat to insects, especially when it is done frequently, such as in roadside verges. Roadside verges comprise large areas worldwide and can serve as habitats for animals and plants and as corridors to connect populations when they are maintained ecologically, for example when mowing is done arthropod‐friendly and with low frequency. Microhymenoptera are highly diverse, mostly show a parasitoid lifestyle and occur in large numbers in meadows and grasslands. Although they have an important ecological function in regulating their arthropod host populations, they were mostly neglected in studies on the influence of mowing on insects. Therefore, we assessed which families of microhymenoptera occur in roadside verges and meadows, examined if they are affected by the mowing process with a conventional mulching mower, and studied which groups benefit from arthropod‐friendly mowing, using the mowing head Eco 1200 plus from MULAG, and a flushing bar made of track tarpaulin. In our experimental grassland plots, we found specimens of 18 families from the six microhymenoptera superfamilies Chalcidoidea, Ceraphronoidea, Diaprioidea, Ichneumonoidea, Platygastroidea and Proctotrupoidea. Mowing with a conventional mulching mower caused a significant loss of up to 64% for parasitoid Hymenoptera. The Eco 1200 plus showed an arthropod‐friendly effect only on the number of individuals of Chalcidoidea, saving 38% of individuals compared with the conventional mower. The flushing bar showed a significant effect on total number of individuals with a reduction only on Chalcidoidea and a tendency for Ichneumonoidea with 30% and 47%, respectively. Our study demonstrates the detrimental effect of mowing with a conventional mulching mower on microhymenoptera and shows that this effect can be partly reversed for Chalcidoidea and Ichneumonoidea through the arthropod‐friendly mower and a flushing bar. Our study highlights the importance to consider microhymenoptera in the context of insect decline.
An underestimated factor that contributes to the decline of insects observed during the last year is probably the mortality, which is caused by mowing of grassland. We studied the negative impact of ...mowing on the arthropod fauna of roadside grassland, which might serve as potential habitat for insects to prevent their local extinction and as corridor for the dispersal in anthropogenic landscapes. In addition, we studied if losses due to mowing can be mitigated by the use of ‘arthropod‐friendly’ mowing technique. In agreement with earlier studies, we found that mowing with a conventional mowing head (MK 1200 from MULAG) caused considerable losses in arthropods, ranging from 29% for Heteroptera over around 50% in Araneae, Cicadina, Hymenoptera and Diptera, up to 73% for holometabolous larvae, and 87% for Lepidoptera. These losses by mowing were fully offset for Araneae, Cicadina, Heteroptera, Lepidoptera and larvae of holometabolous insects when using the mowing head Eco 1200 from MULAG, which was designed to be ‘arthropod‐friendly’. For Hymenoptera and Diptera, the losses were reduced by 15% and 25% respectively. For Saltatoria and Coleoptera, we did not find any significant differences between all treatments. These data demonstrate that mowing of roadsides with conventional mowing technology has a highly detrimental effect on the grassland arthropod fauna. However, this effect can be offset or at least mitigated by the use of ‘arthropod‐friendly’ mowing technique. Therefore, this technique has a high potential to reduce insect decline in roadside grassland, making these areas a habitat for insects.
Abstract
The article explores the history of breeding hogweed Sosnovsky “Severyanin”, its cultivation for preparing silage and feeding cattle in the Soviet Union, the reasons for the refusal to grow ...it and its rapid spread in many regions of Russia, its capture of free spaces and the displacement of other plants. The scale of advancement of cow parsnip has become threatening in the European part of the country. As a result, it was deleted from the Russian State Register of Breeding Achievements and classified as a weed. The article emphasizes that an active fight against wild-growing hogweed is currently being carried out using various methods and means. But it does not give significant results. Since the measures taken to eradicate the hogweed turned out to be untenable, the question arises: what to do with Sosnowsky’s hogweed? The article proposes to solve this problem by cultivating it, mowing it and producing biofuel from it. The potential of hogweed as a useful plant is revealed, the technological scheme of its processing is given. The most important requirement is the creation of a closed, environmentally friendly production in order to prevent the uncontrolled spread of hogweed and protect people from skin burns caused by oils contained in it. The article formulates the tasks that consist in using Sosnowsky’s hogweed in solving the energy problem.
In this study, the interferometric coherence calculated from 12-day Sentinel-1 image pairs was analysed in relation to mowing events on agricultural grasslands. Results showed that after a mowing ...event, median VH (vertical transmit, horizontal receive) and VV (vertical transmit, vertical receive) polarisation coherence values were statistically significantly higher than those from before the event. The shorter the time interval after the mowing event and the first interferometric acquisition, the higher the coherence. The coherence tended to stay higher, even 24 to 36 days after a mowing event. Precipitation caused the coherence to decrease, impeding the detection of a mowing event. Given the three analysed acquisition geometries, it was concluded that afternoon acquisitions and steeper incidence angles were more useful in the context of this study. In the case of morning acquisitions, dew might have caused a decrease of coherence for mowed and unmowed grasslands. Additionally, an increase of coherence after a mowing event was not evident during the rapid growth phase, due to the 12-day separation between the interferometric acquisitions. In future studies, six-day pairs utilising Sentinel-1A and 1B acquisitions should be considered.
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