The project implementation during the period covered the start-up phase (September 2019 to May 2020) which included initiating project communication, the successful recruitment of researchers (one Postdoc and two PhD students), field assistants for 2020, preparation of project-adapted internal workflows for handling samples, as well as the set-up of the two empirical research platforms and purchasing consumables. These include in WP1 a network of 18 sites differing in the landscape context (share of arable land-use and composition of non-arable land-use in a 1000m radius around the sites), in which research plots (pollinator reduction and control subplots) have been established for at least the duration of the project (until 2024). In WP2, a cage experiment with 48 cages has been established at a single site, where newly established grassland vegetation is exposed to a full-factorial combination of pollinators, herbivores and nutrient levels (also at least until 2024). In June to September 2020, the first season of data collection on the empirical research platforms was conducted, including plant and insect surveys, seed set, biomass, and plant-insect interactions. From October 2020 to February 2021, laboratory-based work (identification/analysis of insect, plant and soil samples) was conducted, first preliminary analysis and results for the data from 2020 were communicated at a conference, and the second field season (spring-summer 2021) was planned. The second field season was conducted March to September 2022, recording the same data types as above, as well as a campaign to record pollination-related plant traits in WP1 and WP2. From October 2021 to February 2021, in addition to the identification/analysis of insect, plant and soil samples, we quantified the seed production, seed damage and seedling density and composition (from seed traps) from both WP1 and WP2. Work in WP3 has been initiated in 2020 by contributing to an assessment of the transferability of using prior data from crop pollinators (Blasi et al. 2021) and continued development of spatially-explicit models for central-place foragers. The availability of WP1 data has allowed us to start with building of statistical models (pollinator communities and plant-insect interactions). Over the course of 2020 and 2021 a review paper covering the landscape-scale land-use pollinator plant community ecosystem functioning relationships has been written, submitted and reviewed, it is currently prepared for resubmission.
The main results achieved so far support the effectiveness of the experimental treatments (WP1: reduced pollinator access; WP2: large differences in pollinator visitation between pollinator treatments, differences in herbivore densities) as well as effects of the landscape gradients in WP1 that are pollinator-group specific (bumblebees showing different patterns than solitary bees, hoverflies and other flies) and differ between pollinators and herbivorous insects. Analyses of effects on flower visitation and on plant reproductions (seed production, seed damage, seedling density and composition) are ongoing.
