The loss of resource-rich non-crop habitat is a hypothesized driver of arthropod decline on farms, implying recovery with restoration. Alternatively, chronic arthropod loss may limit colonization to abundant taxa, especially crop pests. Here, we test the impact of restoring marginal farmland on agriculturally important arthropods on 13 conventional farms across a 10,000 km 2 region of central North America with approximately 92% crop cover. We examined local richness by habitat (crops, restored prairie, remnant forest), spatial turnover among habitat and farms, and regional comparisons between farm and non-farms using iNaturalist data. Sampling approximately 13,000 individuals identified to family or lower, restored prairie had twice the abundance of arthropods compared to crop and forest, with 44% of all families detected, 66% of beneficial families, and 94 unique taxa despite their recent construction (<10 years) and small size (~9.6% of farm area). There was some compositional overlap between crop and prairie, while farm forest had mostly unique taxa. Larger restored areas supported more diverse and taxonomically uniform arthropod assemblages, while crop fields were family-depauperate with primarily herbivorous taxa. Unexpectedly, the abundance and richness of arthropods between farms with restored habitat and non-farm areas regionally were similar, although farms possessed more herbivorous species and fewer butterflies and aquatics. The extensive and rapid colonization of restored habitat by beneficial arthropods implies that conventional farms may be habitat limited for many taxa. Our work supports calls for farm redesign that includes habitat reconstruction, which can support arthropods with known benefits to food production.

A growing challenge with industrialized agriculture is compensating farmers for devoting land towards producing ecosystem services, at a time when global food demands are accelerating. Here, we explore revenue thresholds that Payment for Ecosystem Service programs (PES) must approach to be competitive in present-day crop markets, amalgamating long-term North American data especially from Canada on input costs, crop yields, crop revenues after expenses, government subsidies, and land use. Two trends suggest that PES markets with stable revenues can be increasingly competitive, with inflation-adjusted farm input costs now 50x higher than a century earlier and increasingly high revenue instability including net losses for some crops in some years. Since 1994, crop revenues in some regions have averaged $39 acre− 1 US, peaking at $412 but losing money 25.3% of time. Importantly, these data show how government subsidies have been a major stabilizing force, increasing revenues by 37.6% while reducing the frequency of losses by 50% - societal compensation to North American farmers is already the norm. PES programs could be most feasible on marginal lands, which are often targeted for retirement due to higher input requirements. However, trends in Canada reveal that marginal land cropping has increased by 5.2 million acres since 1990 and now constitutes 28.8% of all cropland. Our work reinforces how revenue instability simultaneously creates and constrains opportunities for PES markets, favoring market competitiveness because of shrinking crop revenues but pressuring farmers to expand production, including on marginal lands, as they struggle to offset revenue shortfalls while attempting to capitalize on growing global food demands.

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7Plants with mixed mating systems balance the advantages of selfing and the costs of inbreeding. 8 Previous studies have shown that plant species with the ability to self-pollinate and cross 9 pollinate have strategies to promote outcrossing to increase genetic diversity. Various features of 10 floral morphology are thought to be deliberate mechanisms to manipulate plant mating systems. I 11 hypothesized that within-plant variation in flower stem height is a morphological trait that can 12 reduce geitonogamy by increasing pollinator movement among plants. This hypothesis was 13 tested using coltsfoot (Tussilago farfara); coltsfoot plants host several flowering stems that differ 14 in height, with each stem having a single, terminal flowerhead. I used cut flowers to create 15 'populations' of coltsfoot in which each plant had four inflorescences with equal or unequal 16 flower stalk lengths and measured frequency of insect pollinators that would stay among flowers 17 within a plant or move to other plants. All pollinators (bee flies, hover flies, solitary bees and 18 wasps) showed a marked discrimination in favor of leaving plants with flowers of different 19 heights and stayed when plants had flowers of the same height. This study shows that variation 20 in flower heights is important for reducing geitonogamy in coltsfoot and suggests that the 21 evolution of this morphological trait should be considered in studies of mating systems.22