Abstract In arable farming, weeds provide important floral and seed resources that have the potential to support the provision of ecosystem services such as pollination or pest control. Estimating the production of these weed resources in the landscape is however not trivial as large-scale surveys of weed communities are usually conducted once in the season with a timing that may not coincide with the flowering and fruiting stages of all weed species. More, intraspecific variation in the mortality and phenology of individual weed species may arise from differences in the quality of the growing environment of each plant. In this study, we monitored the phenology of 30 common weed species in the field core and the field edge of 64 commercial fields grown with 6 crop types. Our hypothesis was that the production of resources by an individual plant would be modulated by its within-field location and by the crop type where it grows. We quantified floral (proportion, starting date and duration of flowering, dry biomass at flowering as a proxy for the amount of flowers) and seed resource production (proportion and starting date of fruiting). For most species, flowering and fruiting success were higher in field edges than in field cores and were lower in cereal crops than in other crops. Weeds flowered and fruited earlier and the flowering period was longer in field edges, except those of cereal crops. Dry biomass at flowering varied with field location either way, depending on the weed species, but tended to be lower in cereal crops than in other crops. This important intraspecific phenological variability in the production of seed and/or flower or resources should be considered when evaluating the contribution of weed communities to ecosystem services. It also suggests that within an agricultural landscape, the amount, timing and duration of provision of services by weeds could be enhanced by maintaining sufficient lengths of field edges and by growing a diversity of crop types.

中文翻译：

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作物类型和田间位置是杂草物候和花卉和水果资源生产的种内变异的来源

摘要 在耕作中，杂草提供了重要的花卉和种子资源，有可能支持提供授粉或害虫防治等生态系统服务。然而，估计景观中这些杂草资源的产量并非易事，因为对杂草群落的大规模调查通常在季节进行一次，其时间可能与所有杂草物种的开花和结果阶段不一致。此外，各个杂草物种的死亡率和物候学的种内差异可能是由于每种植物生长环境质量的差异造成的。在这项研究中，我们监测了种植 6 种作物类型的 64 个商业田地的田间核心和田边 30 种常见杂草物种的物候。我们的假设是，单个植物的资源生产将受到其在田间位置及其生长的作物类型的调节。我们量化了花卉（开花的比例、起始日期和持续时间、开花时的干生物量作为花卉数量的代表）和种子资源生产（结果的比例和起始日期）。对于大多数物种来说，田地边缘的开花和结果成功率高于田野核心，而谷类作物的开花和结果成功率低于其他作物。除谷类作物外，田边杂草开花结果较早，花期较长。开花时的干生物量随田间位置和杂草种类的不同而变化，但谷类作物的干生物量往往低于其他作物。在评估杂草群落对生态系统服务的贡献时，应考虑种子和/或花卉或资源生产中这种重要的种内物候变异。它还表明，在农业景观中，通过保持足够长度的田地边缘和种植多种作物类型，可以提高杂草提供服务的数量、时间和持续时间。