Dutch landscapes have lost insect‑pollinated plants over the past 87 years
Abstract
The interruption of plant‑pollinator interactions may threaten global plant diversity, food security and ecosystem stability. Recent reports of strong declines in both insects and plants point to insect decline as a driver of plant decline. However, it is still unknown whether these trends are related as plants often produce seeds without the need for insect pollinators, and to what extent insect‑pollinated plants have declined in relation to plants not pollinated by insects. In this study, we hypothesise that natural plant communities have shifted away from insect‑pollination. We combined 365,768 vegetation plots from 1930 to 2017 in the Netherlands and plant traits to assess the changes in occurrences of plants pollinated by different modes. Furthermore, we included key drivers in plant decline—specifically nitrogen, moisture and habitat types—as interaction factors to explore the persistence of the observed changes under different environmental conditions. The proportion of insect‑pollinated plants has declined while that of wind‑pollinated plants has increased over the last 87 years. This proportional change reflects an absolute decrease in the number of insect‑pollinated species and an increase in the number of wind‑pollinated species. Synthesis and applications. This study implies that Dutch landscapes are losing insect‑pollinated plant species, which is likely due, at least in part, to the decline in pollination services. Our results of quantifying the decline in insect‑pollinated plants support the necessity and urgency of taking conservation initiatives. Several management strategies and policy recommendations could be applied to alleviate the decline of insect‑pollinated plants and ensure crop safety. For example, conserving natural environments by reducing nitrogen deposition may support local plants and insect pollinators. Additionally, there is a particular need for focused efforts to protect natural grasslands, as these areas harbour many insect‑pollinated plants, which have experienced declines. Finally, monitoring and assessing the state of both pollinators and (insect‑pollinated) plants is needed to assess the progress of conservation measures. While recognising the interdependence of pollinators and pollinated plants, it is crucial to extend efforts beyond pollinator conservation alone to effectively safeguard insect‑pollinated plants and ensure crop safety. 摘要 在所有开花植物中, 虫媒授粉植物占据了绝大部分, 世界上80%以上的重要作物都依赖昆虫授粉。因此, 授粉者和虫媒授粉植物的减少可能威胁全球植物多样性、食品安全和生态系统稳定性。最近的报道显示, 昆虫和植物数量都出现了大幅下降, 暗示昆虫数量减少可能是植物减少的原因之一。然而, 目前尚不清楚这些趋势是否相关, 以及依赖昆虫授粉的植物相对于不依赖昆虫授粉的植物数量减少了多少, 因为植物通常可以通过自花授粉或风媒授粉进行繁殖。 在本研究中, 我们假设自然植物群落已经由昆虫授粉主导转向风媒授粉。我们结合了荷兰自1930年至2017年的365,768个植被样方和植物性状数据, 以评估过去近百年不同授粉方式的植物在自然群落中的变化。此外, 我们还将氮、湿度和栖息地类型等植物减少的关键驱动因素作为与授粉方式的交互因素加入到模型中, 探讨以上观察到的不同授粉形式的植物随时间的变化趋势是否因氮、湿度和栖息地类型而变化。 结果表明, 在过去的87年里, 自然群落内昆虫授粉植物的比例已经下降, 而风媒授粉植物的比例却在增加。这种比例变化反映了昆虫授粉物种数量的减少和风授粉物种数量的增加。 本研究表明荷兰的景观正在失去昆虫授粉植物物种, 这可能至少部分归因于授粉服务的减少。我们的结果表明采取措施以保护昆虫和虫媒授粉植物的必要性和紧迫性。相应的管理策略和政策建议包括通过减少氮沉降来保护自然环境进而保护当地植物和昆虫授粉者。此外, 有必要针对自然草地进行有针对性的保护, 因为这些地区具有丰富的昆虫授粉植物, 而这些植物已经在过去87年里大大减少。最后, 需要持续监测和评估授粉者和(昆虫授粉)植物的状态, 以评估保护措施的进展。鉴于授粉者与被授粉植物的相互依赖性, 将来的生物多样性监测必须从昆虫拓展到虫媒授粉植物, 双向评估昆虫以及虫媒授粉植物的变化, 以有效地保护昆虫授粉植物并确保作物安全。
- Publication:
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Journal of Applied Ecology
- Pub Date:
- June 2024
- DOI:
- 10.1111/1365-2664.14649
- Bibcode:
- 2024JApEc..61.1323P