Experimental Test of the Combined Effects of Water Availability and Flowering Time on Pollinator Visitation and Seed Set
Experimental Test of the Combined Effects of Water Availability and Flowering Time on Pollinator Visitation and Seed Set
复制标题
DOI：
10.3389/fevo.2021.641693
复制
发表时间：
2021-03-25
影响因子：
3
通讯作者：
Campbell, Diane R.
中科院分区：
文献类型：
--
作者：
Gallagher, M. Kate;Campbell, Diane R.
气候变化可能会改变植物的开花物候和水分供应。这些变化中的任何一个都可以影响传粉者的访问和植物繁殖成功。然而，物候和水的相对影响，以及它们是否在对植物繁殖成功的影响中相互作用，在很大程度上尚未探索。我们在亚高山多年生毛叶蕨（Boraginaceae）的析因实验中操纵了开花物候和土壤湿度。我们研究了花的性状，花的丰度，传粉者的访问，和组成的访问熊蜂与其他传粉者的反应。为了确定对植物繁殖成功的净效应，我们还测量了种子产量和种子质量。水分减少导致花朵变短、变窄，产生的花蜜减少。晚开花的植物产生更少和更短的花。开花物候和水分供应影响授粉和繁殖成功。开花物候的差异有更大的影响传粉者的访问比水的可用性的变化，但相反的是真实的种子生产和质量，这是提高了更大的水的可用性。随着季节的推移，接受鲜花访问的概率下降，与阵列中花卉丰富度的下降相吻合。在接受访问的植物中，访问率和非大黄蜂访问者的百分比在第一周后下降，并一直保持在低水平，直到最后一周。我们检测到的相互作用的物候和水的传粉者游客组成，其中植物受干旱是唯一的一组经历了一个赛季后期复苏的访问由孤独的蜜蜂和苍蝇。尽管有这种相互作用，净繁殖成功率作为种子生产的两个操纵水和物候反应加性。通常观察到的花的大小和回报下降，由于干旱或物候的变化可能不一定会导致减少植物繁殖成功，这在M。纤毛虫对水资源的反应更为直接。研究结果强调，需要超越研究对气候变化的单一反应，例如单一物种的物候或它如何经历非生物因素，以了解气候变化如何影响植物繁殖成功。
Climate change is likely to alter both flowering phenology and water availability for plants. Either of these changes alone can affect pollinator visitation and plant reproductive success. The relative impacts of phenology and water, and whether they interact in their impacts on plant reproductive success remain, however, largely unexplored. We manipulated flowering phenology and soil moisture in a factorial experiment with the subalpine perennial Mertensia ciliata (Boraginaceae). We examined responses of floral traits, floral abundance, pollinator visitation, and composition of visits by bumblebees vs. other pollinators. To determine the net effects on plant reproductive success, we also measured seed production and seed mass. Reduced water led to shorter, narrower flowers that produced less nectar. Late flowering plants produced fewer and shorter flowers. Both flowering phenology and water availability influenced pollination and reproductive success. Differences in flowering phenology had greater effects on pollinator visitation than did changes in water availability, but the reverse was true for seed production and mass, which were enhanced by greater water availability. The probability of receiving a flower visit declined over the season, coinciding with a decline in floral abundance in the arrays. Among plants receiving visits, both the visitation rate and percent of non-bumblebee visitors declined after the first week and remained low until the final week. We detected interactions of phenology and water on pollinator visitor composition, in which plants subject to drought were the only group to experience a late-season resurgence in visits by solitary bees and flies. Despite that interaction, net reproductive success measured as seed production responded additively to the two manipulations of water and phenology. Commonly observed declines in flower size and reward due to drought or shifts in phenology may not necessarily result in reduced plant reproductive success, which in M. ciliata responded more directly to water availability. The results highlight the need to go beyond studying single responses to climate changes, such as either phenology of a single species or how it experiences an abiotic factor, in order to understand how climate change may affect plant reproductive success.