Data from: Pollen diversity matters: revealing the neglected effect of pollen diversity on fitness in fragmented landscapes

Few studies have documented the impacts of habitat fragmentation on plant mating patterns together with fitness. Yet, these processes require urgent attention to better understand the impact of contemporary landscape change on biodiversity and for guiding native plant genetic resource management. We examined these relationships using the predominantly insect-pollinated Eucalyptus socialis. Progeny were collected from trees located in three increasingly disturbed landscapes in southern Australia and were planted out in common garden experiments. We show that individual mating patterns were increasingly impacted by lower conspecific density caused by habitat fragmentation. We determined that reduced pollen diversity, not inbreeding, was the factor that best explained variation in progeny growth. This provides an alternative mechanistic explanation for the indirect density dependence often inferred between conspecific density and offspring fitness. Consequently, native plant genetic resource management should be refined from not only attempting to avoid inbreeding but also to encourage pollen diversity.

目前鲜有研究同时阐明生境破碎化对植物交配格局及其适合度的影响。然而，为了更深入理解当代景观变化对生物多样性的影响，并指导本土植物遗传资源管理工作，该研究方向亟需得到重视与推进。本研究以主要依赖昆虫传粉的社交桉（Eucalyptus socialis）为研究材料，对上述关联展开探究：我们从澳大利亚南部三处受干扰程度逐级递增的生境中的植株上采集子代样本，并将其定植于同质园实验中。研究结果显示，生境破碎化导致的同种个体密度降低，会对植株的交配格局造成愈发显著的影响。我们进一步明确，能够最佳解释子代生长差异的因素是花粉多样性降低，而非近交。该发现为同种个体密度与子代适合度之间常被推断出的间接密度依赖关系提供了全新的机理解释。因此，本土植物遗传资源管理工作应当得到优化完善：不仅需要规避近交问题，还应主动采取措施提升花粉多样性。