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

Mating system and fitness data for families of Eucalyptus socialis grown in common garden experiments. Families collected across a fragmentation gradient. Open-pollinated progeny arrays were collected and reared in the common garden experiments. These open-pollinated progeny arrays were also genotyped at microsatellite loci to generate the mating system data. Data showed association between fragmentation on mating system, which in turn impacted fitness. Please contact owner prior to use.

Credit
We at TERN acknowledge the Traditional Owners and Custodians throughout Australia, New Zealand and all nations. We honour their profound connections to land, water, biodiversity and culture and pay our respects to their Elders past, present and emerging.

Purpose
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 probably has effects over and above those of inbreeding on progeny fitness. This provides an alternative mechanistic explanation for the indirect density dependence often inferred between conspecific density and offspring fitness.