MORALES Carolina Laura
Scale-dependent effects of conspecific flower availability on pollination quantity and quality in an invasive shrub
CAVALLERO, L.; MORALES, C. L.; MONTERO-CASTAÑO, A.; GOWDA, J. H.; AIZEN, M. A.
Lugar: Berlin; Año: 2018
AbstractPollen limitation can strongly infuence reproduction of pollinator-dependent plants. Flower abundance can afect pollination?quantity? and ?quality? due to its infuence on pollen availability and foraging patterns of pollinators, ultimately impactingon seed production. We complemented individual-based measurements with landscape-level metrics to assess the infuenceof conspecifc fower availability at diferent spatial scales on the quantity and quality components of pollination, and theirimpact on seed production in the invasive shrub Cytisus scoparius. In 2013?2014, we sampled 40 C. scoparius populationsin Nahuel Huapi National Park, Patagonia (Argentina). In each population, we estimated the proportion of tripped fowers,fruit- and seed-set in fve randomly selected individuals. The proportion of tripped fowers and the proportion of them settingfruit were used as proxies of pollination quantity and quality, respectively. Conspecifc fower availability at distinct spatialscales (5?1000 m) was estimated as the area covered by fowering C. scoparius from color aerial photographs. Flower availability infuenced seed output due to contrasting scale-dependent efects on pollination quantity and quality. Increasing foweravailability at the landscape-scale reduced pollination quantity, whereas at the neighborhood-scale it increased pollinationquality. The overall positive efect of fower availability on seed output at the neighborhood scale was slightly higher than theoverall negative efect at the landscape scale. Moreover, pollination quality had a higher positive efect on seed output thanpollination quantity. Our results demonstrate that pollination quality may severely limit plant reproduction. Pollination qualitylimitation can act independently of pollination quantity limitation because these factors operate at diferent spatial scales.