Land-use change has no detectable effect on reproduction of a disturbance-adapted, hawkmoth-pollinated plant species.
OBJECTIVE
Land-use change is cited as a primary driver of global biodiversity loss, with myriad consequences for species, populations, and ecosystems. However, few studies have examined its impact on species interactions, particularly pollination. Furthermore, when the effects of land-use change on pollination have been studied, the focus has largely been on species pollinated by diurnal pollinators, namely, bees and butterflies. Here, we focus on Oenothera harringtonii, a night-flowering, disturbance-adapted species that has experienced a range-wide gradient of land-use change. We tested the hypothesis that the negative impacts of land-use change are mitigated by long-distance pollination.


METHODS
Our study included both temporal (4 yr) and spatial (19 populations range-wide, and 1, 2, and 5 km from the population center) data, providing a comprehensive understanding of the role of land-use change on pollination biology and reproduction.


RESULTS
We first confirmed that O. harringtonii is self-incompatible and reliant on pollinators for reproduction. We then showed that hawkmoths (primarily Hyles lineata) are highly reliable and effective pollinators in both space and time. Unlike other studies, we did not detect an effect of population size, increased isolation, or a reduction in suitable habitat in areas with evidence of land-use change on pollination (visitation, pollen removal and deposition). Furthermore, the proportion of suitable habitat and other fragmentation metrics examined were not associated with population size or density in this plant species.


CONCLUSIONS
We conclude that nocturnal pollination of Oenothera harringtonii via hawkmoths is robust to the negative impacts of land-use change.
Chicago Botanic Garden 1000 Lake Cook Road, Glencoe, Illinois 60022 USA kskogen@chicagobotanic.org.
Krissa A
KA
Skogen
Chicago Botanic Garden 1000 Lake Cook Road, Glencoe, Illinois 60022 USA.
Tania
T
Jogesh
Chicago Botanic Garden 1000 Lake Cook Road, Glencoe, Illinois 60022 USA.|Washingtion State University, School of Biological Sciences, P.O. Box 644236, Pullman, Washington 99164 USA.
Evan T
ET
Hilpman
Chicago Botanic Garden 1000 Lake Cook Road, Glencoe, Illinois 60022 USA.|Iowa Department of Agriculture and Land Stewardship, 2230 S. Ankeny Boulevard, Ankeny, Iowa 50023 USA.
Sadie L
SL
Todd
Chicago Botanic Garden 1000 Lake Cook Road, Glencoe, Illinois 60022 USA.|Department of Ecology and Evolutionary Biology, University of Arizona, P.O. Box 210088, Tucson, Arizona 85721 USA.
Matthew K
MK
Rhodes
Chicago Botanic Garden 1000 Lake Cook Road, Glencoe, Illinois 60022 USA.|University of California Davis Arboretum and Public Garden, One Shields Avenue, Davis, California 95616 USA.
Shannon M
SM
Still
Chicago Botanic Garden 1000 Lake Cook Road, Glencoe, Illinois 60022 USA.
Jeremie B
JB
Fant
D000818:Animals; D044822:Biodiversity; D003710:Demography; D017753:Ecosystem; D035264:Flowers / Q000502:physiology; D018402:Manduca / Q000502:physiology*; D031664:Oenothera / Q000502:physiology; D011058:Pollen / Q000502:physiology; D054817:Pollination; D011156:Population Density; D012098:Reproduction
Hyles; Oenothera; Onagraceae; bee; diurnal pollination; fragmentation; hawkmoth; land-use change; nocturnal pollination; pollinator