Data from: Pollination deficits increase with urbanization in Chicago
Data files
Nov 21, 2024 version files 299.02 KB
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gopro_obs.csv
28.40 KB
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inperson_obs.csv
8.58 KB
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README.md
4.26 KB
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squash_fl.csv
18.11 KB
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squash_seeds.csv
6.13 KB
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tomato_fl.csv
65.48 KB
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tomato_seeds.csv
168.07 KB
Abstract
Urban growth is occurring rapidly, and the land use changes associated with urbanization may have consequences for pollinators and the plants that rely on them. Despite its importance in the face of pollinator declines and expanding urban ecosystems, our understanding of the effects of urbanization on pollination mutualisms is scant. There is both evidence that urban areas support diverse pollinator communities and evidence that they degrade them. The influence of urbanization on the pollination of urban plants is even less understood. Urban agriculture relies on plant-pollinator interactions for crop production, providing a relevant framework to study pollination in an urban context. We therefore grew 240 plants across six sites at varying levels of urbanization in Chicago, Illinois, to investigate how urbanization relates to pollination of a generalized pollination system in Cucurbita pepo (squash) and a more specialized pollination system in the buzz-pollinated Solanum lycopersicum (tomato). We used a pollen limitation experiment to test whether the reproduction of plants at urban farms is pollen-limited and whether the magnitude of pollen limitation varies with the extent of urbanization (quantified as the percent of surrounding impervious surface around each site). We also examined how pollinator visitation rates vary with urbanization. In S. lycopersicum but not C. pepo, the pollen addition treatment had a consistent and significant positive effect on reproductive success, indicating that plants of S. lycopersicum are pollen-limited in our study area. The magnitude of this pollen limitation (the difference in fruit set between paired control and pollen-supplemented plants) increased with greater impervious surface, illustrating that S. lycopersicum plants at more urban sites are more pollen-limited. The limited evidence for pollen limitation in the more generalized C. pepo suggests that plants with more specialized pollination systems are subject to greater pollen limitation in urban environments. Together, our results demonstrate that urban plants are likely experiencing deficits in pollination services, but in ways that vary with both the type of pollination system and the level of urbanization in the surrounding area.
https://doi.org/10.5061/dryad.44j0zpcm6
Description of the data and file structure
gopro_obs.csv : pollinator observations scored from GoPro videos
date: date (mm/dd/yy) of observation
site: observations were conducted at six study sites. Chicago Botanic Garden (cbg), Washington Park Farm (wpf), PCC Austin (pcc), Farm on Ogden/North Lawndale Youth Farm (foo), Legends Farm (leg), Kenneth Street Farm (ken)
time: time of day observation started
length: length of video/observation period in minutes
plant: identity of plant that was observed
num.flowers: number of flowers observed
pollinator: identity of pollinator observed
num.visits: number of flowers visited by each pollinator
inperson_obs.csv : pollinator observations carried out in person
date: date (mm/dd/yy) of observation
site: observations were conducted at six study sites. Chicago Botanic Garden (cbg), Washington Park Farm (wpf), PCC Austin (pcc), Farm on Ogden/North Lawndale Youth Farm (foo), Legends Farm (leg), Kenneth Street Farm (ken)
time: time of day observation started
plant: identity of plant that was observed
num.flowers: number of flowers observed
pollinator: identity of pollinator observed
num.visits: number of flowers visited by each pollinator
Missing data: NA
tomato_fl.csv : information collected on flowers and fruits from individual tomato plants
date: date (mm/dd/yy) on which flowers were counted and fruits harvested
site: plants were grown at six study sites. Chicago Botanic Garden (cbg), Washington Park Farm (wpf), PCC Austin (pcc), Farm on Ogden/North Lawndale Youth Farm (foo), Legends Farm (leg), Kenneth Street Farm (ken)
individual: unique ID assigned to each plant individual
treatment: which group plant belonged to between control (open-pollinated) or supplement (received supplemental pollination)
flowers: number of new flowers produced since last observation date
num_harvest: number of fruits harvested
num_failed: number of aborted ovaries observed since last observation date
tomato_seeds.csv : data collected for individual fruits harvested from tomato plants
site: plants were grown at six study sites. Chicago Botanic Garden (cbg), Washington Park Farm (wpf), PCC Austin (pcc), Farm on Ogden/North Lawndale Youth Farm (foo), Legends Farm (leg), Kenneth Street Farm (ken)
date_harvest: date (mm/dd/yy) on which fruit was harvested
individual: unique ID assigned to each plant individual
treatment: which group plant belonged to between control (open-pollinated) or supplement (received supplemental pollination)
mass: mass of fruit in grams
diameter: diameter of fruit in centimeters
lg_seeds: number of large seeds per fruit
sm_seeds: number of small seeds per fruit
total: total number of seeds per fruit
squash_fl.csv : information collected on flowers and fruits from individual squash plants
date: date (mm/dd/yy) on which flowers were counted and fruits harvested
site: plants were grown at six study sites. Chicago Botanic Garden (cbg), Washington Park Farm (wpf), PCC Austin (pcc), Farm on Ogden/North Lawndale Youth Farm (foo), Legends Farm (leg), Kenneth Street Farm (ken)
individual: unique ID assigned to each plant individual
treatment: which group plant belonged to between control (open-pollinated) or supplement (received supplemental pollination)
total_fl: number of new flowers produced since last observation date
num_harvest: number of fruits harvested
num_failed: number of aborted ovaries observed since last observation date
squash_seeds.csv : data collected for individual fruits harvested from squash plants
site: plants were grown at six study sites. Chicago Botanic Garden (cbg), Washington Park Farm (wpf), PCC Austin (pcc), Farm on Ogden/North Lawndale Youth Farm (foo), Legends Farm (leg), Kenneth Street Farm (ken)
date_harvest: date (mm/dd/yy) on which fruit was harvested
individual: unique ID assigned to each plant individual
treatment: which group plant belonged to between control (open-pollinated) or supplement (received supplemental pollination)
mass: mass of fruit in grams
diameter: diameter of fruit in centimeters
num_seeds: total number of seeds per fruit