Local habitat complexity and its effects on herbivores and predators in urban agroecosystems
Data files
Jan 18, 2024 version files 13.98 KB
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PitfallTrap_1.5.24.csv
4.32 KB
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README.md
4.46 KB
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VisualSurvey_1.5.24.csv
5.19 KB
Abstract
In urban community gardens, cultivated vegetation provides variable levels of habitat complexity, which can suppress pests by promoting predator diversity and improving pest control. In this study, we examine three components of the structural complexity of garden vegetation (cover, diversity, and connectivity) to investigate whether higher garden vegetation complexity leads to fewer herbivores, more predators, and higher predation. We worked in eight community gardens where we quantified vegetation complexity, sampled the arthropod community, and measured predation on cornworm eggs. We found that plots with high vegetation cover supported higher species richness and greater abundance of predatory insects. High vegetation cover also supported a greater abundance and richness of spiders. In contrast, high vegetation diversity was negatively associated with predator abundance. While high predator abundance was positively associated with egg predation, greater predator species richness had a negative impact on egg predation, suggesting that antagonism between predators may limit biological control. Community gardeners may thus manipulate vegetation cover and diversity to promote higher predator abundance and diversity in their plots. However, the species composition of predators and the prevalence of interspecific antagonism may ultimately determine subsequent impacts on biological pest control.
Access this dataset on Dryad: https://doi.org/10.5061/dryad.wpzgmsbvj
These datasets are the summary data from the paper, “Local Habitat Complexity and Its Effects on Herbivores and Predators in Urban Agroecosystems,” by Azucena Lucatero, Shalene Jha, and Stacy Philpott published in Insects in 2024. They describe herbivore and predator biodiversity, predation on corn earworm moth eggs, and vegetation characteristics (cover, diversity, and connectivity) of plots in urban community garden sites in the California central coast sampled in August 2019.
Description of the data and file structure
We include the two datasets that were analyzed in this study:
1) PitfallTrap_1.5.24.csv
This dataset includes the abundance and species richness of arthropods sampled through pitfall traps, egg predation measured through sentinel pest experiments, and sample plot characteristics.
Column Heads:
- Site
- VegTreat (vegetation complexity treatment; highveg = high vegetation complexity, lowveg = low vegetation complexity)
- SamplingRound (1 indicating sampling on August 1st, 2019; 2 indicating sampling on August 3rd, 2019)
Response Variables:
- TotalHerbAbundance (abundance of all sampled herbivores)
- TotalHerbRichness (species richness of all sampled herbivores)
- TotalNEAbundance (abundance of all sampled predators; NE = natural enemies)
- TotalNERichness (species richness of all sampled predators; NE = natural enemies)
- AntAbundance (abundance of all sampled ants)
- AntSpeciesRichness (species richness of all sampled ants)
- SpiderAbundance (abundance of all sampled spiders)
- SpiderSpeciesRichness (species richness of all sampled spiders)
- EggLRR (effect size of predation on corn earworm moth eggs in sentinel pest experiments; calculated as the log response ratio (LRR = LN(proportion eggs removed in open treatments)—LN(proportion eggs removed in bagged treatments))
Predictor Variables
- VegDensity (vegetation cover, measured as the percent cover of plants in 1.5 x 1.5 m sample plot)
- VegDiversity (vegetation diversity, measured as the number of plant species in 1.5 x 1.5 m sample plot)
- VegConnectivity (vegetation connectivity, measured as the 1/the longest distance between two plants in 1.5 x 1.5 m sample plot)
2) VisualSurvey_1.5.24.csv
This dataset includes the abundance and species richness of arthropods sampled through visual surveys of plants, egg predation measured through sentinel pest experiments, and sample plot characteristics.
Column Heads:
- Site
- VegTreat (vegetation complexity treatment; highveg = high vegetation complexity, lowveg = low vegetation complexity)
- SamplingRound (1 indicating sampling on August 1st, 2019; 2 indicating sampling on August 3rd, 2019)
Response Variables:
- HerbAbundance (abundance of all sampled herbivores)
- HerbRichness (species richness of all sampled herbivores)
- AphidAbundance (abundance of all sampled aphids)
- AphidRichness (species richness of all sampled aphids)
- WhiteflyAbundance (abundance of all sampled whiteflies)
- NEAbundance (abundance of all sampled predators; NE = natural enemies)
- NERichness (species richness of all sampled predators; NE = natural enemies)
- SpiderAbundance (abundance of all sampled spiders)
- SpiderRichness (species richness of all sampled spiders)
- AntAbundance (abundance of all sampled ants)
- AntRichness (species richness of all sampled ants)
- EggLRR (effect size of predation on corn earworm moth eggs in sentinel pest experiments; calculated as the log response ratio (LRR = LN(proportion eggs removed in open treatments)—LN(proportion eggs removed in bagged treatments))
Predictor Variables:
- VegDensity (vegetation cover, measured as the percent cover of plants in 1.5 x 1.5 m sample plot)
- VegDiversity (vegetation diversity, measured as the number of plant species in 1.5 x 1.5 m sample plot)
- VegConnectivity (vegetation connectivity, measured as the 1/the longest distance between two plants in 1.5 x 1.5 m sample plot)
- BedSize (length x width of the entire garden bed; 1.5 x 1.5 m plots are each within a gardener bed)
Sharing/Access information
This dataset was analyzed in the following published article:
Lucatero, A., Jha, S., & Philpott, S. M. (2024). Local Habitat Complexity and Its Effects on Herbivores and Predators in Urban Agroecosystems. Insects, 15(1), 41.
These datasets describe arthropods, predation levels, and vegetation characteristics sampled and measured in urban community garden sites in the California central coast in August 2019. Arthropods were sampled using a combination of visual surveys of garden plants and pitfall traps placed in sample plots. Predation levels were measured using corn earworm moth eggs as sentinel prey in sentinel pest experiments at each sample plot. Vegetation characteristics were measured in four 1.5 x 1.5 m sample plots per garden site. We used generalized linear models to analyze relationships between arhtropod abundance/richness, predation levels, and vegetation characteristics. More detailed methods are described in our Insects publication of this study. Details about each dataset are found in the README file.
Datasets included:
1) PitfallTrap_1.5.24
- Abundance and species richness of herbivores and predators (all predators, ants, and spiders) sampled through pitfall traps
- Egg predation (LRR, effect size) measured through sentinel pest experiments
- Vegetation cover, diversity, and connectivity measurements for each sample plot
2) VisualSurvey_1.5.24
- Abundance and species richness of herbivores (all herbivores, aphids, and whiteflies) and predators (all predators, ants, and spiders) sampled through visual surveys of plants
- Egg predation (LRR, effect size) measured through sentinel pest experiments
- Vegetation cover, diversity, and connectivity measurements and gardener bed size for each sample plot
Missing value are inducated by NA. See README file for additional details.