Data and code from: Impacts of urbanization on pathogens and pests of wild and cultivated plants

Understanding how urbanization affects plant interactions with pathogens
and herbivores is important for clarifying how changes in land use,
climate, and biodiversity affect ecological and evolutionary processes,
and for managing urban plants to maximize ecosystem services. We performed
a systematic literature review of relationships between urbanization and
pathogens or pests of wild and cultivated plants. We identified k = 171
relationships from n = 54 studies in which pathogen or pest abundance was
quantified in both urban and non-urban areas, and summarized their
distribution across taxa, geographic regions, and directions and
mechanisms of effects proposed by the authors. Most studies featured tree
hosts and their arthropod pests or fungal pathogens. Grasses and forbs
were the next most commonly studied hosts, followed by crops and shrubs.
We then performed a meta-analysis limited to trees, which had the most
studies with sufficient statistical information (k = 55 relationships, n =
14 studies). In that meta-analysis, we found no overall effect of
urbanization on tree pest or pathogen abundance. However, there was a
significant interaction between urbanization and type of pest/pathogen,
with arthropod pests trending toward lower abundance in urban areas and
fungal pathogens trending toward higher abundance. Drawing on literature
from the broader fields of urban ecology, disease ecology, and plant
pathology, we synthesize our findings and offer insights into mechanisms
by which urbanization influences disease and herbivory in wild and
cultivated plants. We conclude by identifying research gaps, with the goal
of informing management strategies that prioritize food security,
environmental health, and global biodiversity.