Local Habitat Complexity and Its Effects on Herbivores and Predators in Urban Agroecosystems.

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 corn earworm eggs.

Promoting Beneficial Arthropods in Urban Agroecosystems: Focus on Flowers, Maybe Not Native Plants.

(1) Urbanization threatens biodiversity, yet urban native plants support native biodiversity, contributing to conservation and ecosystem services. Within urban agroecosystems, where non-native plants are abundant, native plants may boost the abundance and richness of beneficial arthropods. Nevertheless, current information focuses on pollinators, with little attention being paid to other beneficials, like natural enemies.

Multiple ecosystem service synergies and landscape mediation of biodiversity within urban agroecosystems.

Ecosystem services (ESs) are essential for human well-being, especially in urban areas where 60% of the global population will live by 2030. While urban habitats have the potential to support biodiversity and ES, few studies have quantified the impact of local and landscape management across a diverse suite of services. We leverage 5 years of data (>5000 observations) across a network of urban community gardens to determine the drivers of biodiversity and ES trade-offs and synergies.

Rarity begets rarity: Social and environmental drivers of rare organisms in cities.

Cities are sometimes characterized as homogenous with species assemblages composed of abundant, generalist species having similar ecological functions. Under this assumption, rare species, or species observed infrequently, would have especially high conservation value in cities for their potential to increase functional diversity. Management to increase the number of rare species in cities could be an important conservation strategy in a rapidly urbanizing world.

Natural enemy-herbivore networks along local management and landscape gradients in urban agroecosystems.

Ecological networks can provide insight into how biodiversity loss and changes in species interactions impact the delivery of ecosystem services. In agroecosystems that vary in management practices, quantifying changes in ecological network structure across gradients of local and landscape composition can inform both the ecology and function of productive agroecosystems. In this study, we examined natural-enemy-herbivore co-occurrence networks associated with Brassica oleracea (cole crops), a common crop in urban agricultural systems.