Abstract
Abstract for submitted paper:
Understanding community assembly for wild species in anthropogenic settings has become increasingly important as biodiversity and ecosystem services are threatened by development pressures. Urban hardscape habitats such as parking lots are widespread, extreme, terrestrial anthropogenic environments that influence plant community assembly by way of altered biotic and abiotic conditions.
In this study we ask if urban hardscape habitats select for certain propagule dispersal and pollination mechanisms in plants. We surveyed the vascular plant communities using 17 urban asphalt parking lots in New Jersey, US, as model hardscape habitats. Propagule dispersal determines how plants colonize new areas of habitats, while pollination determines how plants persist via reproduction and form new communities in these extreme environments. We compared the modes of propagule dispersal and pollinators of parking-lot plant communities to those characteristics present in the total regional species pool.
The species assemblages of parking lots were characterized by multiple, generalist dispersal modes. They were also characterized by species with generalist pollination vectors and/or utilize multiple strategies for pollination, including biotic and abiotic vectors, as well as self and unassisted pollination, when compared to the regional species pool. The parking-lot communities show a shift towards a higher number of dispersal modes per species compared with the regional flora, indicating that hardscape habitats filter for plant species that utilize multiple dispersal options. These contrasts to the regional species pool highlight multimodal dispersal and pollination processes as important drivers of species success and community assembly in such novel and urban environments.
Synthesis: Plant species that establish populations in cracks and along edges of hardscape habitats likely persist due to their capacity for propagule dispersal and pollination through diverse vectors, rather than being limited to a single vector type. This difference compared to the regional flora indicates that the composition of hardscape plant communities is highly driven by dispersal and pollination success in these novel habitats.