Thoma, A. E. | bioRxiv Science

bioRxiv2025

Greener, Wilder, Better: Valuing Complexity and Diversity in Urban Riparian Areas

(1) Riparian areas are among the most valuable ecosystems on earth due to their high biodiversity and contributions to human well-being, yet urban riparian areas face significant threats from urbanization and associated expansion. Current management strategies do not consider all the contributions of urban green spaces to human well-being. Over the last decade stated preference studies have been widely used to gain insights into public attitudes towards urban green spaces. However, whether and to what extent the public values urban biodiversity in urban riparian areas remains unclear. (2) We used a discrete choice experiment approach to determine public preference for urban biodiversity and management interventions in urban riparian areas through a discrete choice experiment conducted in Poland. (3) We found strong positive preferences for highly complex and dense vegetation along urban riparian areas, indicating a public inclination towards enhancing natural biodiversity in public spaces. Additionally, respondents expressed a preference for reducing impermeable surfaces, such as concrete pathways, highlighting the value placed on minimizing urban encroachment. (4) Willingness-to-pay (WTP) results suggested that the public in Poland is prepared to financially support certain biodiversity conservation measures and land-conversion interventions in urban green spaces. (5) These results underscore the importance of integrating ecological research and public preferences into urban riparian management strategies, emphasizing the need for policy approaches that prioritize biodiversity conservation while balancing urban development.

ecology↗

bioRxiv2023

Clinal variation in drought response is consistent across life stages but not between native and non-native ranges

Clinal variation, i.e., intraspecific variation that corresponds to environmental gradients, is common in widely distributed species. Studies on clinal variation across multiple ranges and life stages are lacking, but can enhance our understanding of specie[s] adaptive potential to abiotic environments and may aid in predicting future species distributions. This study examined clinal variation in drought responses of 59 Conyza canadensis populations across large aridity gradients from the native and non-native ranges in three greenhouse studies. Experimental drought was applied to recruitment, juveniles, and adult stages. Drought reduced growth at all three life stages. However, contrasting patterns of clinal variation emerged between the two ranges. Native populations from xeric habitats were less inhibited by drought than mesic populations, but such clinal variation was not apparent for non-native populations. These range-specific patterns of clinal variation were consistent across the life stages. The experiments suggest that invaders may succeed without complete local adaptation to their new abiotic environments, and that long-established invaders may still be evolving to the abiotic environment. These findings may explain lag times in some invasions and raise concern about future expansions.

evolutionary biology↗