Publication Date


Long overlooked by conservation groups and ecologists, urban open spaces are now seen as important contributors to biodiversity at various scales. Urban greenspaces often represent the only “nature” millions of human residents around the world ever interact with, and provide cooling and aesthetic relief from the urban hardscape. In the Los Angeles Metropolitan area, over the past three decades, non-profit advocacy groups and institutions have established a network of bike paths, neighborhood access points, habitat restoration, and recreational amenities along the Los Angeles River, a major urban waterway. We investigated the environmental contribution provided by numerous linear landscaped parks along the river, focusing on climate amelioration (i.e., cooling within heat islands) in the parks and surrounding neighborhoods, and on their contribution to local biodiversity, utilizing an indicator species approach. We conducted plant surveys of the parks, documenting locally native, non-local California native, and non-native species, and examined the occurrence of 15 riparian indicator species of wildlife in the parks and in 500-meter buffer zones surrounding each park utilizing citizen science data. We then explore correlations between indicator species richness and environmental variables. We note important occurrences of relict riparian vegetation in several linear parks, as well as both planted and naturally-occurring special-status plant and wildlife species. Finally, we discuss challenges to managing natural habitat in highly-urban parks, many of which support important relict vegetation and/or special-status species, and offer suggestions on how they may be improved.