First time visitors to Los Angeles are often surprised at how many trees occur throughout the city. There are some native trees within the LA urban forest (e.g. California Sycamore, California Black Walnut, and Coast Live Oak). However, most trees are non-native, Mediterranean adapted species that were planted for a variety of reasons. While we have good knowledge of the diversity of the LA urban forest, there still remains a lack of understanding regarding the importance of the LA urban forest for sustaining biodiversity. We are embarking on a series of studies to address this research topic with the hope of providing city planners and managers with relevant information to promote trees that also promote biodiversity.
Sevan Esaian is leading a project documenting foraging behavior by wintering and spring migratory birds throughout the greater LA urban forest (see figure). In particular, Sevan is working to: (a) highlight important tree species of the Los Angeles urban forest that are beneficial to migratory birds, (b) develop a guidebook for city planners for trees to plant and maintain considering future climate change, and (c) identify priority areas in Los Angeles for planting trees that benefit biodiversity along a socio-economic gradient.
(2) Restoration of the Rio Grande/Rio Bravo in Big Bend National Park. Opportunities for bird and butterfly conservation.
The Rio Grande/Rio Bravo is a major riparian system of the US southwest and northern Mexico, and provides habitat for numerous plant and wildlife species. The river has changed dramatically since the turn of the century due to damming, water diversion, and land uses such as agriculture and urban expansion. These pressures have facilitated the spread of invasive plant species into riparian zones, which can reduce habitat quality for riparian associated wildlife species. In response, Big Bend National Park and its Mexican Sister Protected Areas are undertaking a major restoration initiative, using prescribed fire, manual treatments, and biocontrol agents (Northern Tamarisk Beetle, Diorhabda carinulata) to actively remove invasive plant species, including exotic saltcedar (Tamarix chinensis) and giant cane (Arundo donax), along the 118-mile shared stretch of river.
With support from the National Park Service, Julie Coffey is assessing the effectiveness of bi-national Rio Grande restoration efforts by monitoring the status of the floodplain avian and butterfly communities in relation to ongoing vegetation treatments. Further, Heather Mackey is using state-of-the-art population modeling to estimate population trends for the western Yellow-billed Cuckoo and other US/Mexico shared at-risk bird and butterfly species.