Tree Rings: The campus of UC Irvine has over 25,000 trees, which makes for beautiful parks, shady places to study, and ample areas to retreat into nature when the mind needs a break. However, recently hundreds of trees had to be removed due to devastation caused by a new species of beetle from Southeast Asia (the polyphagous shot hole borer, PSHB). At least 1,000 trees have been affected and still need to be removed. They are being replaced and JAIN emitterline tree rings are part of the installation. It appears the PSHB is established in Los Angeles, Orange, Riverside, San Bernardino, and, more recently, San Diego counties.
The vast majority of trees infected on campus are sycamore species, which are the favorite reproductive host. This includes the mature stands of sycamore trees in Aldrich Park and around the Ring Road. Trees under attack have small black holes mostly starting on the north side of the trunk and move up into the branches. The tiny dark black female beetles drill into the tree to lay their eggs and deposit e a fungus that provides food for the adult beetles and its newly hatched larva. It is this repetitive boring process that affects the host tree.
The bores through the center are not something most trees can defend against. Although, in some cases, various trees have shown signs of defense, by over producing sap to push the insect out. The campus is vigorously trying to keep up with the removal and replanting of new tree species to fill the voids left; and to reduce the risk of falling limbs and of course the spread of the PSHB.
It is sad to see these mature trees be cut down, and there is no treatment yet, but an extensive team is in place to study, identity, remove and test treatment options. The team includes representatives from Environmental Planning and Sustainability, Facilities Management, Environmental Health and Safety, Transportation and Distribution Services, Student Affairs, the Irvine Campus Housing Authority, and the Center for Environmental Biology in the Francisco J. Ayala School of Biological Sciences. To manage the infestation, this team is working closely with plant pathology and invasive pest experts from UC Riverside and the University of California Cooperative Extension, which are part of the UC Division of Agriculture and Natural Resources.
Good news For Tree Rings
The good that has come from this ongoing situation is that as new trees are being planted, the irrigation is also being updated from overhead spray to emitterline tree rings. In general, throughout the UCI campus, irrigation efficiency is being addressed and improved. In an effort to assist UCI with the best possible irrigation practice, JAIN designed a tree ring that is now being utilized on all new plantings. Jain emitterline, flush valves and shut off valves have been installed on the new trees in the Student Center and around Aldrich Hall.
New plantings have been a mix of Crape myrtle, Strawberry trees, Brisbane Box, Elm, Jacaranda, and Pines to name a few. All seem to be doing very well with the new drip tree rings. It is clear the reforestation efforts, combined with tree management and irrigation upgrades to replace the infected trees have become top priority. The water needs, size, appearance, and maintenance are all being weighted in identifying suitable replacements in each unique area of campus. Phase 1 has been completed and phase 2 is almost complete.
I would like to thank Rick Ternet , Senior Superintendent of the Buildings & Grounds Department at University of California, Irvinefor sharing his efforts and showing me around campus. If you are resident in Southern CA, and if suspect your trees might be infected, I encourage you to read this leaflet . Please feel free to contact the Jain Landscape team to learn more about the UC Irvine’s reforestation efforts, irrigation solutions or tree ring design.