Sagehen Creek Field Station

23 Jul, 09 AM - 23 Jul, 11 PM

My proposed research will study the occurrence of insects and disease that cross over between urban and natural forest systems. Forest pests that result in damage or death of trees increase the cost of maintenance in urban forests, and decrease the value of trees in natural forests. Studies have shown that proper management of the urban forest provides benefits to the surrounding human community by the reduction in energy use from summer shading, improvement in the air quality, sequestering carbon dioxide, and interception of stormwater runoff (McPherson,G.E. 1994). Previous studies done on Monterey pines in urban and natural forests show that sequoia pitch moth and red turpentine beetle attacks were more common in urban areas, whereas dwarf mistletoe was more common in the natural forest (Nowak and McBride 1992). The question I will address is: What are the differences in pest populations on trees in urban and natural forests? For example, 1) is a specific forest pest more abundant in an urban ecosystem versus the adjacent wildland forest? 2) Could a patchy distribution of conifers in urban environments favor insect attack compared to tree diseases? My study will occur in the Sierra Nevada forests of Truckee, CA. I will be studying a recently developed area that is surrounded by undisturbed forest. Study areas will consist of three urbanization categories: built lot (parcel with existing house), unbuilt lot (parcel with no house), and natural forest (designated open space). All trees within each parcel or open space plot will be identified and located with a global positioning system (GPS). Native conifer species common to the area will be studied: ponderosa pine (Pinus ponderosa), Jeffrey pine (P. jeffreyi), lodgepole pine (P. contorta), and white fir (Abies concolor). Data collected on each tree will include tree species, diameter at breast height (dbh, 4.5ft from ground level), height, crown position, tree condition (scale of 1 to 4) and whether there is any occurrence of insect and disease symptoms. Inventory of tree pests will be limited to those insects that can be identified through non-invasive measures. Common insect pests in that area are mountain pine beetle (Dendroctonus ponderosae), western pine beetle (D. brevicomis), red turpentine beetle (D. valens), and fir engraver beetles (Scolytus ventralis). Identification of species attack is based on the vertical placement of frass and pitch tubes on the trunk of the tree, gallery patterns (if bark removal is permitted), and the tree species attacked. Incidence of pine needle scale (Chionaspis pinifoliae) and black pineleaf scale (Nuculaspis californica), which are outwardly visible on needles, will also be recorded. Pathogens that are easily identified, such as Western gall rust (Endocronartium harknessii), mistletoe (Arceuthobium sp., Phoradendron sp.), will be recorded as well. Understanding pest population effects on native trees in the urban and natural community can provide further knowledge on how pest populations create a new equilibrium in a changed environment. That knowledge can help us improve the landscape quality to benefit natural species within an urbanized landscape, and aid us in the future design of urban landscapes to lessen the impacts on undeveloped forests.

Visit #18662 @Sagehen Creek Field Station

Approved

Under Project # 20266 | Research

Incidence of Forest Pest Populations in Urban & Natural Ecosystems in Truckee, CA

graduate_student - University of California, Berkeley

Reservation Members(s)

Leane Dunn Jul 23, 2009 (1 days)

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Treehouse(Lower Camp) 1 Jul 23 (14 hours)