You're invited to enter the nests of acacia ants in Kenya, trace geologic history in the Sierra Nevada, and track invading plants in San Francisco Bay. Although research at UC Davis continues year-round, summertime brings enhanced opportunities for scientists whose studies take them out of the laboratory and into the field. Now you can bring your viewers and readers along for the adventure, as you visit any (or all) of these UC Davis summer field studies and see science in action -- up close and probably wet or dusty. Contact the researcher or the UC Davis News Service staff member listed for more information. Water clarity of Lake Tahoe Project: Researchers associated with the UC Davis Tahoe Research Group are continuing their studies to better understand impacts on the lake's water clarity. Summer allows access to high elevations around the lake. Dates: Ongoing Activities: Taking sediment cores from the lake bottom to learn how fast sediments settle and the chronological history of the sediments. Examining the impact of prescribed burns, or fires, in the Lake Tahoe watershed. Studying Eurasian water milfoil, an invasive weed that may be detrimental to the lake's near-shore water. Contacts: Bob Richards, staff research associate at the UC Davis Tahoe Field Station in Tahoe City, (530) 583-3279, bcrichards@ucdavis.edu; Lisa Klionsky, News Service, (530) 752-9841, lrklionsky@ucdavis.edu. Geologic frontiers: California's Feather River Belt Project: Graduate student Jason Mayfield will be conducting field mapping and sampling of the ultramafic, or magnesium- and iron-rich, rocks in the Feather River Belt of the northern Sierra Nevada. This 90-mile-long belt of rocks is one of the last terrains in the northern Sierra Nevada to be mapped in detail and, as such, remains one of the last frontiers in California geology. The belt contains mantle scraps of an old ocean plate or plates that have been incorporated into the continent. The accretion process and its significance for plate tectonics are not fully understood, and Mayfield hopes to better characterize the belt's origin and history. Dates: July 13-27 and Aug. 5-Sept. 3 Activities: Field mapping and rock collection in remote parts of the northern Sierra Nevada. Hiking will be involved every day, up to four to six miles, and there will be one major, eight-day backpacking trip down the Middle Fork of the Feather River. Contacts: Jason Mayfield, Geology, (530) 752-0350, mayfield@geology.ucdavis.edu; Sylvia Wright, News Service, (530) 752-7704, swright@ucdavis.edu. Dune plant communities of Mono Lake Project: Professor Catherine Toft will study the sand-dune ecosystems and establishment of plants on bare playas at Mono Lake, a salty, alkaline lake in California's eastern Sierra region. This basic research on how plant communities develop should provide guidelines for restoration projects in arid regions damaged by grazing or water diversion. Dates: Aug. 17-22 and Sept. 22-24 Activities: Surveying and counting rabbitbrush and greasewood populations. Contacts: Catherine Toft, Section of Evolution and Ecology, (530) 752-7614, catoft@ucdavis.edu; Sylvia Wright, News Service, (530) 752-7704, swright@ucdavis.edu. Alien grasses of San Francisco Bay Project: Don Strong, a professor of evolution and ecology, and his students study aggressive Atlantic cordgrasses invading Pacific salt marshes. The alien plants and their hybrid children invade the open intertidal mud, jeopardizing the native plants and animals, including foraging shore birds and harbor seals that pup there. The aliens and hybrids also alter the water-flow patterns of the marshes by collecting sediment, which impedes boat navigation and affects flood control. Officials are very concerned about the alien grasses' continuing spread toward the Sacramento River Delta. Dates: Ongoing Activities: Reporters could visit Strong's laboratory and cordgrass nurseries at Bodega Bay and visit affected salt marshes in San Francisco Bay. Contacts: Donald Strong, Bodega Marine Laboratory, (707) 875-2022, drstrong@ucdavis.edu; Sylvia Wright, News Service, (530) 752-7704, swright@ucdavis.edu. Acacia-tree ants of the Kenya highlands Project: At a new research center in the central highlands of Kenya, professor of evolution and ecology Maureen Stanton and students will study the unusual relationships between swollen-thorn acacia trees and their symbiotic, resident ants. The trees form a canopy over millions of acres of volcanic "black cotton" soils in East Africa. They produce hollow swollen thorns and nectar-producing glands that provide nesting space and food for these small, specialized "acacia ants." Although there are four species of ants that live on the trees, only one ant species is found per tree, and the ant colonies compete intensely for tree possession. Stanton is using this ecological system to test current theories on the maintenance of biodiversity. This field season, she will focus on the process of colonization of young trees by foundress queens of the four ant species. Dates: January-February 2000 Activities: Reporters would see researchers setting out young, uncolonized acacia trees; monitoring the arrival of foundress queens; and recording the effects of removing ants from some trees. The researchers have a borescope with an attached video camera, so queens can be filmed inside sealed, swollen thorns. Ants are very active on the acacia trees and the region is rich with elephants, birds, antelopes and zebras.