Soils for this study were collected at Foping National Natural Reserve (FNNR, 33º33´ - 33º46´´N, 107º40´ - 107º55´E), located in the middle part of southern slope of Qinling Mountains in Shaanxi Province, China. FNNR is in the northern edge of a subtropical area.

The 0.5 cm sections of the core each soil pit will be examined for charcoal content and silica (phytolith) content using standard protocols (Faegri et al. 1987, Pearsall 1989). High silica density indicates dominance by bamboo and high charcoal abundance indicates fire events. Phytoliths are small, hard rock-like bodies formed in the spaces between living cells of a plant through the structured accumulation of silica brought into the cells with water. Phytoliths are especially common in grasses. Charcoal is the blackish residue consisting of impure carbon obtained by removing water and other volatile constituents by fire from animal and vegetation substances; in other words, burned organic matter. Quantification of microscopic charcoal particles preserved in soil is commonly used to study the occurrence of past fires and their effects on vegetation communities (Franklin and Tolonen 2000). Charcoal will be extracted by water flotation, then weighed to the nearest 0.1 ug. Charcoal from 50 soil samples (one soil pit) have been extracted and weighed. It is obvious fire has been extensive in the recent past, and periodically important historically.

Objectives and Hypotheses
The objective to this study is to determine the history of bamboo dominance and fire events in both Bashania-dominated forest and Fargesia-dominated forest of the Qinling Mountains, China. We hypothesize that the occurrence of fire will be strongly related to the dominance of bamboo (a test of the fire-cycle hypothesis). We further hypothesize that bamboo has not continuously dominated a particular site in the mountain, but instead has moved around the mountain following disturbance events.

Qinling Mountains in Shaanxi, China.