Understanding the scope and impact of twentieth century federal and state forest management in California

Abstract:

Understanding historical forest management informs contemporary land management actions. Since the early twentieth century in California, federal and state managers have used different but complementary systems to record silviculture treatments and other land management activities. The U.S. Forest Service uses the Forest Activity Tracking System (FACTS) to document forest management events in national forests and national management basins. At the state level, Cal-Fire is responsible for approving and recording timber harvest plans on industrial and non-industrial private holdings. However, management activity data have been collected in different formats with different information and definitions under FACTS and Cal-Fire, making comparisons challenging. In this study, we directly compare FACTS and Cal-Fire silviculture data by ranking the intensity of silviculture treatments. We defined treatment intensity by the amount of basal area removed from the canopy that can also be aerially detected. Our rankings were determined by consulting with FACTS database users from the US Forest Service in California and timber operators who have written timber harvest plans with Cal-Fire. Our preliminary results suggest that Cal-Fire silviculture treatments are generally comparable to FACTS silviculture treatments, with some notable exceptions. For example, group selection is low intensity in FACTS but medium intensity in Cal-Fire, and shelterwood prep is high in FACTS but low in Cal-Fire. We found that the most intense silviculture treatments occurred in equal amounts on federal and private land. Moreover, treatment type varied over time. For FACTS, the greatest number of clear-cut events (> 500 clear-cuts annually) peaked between 1984 and 1990 and then substantially dropped off (< 125 clear-cuts annually) to the present day. For Cal-Fire, uneven-aged management compared to even-aged management has dominated silviculture treatment since 2003. We will compare and contrast historical estimates with refined estimates of those management areas (see abstract ID# 710867 for ongoing collaboration and validation by remote sensing), which will allow better understanding of past land management and have policy implications.