Avian Monitoring in the Lassen National Forest 2009 Report
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Avian Monitoring in the Lassen National Forest 2009 Report April 2010 Ryan D. Burnett, Diana Humple, Alissa Fogg, and Tim Guida PRBO Conservation Science Sierra Nevada Program PO BOX 634 Chester, CA 96020 PRBO Contribution #1740 Executive Summary .................................................................................................................. 1 Chapter 1. Landbird Monitoring of Fuel Treatments on the Lassen National Forest ................... 2 Background and Introduction ................................................................................................. 3 Methods ...................................................................................................................................... 4 Results ...................................................................................................................................... 12 Discussion................................................................................................................................. 18 Acknowledgements ................................................................................................................. 20 Literature Cited ...................................................................................................................... 21 Chapter 2. Resident and Neotropical Migratory Bird Response to Aspen Enhancement on the Lassen National Forest ................................................................................................................. 24 Background and Introduction ............................................................................................... 25 Project Area ............................................................................................................................. 25 Methods .................................................................................................................................... 26 Results ...................................................................................................................................... 31 Discussion................................................................................................................................. 41 Conclusions .............................................................................................................................. 45 Acknowledgements ................................................................................................................. 45 Literature Cited ...................................................................................................................... 46 Chapter 3. Resident and Neotropical Migratory Bird Monitoring in Mountain Meadows: 2009 Report ........................................................................................................................................... 48 Background and Introduction ............................................................................................... 49 Methods .................................................................................................................................... 50 Results ...................................................................................................................................... 54 Discussion................................................................................................................................. 62 Conclusions .............................................................................................................................. 65 Acknowledgements ................................................................................................................. 65 Literature Cited ...................................................................................................................... 66 Executive Summary PRBO Conservation Science (PRBO) has been conducting songbird monitoring in the Northern Sierra since 1997. In this report we present results from avian monitoring of fuel treatments and aspen restoration on the Lassen National Forest and from meadows across the Northern Sierra with updated information from 2009. Chapter one reports on the first year of our expanded avian monitoring of Herger Feinstein Quincy Library Group Forest Recovery Act fuel treatments on the Lassen National Forest. Recently treated sites across the forest were added in 2009 to compliment ongoing work on the Forest as well as in the Plumas-Lassen study area. Preliminary results suggest the range of treatments (DFPZ, Group Selection, mastication, fire) have varying effects on the avian community. The second chapter discusses results from our sixth year of monitoring landbirds in aspen habitat on the Lassen National Forest. Results show that treated aspen stands support greater total abundance of birds and abundance of key species such as Mountain Bluebird, Chipping Sparrow, and Red-breasted Sapsucker but these initial benefits may be short-lived for some species. In 2009, avian abundance and richness indices showed a decline at treated sites for the second consecutive year. In the third chapter we present results from monitoring of meadows across the Northern Sierra Nevada, primarily within the Feather River watershed. We compared avian community indices across sites and where applicable compared treated areas to adjacent reference sites. Results suggest some Feather River watershed meadows still support diverse and abundant bird populations including several species of conservation concern. However, a number of sites have suppressed avian communities - likely a result of over a century of inappropriate management. Management actions that restore hydrologic and ecological function and minimize the negative impacts created through past management actions will likely benefit a number of avian species including several that are of conservation concern. 1 Chapter 1. Landbird Monitoring of Fuel Treatments on the Lassen National Forest Diana Humple, Tim Guida, and Ryan D. Burnett PRBO Conservation Science 2 Ch. 1. Fuel Treatments PRBO Avian Monitoring in the Lassen National Forest – 2009 Background and Introduction The Records of Decisions for the Sierra Nevada Forest Plan Amendment and Herger Feinstein Quincy Library Group (HFQLG) Forest Recovery Act direct the Forest Service to maintain and restore old forest conditions that provide habitat for a number of plant and animal species (HFQLG 1999, SNFPA 2001, 2004). Simultaneously, they direct the Forest Service to take steps to reduce risks of large and severe fire by removing vegetation and reducing fuel loads in overstocked forests. Striking a balanced approach to achieving these potentially competing goals is a significant challenge to effectively accomplish the various desired outcomes of forest management. Historically, fire was the primary force responsible for creating and maintaining habitat diversity and landscape heterogeneity in the Sierra Nevada (Skinner and Chang 1996). Over the past century, fire return intervals have been lengthened and the area affected by wildfire annually has been dramatically reduced in the interior mountains of California (Taylor 2000, Taylor and Skinner 2003, Stephens et al. 2007). Thus, there is little doubt fires role in influencing the composition of the Sierra Nevada landscape has been reduced (Skinner and Chang 1996). Fire suppression in concert with past silvicultural practices has resulted in increased stand densities, loss of landscape heterogeneity, and increased fuel loads in Sierra Nevada Forests (Vankat and Major 1978, Parsons and DeBenedetti 1979, McKelvey and Johnston 1992, Minnich et al. 1995, Taylor and Skinner 2003). While the ways in which these changes affect fire patterns and vegetation dynamics are frequently discussed, they also undoubtedly impact the wildlife species that inhabit these forests. Mechanical silvicultural treatments have the potential to fill some of fire’s historic role in maintaining disturbance-dependent habitats (Weatherspoon 1996, Arno and Fiedler 2005). There has been considerable study of silvicultural treatments and their effects on landbirds in eastern North American forests (Anand and Thompson 1997, King et al. 2001, Fink et al. 2006, Askins et al. 2007) and the Cascades (Hansen et al. 1995, Hagar et al. 2004, Chambers et al. 2007), but little published information exists on the effects of mechanical fuel treatments on the avian community in the Sierra Nevada (but see Siegel and DeSante 2003 and Garrison et al. 2005). By monitoring the populations of a suite of landbird species we can measure the effectiveness of management actions in achieving a sustainable and ecologically functional forest 3 Ch. 1. Fuel Treatments PRBO Avian Monitoring in the Lassen National Forest – 2009 ecosystem. Specifically, we are interested in determining the responses of landbirds to management practices intended to produce forests with larger trees and high canopy cover along with more open-canopy, smaller size class forest with reduced ladder and ground fuels. In this report we summarize our efforts in 2009 intended to investigate landbird response to changes in vegetation structure and composition that occur when forests are managed to reduce fuels under the Herger Feinstein Quincy Library Group Forest Recovery Act Pilot Project (HFQLG 1999). We summarize what surveys were completed in 2009, the treatment history at each site, and some preliminary analysis of bird community indices by treatment type. We compared community indices and most