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Forest Sciences Commons

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Full-Text Articles in Forest Sciences

Wildland Fire Deficit And Surplus In The Western United States, 1984-2012, Sean A. Parks, Carol Miller, Marc-Andrè Parisien, Lisa M. Holsinger, Solomon Z. Dobrowski, John Abatzoglou Dec 2015

Wildland Fire Deficit And Surplus In The Western United States, 1984-2012, Sean A. Parks, Carol Miller, Marc-Andrè Parisien, Lisa M. Holsinger, Solomon Z. Dobrowski, John Abatzoglou

Forest Management Faculty Publications

Wildland fire is an important disturbance agent in the western US and globally. However, the natural role of fire has been disrupted in many regions due to the influence of human activities, which have the potential to either exclude or promote fire, resulting in a "fire deficit" or "fire surplus," respectively. In this study, we developed a model of expected area burned for the western US as a function of climate from 1984 to 2012. We then quantified departures from expected area burned to identify geographic regions with fire deficit or surplus. We developed our model of area burned as …


Spatial Aspects Of Tree Mortality Strongly Differ Between Young And Old-Growth Forests, Andrew J. Larson, James A. Lutz, Daniel C. Donato, James A. Freund, Mark E. Swanson, Janneke Hillrislambers, Douglas G. Sprugel, Jerry F. Franklin Nov 2015

Spatial Aspects Of Tree Mortality Strongly Differ Between Young And Old-Growth Forests, Andrew J. Larson, James A. Lutz, Daniel C. Donato, James A. Freund, Mark E. Swanson, Janneke Hillrislambers, Douglas G. Sprugel, Jerry F. Franklin

Forest Management Faculty Publications

Rates and spatial patterns of tree mortality are predicted to change during forest structural development. In young forests, mortality should be primarily density dependent due to competition for light, leading to an increasingly spatially uniform pattern of surviving trees. In contrast, mortality in old-growth forests should be primarily caused by contagious and spatially auto-correlated agents (e.g., insects, wind), causing spatial aggregation of surviving trees to increase through time. We tested these predictions by contrasting a three-decade record of tree mortality from replicated mapped permanent plots located in young (<60-year-old) and old-growth (>300-year-old) Abies amabilis forests. Trees in young forests died at a …


Quantifying Environmental Limiting Factors On Tree Cover Using Geospatial Data, Johnathan A. Greenberg, Maria J. Santos, Solomon Z. Dobrowski, Vern C. Vanderbilt, Susan L. Ustin Feb 2015

Quantifying Environmental Limiting Factors On Tree Cover Using Geospatial Data, Johnathan A. Greenberg, Maria J. Santos, Solomon Z. Dobrowski, Vern C. Vanderbilt, Susan L. Ustin

Forest Management Faculty Publications

Environmental limiting factors (ELFs) are the thresholds that determine the maximum or minimum biological response for a given suite of environmental conditions. We asked the following questions: 1) Can we detect ELFs on percent tree cover across the eastern slopes of the Lake Tahoe Basin, NV? 2) How are the ELFs distributed spatially? 3) To what extent are unmeasured environmental factors limiting tree cover? ELFs are difficult to quantify as they require significant sample sizes. We addressed this by using geospatial data over a relatively large spatial extent, where the wall-to-wall sampling ensures the inclusion of rare data points which …