Forest Sciences Commons^™

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

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 …

Suitable Days For Plant Growth Disappear Under Projected Climate Change: Potential Human And Biotic Vulnerability, Camilo Mora, Iain R. Caldwell, Jamie M. Caldwell, Micah R. Fisher, Brandon M. Genco, Steven W. Running

Ecosystem and Conservation Sciences Faculty Publications

Ongoing climate change can alter conditions for plant growth, in turn affecting ecological and social systems. While there have been considerable advances in understanding the physical aspects of climate change, comprehensive analyses integrating climate, biological, and social sciences are less common. Here we use climate projections under alternative mitigation scenarios to show how changes in environmental variables that limit plant growth could impact ecosystems and people. We show that although the global mean number of days above freezing will increase by up to 7% by 2100 under “business as usual” (representative concentration pathway [RCP] 8.5), suitable growing days will actually …

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 …

Forest Fire Risk Assessment Using Point Process Modeling & Monte Carlo Fire Simulation: A Case Study In Gyeongju, South Korea, Hyeyoung Woo

Graduate Student Theses, Dissertations, & Professional Papers

Forest fire risk assessment becomes critical for developing forest and fire management strategies in Korea since the magnitude of damage from fires significantly increased over the past decades. Fire behavior probability is one of the major components in quantifying fire risk, and is often presented as burn probability. Burn probability estimation requires a proper estimation of fire occurrence probability because fire spread is largely influenced by ignition locations in addition to other environmental factors, such as weather, topography, and land covers.

The objective of this study is to assess forest fire risk over a large forested landscape in and around …

A Critical Examination Of Private Conservation Areas On Campesino Community Lands In Peru, Megan Barnhart

Graduate Student Theses, Dissertations, & Professional Papers

Community-owned private reserves are emerging around the world as an alternative to government-run resource management and as a way to more directly involve citizens as stewards of their local natural resources. Despite their recent proliferation globally, voluntary efforts by communities to include their land in protected area systems, and the motivations and expectations of their legal recognition remain largely unknown. This thesis examines community-owned private conservation areas in Northern Peru locally known as Áreas de Conservación Privadas (ACPs) which are voluntary and legally recognized by the Peruvian State. The study investigates the rationales and outcomes of the application of ACPs …

Bamboo Harvesting For Household Income Generation In The Ethiopian Highlands: Current Conditions And Management Challenges, Bridget L. Tinsley

Graduate Student Theses, Dissertations, & Professional Papers

Bamboo is a renewable resource that has been advocated as a means to alleviate poverty and foster rural development throughout the world. Ethiopia holds 67% of continental Africa’s bamboo coverage and is gaining interest by international markets. Despite great speculation about Ethiopia’s bamboo market potential, foundational information regarding household utilization and income reliance is lacking. To understand how bamboo contributes to rural Ethiopian households, a quantitative household assessment was undertaken in this study. A questionnaire census collected data from 371 households. A quantitative assessment of household incomes and assets evaluated what factors influence bamboo harvesting.

The contribution of bamboo to …

An Assessment Of Biochar Amended Soilless Media For Nursery Propagation Of Northern Rocky Mountain Native Plants, Clarice P. Matt

Graduate Student Theses, Dissertations, & Professional Papers

A study was conducted to better inform nursery practitioners of the potential benefits of biochar application in common nursery media for native plant propagation. Biochar – a carbon-rich, recalcitrant charred organic co-product of the bioenergy pyrolysis process – has emerged as a promising potential replacement for various components of soilless media, namely peat, perlite, and vermiculite, in nursery seedling propagation. A strong conceptual basis exists for biochar as a nursery media amendment, but empirical data on biochar-based plant propagation is limited. This greenhouse study examined the effects of biochar displacement of standard soilless nursery media at rates of 0%, 15%, …

A Model For Determining Drivers Of Phenology In Western United States Rangelands, Joseph R. St. Peter

Graduate Student Theses, Dissertations, & Professional Papers

Plant phenology has long been used as an indicator of climate. Recent changes in plant phenology are evidence of the influence of climate change. Modeling plant phenology has become an effective tool to understand the impacts of climate change. Using machine learning techniques I developed a modeling process for accurately predicting phenology across a diverse landscape. This model uses individual site data to set site specific climate thresholds for plant phenology. This model also identifies the limiting factors to vegetation phenology for rangelands in the western United States. NDVI remotely sensed data was used to quantify land surface phenology and …

Decadal Scale Responses Of Soil And Ecosystem Processes To Forest Restoration In Rocky Mountain Conifer Forests, Peter Ganzlin

Graduate Student Theses, Dissertations, & Professional Papers

Decades of fire suppression have left much of the forest in the intermountain western United States exceedingly dense, and forest restoration techniques – including thinning and prescribed fire – are increasingly being used in an attempt to mitigate the potentially disastrous effects of severe wildfire, to enhance tree growth and regeneration, and to stimulate soil nutrient cycling. While many of the short-term effects of forest restoration have been established, the long-term effects on soil biogeochemical and ecosystem processes are largely unknown. In this thesis I present two manuscripts documenting and synthesizing these long-term impacts. The first chapter focuses on the …