Science & Resource Management
Integrating LTER science and resource management with regional environmental change through co-production
Historical records indicate that fire activity has been intensifying in interior Alaska over the past century and current rates of burning now exceed those experienced in Alaska for the last millennium. Continued climate warming will likely cause further increases in fire activity through the current century, raising serious concerns about how fires should be managed in the future and what will be the impacts of accelerating fire activity on human values and ecosystem services across the Alaskan landscape. However, fire activity depends not only on climate and weather conditions, but also on the distribution of vegetation fuels across a landscape. Previous LTER research has suggested that fire driven changes in successional patterns, such as those causing highly flammable spruce forests to be replaced by less flammable deciduous forests, may help mitigate the impacts of climate warming on fire behavior. Such interactions could be enormously important in developing management strategies in response to accelerating fire activity in Alaska, but remain largely theoretical and have yet to be incorporated into the empirical models of fire behavior used in fire management. Here we propose a set of tasks aimed at improving the links between pressing fire management needs and LTER research on ecosystem succession and cross-scale landscape interactions.
Credit: BNZ Photo Archive
Question 1: How will climate and disturbance interact to shape the composition and distribution of vegetation types in Alaska, and what are the implications for future fire behavior and fire management?
Task CP1: Document the impacts of alternate successional trajectories on the abundance and composition of fuels through succession for dominant vegetation types in interior Alaska.
We will quantify fuel composition and distribution across the different types and stages of forest succession within the Regional Site Network. Data from the Regional Site Network will be used to develop a crosswalk between standard LTER measurements of vegetation composition and estimates of 1-, 10-, and 100-hour fuels required by fire behavior models. Based on these calibrations, we will be able to translate many years of LTER vegetation observations into fuel estimates for a wide range of vegetation types. We will work with the fire management community in Alaska to develop a modeling framework that will allow our improved understanding of variations in fuel characteristics across successional trajectories to inform projections of future fire behavior under different climate and management scenarios. This could be through existing LTER models like ALFRESCO, fire behavior models such as BorFIRE, or other models (refs); the exact modeling framework we choose will need to be worked out as a collaborative dialogue between LTER scientists and Alaska fire managers.
Task CP2: Estimate the landscape consequences of different scenarios of changing fire regimes and fire management on patterns of carbon sinks and sources in interior Alaska.
BNZ LTER research has greatly enhanced our understanding of how net ecosystem carbon balance varies among vegetation types and in response to disturbance. In this task, we aim to explore how management choices, in conjunction with dynamic interactions of climate and disturbance, may alter patterns of carbon storage on the landscape and net forcing of ecosystem feedbacks to the atmosphere. We envision two phases of research to accomplish this task: 1) an initial simple spreadsheet model that can be used to explore scenarios of fire activity and vegetation change with managers, and 2) detailed investigation of the most plausible scenarios within the coupled modeling framework of ALFRESCO and TEM. Simple modeling exercises will allow managers and LTER scientists to quickly explore a wide range of possible scenarios and select those with the greatest interest to assess within a more complex and dynamic modeling framework.
We know comparatively little about the effects of human land use legacies on Alaska’s boreal forest, whether from the early influences of Native Alaskan’s, logging, mining, and market hunting of the late 1800s, or how contemporary human disturbances are influencing ecosystem processes and the associated services on which communities depend. The Alaska Department of Fish & Game (ADF&G) surveys moose populations and habitat use within Game Management Units of interior Alaska (ADF&G web data), and LTER collaborations with ADF&G are helping predictions concerning vegetation-moose interactions following fire and other changing disturbance regimes across the region. However, a key management priority is to better understand how smaller-scale human disturbances, such as fire breaks, and timber/biofuels harvests affect successional trajectories and forage availability to moose, and how such activities could be integrated into an adaptive management plan that includes active habitat manipulations to influence distributions of moose in areas readily accessible by hunters. Because of the strong association between hunter access and harvest success, it is important to assess how such disturbances change relationships among plant-herbivore interactions, moose densities, and harvest opportunities.
Credit: BNZ Photo Archive
Question 2: How are moose and hunters responding to human disturbances near communities, and how can a better understanding of disturbance-vegetation-moose-human interactions inform management options to improve food security in interior Alaskan communities?
Task CP3: Quantify vegetation composition and change within fire break and timber/biofuel harvest areas, and assess use by both moose and hunters.
We will establish long-term monitoring plots in existing fire break and harvest areas of different ages to evaluate how these disturbances affect forage availability, successional dynamics, and NPP. Vegetation dynamics and rates of browsing will be compared with similar data from nearby RSN plots to assess moose habitat preference and associated impacts on vegetation dynamics. These data will be combined with interview data with hunters to assess how impacts on access and hunting success change over time since disturbance.
Task CP4: Design and implement a landscape-level experiment to test management scenarios affecting forage availability, moose distribution, habitat use, and hunter behavior.
We will assemble a research working group comprised of LTER scientists and agency personnel (ADF&G, Division of Forestry, AK Fire Service, DOT) to discuss data from Task 1 and options for how multiple land-use practices can be coordinated to achieve a sustainable moose harvest and ensure food security to communities as landscapes and availability of subsistence resources continue to change. We envision an experimental design that includes multiple disturbances (fire breaks and timber/biofuel harvests) and undisturbed plots distributed across stands of different age since fire, with and without access, including corridors cleared to specifically modify access. Vegetation, wildlife, and human use variables mentioned above will be worked into the BNZ LTER monitoring program. Although previous BNZ LTER research has assessed wildlife-vegetation relationships, how human stakeholders affect or are affected by these relationships have been speculative and qualitative. Experimentally integrating the human dimension in the monitoring program will represent a novel effort that fosters linkages between research and management, and creates additional opportunities for science-agency co-production.
Credit: BNZ Photo Archive