Treesearch

Rapidly scaling up the use of prescribed fire is being promoted as an important pathway for reducing the growing damages of wildfire events in the United States, including limiting the health impacts from smoke emissions. However, we do not currently have the science needed to understand how the health impacts associated with prescribed fire smoke in the present compare to wildfire smoke exposure in the future. In particular, we lack an understanding of how the potential long-term public health benefits of prescribed fire on future wildfire smoke and health impacts compare to prescribed...

The development of near-real time forest monitoring systems, which are used to create alerts for events such as logging or fire, often involves tradeoffs between accuracy and timeliness. In the context of forest monitoring, timeliness is measured by the lag between when a change occurs in the forest and the creation of an alert about the event. Conventional accuracy assessments quantify both false negative and false positive errors in change maps, but do not specify those rates as a function of lag. Recent near real-time (NRT) accuracy assessment methods summarize the relationship between...

Accurate estimation of aboveground forest biomass stocks is required to assess the impacts of land use changes such as deforestation and subsequent regrowth on concentrations of atmospheric CO2. The Global Ecosystem Dynamics Investigation (GEDI) is a lidar mission launched by NASA to the International Space Station in 2018. GEDI was specifically designed to retrieve vegetation structure within a novel, theoretical sampling design that explicitly quantifies biomass and its uncertainty across a variety of spatial scales. In this paper we provide the estimates of pan-tropical and temperate...

Underlying policy efforts to address global climate change is the scientific need to develop the methods to accurately measure and model carbon stocks and fluxes across the wide range of spatial and temporal scales in the Earth system. Initiated in 2010, the NASA Carbon Monitoring System is one of the most ambitious relevant science initiatives to date, exploiting the satellite remote sensing resources, computational capabilities, scientific knowledge, airborne science capabilities, and end-to-end system expertise that are major strengths of the NASA Earth Science program. Here we provide...

NASA’s Global Ecosystem Dynamics Investigation (GEDI) mission offers data for temperate and pan-tropical estimates of aboveground forest biomass (AGB). The spaceborne, full-waveform LiDAR from GEDI provides sample footprints of canopy structure, expected to cover about 4% of the land area following two years of operation. Several options are available for estimating AGB at different geographical scales. Using GEDI sample data alone, gridded biomass predictions are based on hybrid inference which correctly propagates errors due to the modeling and accounts for sampling variability, but this...

Phellinus noxius is a fungus that causes brown root rot disease in tree and shrub species of subtropical and tropical regions. It has infected and rapidly killed hundreds of important tree and shrub species in these regions. It is widespread in the Pacific Region including all the island states of American Samoa, the Federated States of Micronesia (Chuuk, Kosrae, Pohnpei, and Yap), the Republic of Palau, the Commonwealth of the Northern Mariana Islands (Islands of Rota and Saipan), and Guam. This report explains how to detect brown root rot disease and its causal pathogen (P. noxius) by...

Mountain pine beetle (MPB) is a native disturbance agent across most pine forests in the western US. Climate changes will directly and indirectly impact frequencies and severities of MPB outbreaks, which can then alter fuel characteristics and wildland fire dynamics via changes in stand structure and composition. To investigate the importance of MPB to past and future landscape dynamics, we used the mechanistic, spatially explicit ecosystem process model FireBGCv2 to quantify interactions among climate, MPB, wildfire, fire suppression, and fuel management under historical and projected...

Mountain pine beetle (Dendroctonus ponderosae) and spruce beetle (D. rufipennis) are two significant native tree mortality agents with expansive distributions throughout North America. The range of spruce beetle is considered coincident with Picea across North America. Although the distribution of mountain pine beetle in Pinus forests has historically been restricted by climate, recent warming has accelerated migration northward in western Canada. Both species are being directly influenced by changes in climate, particularly warming temperatures that can reduce winter mortality and shorten...

Promoting ecological resilience to increasing disturbance activity is a key management priority under warming climate. Across the Northern Hemisphere, tree mortality from widespread bark beetle outbreaks raises concerns for how forest management can foster resilience to future outbreaks. Density reduction (i.e., thinning) treatments can increase vigor of remaining trees, but the longevity of treatment efficacy for reducing susceptibility to future disturbance remains a key knowledge gap. Using one of the longest-running replicated experiments in old-growth subalpine forests, we measured...

A changing climate is altering ecosystem carbon dynamics with consequences for natural systems and human economies, but there are few tools available for land managers to meaningfully incorporate carbon trajectories into planning efforts. To address uncertainties wrought by rapidly changing conditions, many practitioners adopt resistance and resilience as ecosystem management goals, but these concepts have proven difficult to monitor across landscapes. Here, we address the growing need to understand and plan for ecosystem carbon with concepts of resistance and resilience. Using time series...