Treesearch

Aethalometers are widely used to measure aerosol light absorption and to infer concentrations of black carbon (BC) in aerosols. These instruments measure the transmission of light through a particle-laden filter but are known to suffer from decreased sensitivity as the filter is loaded. This so-called “filter loading effect” can be quantified and corrected for by comparing attenuation measured on two filter spots through which the same aerosol has been sampled but at different flow rates. This approach, termed “DualSpot,” is commonly employed in modern aethalometers. Here, we test the...

Prescribed fire is an essential tool employed by natural resource managers to serve ecological and fuel treatment objectives of fire management. However, limited operational resources, environmental conditions, and competing goals result in a finite number of burn days, which need to be allocated toward maximizing the overall benefits attainable with fire management. Burn prioritization models must balance multiple management objectives at landscape scales, often providing coarse resolution information. We developed a decision-support framework and a burn prioritization model for wetlands...

Forest hydrology is a separate and unique branch of hydrology due to the special conditions caused by trees, and the understorey beneath them, comprising a forest. Understanding the forest, with trees that can grow over 100 m tall, may have crowns up to 20-30 m in diameter with roots 5-10 m deep and spread as widely as the crowns, and have lifespans from 50 to 5000 years, presents unique challenges to science.

Next to precipitation, evapotranspiration (ET) is the second largest flux in forest hydrological cycles. Forest ET rates are generally higher than other vegetated ecosystems under the same climatic conditions. ET serves as the nexus of the carbon, water and energy balances in forests. Understanding ET dynamics is critical for quantifying forest–water relationships and ecosystem services (e.g. carbon sequestration, climate and streamflow flow moderation, biodiversity) at multiple scales. This chapter describes the basic ET processes, which include forest canopy and litter interception, tree...

Flooded or wetland forests are commonly continuously inundated for many months. Trees that can survive this have specialized mechanisms for allowing roots to respire. The forests can be classified by the source of the water causing inundation – rainfall, groundwater, flow from an adjacent watercourse or tidal inundation. The latter may include specialized vegetation at the ocean salt/freshwater interface known as ‘mangroves’. These seem to require some input of freshwater, although the mechanism of how this assists their survival is unclear. The hydroperiod is the usual annual period for...

This chapter provides a brief overview of why and how forest hydrological models are applied to answer important global research and management questions. It steps through physical functions that most forest hydrological models represent, how to best select the model for a particular goal, and how to think about model parameterization and calibration. Finally, a suite of example forest hydrology models focused on different model domains (i.e. plots, watersheds, groundwater and coupled surface–subsurface) are discussed.

Forests cover about a third of the world’s land surface area. They represent a distinct biotic community, provide a living for many millions of people, and provide fresh water to sustain communities. Forests capture part of the precipitation and pass the remainder into the soil. Some of this is then passed back to the atmosphere along with some to streams as a regulated outflow. Forest cover is generally the preferred land-use for clean water supplies, recreation, tourism, and other ecosystem benefits around the world. In many cases the value of the water exceeds the value of other forest...

endo-Brevicomin, a pheromone component for tree-killing bark beetle Dendroctonus frontalis Zimmermann, the southern pine beetle, has a “peaked,” biphasic dose-response, being synergistic with attractants (pheromone component frontalin and host odors) at low release rates and attraction-reducing at high rates. Displacing an endo-brevicomin release device up to tens of meters from an attractant-releasing trap can increase synergistic effects. We investigated the interaction of endobrevicomin device release rate and displacement. When one of a pair of 6 m distant, attractant-baited traps...

Smoke plume dynamics involve various smoke processes and mechanics in the atmosphere and provide the scientific foundation for the development of tools to simulate and predict smoke and its environmental and human impacts. The increasing occurrence of wildfires and the demands for more extensive application of prescribed fires in the U.S. have posed great challenges and immediate actions for advancing smoke plume dynamics and improving smoke predictions and impact assessments to mitigate smoke impacts. Numerous efforts have been made recently to address these needs and challenges. This...

The Northern Gulf of America (NGOA, formerly known as Northern Gulf of Mexico) is a key economic region for seafood production, recreation, and marine transportation. This study compared evapotranspiration (ET) and water yield in the Sabine River Basin (SRB) and Pearl River Basin (PRB) along the NGOA, focusing on coastal watersheds between two 40-year weather scenarios: past (1985–2024) and future (2025–2064). The analysis was conducted using the HAWQS (Hydrologic and Water Quality System) model, along with Mann-Kendall (M-K) and Kolmogorov-Smirnov (K-S) tests. Simulations showed a...