Treesearch

Remotely sensed data play a vital role providing auxiliary variables that can improve precision of sample-based estimates without incurring the substantial cost of increasing sample size. In the setting of design-based inference, model-assisted estimators using generalized regression models provide a practical option to exploit such auxiliary variables to obtain estimates with smaller uncertainties than the Horvitz-Thompson (HT) estimator. Spatial heterogeneity is one of the main characteristics of spatial geographical populations and spatial nonstationarity in regression model parameters...

As a forest landowner, you may think about Federal income taxes only when you sell timber. However, many of your forestry activities can have tax implications. Understanding the forest related tax rules and integrating tax planning into your forest management decisions can help increase your after-tax return. New legislation enacted in 2025 reinstates and makes permanent several tax provisions affecting forest landowners and adds new incentives for capital investment. Although many key provisions take effect starting in 2026, some are already effective for the 2025 tax year. This publicatio...

Forest ecosystems in the eastern United States are undergoing significant compositional and demographic shifts. To understand these changes, we used Forest Inventory and Analysis data (2003–2021) to examine landscape-scale trends in the North Carolina Piedmont, focusing on forest type groups, taxonomic family, and species. We assessed metrics such as annual net primary productivity, relative density, and biodiversity, aiming to determine: (i) which forest group types are changing most, (ii) whether these changes extend to higher taxonomic units, and (iii) how stability has shifted over...

This indicator reports the area and percentage of U.S. forests that are used for subsistence activities. In the United States, subsistence rights are codified through Federal laws, State constitutions, and Federal treaties with Tribal Nations and Canada. These bodies of legislation protect subsistence rights in Alaska, the Pacific Northwest (States of Washington and Oregon), Hawaii, and the Great Lakes region (States of Minnesota, Wisconsin, and Michigan), which are the focus of this analysis. More specifically, Alaska and Hawaii are the only States to codify in their constitutions the...

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...

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...

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.

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.

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 an overview and comparisons of the precipitation intensity–duration–frequency (PIDF) and flood (FFRQ) and low-flow (LFRQ) frequencies for return intervals of 25 years or more at ten relatively undisturbed reference watersheds in the US Forest Service Experimental Forest (EF) network. We demonstrate potential effects of recent climate change on the PIDFs, FFRQ and LFRQ developed with high-resolution temporal data at these ten sites with widely contrasting hydrogeological, topographical, climatic and ecological characteristics. Similarly, we evaluate the on-site-based...