Treesearch

1. Modern ecological management problems are characterized by large scales, rapid environmental change, multiple stressors and conflicts between local and global conservation objectives. These problems are too complex to address with field studies alone, and statistical models that assume past system behaviours can predict future responses are risky when systems are changing rapidly. Mechanistic simulation models, though, can avoid that assumption while accommodating important natural complexities. 2. Making mechanistic models credible requires empirical studies, but traditional study...

Forest stocking guidelines traditionally reference self-thinning lines representing the tradeoff between maximum trees per unit area vs. maximum mean tree size for even-aged stands. While self-thinning lines are roughly linear on logarithmic scales, certain forest types display a curvilinear “mature stand boundary” (MSB). The existence of the MSB suggests that beyond self-thinning, processes such as recruitment limitation, density-independent mortality, and their interactions with site quality may also contribute to a more universal maximum size-density boundary (MSDB). To advance forest...

Open forest restoration transitions closed-canopy forests to a structure amenable to shade-intolerant species such as oak and often includes thinning or prescribed burns to promote diverse species composition. We measured how oak restoration treatments influenced ground-layer species assemblages and successional patterns in an ecologically diverse mesic hardwood forest. We tested how repeated prescribed fire, midstory herbicide applications, and the combination of shelterwood overstory harvest and prescribed fire influenced species diversity and turnover, and if species showed affinity to...

Understanding how species of conservation concern interact with natural disturbances provides insights into their evolutionary environment and can inform land management and conservation planning. We examined the breeding season nocturnal space use (i.e., foraging ecology) of three Mexican spotted owls (Strix occidentalis lucida) in southern New Mexico, USA that occurred in areas previously affected by timber harvest, wildfire, and insect-related tree mortality, respectively. We found that individual owls (1) preferentially used the ecotone between forests that were harvested and those...

The frequency and severity of drought events are predicted to increase due to anthropogenic climate change, with cascading effects across forested ecosystems. Management activities such as forest thinning and prescribed burning, which are often intended to mitigate fire hazard and restore ecosystem processes, may also help promote tree resistance to drought. However, it is unclear whether these treatments remain effective during the most severe drought conditions or whether their impacts differ across environmental gradients. We used tree-ring data from a system of replicated, long-term...

Foundational forest and land-use change monitoring programs, with their statistical rigor and long-term baselines, are increasingly important to inform emerging global agricultural and forest commodity trade policies such as the European Union regulation on deforestation-free products (EUDR). The EUDR requires national-scale information on deforestation prevalence as one component of deforestation risk assessments, with additional traceability and risk assessment requirements at the parcel scale for exports to the EU to comply with the regulation. To better understand potential implications...

Mechanical thinning is often prescribed in dry coniferous forests to reduce stand density, ladder fuels, and canopy fuels before using prescribed burning to manage surface fuels. Mechanical mastication is a tool for thinning forests where commercial thinning is not viable. We evaluated the effects of mastication-based thinning – with and without subsequent prescribed burning – on forest structure and fuels in dry coniferous forests of the Pacific Northwest, USA. We thinned stands by masticating small-diameter trees and depositing the resulting slash on the forest floor. We then used...

This resource bulletin consolidates data from the eighth complete survey of Kentucky’s forest resources which was conducted during the period 2014–2019 by the U.S. Department of Agriculture (USDA) Forest Service, Forest Inventory and Analysis (FIA) program in cooperation with the Kentucky Division of Forestry (KDF) of the Kentucky Energy and Environment Cabinet. Data on the extent, condition, and classification of forest land and associated timber volumes, as well as growth, removals, and mortality rates are described and interpreted. Data on forest health and forest landowner characteristi...

Susceptibility of bats to white-nose syndrome (WNS), a lethal disease caused by the fungus Pseudogymnoascus destructans (Pd), may be influenced by the amount of activity outside hibernacula during the winter. We tested the effects of hibernaculum type (aboveground or subterranean) and Pd status (positive or negative) on winter activity of tricolored bats (Perimyotis subflavus) in the southeastern USA along with the effects of ambient temperature, precipitation, and stage of hibernation. We placed acoustic detectors at the entrances of 13 hibernacula (4 aboveground and Pd-positive, 4...

Wildfires have increased in size and severity and so has concern over how wildfires impact water security. The current literature suggests that wildfires may negatively impact surface water quality and community drinking water systems dependent on surface water as their drinking water source. Yet few studies consider the implications for the populations served by these downstream community drinking water systems. This research contributes to a more comprehensive understanding of water security by characterizing community water systems (CWSs) historically exposed to wildfire as well as...