Treesearch

Soil seed banks are the hidden reservoir of forest plant diversity. Seed banking is a reproductive adaptation that allows plants to persist belowground as dormant seeds, where the soil serves as a buffer from aboveground disturbances. They play a key role in the recovery of forests post-disturbance, and it’s the post-disturbance plant recovery that replenishes, or makes seed deposits, in the seed bank. Since certain plant species are favored or disfavored by the type of forest disturbance, seed banks can vary depending on the disturbance affecting aboveground plants, and the abundance and...

This essay examines the important roles of growth and yield models in forest management decision-making in the Pacific Northwest United States. It outlines how these models help managers evaluate and optimize forest productivity on commercial timberlands by incorporating site indices, growth responses to silvicultural treatments like thinning, fertilization, and vegetation control, the potential impacts of climate change, and other factors. The essay reflects on how growth and yield models help forest managers optimize stand development, balance multiple objectives, and adapt to changing...

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...