William Scott Keeton

University of Vermont | UVM · Rubenstein School of Environment and Natural Resources

Managing riparian corridors for flood resilience requires understanding of linkages between vegetation condition and stream geomorphology. Stream assessment approaches increasingly use channel morphology as an indicator of stream condition, with only cursory examination of riparian vegetation. Our research (i) examines relationships between stream...

There is a high degree of uncertainty regarding biomass accumulation and carbon storage potential in secondary temperate forests. Improving this understanding is vital for managing these forests as carbon sinks, a part of climate change mitigation efforts. A critical question is how secondary stand development in eastern U.S. forests has influenced...

Forest management practices emphasizing stand structural complexity are of interest across the northern forest region of the United States because of their potential to enhance carbon storage. Our research is part of a long-term study evaluating silvicultural treatments that promote late-successional for- est characteristics in northern hardwood-co...

Alongside the steep reductions needed in fossil fuel emissions, natural climate solutions (NCS) represent readily deployable options that can contribute to Canada’s goals for emission reductions. We estimate the mitigation potential of 24 NCS related to the protection, management, and restoration of natural systems that can also deliver numerous co...

When management for old-growth characteristics in eastern forests first began to be discussed in the late twentieth century, there was skepticism from some quarters as to whether it was a desirable or even a feasible idea. Old growth will recover on its own. Why not just let nature take its course? There were also those who saw little value in mana...

As canopy closure causes forest stands to face increasing light limitation, trees' lower branches begin to die back. This process, called self-pruning, defines a crown's base and depth and shapes the structure of entire stands. Self-pruning is often thought to occur after shading causes individual branches to transition from net carbon sources to s...

Understanding the impacts of changing climate and disturbance regimes on forest ecosystems is greatly aided by the use of process-based models. Such models simulate processes based on first principles of ecology, which requires parameterization. Parameterization is an important step in model development and application, defining the characteristics...

Global climate change and the push to develop Natural Climate Solutions have increased urgency around the need to quantify, capture, and store carbon to reduce atmospheric concentrations of carbon dioxide—but we may be overlooking a potentially important, long‐term carbon sink. Carbon stored in large woody debris (LWD) in lakes is largely missing f...

As we contemplate the future of forest landscapes under changing climate conditions and land‐use demands, there is increasing value in studying historic forest conditions and how these landscapes have changed following past disturbances. Historic landscape paintings are a potential source of data on preindustrial forests with highly detailed, full‐...

Recent long‐term tree biodiversity experiments have shown that diversity effects on productivity tend to strengthen over time, as complementarity among constituent species increases over the course of forest development. However, these community‐level metrics only account for the net outcome of multiple interactions among species and, thus, do not...

There is increasing evidence that the strength of tree diversity effects on productivity varies considerably over the course of forest development. Evidence points to canopy closure and the subsequent self‐thinning as key phases of forest development during which positive diversity effects emerge. A number of studies have shown that self‐thinning c...

Understanding temporal and spatial variations in historical disturbance regimes across intact, continuous, and altitudinally diverse primary forest landscapes is imperative to help forecast forest development and adapt forest management in an era of rapid environmental change. Because few complex primary forest landscapes remain in Europe, previous...

Protecting structural features, such as tree‐related microhabitats (TreMs), is a cost‐effective tool crucial for biodiversity conservation applicable to large forested landscapes. Although the development of TreMs is influenced by tree diameter, species, and vitality, the relationships between tree age and TreM profile remain poorly understood. Usi...

Unlabelled: With progressing climate change, increasing weather extremes will endanger tree regeneration. Canopy openings provide light for tree establishment, but also reduce the microclimatic buffering effect of forests. Thus, disturbances can have both positive and negative impacts on tree regeneration. In 2015, three years before an extreme dr...

In Europe, forest management has controlled forest dynamics to sustain commodity production over multiple centuries. Yet over‐regulation for growth and yield diminishes resilience to environmental stress as well as threatens biodiversity, leading to increasing forest susceptibility to an array of disturbances. These trends have stimulated interest...

Although there is compelling evidence that tree diversity has an overall positive effect on forest productivity, there are important divergences among studies on the nature and strength of these diversity effects and their timing during forest stand development. To clarify conflicting results related to stand developmental stage, we explored how di...

With accelerating environmental change, understanding forest disturbance impacts on trade-offs between biodiversity and carbon dynamics is of high socioeconomic importance. Most studies, however, have assessed immediate or short-term effects of disturbance, while long-term impacts remain poorly understood. Using a tree-ring-based approach, we analy...

Understanding the processes shaping the composition of assemblages in response to disturbance events is crucial for preventing ongoing biodiversity loss in forest ecosystems. However, studies of forest biodiversity responses to disturbance typically analyze immediate or short-term impacts only, while studies relating long-term disturbance history t...

Functional diversity (FD), represented by plant traits, is fundamentally linked to an ecosystem's capacity to respond to environmental change. Yet, little is known about the spatial distribution of FD and its drivers. These knowledge gaps prevent the development of FD-based forest management approaches to increase the trait diversity insurance (i.e...

Primary forests are critical for forest biodiversity and provide key ecosystem services. In Europe, these forests are particularly scarce and it is unclear whether they are sufficiently protected. Here we aim to: (a) understand whether extant primary forests are representative of the range of naturally occurring forest types, (b) identify forest ty...

Disturbance-based silviculture is of increasing interest as an approach to provide multiple ecosystem services and beta diversity in habitat conditions. One such approach increasingly employed in the eastern U.S. is a set of forestry practices developed to diversify forested bird habitats, called Silviculture with Birds in Mind (SBM). While strongl...

Increased wildfire activity in the Himalayan Mountains due to climate change may place rural livelihoods at risk, yet potential climate change effects on forest fires in this region are poorly investigated. Here we use Bhutan's blue pine (Pinus wallichiana) ecosystems to study the sensitivity of fire behavior to climatic changes. Wildland fires are...

Throughout the United States, many institutions of higher education own forested tracts, often called school forests, which they use for teaching, research, and demonstration purposes. These school forests provide a range of benefits to the communities in which they are located. However, because administration is often decoupled from research and t...

Economic drivers explaining the harvest of biomass for energy use in northeastern forests in the United States are not well understood. However, knowledge of these drivers is essential for bioenergy policy development, biomass supply estimates, and assessments of harvesting impacts on forest ecosystems and carbon stocks. Using empirical data from 3...

Given the global intensification of forest management and climate change, protecting and studying forests that develop free of direct human intervention-also known as primary forests-are becoming increasingly important. Yet, most countries still lack data regarding primary forest distribution. Previous studies have tested remote sensing approaches...

Elements of forest structure are fundamentally associated with an array of ecosystem services and habitat characteristics. However, forest structure varies, in particular, through interactions with natural and human disturbances. Both variation in structural characteristics and associated relationships with ecosystem service outcomes have been poor...

Climate change threatens the provisioning of forest ecosystem services and biodiversity (ESB). The climate sensitivity of ESB may vary with forest development from young to old‐growth conditions as structure and composition shift over time and space. This study addresses knowledge gaps hindering implementation of adaptive forest management strategi...

The largescale recovery of eastern forests from historic clearing is a remarkable example of forest ecosystem resilience (Foster and Aber 2004). More than 150 years after the peak of agricultural clearing in eastern North America, many forests across the region have reached maturity and some are progressing toward an old-growth condition (Brooks et...

Climate change will alter forest ecosystems and their provisioning of services. Forests in the Carpathian Mountains store high amounts of carbon and provide livelihoods to local people; however, no study has yet assessed their future long-term dynamics under climate change. Therefore, we selected a representative area of 1340 km2 to investigate the...

Aim Primary forests have high conservation value but are rare in Europe due to historic land use. Yet many primary forest patches remain unmapped, and it is unclear to what extent they are effectively protected. Our aim was to (1) compile the most comprehensive European‐scale map of currently known primary forests, (2) analyse the spatial determina...

How do structure and function in European old-growth forests compare to other temperate regions? Are old-growth characteristics shared universally or are there regional differences reflecting variation in growth, stand dynamics, and disturbance history? We tested the hypothesis that important ecological functions are provided universally by old-gro...

In the past several decades, a trend in forestry and silviculture has been toward promoting complexity in forest ecosystems, but how complexity is conceived and described has shifted over time as new ideas and terminology have been introduced. Historically, ecologically-focused silviculture has focused largely on manipulation of structural complexi...

Wind is one of the most important natural disturbances influencing forest structure, ecosystem function, and successional processes worldwide. This study quantifies the stand-scale effects of intermediate-severity windstorms (i.e., “blowdowns”) on (1) live and dead legacy structure, (2) aboveground carbon storage, and (3) tree regeneration and asso...

For decades forest scientists have thought that old-growth temperate forests were either carbon neutral or even carbon sources, emitting more greenhouse gases to the atmosphere through respiration and decomposition than they were absorbing through photosynthesis. However, recent research has questioned that assumption, showing that eastern old-grow...

Old growth—the term evokes something deeply rooted in the human psyche. We imagine the forest primeval, something timeless from our distant collective memory or perhaps nostalgia for what we imagine might once have been. Maybe we long for a time when life was less complicated, when the trappings of modern civilization were not so pervasive. There i...

"An important contribution to the burgeoning literature extolling the virtues of forest complexity. As a compendium of the literature on forest heterogeneity alone, this book is an indispensable reference for scholars and practitioners of ecological forest management." Gregory H. Aplet, Senior Science Director, The Wilderness Society "Ecology and R...

The Wildlands and Woodlands (W&W) vision calls for a 50-year effort to conserve 70 percent of New England as forest permanently free from development, plus at least 7 percent of New England as farmland. Through the leadership and commitment of landowners, these conserved lands will continue to power the region’s traditional land-based economy and p...

Dead wood (DW) has great importance for many wildlife species and ecological processes. The volume of DW is considered a useful indicator of the sustainability and maintenance of biodiversity in forests. Though dry-mesic oak forests cover large areas in Hungary, little is known about DW quantities or dynamics in these forests. We investigated DW co...

A disturbance or natural event in forested streams that alter available light can have potential consequences for nutrient dynamics and primary producers in streams. In this study, we address how functional processes (primary production and nutrient uptake) in stream ecosystems respond to changes in forest canopy structure. We focus on differences...

The world is facing numerous and severe environmental, social, and economic challenges. To address these, in September 2015 the General Assembly of the United Nations adopted the resolution Transforming our World: The 2030 Agenda for Sustainable Development. The United Nations' 17 sustainable development goals (SDGs) and their 169 targets are ambit...

Successful tree regeneration is essential for sustainable forest management, yet it can be limited by the interaction of harvesting effects and multiple ecological drivers. In northern hardwood forests, for example, there is uncertainty whether low-intensity selection harvesting techniques will result in adequate and desirable regeneration. Our res...

Reducing emissions from deforestation and degradation (REDD+) is a frequently promoted climate change mitigation strategy. As forest carbon projects proceed, we are learning how they affect local sovereignty and resource access, particularly in developing economies. Central and Eastern Europe’s temperate forests offer potential for projects, yet li...

Studying fire risks in the blue pine forests of Bhutan.

Light availability influences temperature, primary production, nutrient dynamics, and secondary production in aquatic ecosystems. In forested freshwater ecosystems, shading by streamside (riparian) vegetation is a dominant control on light flux and represents an important interaction at the aquatic–terrestrial interface. Changes in forest structure...

Gap-based silvicultural systems were developed under the assumption that richness, and diversity of tree species and other biota positively respond to variation in size of harvest-created canopy gaps. However, varying gap size alone often does not meet diversity objectives and broader goals to address contemporary forest conditions. Recent research...

Understanding the causes and consequences of rapid environmental change is an essential scientific frontier, particularly given the threat of climate- and land use-induced changes in disturbance regimes. In western North America, recent widespread insect outbreaks and wildfires have sparked acute concerns about potential insect-fire interactions. A...

The long-term greenhouse gas emissions implications of wood biomass (‘bioenergy’) harvests are highly uncertain yet of great significance for climate change mitigation and renewable energy policies. Particularly uncertain are the net carbon (C) effects of multiple harvests staggered spatially and temporally across landscapes where bioenergy is only...

Forest management practices directly influence microhabitat characteristics important to the survival of fungi. Because fungal populations perform key ecological processes, there is interest in forestry practices that minimize deleterious effects on their habitats. We investigated the effects on fungal sporocarp diversity of modified uneven-aged fo...

Available at http://www.vtfpr.org/htm/documents/VHG_FINAL.pdf

In recent years, there has been the phenomena of spruce dieback in Europe. Significant areas of spruce low mortality now cover both sides of the Polish southern border. We evaluated ecochemical parameters influencing the heavy dieback occurring in mature spruce stands in the Polish Carpathian Mountains. Dolomite, magnesite and serpentinite fertiliz...

Decades of heavy-cutting and high-grading in the northeastern United States provide an opportunity for rehabilitation and increased carbon stores, yet few studies have examined the feasibility of using carbon markets to restore high-graded forests. We evaluated the effectiveness of rehabilitation on 391 ha of high-graded forest in Vermont, USA. Thi...

Carbon markets have the potential to reward landowners for improved forest management and forest conservation. To date, the Over the Counter (OTC) voluntary market represents the greatest opportunity for forest landowners to participate in carbon transactions. However, lack of a consistent carbon price signal and sporadic demand coupled by high tra...

Light availability strongly influences stream primary production, water temperatures and resource availability at the base of stream food webs. In headwater streams, light is regulated primarily by the riparian forest, but few studies have evaluated the influence of riparian forest stand age and associated structural differences on light availabili...

Background/Question/Methods Management for late-successional forest structure and function is an important element of sustainable forestry in the northern hardwood region. Canopy gaps are a key characteristic of interest and a variety of silvicultural approaches have been proposed to approximate natural canopy gap dynamics. The Vermont Forest Eco...

Old-growth forests around the world are vanishing rapidly and have been lost almost completely from the European temperate forest region. Poor management practices, often triggered by socioeconomic and institutional change, are the main causes of loss. Recent trends in old-growth forest cover in Romania, where some of the last remaining tracts of t...

With growing interest in wood bioenergy there is uncertainty over greenhouse gas emissions associated with offsetting fossil fuels. Although quantifying postharvest carbon (C) fluxes will require accurate data, relatively few studies have evaluated these using field data from actual bioenergy harvests. We assessed C reductions and net fluxes immedi...

Sustainable forest management (SFM) has been challenging in the Carpathian Mountain region of Europe. We explore emerging models and innovative practices that offer guidance on implementing SFM, based on recommendations developed through a scientific atelier held in western Ukraine. Information was gathered through technical presentations, site vis...

Forest carbon cycles play an important role in efforts to understand and mitigate climate change. Large amounts of carbon (C) are stored in deep mineral forest soils, but are often not considered in accounting for global C fluxes because mineral soil C is commonly thought to be relatively stable. We explore C fluxes associated with forest managemen...

Demand for forest bioenergy fuel is increasing in the northern forest region of eastern North America and beyond, but ecological impacts, particularly on habitat, of bioenergy harvesting remain poorly explored in the peer-reviewed literature. Here, we evaluated the impacts of bioenergy harvests on stand structure, including several characteristics...

Background/Question/Methods Riparian forests regulate linkages between terrestrial and aquatic ecosystems, yet relationships among riparian forest development, stand structure, and stream habitats are poorly understood in many temperate deciduous forest systems. Our research in the Adirondack Mountains of New York has 1) described structural attr...

Background/Question/Methods Many former industrial timberlands in the Northeast experienced decades of heavy cutting, including the unsustainable removal of valuable trees with little thought to regeneration. These practices yield immediate monetary returns, but jeopardize long-term forest productivity and ecosystem functioning. Today, thousands...