Louis R. Iverson

US Forest Service | FS · Northern Research Station

Aim Many tree species distribution models use black‐box machine learning techniques that often neglect interpretative aspects and instead focus mainly on maximizing predictive accuracy. In this study, we outline an interpretative modelling framework to gain better ecological insights while mapping abundance patterns of six North American species....

Context Forest type (FT) classification provides useful information to ecologists and forest managers by representing similar sites based on species dominance. Various methods have been developed using stand-level or plot-level information, however, these classifications are not always effective at representing broader landscape patterns of species...

There have been dramatic changes to forest lands since the end of the last ice age, about 14,000 years before present, when boreal ecosystems were eventually replaced by deciduous forest and grassland. In Illinois at the time of Euro-American Settlement (circa 1820), forest lands, including fire-maintained woodlands and savannas, comprised about 42...

While many forestry practitioners and ecologists have a general understanding of the USDA Forest Service, Forest Inventory and Analysis (FIA) program and the type of data collected, most non-expert users of FIA reports and basic data are unlikely to be familiar with the breadth of information available and the many potential uses of the data. We pr...

Remote Amazonian communities are often largely self-sufficient, made possible in part by their agricultural skills and deep ecological knowledge of their landscapes. Mastery of their local flora undoubtedly plays a vital role in daily life, yet communities in the Amazon can vary widely in both the diversity of plants that they utilize and in how th...

Plant phenological processes significantly impact ecosystem function and services across multiple ecological scales and are widely viewed to be among the most sensitive indicators of global environmental change. Remote sensing has crucially expanded our understanding of phenological variability. Yet, we continue to lack a complete mechanistic under...

Climate change is a major environmental challenge that is likely to affect many aspects of life in Illinois, ranging from human and environmental health to the economy. Illinois is already experiencing impacts from the changing climate and, as climate change progresses and temperatures continue to rise, these impacts are expected to increase over t...

Forests provide myriad ecosystem services, many of which are vital to local and regional economies. Consequently, there is a need to better understand how predicted changes in climate will impact forest dynamics and the implications of such changes for society as a whole. Here we focus on the impacts of climate change on Indiana forests, which are...

Aim To evaluate current and future dynamics of 25 tree species spanning United States and Canada. Location United States and Canada. Methods We combine, for the first time, the species compositions from relative importance derived from the USA’s Forest Inventory Analysis (FIA) with gridded estimates based on Canada's National Forest Inventory (NF...

As our climate continues to change, it is increasingly clear that natural landscapes are being affected in a variety of ways. Managers of the Apostle Islands National Lakeshore have observed notable changes in their own backyard, and they are rightfully concerned that continued change will challenge their mission to preserve and enhance the ecologi...

The Landsat program has long supported pioneering research on the recovery of forest information by remote sensing technologies for several decades, and efforts to improve the thematic resolution and accuracy of forest compositional products remains an area of continued innovation. Recent development and application of Landsat time series analysis...

Background The negative impacts of the exotic tree, Ailanthus altissima (tree-of-heaven, stink tree), is spreading throughout much of the Eastern United States. When forests are disturbed, it can invade and expand quickly if seed sources are nearby. Methods We conducted studies at the highly dissected Tar Hollow State Forest (THSF) in southeastern...

The northern United States is both the most heavily forested and the most densely populated quadrant of the nation. Forests in the region cover 69.6 million hectares, or 42 percent of the land area. In this chapter we characterize mid- and long-term projected climate change impacts for trees and forests of the region. Selected examples at the regio...

We modeled and combined outputs for 125 tree species for the eastern United States, using habitat suitability and colonization potential models along with an evaluation of adaptation traits. These outputs allowed, for the first time, the compilation of tree species’ current and future potential for each unit of 55 national forests and grasslands an...

Bastin et al . (Reports, 5 July 2019, p. 76) neglect considerable research into forest-based climate change mitigation during the 1980s and 1990s. This research supports some of their findings on the area of land technically suitable for expanding tree cover, and can be used to extend their analysis to include the area of actually available land an...

Impacts of forest drought on forests of the Midwest and Northeast, and drought management options and considerations including adaptation case studies from forest management projects in the region.

Species distribution models (SDMs) provide useful information about potential presence or absence, and environmental conditions suitable for a species; and high‐resolution models across large extents are desirable. A primary feature of SDMs is the underlying spatial resolution, which can be chosen for many reasons, though we propose that a hybrid l...

Ailanthus altissima ((Mill.) Swingle, tree-of-heaven, Chinese sumac, stink tree) is a nonnative invasive tree that is common throughout much of the eastern United States. It can invade and expand dramatically when forests are disturbed. Anecdotal evidence suggests that fire might facilitate its spread, but the relationship between fire and this pro...

Forests across the globe are faced with a rapidly changing climate and an enhanced understanding of how these changing conditions may impact these vital resources is needed. Our approach is to use DISTRIB-II, an updated version of the Random Forest DISTRIB model, to model 125 tree species individually from the eastern United States to quantify pote...

Mapping forest properties with supervised remote sensing has historically and increasingly remained vital to research and management efforts, and the demand for such products will only increase as better tools and data increase the usability of such maps. Multispectral imagery by the Landsat program has been an invaluable resource for forest type c...

Forest ecosystems will be affected directly and indirectly by a changing climate over the 21st century. This assessment evaluates the vulnerability of 11 forest ecosystems in the Mid-Atlantic region (Pennsylvania, New Jersey, Delaware, eastern Maryland, and southern New York) under a range of future climates. We synthesized and summarized informati...

Oak (Quercus spp.) and hickory (Carya spp.) forests in the eastern United States provide a host of ecosystem services as their mast are prized by wildlife, the timber is a valued commodity, and they are generally more tolerant of extreme weather events under a changing climate. They are, however, undergoing a severe decline in prominence throughout...

The book was inadvertently published with an incorrect affiliation of the author Michael Manton in Chapters 4 & 6 as Faculty of Forest Science and Ecology, Aleksandras Stulginskis University, Kaunas, Lithuania; School for Forest Management, Swedish University of Agricultural Sciences, Skinnskatteberg, Sweden; State Environmental Institution Nationa...

One of the greatest challenges of this century is to develop economic and social systems, and supporting systems of governance from local to global scales, capable of achieving sustainable levels of human population and consumption, while also maintaining the ecosystem life-support services that underpin human well-being. Forest ecosystems provide...

This chapter provides summaries of some key elements from the chapters as well as point to some messages that emerge among four chapters. For example, the ecosystem services provided by forests cross several levels of scale and complexity, and therefore risks and uncertainties are high, especially at broad scales. Yet, planning for ecosystem servic...

Over the last two decades, the topic of forest ecosystem services has attracted the attention of researchers, land managers, and policy makers around the globe. The services rendered by forest ecosystems range from intrinsic to anthropocentric benefits that are typically grouped as provisioning, regulating, supporting, and cultural. The research ef...

Forest ecosystems will face direct and indirect impacts from a changing climate over the 21st century. This assessment evaluates the vulnerability of forest ecosystems across the New England region (Connecticut, Maine, Massachusetts, New Hampshire, northern New York, Rhode Island, and Vermont) under a range of future climates. We synthesized and su...

Forests of the Midwest and Northeast significantly define the character, culture, and economy of this large region but face an uncertain future as the climate continues to change. Forests vary widely across the region, and vulnerabilities are strongly influenced by regional differences in climate impacts and adaptive capacity. Not all forests are v...

Sugar maple (Acer saccharum) is a highly valued tree in United States (US) and Canada, and its sap when collected from taps and concentrated, makes a delicious syrup. Understanding how this resource may be impacted by climate change and other threats is essential to continue management for maple syrup into the future. Here, we evaluate the current...

Ailanthus altissima ((Mill.) Swingle, tree-of-heaven), an exotic invasive tree that is common throughout much of the eastern United States, can invade and expand dramatically when forests are disturbed. Anecdotal evidence suggests that fire facilitates its spread, but the relationship between fire and this prolific invasive tree is poorly understoo...

Context Species distribution models (SDM) establish statistical relationships between the current distribution of species and key attributes whereas process-based models simulate ecosystem and tree species dynamics based on representations of physical and biological processes. TreeAtlas, which uses DISTRIB SDM, and Linkages and LANDIS PRO, process-...

Forests around the world are experiencing increasingly severe droughts and elevated competitive intensity due to increased tree density. However, the influence of interactions between drought and competition on forest growth remains poorly understood. Using a unique dataset of stand-scale dendrochronology sampled from 6405 trees, we quantified how...

The urban forest of the Chicago Wilderness region, a 7-million-acre area covering portions of Illinois, Indiana, Michigan, and Wisconsin, will face direct and indirect impacts from a changing climate over the 21st century. This assessment evaluates the vulnerability of urban trees and natural and developed landscapes within the Chicago Wilderness r...

Climate change is having important effects on forest ecosystems, presenting a challenge for natural resource professionals to reduce climate-associated impacts while still achieving diverse management objectives. Regional projections of climate change and forest response are becoming more readily available, but managers are still searching for prac...

Abstract. By tracking oak-hickory (Quercus-Carya) regeneration for 13 yr across management-manipulated light and topographically driven moisture gradients after partial harvest and three prescribed fires, we document best-case conditions to promote advanced oak regeneration, and thereby provide a promising management tool to reverse the downward sp...

Wildfires in the eastern United States are generally caused by humans in locations where human development and natural vegetation intermingle, e.g. the wildland-urban interface (WUI). Knowing where wildfire hazards are elevated across the forested landscape may help land managers and property owners plan or allocate resources for potential wildfire...

Context No single model can capture the complex species range dynamics under changing climates—hence the need for a combination approach that addresses management concerns. Objective A multistage approach is illustrated to manage forested landscapes under climate change. We combine a tree species habitat model—DISTRIB II, a species colonization mod...

The emerald ash borer (Agrilus planipennis; EAB) is causing widespread mortality of ash (Fraxinus spp.) and climate change is altering habitats of tree species throughout large portions of North America. Black ash (F. nigra), a moist-soil species common in the Northwoods of Minnesota, Wisconsin, and Michigan, USA, is under a double threat of losing...

We synthesize insights from current understanding of drought impacts at stand-to-biogeographic scales, including management options, and we identify challenges to be addressed with new research. Large stand-level shifts underway in western forests already are showing the importance of interactions involving drought, insects, and fire. Diebacks, cha...

The incorporation of the ecosystem service (ES) concept into the framework of forest management stems from a need to create a more holistic perception of forests, recognizing not only their economic value, but also their cultural and ecological values. Yet, despite improved understanding of the potential of landscapes and their land use systems to...

We present an aerial mapping method to efficiently and effectively identify seed clusters of the invasive tree, Ailanthus altissima (Mill.) Swingle across deciduous forest landscapes in the eastern United States. We found that the ideal time to conduct aerial digital surveys is early to middle winter, when Ailanthus seed clusters persist and there...

We lost a great one in ecology, an important person in the development of landscape ecology in North America and a gem of person on July 10, 2014. Paul continued to work in his office as much as he could throughout his many treatments for the decades-long illness that finally killed him, and was in his office until the week before he died. He leave...

Forest ecosystems across the Central Appalachians will be affected directly and indirectly by a changing climate over the 21st century. This assessment evaluates the vulnerability of nine forest ecosystems in the Central Appalachian Broadleaf Forest-Coniferous Forest-Meadow and Eastern Broadleaf Forest Provinces of Ohio, West Virginia, and Maryland...

Department of Geography, University of Wisconsin-Madison, 550 North ParkStreet, Madison, WI 53706, USAThe influence of climate on forest change during thepast century in the eastern United States was evalu-ated in a recent paper (Nowacki & Abrams, 2014)that centers on an increase in ‘highly competitivemesophytic hardwoods’ (Nowacki & Abrams, 2008)an...

Droughts are common in virtually all U.S. forests, but their frequency and intensity vary within forest ecosystems (Hanson and Weltzin 2000). Accounting for the long-term influence of droughts within a region is difficult due to variations in the spatial extent and intensities over a period. Therefore, we created a cumulative drought severity index...

Emerald ash borers were first discovered in Detroit in 2002 and have since taken only a few years to destroy most of the ash trees within the Detroit Metropolitan area and spread throughout many of the Great Lakes States. We integrate economic and ecological models to retroactively assess the economic benefits of different policy options during the...

During the twenty-first century, tree mortality from forest disturbances may switch the United States from a current carbon sink (offsetting 13 % of U.S. fossil fuel greenhouse gas emissions) to a source. Carbon losses from disturbances in western U.S. forests (insects, wildfire) may be partially offset by increased growth in the East, where water...

There is an ever-growing body of literature on forest management strategies for climate change adaptation; however, few frameworks have been presented for integrating these strategies with the real-world challenges of forest management. We have developed a structured approach for translating broad adaptation concepts into specific management action...

The Midwest is home to expansive agriculture, forests, industry, and people. Climate change will tend to amplify existing risks climate poses to people (increased heat waves, flooding, reduced air and water quality), agriculture (reduced yields despite longer seasons and added CO2, springtime cold air outbreaks), forests (species habitats move nort...

Species distribution models (SDM) are commonly used to provide information about species ranges or extents, and often are intended to represent the entire area of potential occupancy or suitable habitat in which individuals occur. While SDMs can provide results over various geographic extents, they normally operate within a grid and cannot delimit...

The degree to which tree species will shift in response to climate change is uncertain yet critical to understand for assessing ecosystem vulnerability. We analyze results from recent studies that model potential tree species habitat across the eastern United States during the coming century. Our goals were to quantify and spatially analyze habitat...

Climate is the primary force that controls forest composition and the broad-scale distribution of forests. The climate has always been changing, but the changes now underway are different—they are faster and they are intermingled with other disturbances promoted by increasing human pressures. The projected climate change during the twenty-first cen...

Abstract The concept of ecosystem services from landscapes is rapidly gaining momentum as a language to communicate values and benefits to scientists and lay alike. Landscape ecology has an enormous contribution to make to this field, and one could argue, uniquely so. Tools developed or adapted for landscape ecology are being increasingly used to a...

Forests provide key ecosystem services (ES) and the extent to which the ES are realized varies spatially, with forest composition and cultural context, and in breadth, depending on the dominant tree species inhabiting an area. We address the question of how climate change may impact ES within the temperate and diverse forests of the eastern United...

The forests in the Central Hardwoods Region will be affected directly and indirectly by a changing climate over the next 100 years. This assessment evaluates the vulnerability of terrestrial ecosystems in the Central Hardwoods Region of Illinois, Indiana, and Missouri to a range of future climates. We synthesized and summarized information on the c...

Climate change will generally increase the risk of negative consequences to forests and associated biosocial systems. Risk management identifies risks, estimating their probability of occurrence and magnitude of impact. A risk framework provides a means to quantify what is known, identify where uncertainties exist, and help resource managers develo...

Key Messages 1. In the next few decades, longer growing seasons and rising carbon dioxide levels will increase yields of some crops, though those benefits will be progressively offset by extreme weather events. Though adaptation options can reduce some of the detrimental effects, in the long term, the combined stresses associated with climate chang...