History, Current Status, and Future of Northeastern Forests (with - PowerPoint PPT Presentation

History, Current Status, and Future of Northeastern Forests (with particular emphasis on forests of eastern New York) Charles Canham Cary Institute of Ecosystem Studies Millbrook, NY

Yale University Press Available February 2020

Focusing in on eastern New York: New York FIA statistics by region, 2015 Net Ratio of Net Area of forest land Growth Removals Net change Gross Growth Growth / Region (acres) (ft 3 /acre) (ft 3 /acre) (ft 3 /acre/yr) (ft 3 /acre/yr) Removals Adirondack Park* 2,780,037 34.8 27.9 6.9 60.2 1.2 Western New York 8,298,735 45.7 17.4 28.3 66.3 2.6 Eastern New York** 5,338,043 43.6 10.2 33.4 68.6 4.3 * Excludes NYS Forest Preserve and other reserved lands ** Eastern region defined as lands south of the Adirondack Park boundary and Delaware and Otsego Counties eastward

Some common misconceptions about the forests of eastern NY (and the rest of the Northeast).. ❖ Very few forests are truly even-aged - “age” as a metric has become meaningless – biomass is far more relevant ❖ The current distribution of forest biomass is strongly skewed towards much lower biomass than would have been present in the presettlement landscape - this is a product of the history of intensive land-use, and is an anomaly in the long-term history of these forests. ❖ Almost none of the forests have reached maximum levels of carbon storage – there is still significant potential for additional carbon sequestration in both live and dead biomass

Great Mountain Forest and a model of forest dynamics ❖ Field research: ▪ Developed new methods to estimate – in the field - all of the critical parameters needed to ❖ Modeling: predict the successional dynamics ▪ Developed SORTIE - a spatially of the 9 tree species at GMF explicit, individual-based simulation model to incorporate all of the field results Pacala, S. W., C. D. Canham, J. Saponara, J. A. Silander, Jr., R. K. Kobe, and E. Ribbens. 1996. Forest models defined by field measurements: II. Estimation, error analysis and dynamics. Ecological Monographs 66:1-43.

The U.S. Forest Service Forest Inventory and Analysis (FIA) Program BASIC NETWORK DESIGN • Stratified random plot locations • 1 plot per 6,000 acres of land • Individual plots recensused ~ every 5-7 years (with a subset of plots sampled each year) • Data posted and publicly available* within ~ 1 year after collection *exact plot locations are confidential, by law… 6

The SORTIE-ND software for simulation of forest dynamics… ❖ Individual-based ▪ Simulates the birth, growth, and death of all seedlings, saplings and adult trees, including processes of natural and human disturbance, and effects of processes including pests and pathogens, air pollution, and climate change ❖ Spatially-explicit ▪ The spatial locations of all individuals are tracked, and can be used in processes ranging from seed dispersal to resource competition ❖ Adaptable ▪ Users create and assemble “behaviors” based on available field data ❖ Open-source ▪ The source code and programming guides are available to all users (www.sortie-nd.org) ▪ changes made by any user are incorporated in the base model available to all

A 40 year voyage, and I’m still not sure where the forests are headed … But this I believe: ❖ Forests have enormous demographic inertia – change is slow (in the absence of direct human intervention) ❖ Some changes are inexorable – the broad outlines of succession are predictable, and are defined by shade tolerance ❖ But the notion of “steady state” is largely meaningless (both practically and theoretically). ❖ And forests are “computationally irreducible” – there are no shortcuts to predicting future states – you have to track the entire journey, with all of its twists and turns, from where ever you are now

Currents that keep me on watch… ▪ Nature of the presettlement forests and Native American impacts ▪ Legacies of European agriculture and forestry ▪ Legacies of 20 th century fire suppression ▪ The fall and rise of white-tailed deer ▪ A sea-change in logging ▪ Air pollution ▪ New passengers – invasive species ▪ Even more unwanted passengers – pests and pathogens ▪ Climate change

Home port: The ebb and flow of presettlement forests Hudson Highlands Adirondack Mountains Whitehead and Jackson (1990) Maenza-Gmelch (1997)

Native American impacts ❖ Extinction of Pleistocene ❖ Presettlement fire megafauna (?) regimes (?) ❖ Native American agriculture (?)

Legacies of European agriculture 1700 1800 Have the forests truly “recovered”? ? 1900 1850

A branch in the river… ❖ Succession on former ❖ Succession on cultivated fields abandoned pastures ▪ Fairly rapid colonization by trees ▪ Long period of oldfield with intermediate-sized wind- succession dominated by little dispersed seeds bluestem grass (red maple, white pine, white ash) ▪ Oaks present throughout ▪ Oaks largely absent except along because scattered oaks in the edges (from seed source in pastures served as a local seed hedgerows) source

Legacies of early forestry Harvest methods may have been low-tech, but forests in the uplands of the northeast were thoroughly exploited…. But with far fewer long-term legacies than Hemlock bark for the tanning industry from agriculture…

Legacies of fire suppression ❖ Is fire suppression responsible for a reduction in the regional dominance of oak species in many parts of the eastern US? ❖ Has the reduction in the abundance of oaks over the past 100 years fundamentally altered the flammability of these forests? 80 70 Presettlement Forests Current Forests 60 Percent 50 40 30 20 10 Composition of the Cary Institute Woods 0 (witness trees in 1750 vs. current Oaks Hickories Hemlock Pine Maples composition) Tree Species

The fall and rise of the white-tailed deer Presettlement density: ~ 10 / sq. mile Current density (northern): ~ 20-40 / sq. mile Current density (southern): > 100 / sq. mile White-tailed deer ( Odocoileus virginanus ) Deer exclosure in the Hudson Valley

Impacts on tree regeneration • 55% of northeastern forests have seedling and sapling densities in the lowest density classes • This is close to regeneration failure by any standard • Regeneration failure is even more pronounced in recently logged forests • Adequate tree regeneration is highest in far north where severe winters and heavy forest cover limit deer densities… Densities of seedlings and saplings in 33,310 FIA plots

Unwanted passengers: Invasive plants The canopy is a zero-sum game, but the understory is not… When does invasion result in displacement of natives? Garlic mustard Toxic to endomycorrhizae Tree of heaven Allelopathic, and incredibly rapid growth

Air Pollution... ❖ Acid deposition and soil calcium depletion ❖ Ozone exposure ❖ CO 2 fertilization ❖ Nitrogen deposition Effect of nitrogen deposition on forest productivity in the northeastern US At the regional average deposition (~ 7 kg/ha/yr), productivity is enhanced ~ 40% over pre-industrial levels Thomas, R. Q., C. D. Canham, K. C. Weathers, and C. L. Goodale. 2010. Increased tree carbon 19 storage in response to nitrogen deposition in the US. Nature Geoscience 3:13-17.

A sea change in logging ❖ Logging accounts for 60% of all adult tree mortality in eastern forests* ❖ After many years when net growth far exceeded harvests, harvest rates now equal or exceed net growth in some areas (e.g. Maine) ❖ this is unsustainable by any definition *For the region from Kentucky and Virginia north to Wisconsin and Maine Canham et al. (2013), Regional variation in forest harvest regimes in the northeastern United States. Ecological Applications 23:515-522 .

Public perception: clearcutting is still the dominant forestry Frequency distribution of the intensity of harvests in different parts of the 9 northeastern states ❖ Reality: clearcutting is uncommon except in certain regions and forest types (i.e. spruce/fir forests and increasingly in beech forests).

Implications of selective logging regimes… ❖ Partial harvesting favors succession towards forests dominated by shade tolerant tree species: ▪ Beech and sugar maple ▪ Eastern hemlock, red spruce, and balsam fir ❖ Regeneration by oaks is still problematic ▪ They need more light ▪ Problems with deer browsing ❖ Emergence of carbon offset markets ▪ Low-grade wood can be worth 2 to 5 times more to a landowner if left in the woods for carbon sequestration ▪ We need a new forestry that embraces the challenge of balancing carbon sequestration with extraction of forest products

Truly destructive passengers: Introduced pests and pathogens ❖ Arguably the most pervasive human impacts on eastern US forests over the past century have been from the introduction of new pests and pathogens… ▪ Chestnut blight ▪ Dutch elm disease ▪ Beech bark disease ▪ Gypsy moth ▪ Hemlock wooly adelgid ▪ Emerald ash borer ▪ Asian longhorned beetle ▪ …? Heavily diseased and resistant beech trees

New York is ground zero for exotic pests and pathogens Number of non-native forest pests per county in the US in 2012. ( Source: Liebhold et al. 2013)

The tree-SMART Trade Initiative (Gary Lovett, Cary Institute)