Pennsylvania’s Forests How They are Changing and Why We Should Care

Pennsylvania’s Forests How They are Changing and Why We Should Care

Will Price Eric Sprague January 2012

This report was prepared with financial support, information, and guidance provided by: Pennsylvania Department of Natural Resources Pennsylvania State University The Richard King Mellon Foundation The Nature Conservancy With special thanks to organizations and individuals who helped with information and analyses, especially: US Forest Service, Forest Inventory and Analysis Program Western Pennsylvania Conservancy

© 2012 Pinchot Institute for Conservation

Contents Introduction ............................................................................2 Section One: The Health of the Forest ....................................3 Forests of Yesterday and Today ..........................................4 Threats to Pennsylvania’s Forests ......................................8 Section Two: Wealth in the Forest..........................................15 Water ..............................................................................15 Wildlife ..........................................................................19 Wood ..............................................................................26 Climate and Energy ........................................................30 Section Three: What are We Doing and What Can We Do?......34 References ............................................................................40

Pennsylvania’s Forests

page 1

Introduction Pennsylvania remains one of the most forested states in the nation. It includes some of the most intact and bountiful hardwood forest lands in the temperate world. This was not always the case. As the early seat of agriculture for a young United States, Pennsylvania was dominated by farms until the early 1900s. Over the last century, Pennsylvania has regained much of its historic forest land, reaching approximately 17 million acres during the last two decades. This is the largest amount of forest to stand in Pennsylvania since it became a state.

Many organizations compile information and data on the value, trends, and threats to the condition and sustainability of forests in Pennsylvania. This report brings together information to offer a complete picture of what we know, what we must learn, and how we must act to conserve the health of forests and sustain the many forms of wealth they provide—the wealth in biological diversity and other very real forms of wealth, like drinking water, timber, and days spent with family in the woods.

A complex, dynamic community of plants, animals, and organisms lives within the forest. Healthy forests exist in many forms—from small re-growing saplings to old stands of gnarly behemoths.

This report contains data and information compiled by many organizations, data that represents a snapshot in time, and earnest effort by the Pinchot Institute to interpret what this data means.

Forests provide invaluable services, like clean water and air, wood for building and heating homes, and places for recreation and spiritual renewal. Pennsylvania’s forests were foundational to the growth of the state. They continue to support a significant part of the economy and enrich the lives of its residents.

We hope this report is both a resource and catalyst for Pennsylvanians —spurring action among government agencies, environmental organizations, and other groups that recognize forest conservation as a key strategy for improving the region’s environment, economy, and quality of life.

Despite these benefits, we are slowly losing and carving up Pennsylvania’s forests. For the first time in a century, the forest lost to clearing is not being replaced with new forest growth. We will never fully inventory and understand the historical diversity of Pennsylvania’s forests, nor the complex ways in which forests provide all the values on which we have come to rely. Therefore, the conservation of forests and sustaining these values into the future must be conservative. This is especially true as changes in climate and land use gain speed and intensity.

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Pennsylvania’s Forests

Section One: The Health of the Forest

A

healthy forest is a complex, dynamic community of plants, animals, and soil. Healthy forests contain multiple layers of vegetation—each providing important functions. It is this complexity of interdependent parts and diversity of structure that makes forestland capable of providing clean water and diverse habitats.

the forest floor. This layer is rich in organic material and a storehouse of nutrients. The litter on the forest floor also protects the underlying soil. Healthy forests often contain more living biomass in the soil below ground than what is found above it.

The top layer, referred to as the canopy, provides protection and shade for plants and animals, while also intercepting and slowing rain. Below the leafy roof is the understory—a layer of smaller trees and shrubs. Here, young trees begin to grow and eventually replace older ones as they die.

Healthy forests also contain a diversity of plant species, ages, and sizes that allow the ecosystem to bounce back from disturbances and provide a variety of habitats. A rich diversity of species provides insurance in case disease, drought, or other conditions severely deplete any one species. Healthy forests are also dynamic, constantly adapting to disturbances like wildfires, storms, and pests.

The next layer, the forest floor, includes the grasses, herbs, vines, mosses, and other plants that live close to the soil. Plants, microorganisms, worms, insects, fungi, bacteria, and other living things populate the rich layer of decaying leaves and wood that forms

A host of interacting factors including land management history, development pressure, pests, and diseases drive this variation. Section One describes how these conditions have combined to create the forests we see today.

Pennsylvania’s Forests

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Forests of Yesterday and Today

Pioneers then launched an aggressive sequence of burning and clearing until most of Pennsylvania’s forests yielded to farms.

Pennsylvania’s landscape currently includes nearly 17 million acres of forest.1 Its character changes from valley to valley, due to human influence as well as the hand of nature. These dual forces shaped Pennsylvania forests for thousands of years. Native Americans used fire to manage the land and the species of plant and animals on which they depended—in some areas burning twice a year.2 Early European travelers recorded grasslands and park-like forests in areas that without fire would have been dense with growth, probably with a different complement of trees. Beyond the areas manipulated by people, forests of hemlock and pine grew older than they have since.

Most of the species once found in the state remain, though in differing abundance. In 1928, the US Forest Service began to inventory the nation’s forests. Their inventory recognizes five main types of forest stands in Pennsylvania: northern hardwoods, oak/hickory, elm/ash/red maple, aspen/birch, and pines.4 The species of each type often occur together due to the natural character of a site and the designs of land managers. The pine and hemlock forests of the past now occupy only a fraction of the landscape.5

Historically, natural disturbances like fire, wind, and ice on the Allegheny plateau upset an estimated 0.15 percent of the landscape every year, leaving a mosaic of younger patches and older stands, a great portion of which included trees approaching 300 years old.3

In Pennsylvania today, northern hardwoods (maple, beech, yellow birch, and black cherry) and oak/hickory forests dominate the state— making up 86 percent of all forest land. Oak/hickory forests are also abundant in each region, and make up a greater portion of the forests in the southeast, south-central, and northeast regions.6 Other forest stands are less well-represented, as they may have been historically.

Forest Types in Pennsylvania by Region

(Source: US Forest Service, Forest Inventory and Analysis Program)

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Pennsylvania’s Forests

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1800

45

1970

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Retaining the same number of trees over a decade or two does not necessarily mean that those species will remain for the long-term. A younger forest has far more trees on each acre than older forest, and in many areas, red maple is growing; it now comprises 90 percent of forest regeneration statewide.8 Red maple resists diseases that affect competing species, survives in a wide range of settings, thrives in a fire suppressed environment, and is often left to grow when prized trees like black cherry and sugar maple are logged. For the past 25 years, red maple has been the most common species in the state, twice as abundant as black cherry.9,10 This was not always the case.

Historical Shift in Species in the Allegheny National Forest

Percent of All Species

Over the last fifteen years, the number of trees for most species remained unchanged, with some important exceptions. Flowering dogwood, a jewel of the forest, declined by 56 percent on private lands. Meanwhile, black birch and red maple proliferated. For most public and private lands, the numbers of black cherry, the most commercially valuable species, have been stable in all parts of the state except the south-central region. Here, numbers of black cherry on private land decreased by almost 30 percent, but increased four-fold on public land.7

Forest types are associated with unique plant and animal communities. Therefore, the type of forest present will greatly determine the biological components of the region. For example, oak/hickory forests include other species reflective of local conditions, including red maple, flowering dogwood, mountain laurel, blueberry, mayapple, and jack-in-the-pulpit.

Pennsylvania’s Forests

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Pennsylvania’s forests today are younger and more uniform.

Age Classes of Pennsylvania Forests

The biggest difference between current and past forests is their appearance. Forest stands considered “mature” today are younger and more uniform than those of the past. Most of the forest we see today began growing between 1900 and 1960 on abandoned farmland and heavily logged forest land. Their age and size are similar. The size of trees indicates forest age and successional stage, both important determinants of forest structure and the type of habitat available to wildlife. In general, as the average tree size increases, the maturing forest becomes more complex—accumulating features that play host to a greater variety of species. Different species of animals and plants occur in forest stands of all stages, from areas dominated by seedling to areas dominated by grand old trees. Disturbances such as fire, wind, ice, pests, disease, and harvesting create a mosaic of forest structures across the landscape. Pennsylvania forests are dominated by stands of trees described by the US Forest Service as “mature”—hardwood and softwood trees of at least eleven and nine inches respectively. Nearly 60 percent of all private forest is classified as mature. The relative proportion of forest area in each size class (seedling, young, or mature) is different on public (2:6:15) and private lands (2:5:9).11 Based on data on historical forest leveling disturbances such as fire, ice, and wind, this proportion was likely much different (approximately 2:8:70). Public lands have proportionally more mature forest stands than private lands. In the past 15 years, forests on both public and private lands have become older—but are nowhere near what they were historically. Mature forests have increased by 43 percent on public land, double the 15 percent increase on private land; and the land area in younger forests has decreased.12

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Proportion of Pennsylvania’s forests in different age classes (seedling, young or pole-sized, and mature or 12-inch diameter and larger).

Pennsylvania’s Forests

Most of Pennsylvania’s forests are in private hands. While large expanses of Pennsylvania forests are public—owned by towns, the state, and the federal government—the bulk of Pennsylvania’s forest lie in the hands of families, timber companies, and investment firms. These private parties own close to threequarters of Pennsylvania’s forests. Most public lands were acquired well after private interests had made their pick, with some acquired through purchases, donations, and foreclosures over the last century. Most of the public lands are in the hands of the Pennsylvania Bureau of Forestry, Pennsylvania Game Commission, and Bureau of State Parks, which oversee 2.1 million, 1.4 million, and 276,000 acres, respectively. The federal government oversees another 677,000 acres in Pennsylvania, much of it part of the Allegheny National Forest in the northern part of the state. These lands are bound to stay forests and continue to provide Pennsylvanians with many kinds of wealth.13 Private forest lands have always changed hands and uses, depending on the needs and values of the landowners.

Owners of Pennsylvania Forestland

Number of Forest Owners by Tract Size and Primary Reason for Family Ownership

People own forest land for a variety of reasons, but the reasons tend to be similar for tracts of the same size. Owners with less than 50 acres most often say they love the sense of ownership, and the solitude and natural connection forestland provides. Landowners with 50 to 500 acres principally value their lands as places to hunt. The north-central region of Pennsylvania has the largest tracts of privately owned forest, held by relatively few individual owners. These tracts are more contiguous and more likely to be managed for timber and game. In the more populous regions of the state, private forest tracts are smaller and more numerous—they are more parcelized.14

(Source: US Forest Service, National Woodland Owner Survey and Forest Inventory and Analysis Program)

Pennsylvania’s Forests

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Threats to Pennsylvania’s Forests Forest parcelization occurs when large tracts are subdivided and sold to multiple owners. Of the family-owned forests, which encompass almost 9 million acres, 90 percent are parcels of fewer than 50 acres.15 Throughout the state these parcels become smaller and more numerous over time, as families sell off portions to others or divide the land among relatives. The average family landowner keeps their land for 21 years.16 Landowners with larger parcels tend to keep their land longer than those with smaller parcels. The lands may remain mostly forested, but smaller tracts mean more decision-makers who generally have less invested in their lands. While there are important exceptions, the size of a forest holding is an important factor determining whether the owner feels “connected” enough to their land to keep it in good condition and resist pressures to sell it.17 A number of factors spur forest parcelization, including rising land values, the sale of company forest lands, and use of large lot zoning by local governments. Sometimes a self-reinforcing cycle emerges; as development brings new roads, sewers, and other infrastructure into forested areas, even more surrounding forests become accessible for development. As land values rise, forest owners consider subdivision and sales to offset increasing taxes.

Dozens of ownerships (blue) dissect the riparian forest corridor (red) increasing the difficulty of managing and conserving the forest. (Photo: Baltimore County, Maryland)

According to the National Woodland Owners Survey, parcelization will continue into the future. In the next five years, Pennsylvanians will sell or subdivide over 11 percent (1,035,000 acres) of the entire family forest land holdings. Over the same period, they will also pass to their heirs another 12 to 13 percent (approximately 1.1 million acres). All told, almost 25 percent of the family forest lands will change hands—and the children of current landowners will likely determine the ultimate fate of these forests.18

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Pennsylvania’s Forests

Pennsylvania is starting to lose forests. Parcelization breaks forests into smaller chunks, interrupting the movement of water, wildlife, hunters, and hikers through the forest. It also hastens forest loss. Pennsylvania’s population is growing more slowly than all but three other states, at a rate of just 3.4 percent. Yet over the over the past fifteen years, Pennsylvanians developed 47 percent more of the state and added more than 3,000 miles of road—the sixth fastest rate of land consumption in the country.19 Some of the deforestation occurred near urban centers that are actually losing population. Inefficient land use unnecessarily destroys forests and other natural resources, and it diminishes the ability of the remaining forests to provide services on which we depend. In the last 15 years, the area of forest declined in every part of Pennsylvania except the northwest. The largest losses occurred in the south-central and southeastern regions, where counties have rapidly grown. Over the same period, the northeastern part of the state lost 4 percent of its forest land. In all, more than 680,000 acres of forests disappeared, reversing Pennsylvania’s century-long trend in forest recovery.20 The amount of forest in the state is closely related to trends in agriculture and development. Nearly two-thirds of the forest was lost to residential and industrial development and the loss is likely permanent. Approximately 350,000 acres of farmland reverted to forest land through natural succession, and this will help to offset the loss.21 However, we surrender agricultural production for forests that will not provide all the wealth of well-established forests for quite some time.

Change in Forestland Area from 1989 to 2004 by Landowner and Region

(Gray bars project forest residential development through 2030) (Source: US Forest Service, FIA)

The stage for increased loss and parcelization is often set by changes in ownership for large tracts of forests. In the last fifteen years, Pennsylvania witnessed a transfer of nearly 400,000 acres from

Pennsylvania’s Forests

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traditional timber companies to a new type of owner: corporate owners from investment organizations, real estate investment trusts, and forest management companies.22 Corporate owners keep land as long as it is profitable. Since they typically do not own timber mills, they often look more favorably on development opportunities. The impact on future forest parcelization and loss has yet to be seen. Predictions for 2030 indicate that forest loss will continue. An estimated 6 percent or 761,000 acres of all privately owned forest will succumb to residential development—an area equivalent to 20 cities the size of Pittsburgh.23

Pests and diseases ravage Pennsylvania’s forests. “The caterpillar Tropaea luna, the magnificent green moth...feeds upon the oak, sycamore, and other trees...” — Etienne Leopold Trouvelot Greater interest and ability to collect, import, and propagate plants and animals from around the world sparked a nineteenth-century invasion of unfamiliar species. Beginning in the mid-1800s, plant nurseries and arboretums sprouted throughout the East to supply new and fascinating plants for gardens and collections. Species illsuited to North American weather and forests stayed put. Plants from Europe and temperate parts of Asia found a similar climate and simply grew and spread on their own. The horticulture industry shipped plants all over the country, spreading the species and whatever pests may be tagging along.

Illustration of Tropaea luna larvae, the luna moth, by Etienne Trouvelot (Source: American Midland Naturalist)

Early effort (ca. 1890) to eradicate gypsy moth in Massachusetts (Source: US Forest Service)

When Etienne Leopold Trouvelot reported in 1862 to the American Midland Naturalist on silkworms found near his home in Medford, Massachusetts, he could not imagine the devastation his hobby would cause. Among the many species of American silk producers, he could find none to launch a commercial silk industry. Whether for industry or simply to expand his collection, at some point in the 1860s he brought from Europe another silkworm, the gypsy moth. As soon as the moth left his backyard, he notified state officials, who began a futile battle that they surrendered in 1900. The gypsy moth escaped and spread over the next century to consume the forest. page 10

Pennsylvania’s Forests

Trouvelot’s relatively innocent introduction of an exotic species that came to invade the landscape recurred throughout the US over the next century and continues today. Naturally, species of fungi, plants, and animals spread on their own, sometimes finding new continents where rapid dispersal wreaks havoc on native ecosystems. However, the natural process is much slower, leaving time for populations to adapt to newcomers. The exotic invasive plants, animals, diseases, and pests that decimate or displace species of Pennsylvania’s forests are, for the most part, introduced and encouraged by people. Perhaps the most tragic of these stories involves the American chestnut. About the same time that the gypsy moth moved beyond Massachusetts, a fungus infecting American chestnuts started to spread from New York. Nurseries began importing Chinese and Japanese chestnut trees in 1876. A nurseryman in Flushing first noted a fungal blight infecting and killing native chestnuts in the area in 1904. In four years, the blight drew notice as far north as Poughkeepsie, New York, and central New Jersey. The next year, as an experiment to test whether the imported chestnuts were spreading harm, horticulturalists planted some chestnuts in plots near the Delaware Water Gap. Whether a result of this misguided experiment or another route, chestnut blight spread rapidly through Pennsylvania. At the time, chestnut was the dominant tree of Pennsylvania’s forests, composing 40 to 50 percent of the forest in some counties.24 An originally grand species, vital to wildlife and lumbering, chestnut quickly vanished. Today, forest inventories conducted by the US Forest Service can barely detect chestnuts on the landscape (an uncertain calculation of 0.04 percent of Pennsylvania trees), most stricken and only sprouting from stumps.25

Pennsylvania’s Forests

Historical Natural Range of the American Chestnut Encompassing 200 Million Acres of the Eastern United States

(Source: American Chestnut Foundation)

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Other pests are still at work too, inexorably moving across the state. Gypsy moths started out more than a century ago but remain a major and growing threat to Pennsylvania’s oaks. The moths prefer oaks, in many cases entirely defoliating trees. After repeated assaults, and when even the healthy trees succumb, more than half of the oaks in a grove of trees die. As gypsy moths move through a landscape heavy with oak—wandering from place to place—they can infest more than a quarter of the forest.

Global Distribution of Tsuga Species, including the Eastern and Western Hemlock

The small hemlock woolly adelgid now ravages the remaining eastern hemlock in Pennsylvania, moving across the land at an average rate of 15 miles a year. Once found in 20 percent of the forest, lumbering and land use change have reduced hemlocks to little more than 5 percent of the forest. However, hemlock is still an important species for wildlife that relies on hemlock stands as a food resource or winter cover. The spread of the adelgid highlights the danger, complexity, and seeming invincibility of insect pests. Recent genetic work shows that the adelgid came to the US from Honshu, Japan, on nursery stock imported to Richmond, Virginia, likely in the late 1940s. It does not kill fast growing spruces in the maritime forests of Japan—and a native western adelgid that likely came across the Bering Strait eons ago does not kill the hemlocks of the US West. However, within several seasons the adelgid began to kill hemlocks in Pennsylvania. At present, hemlocks in the western counties of Pennsylvania show no sign of infestation, but the adelgid still spreads.

Collection sites of scientists studying the origin of hemlock woolly adelgids are represented as white dots. The adelgid infecting hemlocks in Pennsylvania matched those collected in southern Honshu Japan.

(Source: Havill, Montgomery, Yu, Shiyake, & Cacchone 2006)

The list of pests and diseases that threaten Pennsylvania’s forests still grows. A bark disease spread by beetles now infects much of the beech in northeast trees and is spreading to the southwest. Trees with beech bark disease develop cankers and “scales,” typically dying before mature enough to produce the beechnuts that feed many mammals and birds. Emerald ash borer, a beautiful green beetle that girdles and tunnels through trees, started from Michigan in 2002

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Pennsylvania’s Forests

and has already been detected in seven Pennsylvania counties (first in Butler and Allegheny). The Asian long-horned beetle, which feeds on many hardwood species such as maple, birch, poplar, and sycamore, is right at Pennsylvania’s doorstep in New York and New Jersey.

Timeline of Infestation in Pennsylvania Counties for Hemlock Woolly Adelgid

In many areas, invasive plants are now permanent. Invasive trees, shrubs, vines, and grasses have become so common that some are now permanent components of Pennsylvania forests. Certainly new species will arrive in the state and change in abundance and distribution. Landscape changes wrought by human hands often lay the groundwork to favor one species or another. Perhaps most importantly, people have provided the transport for new species. This latter influence most enables plants to become invasive. When purposely put in the landscape, or tracked in on the bottom of shoes, alien species sometimes find environments without natural enemies to keep their numbers in check. Alternatively, they may come from another climate where fast growth trumps cold-hardiness. Whatever the reason, some new species thrive, displacing and sometimes smothering the native plants. In doing so, invasives alter the habitat on which native species rely. They can lower the quality of food and shelter options for wildlife, eliminate host plants of insects, and compete with plants for pollinators. Invasive plants are especially problematic for a forest reestablishing in a clearing. There are dozens of invasive trees, shrubs, vines, and grasses in Pennsylvania. Tree of Heaven (Ailanthus) is well-established in Pennsylvania and grows rapidly in a variety of conditions, forming dense stands that displace native trees. It actually produces chemicals that kill other plants or prevent them from growing nearby. Japanese stiltgrass, once seeded after a logging job, now blankets the ground in many forest clearings. Dense tangles of oriental bittersweet block out light, girdle plants, and topple trees with its immense weight.26

Pennsylvania’s Forests

Timeline of Infestation in Pennsylvania Counties for Beech Bark Scale

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A changing climate will alter Pennsylvania’s forests. Emissions from human activities, such as the use of fossil fuels and deforestation, are raising carbon dioxide concentrations and causing an increase in long-term atmospheric temperatures, precipitation, and other weather-related events such as hurricanes. Elevated carbon dioxide levels and a changing climate will undoubtedly alter the forests of Pennsylvania. Evidence mounts that certain parts of Pennsylvania will be wetter and battered by more storms and floods. All of Pennsylvania will likely be warmer with more days of growth and activity for plants and animals, earlier springs, and shorter winters. The heat of summer could escalate to drought for part of the summer. The net effect of these predicted changes on forests is still an educated guess.27 Climate models must not only consider changes in temperature and precipitation, but their impact on soils and ecosystems. Some animals can move, but many cannot. Most of Pennsylvania’s imperiled vertebrates (aside from birds) cannot traverse the landscape very quickly and often find a highway or river blocking their way. Birds that wait for a certain species of tree to show up in a northerly spot at the right time of spring or fall may have to wait centuries.

Current and Predicted Importance of Pennsylvania Tree Species -150% -100%

-50%

0%

50%

100%

150%

red maple (1) black cherry (16) sugar maple (4) white ash (11) American beech (19) northern red oak (9) chestnut oak (6) post oak (7) sweet birch (22) white oak (2) eastern hemlock (33) sassafras (15) yellow-poplar (13) black oak (3) flowering dogwood (5) eastern white pine (31) blackgum (10) American elm (27) black locust (29) eastern hophornbeam (28)

Despite the inability to make specific predictions, it is clear that higher temperatures and altered precipitation regimes could change forest composition and function and the benefits that forests provide to Pennsylvania residents. Tree species occupying cooler, moister habitats like sugar maple, black cherry, white ash, northern red oak, and American beech are more likely to be forced northward. Based on modeling by the US Forest Service, black cherry will decline by 75 percent of its relative abundance. Stands of maple/beech/birch forests will shift northward as oak/hickory forests take their place. In general, more southerly species move up the rankings of importance, species such as eastern red cedar (600 percent increase) and shortleaf pine (7,000 percent increase).28

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Rank order of importance for current Pennsylvania tree species (and future rank in one century) based on an average of existing climate models. Bar chart shows loss or gain in importance over the next century, as percentage. Importance is a calculation based on prevalence of tree species relative to others. (Calculations based on models developed by US Forest Service Northern Research Station.)

Pennsylvania’s Forests

Section Two: Wealth in the Forest Pennsylvania residents, whether in urban or rural communities, benefit from the wealth in the forest every day: water, wildlife, jobs, clean air, energy, etc. The continued provision of these benefits depends on past and current management, land use, pests and diseases, and many other forces of change. While forests have long been subject to change, today’s challenges are happening more quickly and are interacting in unknown ways.

Water Nationally, two-thirds of the water that fills streams and replenishes groundwater flows from forested lands.29 Forests normally provide higher quality water than other land uses. They also provide a more steady supply of water, gradually filtering and releasing clean water throughout the year. In watersheds dominated by agriculture or development, remaining forests help lessen the impacts of more intensive land use, giving cover to the ecological functions that maintain productive streams.

The Susquehanna River carving its way through central Pennsylvania. (Source: eospso.gsfc.nasa.gov)

Forests are also a large part of the Pennsylvania’s water management infrastructure. A recent survey of water suppliers conducted by the Trust for Public Land and the American Water Works Association showed that treatment costs for drinking water increase when the amount of forest land and wetlands decrease. The differences in water treatment costs across the country heavily depend on whether or not the source areas for drinking water are forested.30

Pennsylvania’s Forests

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Pennsylvania has three major drainage basins: the Ohio River, the Susquehanna River, and the Delaware River basins. Another two, the Genesee River and Lake Erie basins, are much smaller. The condition of the waters flowing through these basins reflects the condition of the forests and will likely mirror the trends in forest loss and parcelization. Presently, only 0.6 acres of forest support each person that depends on the Delaware River, and 84 percent of this forest is in private hands. The Susquehanna River and Ohio River basins in Pennsylvania offer 3.0 (76 percent private) and 3.7 (84 percent private) forested acres per person, respectively.31 In the next 30 years, the Delaware basin alone might lose more than 200,000 acres of private forests32, and through gaining millions more people, might approach 0.2 forested acres per person. The cost of managing stormwater and providing drinking water may become one of the region’s largest challenges.

Percent of Forest in Small Watersheds

>65%

Streamside or riparian forests are the “last line of defense” for Pennsylvania streams.

55–65%

45–55%

25–45%

70%

60–70%

40–60%

20–40%