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Protecting Maryland’s Green Infrastructure:

The Case for Aggressive Public Policies

Draft submitted

February 2002

Maryland Department of Natural Resources

Chesapeake and Coastal Watershed Service

Parris N. Glendening, Governor

Kathleen Kennedy Townsend, Lt. Governor

j. Charles Fox, Secretary DNR

karen m. white, deputy secretary

 

Maryland Department of Natural Resources

580 Taylor Ave., Annapolis, MD 21401

www.dnr.state.md.us

Toll Free in Maryland: 1-877-620-8DNR ext. 8710 or 410-260-8710

Copyright 2002

 The facilities and services of the Maryland Department of Natural Resources are available to all without regard to race, color, religion, sex, sexual orientation, age, national origin, or physical or mental disability.

 
Executive Summary

Maryland is rich in natural resources.  Recognizing this, leaders and citizens have developed programs and policies that promote conservation, preservation and stewardship.  The commitment to preserve and restore water, land, and wildlife resources has been demonstrated through cooperative approaches like the Chesapeake Bay Agreement, the Coastal Bays Management Plan, and tributary strategies, along with successful implementation programs such as the Maryland Agricultural Land Preservation fund, Program Open Space, Rural Legacy, and GreenPrint.   These nationally renowned programs have served as the backbone to many Smart Growth efforts throughout the state.

While much attention has been focused on the health of various resources, there is a growing awareness of the need to preserve ecosystem functions.  Preservation of ecosystem functions requires attention to the amount, configuration, and diversity of resources and, in particular, resource lands (forests and wetlands).  The ecological and economic benefits of preserving sufficient lands to support ecosystem services are critical to the long-term health of waterways, wildlife, and humans.  

The many ways that ecosystem services touch the lives of Maryland residents are extensive.  In fact, they play a significant role in the life of all aquatic, amphibious, and land species.  Basic life support functions such as breathing and drinking are dependent on ecosystem functions.  Protection from hazards (floods, disease) and maintaining a hospitable climate, along with recycling of nutrients, and provision of soil, pollination, and water for crops are all ecosystem services that are critical to survival.

This paper was prepared to stimulate thinking on the many ways humans depend on ecosystem services, what it costs to replace lost ecosystem services, and how conserving land today can help ensure a healthy and prosperous way of life for current and future residents.  The goal is to develop greater support for strong, consistent public polices that ensure the continuation of land conservation programs, in spite of the many demands on public funds.  There is perhaps no greater long-term cost to Marylanders than destroying natural lands needed for provision of multi-beneficial ecosystem services.  Although many factors are associated with rising illness and degradation of resources, protection of key ecosystem lands will have a positive impact on overall conditions, and loss of these lands will likely exacerbate problems.

To achieve proper protection for Maryland’s ecosystem services, public policies must be designed that acknowledge and aggressively preserve lands that sustain these natural ecosystem functions, and government budgets must reflect the importance of preserving these lands for the health and well-being of current and future generations.

Protecting Maryland’s Green Infrastructure:

The Case for Aggressive Public Polices

February 2002

This paper is a compilation of facts and information on how protection of Maryland’s green infrastructure (and supporting natural resource lands of local significance) affects the economy, quality of life and ecosystem functions throughout the state.  The goal is to raise the awareness of citizens and leaders of the inter-relatedness of ecological systems and the kinds and magnitude of costs associated with altering these systems.  In some examples, the scientific or statistical analysis needed to isolate and determine the extent of the relationships and correlations mentioned has not been conducted.  However, the environmental impacts discussed are widely accepted as major factors in ecological decline and can logically be included in the overall cost to address and repair these associated impacts. 

 Understanding What’s at Risk

When wetlands and forest lands rich in natural resources, plant, and wildlife habitat are developed, there are costs incurred that are typically not accounted for in the marketplace.  These hidden costs are in the form of lost or severely impaired ecosystem services.  These services, such as cleansing the air and filtering water, are fundamental needs for humans and other species, but in the past, they have been so plentiful and resilient, that they have been largely taken for granted.  In the face of tremendous rises in both population and land use rates, many now realize that these natural or ecosystem services must be afforded greater consideration.  The breakdown in ecosystem functions is causing damages that are difficult and costly to repair as well as taking a toll on the health of plant, animal, and human populations.

In Maryland, the remaining important, high-functioning ecological lands have been identified as the statewide green infrastructure.  This system of lands is comprised of more than two million acres, of which 26% is currently protected by public ownership or under easements.  The vast majority, 74%, is in private ownership.  There are additional natural resource lands of local significance that supplement the statewide green infrastructure and also provide ecological benefits. 

Despite efforts to direct growth and cluster development, significant portions of Maryland’s remaining green infrastructure will be vulnerable to development pressures in the next two decades.  Some fast-growing areas of Maryland, such as Howard County, will reach build-out within the next 20 years, even with the utilization of increased densities and redevelopment.   Approaching this threshold has touched off a sense of urgency among many land use planners and conservationists, and many are starting to see public land acquisition as the primary and most effective Smart Growth tool available.

When natural lands are developed, it is not just the forests and wetlands that disappear.  Valuable ecosystem functions that shared interdependency with the natural landscape are at best compromised, and at worst destroyed, due to the altered land use.  Technological and structural solutions are often employed to offset these changes, but these fixes rarely duplicate the quality of the naturally occurring ecosystem services and they are typically costly to create and maintain.  Storm water management facilities, water treatment plants, dams, and bulkheads are examples of some of the man-made structures designed to address problems associated with the degradation of ecosystem services.  Health alerts for drinking water, water contact sports, and air quality are other, non-structural responses. These expensive remedies and alarming warnings could be minimized or avoided in many cases by preserving the green infrastructure that supports natural systems. 

The varied landscapes in Maryland are not all equally sensitive to impacts from urban and agricultural land use activities.  Impacts to the landscape in the form of stream channel and land surface erosion, groundwater contamination, nutrient flux, and habitat degradation are partly dependent on the physiography, location, and land use history of the watershed.  Through intelligent land use planning and conservation of Maryland’s green infrastructure cumulative impacts at the local and regional level can be minimized.

 As land acquisition costs continue to rise, protecting the green infrastructure is a good investment now and for the future, providing continuing annual benefits.  Conversely, reductions in green infrastructure often trigger a series of on-going costs to the public and achieve a relatively short-term economic gain.  While development of a specific tract of land may appear to have only a local impact, ecologically, it may have system-wide effects that impact not only the current population, but future generations as well.

 Following are some specific examples of how loss of green infrastructure lands can degrade ecosystem services in Maryland, along with some of the costs associated with this decline in natural functions.

Air Quality

Clean Air

Air quality affects the health of everyone and is a major factor in illnesses ranging from cardiovascular disease to cancer and respiratory ailments.   The average American breathes 3,400 gallons of air each day. 1

Air pollution is a major concern in Maryland and maintaining forested green infrastructure lands helps provide a natural means of combating this pollution. Cleaning the air is a basic function of trees.  They absorb carbon dioxide and release oxygen. They also absorb sulfur dioxide and nitrogen oxide, two major components of acid rain.   In addition they can trap particles in the air and ozone that can be harmful to humans.  Air purification functions of forests are particularly important in urban environments where air pollution tends to be greater.  Trees also help to regulate climate and rainfall by providing shade and recycling water.

According to the State of the Air 2001 report issued by the American Lung Association, 10 Maryland counties and Baltimore City received an air quality grade of “F.”  This is of critical concern to those with respiratory problems.  In the U.S., respiratory illnesses such as asthma are on the rise.  Maryland, in particular Baltimore City, has one of the highest asthma rates in the country.   Nationally, asthma accounts for an estimated three million lost workdays annually, and the annual direct health care cost of asthma is estimated at $8.1 billion. 2

Carbon Sequestration

Forests help remove large amounts of carbon dioxide (CO2) from the air.  Burning of fossil fuels (coal, oil, and natural gas) produces large amounts of carbon dioxide, one of the greenhouse gases.  Greenhouse gases trap the heat of the sun, and as these gases build up, temperature rises.

During photosynthesis, trees absorb (or sequester) CO2 and convert it into oxygen; carbon is also stored in the body of the tree, in the soil surrounding its roots, and in debris that falls to the ground.  While increasing forests and preserving natural lands help to reduce and maintain carbon levels, developing these lands produces the opposite effect and increases CO2 levels by releasing previously stored carbon into the atmosphere.

There is growing interest in the monetary value of forests for carbon sequestration.  Internationally, industries and governments have a growing concern about rising levels of greenhouse gases, and there are initiatives to substantially reduce or mitigate emissions.  The World Bank Prototype Carbon Fund, created to fund projects that reduce emissions, currently seeks to trade carbon sequestration credits at $20 per ton of carbon.  It is estimated that Maryland’s 2.9 million acres of forests sequester from 1.8 to 4.1 million metric tons of carbon per year. 2  Using the World Bank’s figure, Maryland’s forests have the ability to store from $23 million to $84 million worth of carbon on an annual basis.3

Human Health Impacts

Drinking Water

In Maryland, surface drinking water is generally impounded in reservoirs or is withdrawn from certain streams.  The forests that make up green infrastructure lands help protect these water bodies by filtering nutrients and other contaminants from runoff.  While natural lands absorb and filter water, developed land and highly altered landscapes typically add pollutants and sediment.  In Maryland, like the rest of the United States, the quality of drinking water is relatively high.  In spite of high standards and government oversight, each year almost a million Americans still become sick as a result of drinking contaminated water, and many people die. 4

In Maryland, excess nutrients are a key water quality concern, both for drinking water and for stream health and aquatic life.  A recent study by DNR’s Monitoring and Non-tidal Assessment Division found that about 57% of the state’s non-tidal stream miles have unnaturally elevated nutrient concentrations, and these concentrations are generally higher in watersheds with more agricultural land use.  The study reports that some sites in the Middle Potomac and in the Nanticoke/Wicomico, Chester, and Choptank River watersheds with greater than 50% agricultural land use have measured nitrate concentrations as high as 24 mg/L. 5   Nitrate levels greater than 10 mg/L surpass the human health standard for drinking water.  Nitrate levels are also a concern for groundwater sources.  Because of increased nitrate levels, some community water systems have had to switch to deeper aquifers, and others, where deeper aquifers were not an option, have had to install additional treatment.

Spread of Disease

Adequate green infrastructure provides the necessary habitat for a variety of plants and animals, and this natural biodiversity helps maintain balance and stability.  On the other hand, fragmentation of the landscape encourages the proliferation of certain edge species that thrive in disturbed habitat.  As their numbers increase, so do the incidents of human contact and transmission of disease. 

Lyme disease is one such disease, and cases have risen significantly in Maryland over the last two decades.  Reports from the Maryland Department of Health and Mental Hygiene (DHMH) show an increase statewide from 289 cases during the period 1980-1989 to 4,067 during the period 1990-1999.  The metropolitan counties, where the land is highly fragmented and deer populations have escalated, show the greatest number of incidents.  Allegany County and Garrett County, which have the most acres of forested green infrastructure, reported the fewest cases of Lyme disease (6 and 3 respectively) for the latter period and none during the 1980s. 6

Cardiovascular Disease (CVD) and Obesity

Numerous reports point to a lack of physical activity as a key factor in CVD and the increasing weight of Americans. Having convenient, safe, local access for walking and outdoor recreation can help encourage people to be more active, and small amounts of regular activity contribute substantially to health.

CVD was the leading cause of death in Maryland in 1999 and led to almost $900 million in hospital expenses.  Obesity is increasing in Maryland and is the primary risk factor for cardiovascular disease as well as some cancers and arthritis. 7  According to a report on Obesity and Overweight in Maryland by DHMH, the rate of obesity in Maryland increased by 75.8% between 1991 and 1998, with 20.5% of adults falling into this category in 1998.  The report further states that in 1994, approximately $2.5 billion was spent in Maryland on direct (health care) and indirect (lost productivity) costs associated with cardiovascular disease alone, and that nationally, the health care cost attributable to obesity was $99.2 billion, or 10% of total national health care costs.

Keeping Pace with Development

Growth and Land Use

The 2000 Chesapeake Bay Agreement calls for partners to permanently protect 20 percent of the land area in the watershed from development by 2010.   To meet this goal and to ensure adequate protection of key components of the remaining green infrastructure, Maryland must continue to be aggressive in the land conservation arena.

In pre-settlement days, Maryland and other east coast states were entirely forested.  Agriculture and residential/commercial development have since replaced much of these treed areas.  In 1999, American Forests found that average tree cover in the Chesapeake Bay watershed declined from 51% to 39% between 1973 and 1997.  As of 1997, areas with little tree cover made up over 50 percent of the area.8   The Maryland Department of Planning (MDP) has projected forest cover will decrease another 9 percent by 2020 from the 1997 levels and that urban land use will increase by more than 25 percent for the same time period.   It is difficult to predict the toll this increased development will take on already stressed ecosystems, but there will clearly be a serious impact.  Efforts to direct and control growth offer some consolation, but the surest way to preserve ecosystem services is through targeted conservation of the green infrastructure.  With the additional funding provided in 2000 and 2001 for Rural Legacy and GreenPrint, Maryland’s rate of land conservation is, for the first time, keeping pace with the rate of development.

Public Support for Land Preservation

An analysis of the 15-year trend in public attitudes toward environmental protection and economic growth found that a majority of Americans (always over 60 percent) value the environment over the economy.9   This seems to hold true in Maryland.

A 1995 survey of Maryland residents shows that citizens are concerned about loss of natural lands and that they support public land conservation programs: 10

Cost-Benefit Analyses

Preserving green infrastructure can help provide a solid tax base because these lands require significantly less in services from the local government.  A cost-benefit analysis of development versus land preservation for a specific area tends to show a net loss over time for developed lands.  In particular, residential development consistently costs more in required public services than it generates in tax dollars.  Numerous studies have shown that natural lands are not a drain on the local tax base, and in addition provide ecological services that prevent or reduce public costs that might othrewise be incurred (e.g. water treatment, stream restoration, flood damage).

 

Watershed Services: Water Quantity and Quality

Forests recharge drinking water supply aquifers and buffer the impacts of development on streams and aquatic life.  The primary and most widespread source of nutrients in Maryland streams is runoff from farm fields and lawns. 11

Nutrient Reduction

Forests and wetlands help filter nutrients, sediments and other pollutants from runoff as well as remove nutrients from groundwater.  In developed or farmed areas where forest has largely been removed, forest buffers represent an important resource protection tool.  Buffers are particularly effective in reducing the nutrient loads produced in agricultural areas. 

According to scientists in DNR’s Watershed Management and Analysis Division, urban land contributes seven times as much nitrogen and over ten times as much phosphorus as forested land.  Enhanced storm water management can reduce urban loads from 14 lbs per acre to 9.6 lbs per acre, but even so, this is much higher than the contribution by forest lands (2 lbs per acre).  Reducing nitrogen loads to the Chesapeake Bay using forest buffers costs only $5 per pound, making this practice one of Maryland’s most affordable nutrient reduction practices.12

Groundwater Supply and Stream Flows

Forested watersheds capture, store and provide for infiltration of water, thus contributing to the quantity of water available and the seasonal flow of water in streams.  The rate of infiltration depends on a number of factors, including land use, geology, soils, and precipitation.   Rain that falls in developed areas does not have the opportunity to follow the normal recycling process.  The U.S. Department of Agriculture Natural Resources Conservation Services (NRCS) reports that water runoff on developed land is 10 times faster than on natural land.  NRCS also states that the management of precipitation is a major factor in whether or not there is sufficient quantity and quality of potable water.13

Clean water from forest ecosystems is important to all Marylanders. Almost two million people get their water from the Baltimore City reservoirs.  These surface waters are surrounded and protected by 17,580 acres of forest.  Most municipalities outside of the metropolitan areas depend on ground water sources.  In addition, MDE reports that approximately half of all stream flow in Maryland originates as ground water.  Forested watersheds are by far the best land use for recharging ground water supplies.  In addition to providing absorption that supplies ground water sources and regulates stream flows, forests and other plant life help generate rainfall.  Trees absorb water from the soil and release it into the atmosphere, and this water is eventually returned as precipitation.   A large tree can put 10 gallons of water a day back into the water cycle.  Scientific studies of desertification have shown that vegetation is a controlling factor in the exchange of water and energy between the land and the atmosphere and that large-scale deforestation dries up an area’s climate. 14

According to articles published by U.S. Water News Online, over the last six months, precipitation in Maryland and other mid-Atlantic states is down a third or more.  The autumn of 2001 was reportedly the third driest in the region since 1871, with 18 Maryland counties under a drought watch.  As of January 2002, Baltimore’s reservoirs are at the lowest point on record, and the City has had to start pumping 50 million gallons of water a day from the Susquehanna River to supplement water supplies.  The Susquehanna itself is running at only 36% of its normal flow.  Additionally, Maryland has put the Monocacy River off-limits, drastically reducing the available water supply for Frederick, one of the largest and fastest growing cities in Maryland. 15

In addition to drinking water supplies, these same ecosystem services (regulating flow, reducing erosion, filtering sediment, moderating flooding, recharging groundwater, and stabilizing stream banks) also help with the generation of hydroelectric power.   Regulating the flow of streams helps hydroelectric plants predict and manage the water needed for power generation and can even reduce potential losses from spillovers that could result from highly fluctuating flows.16  Reducing erosion and filtering sediment are helpful by limiting the sediment loads at reservoirs, thus maintaining their capacity to hold water and avoiding dredging costs.17  Addressing the loss of retention capability due to sediment at dams along the Susquehanna is a component of the 2001 Chesapeake Bay Agreement.

Maryland has eight hydroelectric projects, with two stations (Conowingo and Deep Creek) providing the bulk of the state’s hydroelectric production.  It is estimated that these eight facilities provide almost $123 billion worth of hydroelectricity each year.18

Stream Restoration

Forests and forest buffers help stabilize streams by sheltering the stream banks and providing structure.  Trees and vegetation also reduce the impact of driving rains and slow runoff, helping to avoid scouring.  Once a stream is degraded, it is very expensive to restore.  According to DNR’s Watershed Restoration Division, and Baltimore County’s Department of Environmental Protection and Management, the unit cost for stream restoration, design, and construction is currently averaging $1.2 million per mile in urban and suburban watersheds.  DNR estimates that stream restoration in non-urban watersheds costs approximately $0.6 million per mile.

It is important to provide protection along the entire length of a stream, and especially important in the headwater areas.  Green infrastructure surrounding streams preserves natural stream channels, maintains moderate flow rates, and prevents erosion.

Stormwater

Green infrastructure lands can absorb stormwater and recycle it through the hydrologic system.  Developed land, however, has little ability for absorption and instead creates a large volume of fast moving (and more polluted) runoff.  Maintaining natural landscapes helps to minimize the amount of runoff generated during rainfall.

An analysis by American Forests estimated that the total storm water retention capacity of the remaining forest in the Baltimore-Washington region in 1977 was worth $4.68 billion, down from 1973’s value of $5.7 billion.  Tree loss in the Baltimore-Washington area from 1973 to 1997 reportedly resulted in a 19% increase in runoff, an estimated 540 million cubic feet of water.  The findings state that costs to build storm water facilities to intercept this runoff would cost $1.08 billion ($2/cubic foot of storage).19

Erosion and Sedimentation

Forest vegetation helps stabilize soils and prevent erosion.  The harmful impacts associated with erosion include reduced soil productivity, damaged roads and structures, increased sediment loads in streams and reservoirs, reduced water quality, and damage to fish populations. 

One cost of increased sediment loads comes in the form of repeated requests to public agencies for dredging of channels.  According to a November 21, 2001 press release by the office of Maryland Senator Paul Sarbanes, in fiscal year 2002, Congress appropriated over $50 million for various U.S. Army Corps of Engineers projects in Maryland.  Almost half of the funds ($23 million) are for the annual maintenance dredging of Baltimore shipping channels.  Another $2.8 million is for maintenance dredging of the Ocean City Harbor, Inlet and Sinepuxent Bay.  A large portion of the funds, $18.2 million, is for Phase II of the beneficial use of dredged material project at Poplar Island.  Over $2 million of the funding is for new dredging projects in Dorchester, Wicomico, Charles, and Anne Arundel counties.   While federal sources contribute greatly to dredging costs, state and local sources contribute significant amounts as well.  In fiscal year 2001, DNR’s Waterway Improvement Fund provided over $1.4 million to applicants for dredging projects.  At the local level, Baltimore County reports spending about $6 million on dredging projects since 1988 (through 2001).

Flooding

Green infrastructure can help reduce flood damage by regulating water flow and by preserving flood plains and wetlands that can absorb and store overflows.  Also, heavy vegetation and wetlands can slow the runoff of precipitation into waterways, permitting some of the runoff to seep into groundwater aquifers and reducing peak flows.  Maintaining natural flood plains prevents building and structural encroachments from impeding hazardous flood flows that, nationwide cause over $4 billion in damage in an average year.20   In 1999, a single flood event resulted in $6,408,180 in public assistance from the Maryland Emergency Management Administration for damage to government properties. 21

Maintaining naturally vegetated floodplains helps capture excess sediment and nutrients that are transported during peak flood flows. These can be absorbed and utilized by adjacent riparian plant communities.  This not only makes productive use of fertile soil material, but also prevents downstream deterioration of receiving waters that would otherwise suffer from increased levels of nutrients and sediments.

Wildlife Habitat and Biodiversity

Species Richness

Habitat loss and fragmentation have contributed greatly to a continuing loss of biodiversity in Maryland.  At least 180 plant and 35 animal species have been extirpated from Maryland, including elk, gray wolves, bison, and mountain lions.  Another 310 plant and 165 animal species are rare, threatened, or endangered.22  

Biological diversity is basic to the health of natural ecosystems and humans.  Biodiversity is estimated to produce about $1.9 billion in economic and environmental benefits in Maryland, including services such as crop and natural plant pollination, waste disposal, nitrogen fixation, biotechnology, biological pest control, soil formation, as well as seafood, wood products, and recreation.23  The $1.9 billion figure for biodiversity benefits is considered an incomplete estimate.

Habitat Fragmentation

Habitat fragmentation is considered by some to be the greatest threat to forest wildlife, and the main cause of species extinction. The scattered pattern of development in Maryland consumes an excessive amount of land and fragments the landscape, causing increasing damage to ecosystems.  While many species suffer due to these changes in habitat, other edge species (such as white-tailed deer) thrive, disrupting the natural balance and exacerbating a variety of problems.

According to DNR’s Wildlife Division, current deer populations throughout most of Maryland are at an all-time high.   Urban and suburban sections of the state have the most rapidly growing populations.  Escalating forest fragmentation created by urban sprawl enhances deer habitat.   Deer population growth is slowing in rural Maryland, and some areas have stable numbers of deer.  Contrary to the intuition of some, preserving forests can have a positive impact on controlling deer and other edge species.  Decreasing forest fragmentation by protecting, connecting, and restoring large contiguous blocks of forest lands may decrease rather than increase deer populations by reducing edge habitat.

According to a 1998 DNR press release on deer management, reported deer/vehicle collisions more than doubled during the period 1988-1996, rising from 1,500 reported incidents to 3,200.  These collisions result in property damage estimated at over $9.7 million annually.  In addition, the total estimated crop damage in Maryland due to deer damage was almost $38 million in 1996.24 

Pollution and Rising Temperatures

In a 1999 report on the state of Maryland’s freshwater streams issued by DNR’s Monitoring and Non-tidal Assessment Division, development is cited as a major factor in wildlife declines and extinctions. Loss of forest generally leads to a decline in water quality and often to increased water temperatures.  According to the DNR report, when watershed imperviousness exceeds 25%, only hardy, pollution-tolerant reptiles and amphibians can thrive.  Other species decline or become extinct.  Above 15% watershed imperviousness, stream health is never rated good (using a combined fish and benthic macro invertebrate Index of Biotic Integrity), and even very low levels of imperviousness can have detrimental effects.  When upstream impervious land cover is above 2%, pollution-sensitive brook trout are never found.  Maryland streams are now home to only about 300,000 brook trout, which once numbered more than three million.  Currently, very few Maryland streams are cool enough to support brook trout, particularly in the eastern half of the state.  Loss of forests is a key factor in the decrease in brook trout habitat.25

Strong Public Polices Needed

Maryland’s green infrastructure lands have enormous potential to provide essential services for many years to come. Without doubt, protecting as much of these remaining, high-functioning ecological lands as possible will result in greater environmental, economic, and human health benefits.  Targeted protection of the most vital components and restoration of critical gaps is essential to long-term improvements in the Chesapeake Bay, the Coastal Bays, and streams throughout Maryland. Continued development of these lands will result in higher costs to residents and a lower quality of life.

Adequate protection of ecosystems and the services they provide is gaining wider attention and becoming part of Smart Growth and conservation efforts.  The subject of ecological economics is moving into the foreground of planning and policy at both national and international levels.  As more people gain an understanding of the natural capital associated with forest and wetlands and the true costs of extensive and permanent changes to key segments of the landscape, the demand for preserving natural lands and ecosystems will likely increase.  As demonstrated by a West Virginia utility recently seeking to double the assessment of one of its land holdings by incorporating the value of the ecosystem services, it will not be long before market forces begin to recognize and capitalize on the commercial value of natural systems.  Conserving land now is an outstanding bargain and solid investment for the future.  To achieve proper protection for Maryland’s ecosystem services, public policies must be designed that acknowledge and aggressively preserve lands that sustain these natural ecosystem functions, and government budgets must reflect the importance of preserving these lands for the health and well-being of current and future residents.

References:

1.         American Lung Association. Best Practices and Programs Services. Trends in Air Quality. August 2001.

2.         American Lung Association Fact Sheet: Asthma in Adults.  December 2001. [on-line]; available from American Lung Association

3.         Dr. Christine Conn (Maryland Department of Natural Resources) to Teresa Moore (Maryland Department of Natural Resources).  Personal e-mail.  January 12, 2002.

4.         James Salzman, Barton H. Thompson, Jr., Gretchen C. Daily.  20 Stan.Envtl.L.J.309. 309 Protecting Ecosystem Services: Science, Economics, and Law. May 2001.

5.         903-R-99-023 Environmental Protection Agency.  Maryland Department of Natural Resources, Monitoring and Non-tidal Assessment Division.  From the Mountains to the Sea; The State of Maryland’s Freshwater Streams. 1999.

6.         Maryland Department of Health and Mental Hygiene.  Reported Cases of Lyme Disease in Maryland, By County and Year, 1980-1989 and 1990-1999. [on-line]; available from DHMH

7.         Maryland Department of Health and Mental Hygiene, Community and Public Healthy Administration Division of Cardiovascular Health and Nutrition.  Obesity and Overweight in Maryland.  November 1999.

8.         American Forests.  Regional Ecosystem Analysis Chesapeake Bay Region and the Baltimore-Washington Corridor.  Calculating the Value of Nature.  March 1999.

9.         H. Ken Cordell and Christine Overdevest, Footprints on the Land: An Assessment of Demographic Trends and the Future of Natural Lands in the United  States (Sagamore Publishing, 2001), 9.

10.       Maryland Greenways Commission.  Attitude Survey of Maryland Residents Regarding Greenways and Open Space.  April 1995.

11.       903-R-99-023 Environmental Protection Agency.  Maryland Department of Natural Resources, Monitoring and Non-tidal Assessment Division. From the Mountains to the Sea; The State of Maryland’s Freshwater Streams. 1999.

12.       Helen Stewart (Maryland Department of Natural Resources) to Teresa Moore (Maryland Department of Natural Resources), January 11, 2002, “Forest Value Research,” personal e-mail.

13.       U.S. Department of Agriculture, Natural Resources Conservation Service, National Water and Climate Center.  Agriculture Information Bulletin No. 326.  Conservation and the Water Cycle. [on-line]:  Content revised for the Internet March 6, 2001.

14.       Alexander L. Alusa. Scientific Linkages and Complementaries between the Conventions on Climate Change, Biological Diversity, Desertification and the Forest Principles.  March 1997. Atmosphere Unit United Nations Environment Program. [on-line]

15.       ”Drought Strikes Hard from Maryland to Maine; Rivers Run Low.” February 2002.  Available from U.S. Water News Online [on-line]

16.       Maryland Department of Natural Resources, Power Plant Research Program, Draft Document, An Assessment of the Economic Value of Hydroelectric Power Generation in Maryland and the Potential Impacts of Growth-Induced Changes in Forest Cover.  February 2002.  Provided via email from Bill Hodges to Teresa Moore.

17.       Ibid.

18.       Ibid.

19.       American Forests.  Regional Ecosystem Analysis Chesapeake Bay Region and the Baltimore-Washington Corridor.  Calculating the Value of Nature.  March 1999.

20.       James Salzman, Barton H. Thompson, Jr., Gretchen C. Daily.  20 Stan.Envtl.L.J.309. 309 ProtectingEcosystem Services: Science, Economics, and Law. May 2001.

21.       Bud Howard (Maryland Emergency Management Agency) to Teresa Moore (Maryland Department of Natural Resources).  Phone conversation and voice mail.  February 2002.

22.       E. Williams (ed.) Mountains to Marshes: The Nature Conservancy Preserves in Maryland.  The Nature Conservancy, Maryland Chapter. 1991.

23.       David Pimentel.  Cornell University, College of Agriculture and Life Sciences.  Benefits of Biological Diversity in the State of Maryland.  August 1998.

24.       Maryland Department of Natural Resources.  Press Release.  DNR Releases Maryland’s First Statewide Deer Management Plan. March 6, 1998 [on-line]:  

25.       903-R-99-023 Environmental Protection Agency.  Maryland Department of Natural Resources, Monitoring and Non-tidal Assessment Division. From the Mountains to the Sea; The State of Maryland’s Freshwater Streams. 1999.

26.       Gretchen C. Daily, Susan Alexander, Paul R. Ehrlich, Larry Goulder, Jane Lubchenco, Pamela A. Matson, Harold A. Mooney, Sandra Postel, Stephen H. Schneider, David Tilman, George M. Woodwell.  Ecosystem Services: Benefits Supplied to Human Societies by Natural Ecosystems. Ecological Society of America. [online]: 

27.       Ibid.

28.       Ibid.

29.       Department of Health and Mental Hygiene.  Division of cardiovascular Health and Nutrition Maryland Cardiovascular Disease Surveillance.  Statistics for Cardiovascular Disease.2001. [online]: