Nicole Balloffet, Washington Office, State and Private Forestry;
Robert Deal, Pacific Northwest Research Station;
Sarah Hines, Northeastern Area State and Private Forestry and Northern Research Station;
Beth Larry, Washington Office Research and Development;
Nikola Smith, Pacific Northwest Region, National Forest System and State & Private Forestry
Climate change, coupled with other stressors, is affecting the ability of many landscapes to continue providing the quality and quantity of ecosystem services demanded by the public.
Ecosystem services are commonly defined as the benefits people obtain from nature. The Millennium Ecosystem Assessment, a United Nations report describing the condition and trends of the world's ecosystems, categorizes ecosystem services as:
Provisioning Services such as food, clean water, fuel, timber, and other goods;
Regulating Services such as climate, water, and disease regulation as well as pollination;
Supporting Services such as soil formation and nutrient cycling; and
Cultural Services such as educational, aesthetic, and cultural heritage values, recreation, and tourism.
Forests and grasslands provide a wide range of ecosystem services. In addition to providing food, fuel and fiber, forests clean the air, filter water supplies, control floods and erosion, sustain biodiversity and genetic resources, and provide opportunities for recreation, education, and cultural enrichment. Sequestering (or releasing) carbon is a form of climate regulation, which is another important ecosystem service provided by forests and grasslands; specifics of climate regulation depend upon ecosystem structure, composition, and management.
Ecosystem services may be local, regional, or global in scale. For example, the provision of clean water is most often a regional service, most accessible to those within a watershed's boundaries. Climate regulation can be local or global. By removing and releasing carbon dioxide and other gases, ecosystems regulate the global climate, but land-use change can affect local micro-climates by influencing variables such as temperature and precipitation.
In 2005, the Millennium Ecosystem Assessment found that large-scale ecosystem change had reached a tipping point, significantly impacting the ability of many of the world's ecosystems to provide critical ecosystem services to human society. Drivers of ecosystem change are an interrelated set of challenges, including land-use change and degradation, biodiversity loss, nutrient loading, invasive species, and climate change.
Climate change is a significant driver of ecosystem change and the loss of services, primarily because climate change is a global phenomenon with far-reaching impacts that is expected to become more severe in coming decades. Climate change will alter the world's forest and grassland ecosystems in ways that will affect their ability to deliver the critical ecosystem services that support human health and well-being (1). In anticipation of wide-scale ecosystem change and the potential loss or change in the supply or distribution of ecosystem services, land owners and managers can focus on strengthening forest and grassland resiliency and adaptive capacity so these landscapes might continue to provide life-supporting benefits into the future (2).
As climate change intensifies, scientific research has provided "established but incomplete evidence that changes being made in ecosystems [which may be partially driven by climate change] are increasing the likelihood of nonlinear changes in ecosystems (including accelerating, abrupt, and potentially irreversible changes)" (3). Recent research suggests that the majority of ecosystem services will be negatively impacted as temperature increases; while a 2°C (3.6° F) rise may benefit some ecosystem service values slightly, a 4.5° C (8.1°F) increase will be very disruptive to almost all ecosystem service values (4). As the climate regulation capacity of many ecosystems deteriorates and/or experiences abrupt and non-linear changes, plant and animal populations will experience negative impacts at local and regional scales. These impacts may include all of the climate change effects already predicted or chronicled - changes in the timing and distribution of water (e.g. droughts, floods, snowpack availability); increases in insects, invasive species, and disease; habitat and biodiversity loss; and species range shifts. In addition, ecosystem services degradation often leads to declines in human well-being. This is especially true in agrarian/rural communities and developing nations, where declines in ecosystem services can have a rapid, direct impact on incomes and standards of living, exacerbating poverty and increasing inequality (5, 6).
In many places, climate change impacts are coupled with other ecological drivers, such as land-use change, and scientific research is important in helping us to isolate variables and understand implications. For example, in 2009, the nation’s forests sequestered approximately 235 million tons of carbon, an amount equivalent to roughly 16% of US annual carbon dioxide emissions (or approximately 13% of US annual greenhouse gas emissions) (7). However, these figures are the result of many different drivers, only some of which are climate related: on one hand, many former agricultural lands are reverting back to forests, helping to increase overall sequestration; on the other hand, insect outbreaks, extreme weather and other forest health issues, exacerbated by climate change, compromise the sequestration rate and capacity of affected forests.
Crucial Questions / Options for Management
Options for stemming the degradation of ecosystem services in the United States and creating conditions to enhance or sustainably manage their use and production vary across the landscape and may partially depend on land ownership. An ecosystem services perspective may help land agencies frame management with a focus on ecological functions and processes and the public benefits that result. Using this approach may help managers protect and sustain the delivery of ecosystem services and create a resilient landscape in response to -- and in anticipation of -- climate change. Private landowners that restore or enhance ecosystem services may be able to benefit from new financing mechanisms, such as payment for ecosystem services (PES) incentive programs and emerging environmental markets.
Managing for change - an ecosystem services approach. An ecosystem services approach, one that considers all of the benefits that people receive from nature, is beginning to shape an alternative way of thinking about forest management in an era of change. The 2007-2012 Forest Service Strategic Plan states that "the National Forest System (NFS) delivers multiple ecosystem services and can serve as a natural laboratory for informing scientific knowledge and policy" (8). The proposed Forest Service Planning Rule includes enhancement of ecosystem services in the Agency’s management goals (9). In a 2010 address to the Society of American Foresters, Forest Service Chief Tom Tidwell articulated a shift in forest management that emphasizes an integrated approach to stewardship of ecosystem services and ecological processes:
"Where once we tended to compartmentalize, managing for a particular good or service-timber here, forage there, recreation over here, urban forest over there-today we tend to focus more on restoring a whole range of goods and services across entire landscapes. We do that by restoring the functions and processes characteristic of healthy, resilient forest ecosystems-ecosystems capable of delivering clean air and water, wildlife habitat, carbon sequestration, and all the other benefits that Americans want and need."
A few case study examples can help illustrate how land management is evolving to incorporate an ecosystem service approach. The Forest Service’s Rocky Mountain Region is partnering with Denver Water, a municipal water utility, to reforest areas damaged by wildfire in order to decrease sedimentation and erosion, which severely compromise water quality, and reduce the risk of future wildfire in watersheds critical to the city’s water supplies and infrastructure. The Forest Service and Denver Water are sharing an investment of $33 million over a 5-year period (2010-2015). Management treatments and reforestation activities will improve water quality, therefore providing benefits for both society (Denver Water’s customers) and fish and wildlife. Improvements in forest health will also make forests more resilient and adaptive to the impacts of a changing climate.
In the Forest Service’s Pacific Northwest Region, the Deschutes and Willamette National Forests are exploring how an ecosystem service approach can serve evolving forest management needs and priorities. Forest staff are experimenting with how ecosystem service outcomes can help frame proposed projects and articulate the rationale for management decision-making (10). While the Forest Service's reporting systems tend to focus on outputs (acres treated to reduce wildfire risk, etc.) , the agency and our partners are also interested in new ways of expressing holistic outcomes for ecosystem services. Emphasizing forest management from an ecosystem services perspective also has the potential to strengthen relationships with the public by expressing management objectives in terms of these beneficial outcomes. Collaboratively managing mutually-valued services can sustain resources over time (10, 11).
New markets and incentives. National Forests do not currently engage in emerging markets and market-based payments for ecosystem services, but these opportunities can potentially play a role in ecosystem restoration and protection on private and non-federal land. Markets provide a means for land owners to be financially compensated for specific voluntary restoration activities that improve ecosystem services; This includes management activities that generate ecosystem services - such as management that enhances carbon sequestration and or restoration activities that lead to improvements in water quality and watershed health, streams and wetlands, and fish and wildlife habitat. Those that pay for the provision of ecosystem services, in the form of tradable environmental credits, are most often entities that are mitigating their activities in order to comply with state and federal environmental regulations. Forest owners that increase carbon sequestration on their land, for example, may generate carbon "offsets" that can be sold to greenhouse gas emitters or to carbon-conscious consumers aiming to reduce their carbon footprint through a voluntary marketplace. Landowners that set aside and manage land for species habitat and protection can establish a "conservation bank" and sell endangered species or habitat credits to land developers and other entities that must comply with the Endangered Species Act. Organizations, municipalities, and individuals with an interest in improving the delivery of an ecosystem service might also willingly pay for conservation or restoration activities either for philanthropic or identity reasons or because they’ve found that investments in ecosystem protection are a more cost-effective alternative to building or improving traditional infrastructure designed to meet the same societal goals. Well-designed markets and market-based payments for ecosystem services can provide an economic incentive for private landowners to own and sustainably manage forestland and to be rewarded for providing critical, life supporting services for the benefit of society. (12, 13).