Climate Change Effects

Climate Change Effects Temperature & Precipitation Vegetation Sea Level Rise

Global sea level is projected to rise up to two feet by the end of the century. Much of downtown Damariscotta is already vulnerable to high water levels such as those anticipated during 100-year storms. Except for the area immediately along the waterfront and the large drainage in the southern part of the site, Round Top Farm's elevation will prevent widespread flooding from the river on the property. However, most of downtown and other low-lying areas along the river are likely to be inundated by increases in sea level with damaging effects for the community.

Climate change is anticipated to affect several factors on site, including temperature, hydrology, and vegetation. It will be critical to provide cool rest areas for visitor comfort, as well as implement measures to slow and infiltrate stormwater to reduce erosion, protect water quality, and retain water on site. CRCT should also plan for succession in site vegetation, particularly in vulnerable areas along water bodies, by planting and encouraging species appropriate for future climate conditions such that large gaps do not occur. As a result of changing temperature and precipitation Average temperatures across the Northeast have already risen an patterns, many tree species are predicted to shift their estimated 1.5 degrees Fahrenheit since 1970. Average temperatures in distributions. The Northern Institute of Applied Science Maine are projected to rise another five to ten degrees by the end of has partnered with various agencies to generate projecthe century depending on emissions scenarios, creating a climate sim- tions for major tree species in the Northeast based on ilar to the current Mid-Atlantic. This may result in increased incidence their ability to tolerate predicted future climate condiof heat stress and respiratory ailments such as asthma for many site tions and their ability to migrate rapidly enough to keep visitors. pace with these changes. Some species, such as northern red oak and red maple, are predicted to adapt well Winter precipitation is projected to increase, with a higher percentage and remain important components in the eastern Maine falling as rain instead of snow. Summer rainfall is expected to become woods. Other signature species such as eastern white more unpredictable, with more frequent and intense storms. As a pine and eastern hemlock, may decline. result, periods of drought may alternate with damaging storm events, increasing the likelihood of localized flooding and erosion and stress to These projections do not include additional pressures both infrastructure and vegetation. from pests and disease, whose effects are anticipated to become more severe with climate change. Of particular concern in Midcoast Maine are the hemlock woolly adelgid, emerald ash borer, browntail moth, and bark and leaf diseases affecting beech and pine species. Browntail moth infestations result in partial or whole defoliation of hardwood trees, particularly oak and apple, which can lead to tree mortality. Round Top Farm currently has many mature shade trees around the buildings on site, primarily northern red oak and some maples. These trees appear to be in generally good to fair condition despite past defoliation due to browntail moth. The most immediate danger to most of the individual trees is root compaction from the adjacent driveway. There are two particularly notable red oaks near the farmhouse that are believed to be the oldest specimens on site and are much loved for their distinctive size and growth patterns. While oaks are projected to fare well in this area in the future, Coastal Rivers will need to monitor for pest activity and may need to take specific measures to protect and extend the lifetime of the two oldest trees. Many of the trees currently growing along the riverfront and drainages are white pine and hemlock, many of which already appear to be in poor health. Coastal Rivers will need to plan for succession of these trees to maintain a vegetated buffer along these sensitive waterways, particularly as many are similar in age and likely to leave large gaps upon mortality.

Climate Change Projections for CLIMATE CHANGE PROJECTIONS FOR INDIVIDUAL TREE SPECIES

Individual Tree SpeciesEASTERN AND COASTAL MAINE (Eastern and Coastal Maine)

This region’s forests will be affected by a changing climate and other stressors during this century. A team of managers and researchers created an assessment that describes the vulnerability of forests in the region (Janowiak et al. 2018). This report includes information on observed and future climate trends, and also summarizes key vulnerabilities for forested natural communities. The Landscape Change Research Group recently updated the Climate Change Tree Atlas, and this handout summarizes that information. Full Tree Atlas results are available online at www.fs.fed.us/nrs/atlas/. Two climate scenarios are presented to “bracket” a range of possible futures. These future climate projections (2070 to 2099) provide information about how individual tree species may respond to a changing climate. Results for “low” and “high” emissions scenarios can be compared on the reverse side of this handout. The updated Tree Atlas presents additional information helpful to interpret tree species changes: • Suitable habitat - calculated based on 39 variables that explain where optimum conditions exist for a species, including soils, landforms, and climate variables. • Adaptability - based on life-history traits that might increase or decrease tolerance of expected changes, such as the ability to withstand different forms of disturbance. • Capability - a rating of the species’ ability to cope or persist with climate change in this region based on suitable habitat change (statistical modeling), adaptability (literature review and expert opinion), and abundance (FIA data). The capability rating is modified by abundance information; ratings are downgraded for rare species and upgraded for abundant species. • Migration Potential Model - when combined with habitat suitability, an estimate of a species’ colonization likelihood for new habitats. This rating can be helpful for assisted migration or focused management (see the table section: “New Habitat with Migration Potential”). Remember that models are just tools, and they’re not perfect. Model projections can’t account for all factors that influence future species success. If a species is rare or confined to a small area, model results may be less reliable. These factors, and others, could cause a particular species to perform better or worse than a model projects. Human choices will also continue to influence forest distribution, especially for tree species that are projected to increase. Planting programs may assist the movement of future-adapted species, but this will depend on management decisions. Despite these limits, models provide useful information about future expectations. It’s perhaps best to think of these projections as indicators of possibility and potential change. SOURCE: This handout summarizes the full model results for Eastern and Coastal Maine, available at www.fs.fed.us/nrs/atlas/combined/resources/summaries. More information on vulnerability and adaptation in the New England region can be found at www.forestadaptation. org/new-england. A full description of the models and variables are provided in Iverson et al. 2019 (www.nrs.fs.fed.us/pubs/57857 (www.nrs.fs.fed.us/pubs/58353). and www.nrs.fs.fed.us/pubs/59105) and Peters et al. 2019 www.forestadaptation.org

CLIMATE CHANGE CAPABILITY

POOR CAPABILITY CLIMATE CHANGE PROJECTIONS FOR INDIVIDUAL TREE SPECIES American mountain-ashEASTERN AND COASTAL MAINE Pitch pine Balsam poplar Red pine This region’s forests will be Black spruce Serviceberry Bur oakaffected by a changing climate Striped maple Jack pineand other stressors during this century. A team of managers and Tamarack (native) Mountain mapleresearchers created an assessment that describes the vulnerability White spruce of forests in the region ( Pin cherryJanowiak FAIR CAPABILITY et al. 2018). This report includes information on observed and Balsam firfuture climate trends, and also Northern white-cedar summarizes key vulnerabilities for forested natural communities. The Landscape Change Research Eastern hemlock Red spruce Gray birchGroup recently updated the Climate Change Tree Atlas, and this handout summarizes that information. Full Tree Atlas results are available online at GOOD CAPABILITYwww.fs.fed.us/nrs/atlas/. Two climate scenarios are presented to “bracket” American beecha range of possible futures. These future climate projections (2070 to 2099) provide information about how individual tree species may respond to a Northern red oak American elmchanging climate. Results for “low” and “high” emissions scenarios can be compared on the reverse side of this handout. Quaking aspen Bigtooth aspen Red maple The updated Tree Atlas presents additional information helpful to interpret tree species changes: Black cherry Sugar maple • Black oakSuitable habitat - calculated based on 39 variables that explain where optimum conditions exist for a species, including soils, landforms, and Swamp white oak climate variables. Ironwood White oak • Adaptability - based on life-history traits that might increase or decrease tolerance of expected changes, such as the ability to MIXED RESULTS withstand different forms of disturbance. American basswood Green ash • American hornbeamCapability - a rating of the species’ ability to cope or persist with climate change in this region based on suitable habitat change (statistical Paper birch

Black ashmodeling), adaptability (literature review and expert opinion), and Silver maple

Boxelderabundance (FIA data). The capability rating is modified by abundance information; ratings are downgraded for rare species and upgraded for White ash abundant species. Eastern white pine Yellow birch • NEW HABITAT WITH MIGRATION POTENTIALMigration Potential Model - when combined with habitat suitability, an estimate of a species’ colonization likelihood for new habitats. This

Bitternut hickoryrating can be helpful for assisted migration or focused management (see the table section: “New Habitat with Migration Potential”). Pignut hickory Black walnut Sassafrass Remember that models are just tools, and they’re not perfect. Model projections can’t account for all factors that influence future species Blackgum Scarlet oak Chestnut oaksuccess. If a species is rare or confined to a small area, model results may be less reliable. These factors, and others, could cause a particular species Shagbark hickory Eastern redcedarto perform better or worse than a model projects. Human choices will also Slippery elm continue to influence forest distribution, especially for tree species that Mockernut hickoryare projected to increase. Planting programs may assist the movement of Yellow-poplar future-adapted species, but this will depend on management decisions. Despite these limits, models provide useful information about future expectations. It’s perhaps best to think of these projections as indicators of possibility and potential change. SOURCE: This handout summarizes the full model results for Eastern and Coastal Maine, available at www.fs.fed.us/nrs/atlas/combined/resources/summaries. More information on vulnerability and adaptation in the New England region can be found at www.forestadaptation. org/new-england. A full description of the models and variables are provided in Iverson et al. 2019 (www.nrs.fs.fed.us/pubs/57857 (www.nrs.fs.fed.us/pubs/58353). and www.nrs.fs.fed.us/pubs/59105) and Peters et al. 2019 www.forestadaptation.org

CLIMATE CHANGE CAPABILITY POOR CAPABILITY

American mountain-ash Pitch pine Balsam poplar Red pine Black spruce Serviceberry Bur oak Striped maple Jack pine Tamarack (native) Mountain maple White spruce Pin cherry

FAIR CAPABILITY

Balsam fir Northern white-cedar Eastern hemlock Red spruce Gray birch

GOOD CAPABILITY

American beech Northern red oak American elm Quaking aspen Bigtooth aspen Red maple Black cherry Sugar maple Black oak Swamp white oak Ironwood White oak

MIXED RESULTS

American basswood Green ash American hornbeam Paper birch Black ash Silver maple Boxelder White ash Eastern white pine Yellow birch

NEW HABITAT WITH MIGRATION POTENTIAL

Bitternut hickory Pignut hickory Black walnut Sassafrass Blackgum Scarlet oak Chestnut oak Shagbark hickory Eastern redcedar Slippery elm Mockernut hickory Yellow-poplar Projected summer climate equivalent for the state of Maine under different climate change scenarios (Union of Concerned Scientists)

Maine 1961–1990 Migrating State 2010–2039 Climate 2010–2039 Changes in average summer heat index—a measure of how hot it actually feels, 2070–2090 given temperature and humidity—could strongly 2070–2090 affect Mainers’ quality of life in the future. Red arrows track what summers could feel like over the course of the century under the higher-emissions scenario; yellow arrows track what summers in the state could

Higher-Emissions Scenario feel like under the lowerLower-Emissions Scenario emissions scenario. Photos: (from top) iStockphoto.com/Andy Thorington; Maine Department of Inland Fisheries and Wildlife; iStockphoto.com/Greg Nicholas; Captains of Industry; iStockphoto.com/Ben Thomas

emissions is lowered, however, projections show that many of the changes will be far less dramatic. Emissions choices we make today—in Maine, the Northeast, and worldwide—will help determine the climate our children and grandchildren inherit, and shape the consequences for their economy, environment, and quality of life.

The research summarized here describes how climate change may affect Maine and other Northeast states under two different emissions scenarios. The higher-emissions scenario assumes continued heavy reliance on fossil fuels, causing heat-trapping emissions to rise rapidly over the 2040–2069 2040–2069 course of the century. The loweremissions scenario assumes a shift away from fossil fuels in favor of clean energy technologies, causing emissions to decline by mid-century.

The research also explores actions that individual households, businesses, and governments in the Northeast can take today to reduce emissions to levels consistent with staying below the lower-emissions scenario, and to adapt to the Precipitation and winter snow. The Northeast region is projected to see an increase in winter precipitation on the order of 20 to 30 percent. Slightly greater increases are projected under the higher-emissions scenario, which would also feature less winter precipitation falling as snow and more as rain. Snow is nearly synonymous with winter in Maine and an integral part of many favorite winter activities and traditions. If higher emissions

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