Why Should I Care About Land Trends?

  • Of great public health concern is the predicted rise in the incidence of Lyme disease as deer tick habitat range increases further north. Children aged 5-14 were found to be most impacted by Lyme disease in 2013 cases.
  • Tick disease, along with heat stress, will also put wildlife populations, such as moose, at great risk.
  • The rise in exotic species, invasive diseases, and pests (e.g., winter moth) will push out native species in the Kezar Lake watershed, leaving a much different landscape for future generations to enjoy.
  • Sap collection may arrive earlier by as much as 3 weeks by 2050. Sap may actually flow longer than the typical 8 weeks, but the southern extent of sugar maples may move north.

How Can I Help?

Plant Trends


Earlier and warmer summers will lengthen the growing season, but potentially more days above 90 degrees and variable precipitation patterns may mitigate anybenefits for farming in the region.Watermelon, tomatoes, peppers, peaches, andothers will benefit from higher air temperatures, but corn, wheat, and oats will have lower yields. Cabbage, potato, apples, blueberries, and winter wheat that need cool weather and cold winters will also decline. Flowering, fruit set, and seed production will decline inmany species due to loss of pollinators.

Species Composition

Warming air temperatures and changing precipitation patterns will cause shifts in the geographic extent of native plant and tree species in the area. Many plant and tree species that thrive under cooler, drier conditions will die out, giving opportunity for southern plant and tree species to take root. This will cause a gradual change in plant and tree species composition and distribution within the watershed. For example, spruce and fir will move farther north and to higher elevations. The sap season for maples will come earlier and sugar maples may be restricted to northern Maine. Different plant and tree species have varying levels of nutrient and water needs, a change in which will alter ecosystem cycling dynamics.

University of Maine studies over the last 30 years show that, due to increased temperatures and precipitation, the abundance of beech trees have increased in abundance at the expense of birch and maple in the forests of the northeast, notably in the White Mountains, echoing other work that environmental changes are squeezing out important tree species. Beech, often used for firewood, is a less valuable a commodity than hardwoods used for furniture and flooring.

Seasonal Timing

Joshua Halman, a Forest Health Specialist with the Vermont Department of Forest, Parks and Recreation, has been monitoring trees in Underhill State Park for 25 years by recording color change and leaf drop. These data show that the timing of peak color and leaf drop have come later in the season by about eight days in the last 25 years. Comparable data are not available for Lovell; however, Underhill State Park is at approximately the same latitude, and therefore, can be extrapolated as relevant to the White Mountain National Forest and the Kezar Lake watershed.

Invasive Species

In 2004, a survey was undertaken to document non-native and invasive species on all GLLT-owned properties. Surveys documented the presence of non-native species sheep sorrel (Rumex acetosella) and coltsfoot (Tussilago farfara). While some might consider these plants to be invasive, they are not often targeted for management efforts. Later that year, GLLT conducted surveys in the town targeting areas where invasive plants would most likely occur, such as power lines, roadsides, logging roads, informal camping spots, playing fields, and disturbed areas. Japanese knotweed (Fallopia japonica), sheep sorrel, coltsfoot, black locust (Robinia pseudoacacia), and non-native honeysuckle (Lonicera sp.) were detected during these surveys.

Of all observed non-native plants, Japanese knotweed was observed to be the most pervasive. GLLT also surveyed 12 private properties, which revealed the presence of additional non-native invasive plants, including Japanese barberry (Berberis thunbergii), non-native honeysuckle, autumn olive (Elaeagnus umbellata), asiatic bittersweet (Celastrus orbiculatus), and purple loosestrife (Lythrum salicaria). Anecdotally, Tom Henderson of GLLT reports that an infestation of purple loosestrife was also found on a member’s property, but was eradicated. Other non-native, invasive plant species known to occur in neighboring towns include glossy false buckthorn (Frangula alnus) and yellow iris (Iris pseudacorus).

Non-native and invasive species are an increasing concern in Maine because of their potential to outcompete native species and upset the native ecosystem. Maine has identified 33 invasive terrestrial plants that are illegal to import, export, buy, or intentionally propagate for sale, including Japanese barberry and asiatic bittersweet. The State of Maine takes responsibility for combating the spread of invasive plants with integrated management tools such as prescribed fire, mechanical treatments, and herbicides. A compilation of invasive species of concern in Maine is provided in Appendix B, which provides a description and image of these invaders and lists sources for more information on each species’ identification and mitigation.

Bird Trends

Bird counts and movements can be monitored easily and can serve as an indicator of climate change. Changes in air temperatures and precipitation amounts can shift habitat ranges and limit mating and nesting seasons. Late spring storms can kill migrating birds and cause behavioral shifts. Available food sources can change, forcing birds to find new suitable habitat.

Birds in the Kezar Lake watershed that are most likely to decline due to climate change include the Black-capped Chickadee (Maine State Bird), Evening Grosbeak, Ruffed Grouse, Wood Thrush, and all high-elevation species. Birds that may increase or move into Maine include the Tufted Titmouse, House Finch, Brown-headed Nuthatch, and Loggerhead Shrike.

Long-term (1966-2010) and short-term (2000-2010) population trends based on data from the North American Breeding Bird Survey for 5 songbird species in Maine (and likely within the Kezar Lake watershed) showed two species declining (Barn swallow and Bobolink), one species stable (Ovenbird), and two species increasing (Northern Cardinal and Tufted titmouse). Under the high emissions scenario, western Maine is projected to show a net increase in bird species richness as a warming climate allows southern species to invade (Rustad et.al. (2014).

Mammal, Reptile, and Amphibian Trends

Moose are an iconic mammal in Maine and a local inhabitant of the Kezar Lake watershed. This iconic species is vulnerable to heat stress and ticks that proliferate following mild winters. Moose studies have shown that ticks are killing 70% of calves in Maine and New Hampshire due to mild winters. The observed decline of moose in Maine from disease or migration north is a clear signal of climate change.

Attempts by the KLWA to find detailed information on historical moose populations in Lovell were not successful (this included an evaluation of the Statewide permit and harvest data). The last estimate of moose population was in 2012 when the State of Maine reported a population of 76,000. While hunting permit numbers are not linearly related to the total population, Maine Inland Fisheries and Wildlife (MIFW) reports moose harvests by individual towns. Very few moose harvests have been recorded in Lovell with the maximum in 2009 at only two individuals. Moose are also unevenly distributed throughout the State and primarily occupy the commercial forestlands in northern Maine. The State division that includes Lovell (Division 15) receives 25 permits per year and reports approximately a 50% success rate (ranging from 24% – 60% historically).

Detailed Statewide information is needed to make assessments of the moose population in Lovell. Unfortunately, data on other mammals, such as bear, deer, and wild turkey are also limited. Generally, bat populations are declining from white nose syndrome (some areas like Vermont by as much as 90% in the last decade). MIFW has more information regarding these mammals on their website.

Insect & Pathogen Trends

With the onset of climate change, more warm and wet weather pests are moving into New England. Migratory insects are arriving earlier with earlier snowmelt and rising air temperatures, and insects that are only marginally-adapted to the region are beginning to invade as the climate warms. Increases in balsam woolly adelgid, spruce budworm, Beech bark disease, and winter moth are already causing serious injury and death of large tree populations. Inadequate winter chill will adversely affect agriculture by increasing populations of insects and disease, including flea beetle and Steward’s wilt. Wetter conditions will also increase the likelihood of white pine needle disease caused by pathogenic fungi.

Maine has been invaded by many exotic and destructive species beginning with the colonization of the North American continent via the import, both accidental and deliberate, of European and Asian species. Non-native invasive species compete for natural resources and alter the native dynamics of forests, wetlands, rivers, lakes, and ponds. Some of these non-native species have been in New England since the beginning of colonization but most have arrived in recent decades by the increase in overseas and local commerce. They spread mainly by transport on boats, trucks, birds, animals, and plants. Changing climatic conditions, including shorter winters, reduced snowpack, and increased air temperatures, allow increased survival of non-native species and expedite the spread of more southern species into New England. Before European settlement, insect and disease outbreaks in forests were caused by native species such the spruce budworm and forest tent caterpillar. More recently, insect and disease outbreaks have occurred at an increasing frequency because of the introduction of non-native insects and disease agents. The introduction of the hemlock woolly adelgid insect has caused complete mortality of eastern hemlock in parts of Massachusetts and Connecticut, and this damaging pest has now crossed the Maine border. In addition to damaging insect pests, the introduction of earthworm species by the colonists into previously-glaciated regions of the northeast has dramatically altered soil composition and structure, changed organic matter decay rates and processes and made seedbed and germination conditions less favorable for some native plants.

Of great concern is the invasive emerald ash borer (Agrilus planipennis), which was first seen in northern Aroostook County, Maine in the spring of 2018. Several more sightings were reported in western York County, Maine in the fall of 2018. The emerald ash borer (EAB) is an Asian, wood-boring beetle that has cleared a destructive path in 45 states (including the entire eastern seaboard, except Florida) and four Canadian provinces. It likely hitchhiked to North America across oceans in packing crates and shipping materials (Cappaert, Mccullough, Poland, & Siegert, 2005). It is the lifecycle of EAB that is so perilous for trees. The adult beetle lays its eggs in the cracks of ash trees (Fraxinus sp.). When the eggs hatch, the larvae burrow into the tree and feed on the inner bark and phloem, which disrupts the transport of nutrients and water throughout the tree. The beetle’s eating pattern creates distinct “S”-shaped carvings in the bark. In Maine, there are three species of ash trees, and this beetle poses a threat to all of them. Preference is given to black and green ash (Fraxinus pennsylvanica and Fraxinus nigra) and to trees that are already compromised or sick. When trees are infected, leaves sprout from roots and trunks, bark splits, and the canopy dies.

Loss of black ash trees in Maine will not only have ecological impacts but cultural impacts as well. The black ash tree is a cultural keystone species and an important economic resource for the Wabanaki people, who use black ash trees for basketmaking.

Communities have learned a lot in the last seventeen years since EAB was first sited in the Midwest in 2002. Although climate change is enhancing the EAB’s preferred habitat into northern regions like Maine, Maine is also in a unique place to have a delayed invasion of EAB by taking advantage of research and trial and error management strategies used in other states. Non-infested communities should monitor and prepare for the spread of the invasive beetle to ensure early detection and action. Sticky, purple traps can be set out to trap and monitor for the EAB. Woodpeckers and wasps are natural predators and natural monitors for the EAB because they feed on the EAB and will increase activity on host trees. Firewood has been cited as the predominant mode of travel for the EAB, so it is critical that vacation communities like those of Kezar Lake be extremely vigilant about people bringing in firewood from other places in Maine or other states. When the EAB is found in an area, property owners or land managers can selectively harvest ash trees to reduce the food source and employ biological controls on the EAB, such as increasing the populations of native woodpeckers and native or imported parasitic wasps.

The Surveillance, Outreach, Involvement section on Maine’s EAB page (www.maine.gov/EAB) provides a wealth of resources for getting involved with state-wide monitoring efforts. The State of Maine takes responsibility for the mitigation of invasive insects with integrated pest management tools, including prescribed fire, mechanical treatments, and herbicides. If Maine communities work together, it is possible to mitigate the risks associated with these invasive insects to ensure sustainable native populations and tree resource for decades to come.

A compilation of invasive species threatening Maine is provided in Appendix B of the 2018 CCO Annual Report, including aquatic fauna, wetland plants, algae, forest fauna, and forest insects. A description and image of each invader is provided, along with sources for more information on each species’ identification and mitigation.

The Maine Center for Disease Control and Prevention (Maine CDC) data shows that the number of reported Lyme disease cases in Maine is increasing. This increase in reported cases is likely due to a combination of climate-induced factors. Warming air temperatures (especially in winter), more precipitation, a longer growing season, and a proliferation of their primary hosts (mice, chipmunks, and other small mammals) are promoting the northern migration of and thus increasing populations of disease-carrying ticks in the state. Although deer, moose, and other large mammals are also hosts to ticks, small mammals are considered their primary hosts and generate a far greater threat to humans because small mammals live closer to where we live, work, and play.

Deer ticks carrying Lyme disease can be found in wooded areas or open, grassy areas, especially along the edges of forests. To best control tick populations around your property, clear brush and leaves and deter deer, mice, and chipmunks. Be vigilant in checking for ticks and seek immediate medical help if you were bitten by a deer tick. Lyme disease can be easily treated with antibiotics, but if left untreated, can cause severe illness, arthritis, and neurological problems.

There are several other tick-borne diseases that threaten public health and may increase with a changing climate. These include anaplasmosis, babesiosis, ehrilichiosis, powassan virus, spotted fever rickettsiosis, as well as other less common diseases. Each of these has shown an increase over the years, especially anaplasmosis.

For more information on prevention and treatment, please visit https://www.cdc.gov/ticks and http://www.maine.gov/dacf/php/gotpests/bugs/ticks.htm.


About 37% of Maine’s plant and animal species are predicted to be at high risk from climate stress, particularly as pollinators decline and variable precipitation and warmer air temperatures force more sensitive or cold-weather species and agricultural crops out of the area. Most vulnerable are species living in wetlands, alpine areas, or central/northern uplands. For example, spruce and fir will move farther north and to higher elevations, while oak-pine forests take over.

The sap season for maples will come earlier and sugar maples may be restricted to northern Maine.

Birds in the Kezar Lake watershed that are most likely to decline due to climate change include the Black-capped Chickadee (Maine State Bird), Evening Grosbeak, Ruffed Grouse, Wood Thrush, and all high-elevation species. Birds that may increase or move into Maine include the Tufted Titmouse, Canada Goose, House Finch, Brown-headed Nuthatch, and Loggerhead Shrike.

Local Land Trends Summary

Climate affects the abundance, extent, and diversity of all life on the planet – plants and trees, birds, mammals, and insects and pathogens. As the climate changes, terrestrial species will need to adapt to or move from these changing environments.

Two-thirds of Maine’s animal and plant species are predicted to be at risk from climate stress. We can watch for change in these populations as indicators of climate change. The CCO intends to collaborate with existing phenology networks across the country to better understand the periodic plant and animal life cycle events and how these are influenced by seasonal and interannual variations in climate, as well as habitat factors.

References for Land Trends

Duchesne, L., and D. Houle. “Interannual and spatial variability of maple syrup yield as related to climatic factors.” PeerJ 2 (2014):e428.

Fernandez, I.J., C.V. Schmitt, S.D. Birkel, E. Stancioff, A.J. Pershing, J.T. Kelley, J.A. Runge, G.L. Jacobson, and P.A. Mayewski. “Maine’s Climate Future: 2015 Update.” Orono, ME: University of Maine (2015): 24 pp. www.climatechange.umaine.edu/research/publications/climate-future

Fleming, D. Winter ticks raise concerns about future of Maine’s moose herd. Portland Press Herald, 14 June 2014. http://www.pressherald.com/2014/06/14/winter-ticks-raise-concerns-about-future-of-maines-moose-herd/

Leighton, P.A., J.K. Koffi, Y. Pelcat, L.R. Lindsay, and N.H. Ogden. “Predicting the speed of tick invasion: an empirical model of range expansion for the Lyme disease vector Ixodes scapularis in Canada.” Journal of Applied Ecology 49 (2012):457–464

Robinson, S. Infectious Disease Epidemiology Report: Lyme Disease Surveillance Report—Maine, 2013. Augusta, ME (2014): Maine Center for Disease Control and Prevention. http://www.maine.gov/dhhs/mecdc/infectious-disease/epi/publications/2013-lyme-surveillance-report.pdf

Rodenhouse, N. L., et al. “Potential effects of climate change on birds of the Northeast.” Mitigation and Adaptation Strategies for Global Change 13.5-6 (2008): 517-540. http://www.ucsusa.org/sites/default/files/legacy/assets/documents/global_warming/pdf/miti/rodenhouse_et_al.pdf

Skinner, C.B., A.T. DeGaetano, and B. Chabot. “Implications of twenty-first century climate change on Northeastern United States maple syrup production: impacts and adaptations.” Climatic Change 100 (2010):685–702.

Whitman, A., et al. “Climate Change and Biodiversity in Maine: Vulnerability of Habitats and Priority Species. Brunswick, ME (2013): Manomet Center for Conservation Sciences. https://www.manomet.org/sites/default/files/publications_and_tools/2013%20BwH%20Vulnerability%20Report%20CS5v7_0.pdf