Terrestrial Plants & Trees
Farming
Earlier and warmer summers will lengthen the growing season, but potentially more days above 90 degrees and variable precipitation patterns may mitigate any benefits for farming in the region.Watermelon, tomatoes, peppers, peaches, and others 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 in many 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 reported 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.