Do you recall the first time you saw Disney’s early cartoon Fantasia? I do. A small child, I sat gaping in a darkened movie theater while a glowing fairy swung a sparkly wand over the world, conjuring plants and flowers into assigned spots as she flitted around the screen. The background music was Tchaikovsky’s “Waltz of the Flowers,” which created a mood of excitement and joy.
Recently, I was reminded of those scenes, ironically, while watching a TEDTalks program on global warming. Instead of a fairy, vegetation on a map was brought into view and moved by the sweep of a commentator’s laser pointer. No music, no joy, just grim images of an inexorably changing landscape.
Climate change is already with us, in our region, in the state of Massachusetts, in our own woods and wild lands and yards and farms. The trends are discernable. Since about 1970, temperatures have risen nearly 2 degrees F. in New England, according to the Northeast Climate Impact Assessment Team (NCIAT). A cascade of effects emanate from that change. Last winter notwithstanding, winter temperatures are rising faster than summer ones. Snow melts earlier. Spring comes earlier. We are experiencing hotter, more humid summer days, short-term droughts in summer and fall, and more intense storms in all seasons. More precipitation is falling as rain rather than snow. Growing seasons are longer, some plants are blooming earlier, pests are on the move, and water supplies are unstable.
One familiar plant in our part of the world is definitely being affected, the sugar maple. A neighbor’s father, who works a large sugarbush in Vermont, confirms that the sap is flowing as much as two weeks sooner than it did just a decade ago—that is, he is tapping earlier and earlier. This effectively shortens the season and reduces production. He and others fear there may come a day when sugar maples are no longer viable for this use. Not only will a major crop sputter out, but the vivid fall foliage of maples—such a delight to behold and, of course, also an iconic tourist attraction in Vermont as well as the rest of New England—will fade. With these changes and losses, longtime lifestyles and economies will falter.
Along with beeches and birches, maples are projected to shift northward in order to survive and prosper in the colder climates they are best suited to. So, too, are coniferous forests projected to move up (to higher altitudes, where possible) and out (north)—I am speaking specifically of the potential shifting or even eradication of spruces and firs, but hemlocks and larches could follow.
What will fill the vacancies is unclear and undoubtedly depends on many factors. Perhaps we will see more of what are now considered more Southern deciduous trees such as magnolias, dogwoods, and sweet gums. Or perhaps ones that prosper in warmer, drier conditions will take the stage and we’ll see mainly more oaks and pines. At higher altitudes, the current plant residents—alpine and tundra species—may have nowhere to go and die out altogether.
One thing that has been thoroughly studied in the past is how gaps are filled. Clearing out sections of forest trees, whether for development, farming, or harvesting of timber has been a common practice in this part of the world for centuries. Succession is the process by which vegetation fills back in; post-agricultural succession in particular has been well-studied. Sun-loving herbaceous plants may have their day but eventually get shaded out as shrubs and trees return. Farewell to the asters and goldenrods, the white pines or red maples are resurging. As the saying goes, “nature abhors a vacuum.”
Climate change affects what fills the gaps in the landscape. Rising summer and winter temperatures favor certain plant pests, allowing them to move into and prosper in new areas or even to have population explosions. Take the woolly adelgid, an introduced aphidlike insect that decimates our native hemlocks. Or the destructive emerald ash borer, whose damage is already well-known in the few years since it has been on the public radar. As these pests spread, the plants they favor will die off or retreat, very possibly with little prospect of resurgence in their now-altered habitat.
Particularly positioned to grab openings are non-native invasive plants, which grow and spread quickly. Oriental bittersweet and buckthorn in our forests and phragmites in our wetlands are familiar examples. These aggressive plants elbow out the natives, multiply unchecked by indigenous insects or animals and, thus, of course, alter ecosystems. How could they not? Thus succession as it has usually operated does not occur, and the result is that the composition of wild or uncultivated areas is altered. Furthermore, as frost lines push ever northward, it is not impossible that we will see incursions from additional warm-climate invaders, such as the ominously named mile-a-minute vine (which actually has already been sighted in this state) and even kudzu.
Tree species with similar needs tend to form regional plant communities, such as the maple/beech/birch or the oak/hickory forests. Also, certain understory shrubs and wildflowers and groundcovering plants associate with these communities. But in addition to temperature, bear in mind that every single species, big and small, has its own requirements for soil, light, and moisture. Under changing climatic conditions, individual species are likely to react differently—in terms of migration rates, not to mention seed-dispersal mechanisms and the speed and success of establishment. In the forests of the future, it may not be a simple matter of entire, familiar “communities” shifting northward or into higher elevations. It’s conceivable that even minor shifts and losses will instead redefine the makeup of our landscapes. Pessimistically speaking, everything may go haywire. Optimistically, it becomes a large-scale recalibration process for the plants.
Wetlands and marshes will likewise be impacted. As water levels rise, and/or the composition of the water changes (becoming more or less saline depending on the location), some plants may adjust. Sedges and cattails, for instance, are already adapted to seasonal changes including shifting water levels. Others such as buttonbush and pickerel weed may not fare as well. The creatures and insects that are associated with various wetland plants stand to be affected as their traditional food and shelter alters. Already, non-natives such as common reed and purple loosestrife have encroached upon or overtaken areas where openings occurred and the existing plants could not adapt or adapt quickly enough. Resilient invaders are able to outcompete native flora, and are tenacious. The original plants—without intervention—may never regain a foothold.
Farmers and orchardists are also being affected, which in turn impacts what we eat and drink and how far things travel to get to our kitchens. For example, in southeastern Massachusetts, cranberry bog owners are fretting about climate change’s adverse effects on their livelihood. The CEO of a large production bog in Wareham that supplies Ocean Spray laments that “we’re having warmer springs, we’re having higher incidences of pests and fungus, and we’re having warmer falls when we need to have cooler nights.” Some cranberry production is moving north into New Brunswick, Canada, and investing in land in cooler areas of Chile is also being considered.
In recent years, erratic spring weather has been at best a nail-biter and at worst a fiasco for apple orchards in part of this region. An unseasonable warm spell in March a few years ago caused early blooms, but pollinators were not yet active or active enough. Late-spring frosts followed, harming and killing buds. The result? A crop disaster. I’m not aware that Northeast apple growers are looking at real estate in colder areas in an effort to meet demand and continue their livelihood. Tactics of this sort are likely not an option for small, local producers.
The challenging growing conditions facing fruit producers in a time of climate change isn’t just an agricultural or horticultural problem. It’s also an economic and social problem and relates to the big picture. The growing popularity of local foods may be seriously challenged. Think: are you willing to pay more, factoring in shipping, to continue to enjoy cranberries, once they can no longer be a local crop? Are you willing to buy apples imported all the way from the Southern Hemisphere? Global warming is likely to compel us to change our buying and eating habits. Clinging to what we’ve always known could become quixotic, expensive, and eventually untenable.
Meanwhile, producers may have to adjust to new conditions. What will they grow? What will be in our markets and farmstands in the future? More peaches? Peanuts? Avocadoes and citrus? Don’t laugh—if our region gets significantly warmer, and we want to stay here, such produce may be on the “eat local” table.
The same goes for horticulture. Will popular garden rhododendrons die out and our children and grandchildren grow azalea cultivars, currently so emblematic of the Southeastern states, instead? Will we shift to planting and harvesting long-season crops like hot peppers and okra in our vegetable patches? Will we grow tropical plants outdoors, perhaps even in-ground? Will tulips falter and will we be compelled to switch our affections to alstromerias? With the changing plant zones, gardeners are already contemplating these upcoming choices. With a pang, some are even imagining the coming changes as opportunities.
Skepticism, indifference, denial, guilt, worry, disbelief—this may be the spectrum of layman responses to climate change’s effects on the plants we know and love. Individually and collectively, we can and ought to limit our “carbon footprint” in our travel, home heating and cooling systems, and shopping habits. We must lobby lawmakers to create and enforce plans for reduction and mitigation. We must heed the recommendations of regional task forces. For nature and plant lovers, another pragmatic, proactive response is to support research on all this. The upcoming generation of scientists will have a lot of work to do, and—if current predictions are correct—not a lot of time to do it in.
Data is already being collected. Researchers at the Arnold Arboretum spend early spring into summer checking the grounds weekly, noting what comes into bloom when. Some of us do this informally already; if you are interested in contributing information and dates, google “Project BudBurst.” It’s a national program that collects observations from ordinary citizens. Let’s hope and trust that knowledge is power. Participating will also make you hyper-aware of what is happening right in your own corner of the world, in your town or yard or garden. Many people already believe they know the ways the data are trending, but gathering plentiful data remains critical.
Another response is to try and preserve species before they are exterminated or their habitats altered. New England Wild Flower Society in Framingham is a leader in this region with its seed bank and various ongoing scientific projects that study the coming changes. Research and modeling is also underway in our state Natural Heritage programs. I urge you to support such efforts, perhaps by volunteering time or donating money.
Used to be, the greatest detrimental human impact on natural systems and plant communities was from pollution and encroaching development. Now that we recognize climate change at the macro level, our culpability is arguably harder to rein in and more alarming. It’s also harder to understand and to arrest at the local level. But this is where it will hit home.
The TEDTalks fellow spoke of earth’s energy being “out of balance,” referring to feedback loops and, hence, overall warming. Floods, droughts, monster storms, and “polar vortexes” are increasing. It’s frightening to watch landscapes and habitats start to change and long-familiar patterns unravel. I miss the innocent days when we assumed such things were relatively stable, not so very long ago; I miss the innocent days of my childhood. But we need to turn our attention to what the world will be like going forward.
A version of this article originally appeared in Sanctuary: The Journal of the Massachusetts Audubon Society, Summer 2014.