Climate Change: A View Over Thirty Years

This article by Lisa Lofland Gould first appeared in WildfloraRI, Winter 2018

In October 1988, the fledgling RI Wild Plant Society sponsored my attendance at a conference in Washington, D.C., The Consequences of the Greenhouse Effect on Biological Diversity. Among all the bigwig academic institutions, government agencies, and NGOs present at the conference, RIWPS was the only state plant society represented—kudos for foresight! My original article, a brief overview of the conference, is reprinted here, followed by a bit of commentary.

Scientists have been talking about the greenhouse effect for many years, but only recently has the term captured the public’s imagination, aided partly by 1988’s unusual summer of heatwaves and freak storms. That the greenhouse effect does exist is not seriously disputed, although its exact consequences are impossible to predict with current data. Just what is the greenhouse effect? When certain gases build up in the atmosphere, their increased presence has the effect of holding more of the sun’s energy within the atmosphere, rather than the energy radiating back into space. Carbon dioxide is the major component of the greenhouse gases, which also include nitrous oxide, methane, ozone, and fluorocarbons.

The amount of carbon dioxide in the atmosphere has increased about 25% since pre-industrial times and in the past 30 years has increased fairly dramatically. This trend is expected to continue during the next century (some predict a doubling of carbon dioxide within the next 50 to 60 years) and into the foreseeable future unless drastic measures are taken to control emissions into the atmosphere.

Most of this excess carbon dioxide comes from living things. Carbon dioxide is given off by the respiration of both plants and animals and is released when plant materials (such as wood) and fossil fuels (such as oil and gasoline) are burned. As the human population increases, so does the demand for advanced technology; the greater the use of technology by each person, and the larger the human popula- tion, the greater the release of greenhouse gases into the atmosphere. And the problem feeds on itself; the increase in greenhouse gases increases the temperature of the earth, which increases the speed at which living materials decay and release gases into the atmosphere.

All this might not be quite so bad, if it weren’t for another activity going on at the same time: deforestation. Just as the human population is growing and using energy at unprecedented rates, we are stripping the planet of the major absorbers of carbon dioxide, the forests. In a balanced ecosystem the amount of carbon dioxide released into the atmosphere is no more than the amount absorbed by plants during photosynthesis. Currently, however, there is an annual net increase of three billion tons of carbon dioxide into the atmosphere. If we could stop all burning instantly and reforest, it would reduce the annual carbon release into the atmosphere by 50%.

Scientists predict that this increase in gases in the atmosphere is changing global climate. Now climate change is nothing new; it’s been going on since the planet formed. Since the last ice age, about 12,000 years ago, the Earth has warmed approximately 5 degrees centigrade [41 degrees Fahrenheit]; if current predictions hold, scientists expect global temperature to rise by 3 to 5 degrees centigrade within the next 50 to 75 years. It is this rate of change that has scientists alarmed; what has been happening over tens of thousands of years will be occur- ring over a few decades and in conjunction with other global changes (such as acid rain and ozone depletion) brought on by human activity.

Predicting the extent of climatic change, where specific changes will occur, and how organisms will be affected, is much more difficult. Scientists are using computer models to make these predictions, but the models are only as good as the information put into them. In many areas of study, decades of underfunding in basic research have led to major gaps in our knowledge of ecosystems and how they function. In general, however, the models predict the following kinds of changes:

The Geosphere. Warming is predicted to be greatest at the highest latitudes (probably twice as great at the poles as in the equatorial regions) and to increase the most during winter months. This is likely to cause some melting of the polar ice caps and a rise in global sea levels of 30 centi- meters to 1.5 meters. (To put this in perspective, go to the beach and imagine the sea level 4.5 feet higher than it is at high tide; then imagine what coastal areas such as Florida would be like.) There will also be altitudinal climate shifts; for example, the present climate at 3000 feet of elevation on Mt. Washington in New Hampshire will be found (roughly) at 6000 feet.

Because the warming will not be evenly distributed over the globe, there will be changes in the circulation patterns of winds and ocean currents and therefore changes in rainfall distribution patterns. This moisture redistribution is predicted to produce less rainfall in the northern hemisphere and more in the southern hemisphere. Over the planet as a whole, there may be a 7–10% increase in rainfall. Weather patterns will become increasingly erratic, with an increase in the frequency of severe storms and new highs in storm surges.

The Biosphere. During the last ice age, spruce-fir forests, moving ahead of the glaciers, extended into the southern states; Rhode Island was covered with a sheet of ice. As the glacier melted, the boreal forest retreated north, leaving only scattered remnants on the highest peaks of the southern Appalachians. These forests had thousands of years to adapt to the changing climate, and even given this much time, many species—both plants and animals—became extinct. With a comparable climate change predicted for the next century, scientists have far more questions than answers about how the living world will be affected.

There is serious concern for any species that is slow growing, unable to migrate in the face of change, and/or has a limited habitat (which includes most of our rare species). Kirtland’s Warbler, for example, nests only in the Jack Pine forests of Michigan. If the climate changes as predicted, these forests will be gone by 2040, leaving Kirtland’s Warbler without its breeding site. For many species of trees, the mature tree can withstand a fairly broad range of temperature and precipitation, but the juvenile stages—the seeds and seedlings—tend to be much more sensitive, especially to changes in moisture patterns; this leads scientists to predict that some forests will lose diversity or change to other types of ecosystems. Overall, the composition of forests will change from within, with some species dying out in a particular area, and other species able to tolerate the changes.

As the vegetation changes, so will the animals and microbes. In the tropics, for example, many insects reproduce when certain plants are in flower or fruit; those plants, in turn, flower and fruit in response to seasonal rainfall patterns. We do not know if tropical plants will be able to change their reproductive patterns as rainfall patterns change, or if the animals that rely on the plants can make similar changes, but most scientist who are aware of the current “extinction spasm” occur- ring right now in the tropics are very gloomy about the tropics’ ability to with- stand the combined effects of deforesta- tion and the greenhouse effect.

The key issue for all organisms and ecosystems is their ability to respond to climate changes occurring at an unprec- edented rate. Species interact with one another in all ecosystems; nothing, includ- ing human beings, stands alone. The changes we expect from the greenhouse effect will influence all ecosystems, from the tropics to the poles, from the highest mountains to the oceans; and human endeavors will certainly be affected. Agriculture, fisheries, lumbering, and recreation are often mentioned, and there is concern over changes in where people will live, as both coastal waters and the human population rise. Climate change will bring shifts in the ranges of parasites and disease organisms that plague people and their livestock and crops. With human systems already failing miserably to feed, clothe, house, and heal the world’s people and giving even less respect to the rest of the planet, how will we respond to far greater pressures?

“We are headed into a new biological world,” stated one of the conference speakers. We cannot halt the climate chang- es—for the next fifty years or so, the stage is set—but we can work on slowing down the rate of change. The time has come for new ways of looking at the world. We can no longer view the planet as an endless source of resources for human beings to exploit but must take our place among all living things. If we act now, each of us can help heal the Earth.

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As I reread this article, I was struck by how spot on the conference presenters were, those thirty years ago. Think of the intense hurricanes of the past decade or so; salt-water incursion on calm days in places like Miami and Virginia Beach; wildfires in the West; the movement of Dengue, West Nile, and Zika into temper- ate zones; and the fact that the 10 hottest summers recorded since 1880 all occurred since 1998. It’s now estimated that atmo- spheric CO2 has increased by 45% since pre-industrial times. The USDA revised its Plant Hardiness Zone Map in 2012 and entire states were placed in warmer zones. Arctic ice is melting, and scientific stations in Antarctica have had to move further inland, away from collapsing ice shelves.

Other pressures are also bearing down on the Earth’s ecosystems, as global trade has carried myriad species around the planet and increased the introduction of invasive species. Development and human population growth bring habitat destruc- tion and more impact on ecosystem health. While the Clean Air Act helped to reduce acid rain in North American waters and forests, oceans have experienced approxi- mately a 30% increase in acidity since pre- industrial times due to the interactions be- tween CO2 and calcium compounds. This especially affects shelled animals (think clams, oysters, corals, etc.), resulting in a huge impact on sea life and corresponding impact on people who rely on the ocean for jobs and food.

I could continue to update facts and figures, but the sentence that really struck me in that article was “That the greenhouse effect does exist is not seriously disputed.” Weren’t those the good ol’ days, when our nation’s leaders actually listened (sort of) to the scientific community? I don’t begin to understand how the political pendulum has swung so far toward irrationality and disregard for scientific process and data, but I fear that such attitudes are seriously compounding the problems we face.

But Hurrah for states like Rhode Island, whose Division of Planning now has an Executive Climate Change Coordinating Council and a Chief Resiliency Officer to help deal with climate-change challenges! Young people are also involved, via the RI Student Climate Coalition, as is the faith community—Rhode Island Interfaith Power & Light will hold its 10th annual interfaith conference on climate change this fall—and Rhode Island’s fine array of academic institutions and environmental organizations. Keep up the good work, folks. You are serving as a great model for other states to follow!

And to end on a happy note, thanks to management of Jack Pine forests and control of Brown-headed Cowbirds, the Kirtland’s Warbler population has actually increased in recent decades, and the warblers have been reported breeding in Wisconsin as well as Michigan. Let us all work toward ensuring that not all the direst predictions come true and help our citizens and leaders understand that forward movement comes not from denying reality but by facing it squarely.

Lisa Lofland Gould majored in Biology at the University of North Carolina and earned an MS in Zoology at the University of Rhode Island, where she taught biology for many years, was a research associate in the Department of Natural Resources Science, and a co-founder and first executive director of the RI Natural History Survey. She was also a co-founder of the RIWPS. Among other publications, she is a co- author of Vascular Flora of Rhode Island and Coastal Plants from Cape Cod to Cape Canaveral (UNC Press). Now that she is back in North Carolina, she enjoys participating in the Audubon Society of Forsyth County, Audubon NC, the Piedmont Land Conser- vancy, the Carolina Butterfly Society, and the NC Native Plant Society.

Book Review – Spring Wildflowers of the Northeast: A Natural History

by Carol Gracie, Princeton University Press 2012
This review by Pat Cahalan, originally appeared in WildfloraRI, Winter 2018

To say this book is a collection of essays on spring-blooming wildflowers of the northeastern US and adjacent Canada, while accurate, doesn’t begin to capture its appeal. Unlike so many others, this book seamlessly blends the science, culture, and beauty of these plants, illustrating it all with photographs that are almost like being in the field with a 10x lens.

The author looks at 30 or so flowers from a botanical viewpoint, letting us in on what is happening in the plant’s life and why. What’s that insect doing on that plant? Why is that bloom shaped the way it is? What’s its pollination strategy? She delves into the life stories of not just familiar favorites like trillium, columbine, and lady’s-slippers, but also less popular ones like skunk cabbage and false hellebore, saxifrage, featherfoil, and fringed polygala (also known as gaywings or bird-on-the-wing). Throughout, she relates how a particular flower compares to others in its family, citing examples not only in the northeast and other parts of the U.S. but also in far- flung lands around the world.

Gracie talks about how these wildflowers got their names, both the common and scientific, and why the scientific names are changing—how new methods of studying plants (e.g., DNA sequencing) have led to a better understanding of the relationships between plants and their subsequent reclassification. But as she says in her essay on early saxifrage, now Micranthes virginiensis, “. . . there is generally good reason for such taxonomic changes, but it can drive one crazy—a saxifrage that is not a Saxifraga!”

In many of the essays she discusses the plant’s cultural history in folklore and literature. She mentions how these plants have been used medicinally and as food by native American tribes, ancient cultures, and colonial herbalists. However, she by no means endorses these uses, pointing out the very real possibility of disastrous results from such experimentation.

In each chapter Gracie discusses the latest scientific research on that plant, and for the reader who wants to pursue the science further, she includes an extensive list of references in the back of the book. While she does use botanical terminology throughout the text, those of us who are unfamiliar with the terms will have little trouble following her, as her easy-to-read style makes clear the meanings of words within the context of the text. In addition, she includes an extensive glossary in the back of the book.

More than 500 of the author’s color photographs illustrate the book. They include both plant portraits and plants in their natural settings, and give us an intimate look at what is going on in each plant’s life. Particularly fascinating are the many close-ups highlighting the botanical details she discusses and giving us a glimpse of nature at work, including the seven photos showing interior details of a Jack-in-the-pulpit flower, a native bee hanging upside-down from the stamens of a trout lily as it collects pollen, and an ant grasping a seed of Dutchman’s breeches by its edible appendage to drag it back to its nest.

This is not a substitute for a field guide to identifying plants, nor will it tell you how to garden or landscape your property. Rather, it is simply a collection of delightful, botanically accurate stories about our spring wildflowers.

Growing Native Plants from Seed

This article by Dorothy Swift originally appeared in WildfloraRI, Spring 2018.

Why grow wild plants from seed?

Grow­ing plants from seed provides more plants for your property than buying larger, more costly plants from a com­mercial or nonprofit source. Certainly, either Lobelia cardinalis or Penstemon digitalis is lovely as a single plant, but most people want multiple cardinal flow­ers or groups of penstemon throughout a planted area.

When you grow plants from seed, you may be able to obtain seed of local origin for a species. Using locally-sourced seed is a sound ecologi­cal approach for establishing wild plants on your property and for including spe­cies that are not readily available com­mercially or are prohibitively expensive.

Finally, there is the challenge of doing something that might be difficult and the satisfaction of acquiring knowledge and experience in the propagation of native plants.

For a home gardener, how might this be different from growing vegetables and flowers from commercial seeds? Generally, commercially available vegetable and flower seeds germinate readily, whether you sow them in the ground, start them earlier under arti­ficial lights, or use natural light from a window. Many of these plants are annuals or are tender perennials treated as annuals horticulturally. Only a few native species respond with immedi­ate germination, as popular commercial vegetable and flower garden seeds do.

Most native species require a cold period before the seed will germinate. This is often referred to as “cold stratification,” a technique that exposes seeds to moist, cold conditions for a period of time. (The seeds must be in a moist medium, such as a seed-growing mix. Dry storage of seed in the refrigerator does not meet the need for cold, moist stratification.) A few species have even stricter requirements, such as a warm period followed by a cold period followed by a warm period. It can take up to a year or longer for some seeds to germinate. You must be prepared for a longer investment of time and nurturing when growing most native species from seeds.

How do you learn the best method for starting a native species from seed? There are several ready sources. For 30 years, every WildfloraRI issue has had a Cultivation Note which includes information about the best habitat for a species, how to propagate and grow the plant, and in most cases, how to grow the species from seed.

Our favorite source of advice in Seed Starters East is Willam Cullina’s book, Growing and Propagating Wildflow­ers. Cullina worked in the propagation and nursery operation at New England Wild Flower Society for many years and writes about his personal experi­ence propagating numerous native species. He explains their requirements for germination and provides advice on techniques to save time with some of the slower species. Though out of print, used copies of Cullina’s book are available from online services, such as Alibris.

Doing an online search can also be useful. Use the species name and “seed propagation” to find information, par­ticularly from various other native plant and conservation organizations. Your results will include a lot of sources, but for most species the first two listed are adequate.

If you have difficulty finding informa­tion on a species, you may want to use the work of Norman C. Deno, Seed Germination Theory and Practice, 2nd edition. Deno’s work concentrates entirely on germination, not on how to grow plants further. His presentation of information can be a bit difficult to understand, but the work encompasses hundreds of plant species. The entire work can be found online.

What are some of the basics of wild plants from seed?

1. After you collect and clean or pur­chase seed, refrigerate it if you are not going to sow it right away. I put envelopes of dried seed on a shelf of my refrigerator door for storage. Alternatively, put seed into small bottles or vials, together with a desiccant. (You can save the little packets of desiccants from commercial products, such as large bottles of pills). Do not store seed at room temperature

2. When you are starting out, use a seed starting mix rather than a general potting mix. Some plants germinate readily and grow vigorously, so potting mix can be suitable, but in general, a fine-textured mix formulated for starting seed works best. I use a mix from Gardener’s Supply Company. It is expensive but is free of weed seeds and contaminating microorganisms. Published instructions for some plants, such as lily species, may recommend milled sphagnum moss, which is also very finely textured. Al­ternatively, you can purchase sphagnum moss and rub it through a fine sieve or between your fingers to get fine particles. Also, carefully clean any used pots or containers to avoid bringing fungus pests to your seed-starting. You can run your pots or seed boxes through a dishwasher to remove disease organisms.

3. Carefully moisten the seed-starting mix. This is more critical for seed-starting than for transplanting. Proper wetting of the mix may require less water than you might think is correct. Moist, but not too much, is the key. To control moistening more easily, prepare a small volume of mix at a time. Then fill the seed-starting container, and settle the mix by rapping it against a hard surface.

4. Learn whether the seed should be covered or uncovered by the seed­ing mix. Several kinds of seeds, such as Lobelia cardinalis and Rhododendron species are small and need light, so spread them onto the surface of the mix. Avoid sowing the seeds heavily. You do not want the baby plants coming up like a lawn. For seeds that need to be covered, the depth should be approximately the diameter of the seed. Label the container with the species name and the date. Mist the container with water.

5. Maintain moisture after sowing. Enclose the seed container in a Ziploc bag or a takeout food container with a tight semi-transparent cover, especially if seeds are indoors under lights. If you rely on window lighting, never place the container of sown seed where direct sun shines on it. Check periodically that the container is still moist, and mist if neces­sary.

Many seeds, as mentioned, need a cold period after sowing. Put the container into your refrigerator or outdoors with protection from rodents. Outside, place plastic-covered containers under shrubs for shade, or cover larger seed flats with rigid metal hardware cloth or screening. Alternatively, you can use a cold place, such as an enclosed unheated breezeway, the stairs of a bulkhead entrance to a basement, or a cold frame. Light is not required during this cold period.

6. When germination begins, remove any plastic covering, and keep the mix moist by using a mist bottle or by setting the container in water so that moisture is absorbed from the bottom. If you must water from above, use a small watering can with a small-diameter spout that can dispense water very gently.

7. Do not transplant seedlings until they have a pair of true leaves, which emerge after the cotyledons or seed leaves. When transplanting, hold a seedling by a leaf to prevent damage to the stem. Seedlings don’t do well with too much space, so transplant several into a pot, or plant seedlings in rows in a takeout food container.

These suggestions should help you get started in growing native plants. Seed Starters East has sold seeds of several species this year. We selected ones that are likely to succeed if you fol­low simple directions. For species that need no special treatment, try Lobelia cardinalis, Penstemon digitalis, and Aquilegia canadensis. The milkweed species, Asclepias tuberosa and Ascle­pias incarnata are easy species but need a cold period.

Learn about our Seed Starters

A home landscape transformed into a coastal wildlife refuge habitat

Despite two changes in dates due to rain, a full compliment toured the landscape of veteran RIWPS member, Sally Johnson, on September 27.  Sally and her husband Curtis have worked to make their garden serve as a coastal wildlife refuge.