Tuesday, August 29, 2017

Acid Rain Still Impacting Adirondack Lakes and Forests

In a recent newsletter from Congresswoman Elise Stefanik, she mentioned visiting the facilities of the Adirondack Lakes Survey Corporation to discuss strategies for measuring and combating acid rain in the Adirondacks. Although acid rain remains an important topic of study and discussion, the once commonplace phrase has become somewhat obscure in recent years and the problems associated with acid rain have taken a back seat to other, more widely discussed environment-impacting issues.

Like global warming, acid rain results from burning fossil fuels, either to generate electricity at large power plants or to run vehicles and heavy equipment. As the resulting ‘acid gasses’ are released into the air, they combine with water vapor, producing sulfuric and nitric acids, which fall to earth in acidified rain, snow, sleet, fog, mist, or hail.

One of the most significant impacts of acid rain is the acidification of lakes and streams, which has been a serious environmental problem in many areas of the world for more than a half-century. Scientists in our region first became alarmed about acid precipitation in the 1970s, when small lakes in the Adirondack Park were found to be so abnormally acidic that fish were no longer able to live in them. Recovery in some Adirondack lakes has been very slow since then, even with a decline in acid precipitation. U.S. emissions of sulfur and nitrogen decreased by 51 and 43 percent between 2000 and 2010, after regulations targeted power plant emissions and vehicle exhaust.

The problem is one of balance. Nature depends upon balance. Normal precipitation reacts, for example, with anhydrous (or water-free) ammonia and other alkaline chemicals found naturally in the air and in alkaline bedrock and soils (limestone, for example) which help to neutralize the effects of acid rain and snow. In many regions of the world, the soil within lake watersheds provides ample acid-neutralizing-capacity to mitigate the effects of acid deposition. (Nonetheless, if precipitation remains highly acidic, it can eventually deplete available acid-buffering chemicals, in which case, the buffering effect will no longer occur and nature’s ability to maintain balance will have been destroyed.)

The surrounding soils and underlying bedrock of the majority of lakes within the Adirondack Park are comprised of minerals which are slow to weather and, as such, have little capacity to neutralize or buffer acidic water. Consequently, as acid precipitation falls (or thaws) into Adirondack lakes and the streams that feed them, these bodies of water gradually becomes more and more toxic. At one time, 409 Adirondack lakes supported brook trout. Many are known to have lost their trout populations because of acid rain.

In the 1970s, people also began to see dead and dying trees in many areas of the Adirondack forest and suspected that the cause was acid rain. Today, scientists almost unanimously agree that acid rain threatens the well-being of some native tree species and that harm to trees is compounded when acid rain is present with other stress factors (i.e. abnormal weather conditions, insect damage; both of which are also often tied to global warming associated with the burning of fossil fuels).

One of those threatened species, the sugar maple, which gets its Latin name, Acer saccharum (sweet maple), from its remarkably sweet sap, is quite possibly the most economically valuable tree species in the eastern United States and Canada, because of its role in the multi-million dollar maple syrup industry, the value of its in-demand, high-quality, hardwood lumber (used in making furniture, cabinets, and floors, including bowling alley floors and basketball courts), and regional tourism generated by the magnificence of its fall foliage. It’s one of the region’s most ecologically important trees as well, and the official state tree of both New York and Vermont. It’s the national tree of Canada, too. And the sugar maple leaf is the Canadian national emblem.

Research conducted in recent years by State University of New York (SUNY) College of Environmental Science and Forestry (ESF) scientists involved analyzing growth rings from hundreds of sugar maples from across the Adirondacks. The results of the study, which were published on Oct. 21, 2015, in the open-access journal ‘Ecosphere,’ showed that a decline in the growth rate for a majority of sugar maples began after 1970, although the study concluded that the reasons for the decline are unclear.

An earlier study of acid rain impacts on sugar maple forests in the Adirondacks, led by Dr. Timothy Sullivan at E&S Environmental Chemistry of Corvallis, Oregon, and Dr. Gregory Lawrence of the U.S. Geological Survey, whose ongoing research includes study of recovery processes in an Adirondack watershed where acid deposition has acidified soils and stream water, and assessing acid deposition effects throughout the Adirondack ecoregion through the use of stream surveys and soil sampling, showed lower regeneration and poor health of sugar maple in forests heavily impacted by acid rain.

Prior research by U.S. Forest Service Northern Research Station scientists suggests similar growth declines might be occurring widely across the northeast, but further study is needed to verify their observations.

Richard Gast

Richard Gast is a retired Extension Program Educator and has been contracted by Cornell Cooperative Extension Franklin County to continue his informative and thought provoking articles.

15 Responses

  1. Boreasfisher says:

    Richard, this is interesting and helpful, especially in its citations of relevant studies, but also, as you probably agree, exasperatingly inconclusive. How does one evaluate and respond to the various adverse trends….the slow growing maple, as you point out, but also in my neck of the woods, the die off of red pine.

    I guess we should all support more funding for scientific research and do all we can to mitigate the other factors– global warming and the spread of invasives. Thank you for keeping us informed!

  2. Boreas says:

    Thanks Richard. It seems to be a common belief that we have put acid rain behind us. In reality, it has only been temporarily reduced. I say ‘temporarily’ because politics is getting in the way of continuing the regulations to lower powerplant emissions. Cheap, dirty energy is only cheap until you factor in all of its consequences.

  3. Charlie S says:

    “I guess we should all support more funding for scientific research and do all we can to mitigate the other factors–..”

    > We’re going to need all the help we can get these next 44 months….and then some!

  4. Brian M. says:

    “Natural gas is a fossil fuel, though the global warming emissions from its combustion are much lower than those from coal or oil. Burning natural gas does produce nitrogen oxides (NOx), which are precursors to smog, but at lower levels than gasoline and diesel used for motor vehicles. DOE analyses indicate that every 10,000 U.S. homes powered with natural gas instead of coal avoids the annual emissions of 1,900 tons of NOx, 3,900 tons of SO2, and 5,200 tons of particulates.”

    Too bad Politican Cuomo continues to fight against natural gas.

  5. Paul says:

    “although the study concluded that the reasons for the decline are unclear”

    Despite the fact that the study concluded that it is not clear what the cause of the decline was – it sounds like you are trying to make a link between maple declines and acid rain. Is that right?

    • Jesse B says:

      Ecological and observational studies can never definitively link an exposure (e.g. acid rain) with an outcome (e.g. maple declines). It is not their purpose to provide a ‘smoking gun.’ However, these studies are beneficial by providing evidence of statistically significant associations (e.g. maples have significantly declined since the 1970’s). Examining these results as part of the greater scientific literature (e.g. acidic water in the lab reduces maple seedling growth; Adirondacks experienced high acidity in 1970’s; sulfur dioxide combines with H20 to produce sulfuric acid; downwind SO2 emissions cause acid rain conditions upwind), we can develop a scientifically justified picture of what is taking place.

      Did this article definitively link maple declines to acid rain? No. Does the broader scientific evidence (of which this is a piece) support that maples decline under acid rain conditions? Yes.

      • Paul says:

        These comments made me take a look at what some of the scientists on the ground are seeing. I saw this article written by two DEC scientists who I assume are pretty well studied on the topic. Their conclusions seem to be that things are on the road to recovery in what they describe as “all indications”. Surprised they didn’t discuss this link you describe. Maybe there is actually a totally unrelated reason that there is a maple decline?:


        • Boreas says:


          I am not sure what link you are referring to. But from the 2013 article you noted, “Perhaps due, at least in part, to this
          progress, many people think of acid rain
          as a “problem of the past.” But this is
          not the case. Although acid deposition
          is considerably lower in New York than
          it was several decades ago, and many
          Adirondack lakes have improved, some
          lakes continue to be impaired. In addition,
          there appears to be more of a delay in
          biological recovery. Not all lakes in the
          region have recovered sufficiently for
          fish populations to be sustainable.”

          In this case the authors are referring to native fish, but other flora and fauna are in the same ecosystem. Trees, which take decades to mature, are going to be slower at providing clear answers. What does halving the amount of acid precipitation today really mean at ground level? How much of the available buffering capacity of the original ecosystem were damaged from the initial onslaught of acid precipitation decades ago? How much of the invisible micro-organism community in the soil has been harmed or altered? How much have changing precipitation and temperature patterns effected the ecosystem?

          None of these factors occur in isolation. The question shouldn’t be, do we have the proof that acid rain is a direct causation of tree die-off, but rather, what can we do to mitigate these environmental impacts on the ADK ecosystem as a whole? It might take centuries worth of studies to demonstrate the impacts of all of the many variables acting concurrently. Do general warming trends, increased summer precipitation, decreased snowfall, and acid rain have impacts on the forests and waters? I believe most people would say yes. The question is, which variables do we have the power to control in our lifetime? Acid rain due to coal and emissions seems to be the one aspect that we have been able to tame, even if we haven’t been able to eliminate. Even if maple/tree die-off is not directly linked to acid rain, I believe we should still strive to minimize as many potential sources of acid rain as possible.

        • Jesse B says:

          It’s certainly possible there is an unrelated reason. However, the evidence is overwhelmingly supportive that acid rain causes harm to forest ecosystems.

          Paul, if you’re interested in reading more here’s the link for Google’s scientific search engine (https://scholar.google.com/). While not all the articles are free, you can at least read the Abstracts (most local college libraries will have full access). Feel free to type in the terms ‘acid rain maple trees’ and you can see a pretty comprehensive picture of the research out there.

          • Paul says:


            Thanks I use Google Scholar almost on a daily basis. I am well aware of it.

            I have excellent access to almost all scientific journals.

            I am not disputing the negative effects of acid rain in any of my comments.

  6. JH says:

    Where is the beef?
    This article told us nothing. Any real numbers anywhere? You can’t just assume the lake levels or dead trees come from acid rain. What are the measurements of the rain as opposed to what is found in lakes and streams. That is real data.

    • Boreas says:

      This is an article the Adirondack Almanack, not a research paper in a scientific journal. There are decades worth of research and numbers out there if you are indeed interested in them. An acid-rain denier in the Adirondacks is a rare bird indeed.

      • JH says:

        The title of the article: “Acid Rain Still Impacting Adirondack Lakes and Forests”
        Where is the data?
        It is a general rehash article that tells nothing.

      • Paul says:

        Couple things:

        Why would questioning some of the content in this article make someone and “acid-rain denier” (whatever that is)?

        People that want good solid facts on any issue are not “deniers”. That is one of the problems with discussions regarding things like climate change or GMOs. People seem to flip out very quickly.

        I would guess that many folks that comment here are not IN the Adirondacks.

        • Boreas says:


          Talking of jumping to conclusions! If I wanted to label Jh a “denier”, I simply would have. He/she didn’t seem to take it that way. “An acid-rain denier in the Adirondacks is a rare bird indeed.” is what I said. What that means is that most people in the Adirondacks believe in acid rain and its effects – many through first-hand experience. As I have said before, most of my statements here should be taken at face value, as I am not a very deep thinker.

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