Long Island Botanical Society Vol. 28 No. 2 The Quarterly Newsletter Spring 2018 Why Are Plants on the Stony Brook Campus Thriving Despite Acid Rain and Acid Soil? by Jeffrey E. Hudson and Gilbert N. Hanson, Stony Brook University In this report we on the Harbor Hill present data relating moraine just as to the effects of the Stony Brook acid rain on the campus is. Greller et soil and plants in al. (1990) restudied the wooded areas the pH of soil and of the Stony Brook plant distributions University campus. in 1985. They The data include found a significant soil pH with depth, decrease in pH exchangeable1 compared to that calcium (Ca) and found by Wherry aluminum (Al) in (1923) (Table 2) soil with depth, the and concluded that species distribution the decrease in soil of plants, pH of pH was a result of soil and the Ca and acid rain. Greller Al concentrations et al. (1990) also of leaves and roots found that there on the Stony Brook Figure 1. Location of study sites on the Stony Brook University campus. The yellow five-pointed were fewer species University campus star identifies the Ashley Schiff Park Preserve, location of soil-pH and leaf-collection sampling. of dominant plants The four-pointed star is the location of cation exchange capacity (CEC) analysis of soil. (Fig. 1). A more within the forest, an complete presentation of these results is on the web at: www. increased dominance of acid-tolerant plants, and a loss of geo.sunysb.edu/reports. acid-sensitive plants. Acid rain has been falling on Long Island for at least the last 70 Hedin and Likens (1996) suggest that acid rain inhibits the years. The pH of rain was 5.6 before industrialization. By 1987 growth of plants because acid rain washes plant nutrients it was 4.3, an increase in acidity by a factor of 30. From that (mainly exchangeable Ca) from the soil and makes available low point in 1987 pH has increased to 5.0 in 2013 (Table 1). toxic aluminum. However, atmospheric dust replenishes some So, things are getting better as a result of the Clean Air Act of of the lost Ca. 1963 and later amendments. When acid rain infiltrates the soil, it enriches exchangeable Wherry (1923) studied the plant distributions and the pH hydrogen ions on soil particles. These hydrogen ions of soil in a deciduous forest in Locust Valley some 40 km promote the production of exchangeable aluminum and west of the Stony Brook University campus. This forest is (Continued on page 9) 1 Exchangeable elements are available to plants in the soil. Exchangeable, positively-charged elements (cations) that are soil nutrients are calcium, magnesium and potassium. Calcium is used as a proxy for all of these nutrients because it is usually the most abundant. Page 8 Long Island Botanical Society Vol. 28 No. 2 Long Island Society News Botanical Society Founded: 1986 • Incorporated: 1989 Lois Lindberg, LIBS Membership Chair, offers the following report: The Long Island Botanical Society is dedicated to the promotion of field botany and a LIBS Membership by the Numbers greater understanding of the plants that grow wild on Long Island, New York. As the long-time membership chair, I recently reviewed some noteworthy facts about our 30-plus year history. The Society currently has a Visit the Society’s Web site membership of approximately 175, with 18 professional organizations www.libotanical.org represented. Although most of our members hail from New York, people have joined from 14 states across the country, and Canada. Our first Executive Board President Life Member signed up in 1998, and now 29 people are part of that Eric Lamont 631-722-5542 elite group. Looking back to the Society’s beginnings, ten of the original “class of 1986” are still members today. And LIBS certainly builds a loyal [email protected] following: almost 70 of you folks have been members for at least twenty Vice President years – Wow! And such diverse professions and interests – teachers, field Andrew Greller [email protected] researchers, ecologists, gardeners, authors, artists, citizen scientists – all Treasurer with a common goal to protect our botanical heritage. Thank you to Carol Johnston everyone for your support of LIBS. [email protected] Recording Secretary Sue Avery [email protected] JOIN LIBS TODAY! Corresponding Secretary Annual Membership is $20 payable to: Rich Kelly [email protected] Long Island Botanical Society Committee Chairpersons Mail your dues to: Flora Carol Johnston, LIBS Treasurer Eric Lamont [email protected] 347 Duck Pond Road Andrew Greller [email protected] Locust Valley, NY 11560 Field Trips Allan Lindberg [email protected] Programs Rich Kelly [email protected] Announcements: Membership April 13-15, 18th Northeast Natural History Conference (NENHC), Lois Lindberg [email protected] Burlington, VT Conservation Bill Titus [email protected] This conference has been the largest regional forum in which researchers, John Turner [email protected] natural resource managers, students, and naturalists can present current Education information on the varied aspects of applied field biology (freshwater, MaryLaura Lamont marine, and terrestrial) and natural history of the Northeastern United [email protected] States and adjacent Canada. By bringing together people with diverse Hospitality backgrounds it will serve as a premier venue for identifying research and management needs, fostering friendships and collegial relationships, and Kathleen Gaffney [email protected] encouraging a greater region-wide interest in natural history. https://www. Dorothy Titus [email protected] eaglehill.us/NENHC_2018/NENHC2018.shtml Newsletter Editor Margaret Conover The Town of North Hempstead offers classes in: Composting, Installing [email protected] and Using a Rain Barrel, Sustainable Yard Care, Creating a Rain Garden, with special thanks to and Native Plant Gardening. http://www.northhempsteadny.gov/ Skip & Jane Blanchard Composting-Rain-Barrels-and-Gardens Webmaster Donald House [email protected] Long Island Botanical Society Vol. 28 No. 2 Page 9 (Why Are Plants Thriving, continued from cover) Table 2. Soil pH using distilled water1 in Table 1. pH of rain on Long Island a forested area in Valley Stream, NY. Date pH Ridgetop Slope Bottomland 1955-561 4.8 Wherry 4.5 5.5 6.5 2 1987 4.3 (1923) 2 2005 4.6 Greller et al 3.8 3.9 4.1 3 2013 5.0 (1990) 1 Mackenzie & Mackenzie, 1995 1 Distilled water gives a pH about 0.6-0.7 pH units greater than that 2 NYSDEC, 2005 given by using 0.01 m CaCl2 (Bauch, 2007). 3 Extrapolation based on pH of rain in Washingon Crossing, NJ which also had a pH of 4.3 in 1987 and a pH of 4.5 in 2005. In 2013 the pH of rain had increased to 5.0 New Jersey DEP, 2016. Table 3. Estimated plant cover Fagus grandifolia 1% replace the exchangeable Ca on the soil particles (Hedin American Beech and Likens, 1996). Exchangeable Ca ions are essential for healthy plant growth, whereas exchangeable species of Al Viburnum acerifolium 44% impede plant growth (Ericsson 1995). Cronan and Grigal Maple-leaved Viburnum (1996) found that there is a greater than 50% risk of adverse impacts on plant growth if the Ca/Al molar ratio Thelypteris noveboracensis 3% is less than 12.5 in plant leaves, 1.0 in soil solution and New York Fern 0.2 for fine root tissue. Toxicodendron radicans 6% Poison Ivy Results All the plants in the Stony Brook study areas (Table 3) Acer rubrum 1% are considered acid tolerant (Gawler and Sneddon 2015). Red Maple Maple-leaved viburnum (Viburnum acerifolium) is the most abundant species by groundcover. These species were also Sassafras albidum 5% found by Greller (1990) and Wherry (1923). Sassafras Soil pH was determined in the Ashley Schiff Park Preserve Gaultheria procumbens 2% in October 2017 by Karim Hanna (pers.comm.) (Fig. Wintergreen 2). The pH of the soil on the ridge and along the slope is less than that in valley floor (bottomland) even though Total 62% the change in elevation is only three meters. For each site the pH value of the organic matter in the O-horizon (0 to +5 cm) is significantly higher than at the boundary with the underlying topsoil. These data suggest that as the rain There are, however, not enough samples to show a seasonal passes through the O-horizon it releases organic acid. pattern of changes in the Ca/Al ratio for the various species (Table 4). Maple-leaved viburnum, the most abundant We collected leaves in the Ashley Schiff Park Preserve for groundcover plant, has the lowest Ca/Al ratio. It is not clear chemical analysis at three different times, newly fallen if the deviations are related to changes in leaf chemistry leaves in November 2015, leaves on the plants in July 2016, associated with the season of collection or to other factors. new buds In April 2017. For both sassafras and black birch, the only two species (Continued on page 10) Page 10 Long Island Botanical Society Vol. 28 No. 2 (Why Are Plants Thriving, continued from page 9) Table 4. Chemical analysis of leaves Date Ca/Al collected molar Fagus grandifolia April 2017 56.2 Beech Betula lenta April 2017 220 Black Birch Betula lenta July 2016 121 Betula lenta Nov. 2015 78.5 Figure 2. Depth versus soil pH above and below the organic- mineral boundary at the top of the soil horizon Acer sp? July 2016 195 Maple sampled in more than one season, the fallen leaves collected in November have a lower Ca/Al ratio than those collected in the Viburnum acerifolium July 2016 17.2 spring or summer.