A Paleolimnological study of precipitation variability in the Adirondacks over the last thousand years
Mon, 12/02/2013 - 20:40
Abstract: At present, most regional climate models anticipate wetter conditions by the end of this century, but a few models anticipate drier conditions. This study uses foresight to test these models, as well as describe the relationship between the dominant climate system in the region and past precipitation in the Adirondacks. Precipitation was inferred from diatom assemblages observed along a lake sediment core extending into the 1000 years. This study shows that abrupt, extreme wet events were common during the last 1000 years, and a relationship between the dominant climate system (North Atlantic Oscillation) and precipitation was irregular during the cool Little Ice Age but negatively associated during the warm Medieval Climate Anomaly. With temperatures in the Northeast projected to increase by 2-5 degrees C by 2100 AD, our study suggests the region may become more arid rather than wetter, opposite of what models currently suggest.
Literary Rights: On
Major: Biology, Environmental Sciences
File Attachments: regalado.serwatka.docx
Alternative Management Methods for Acid Deposition in Lakes
Fri, 04/26/2013 - 18:09
Abstract: Acid deposition has been causing the acidification of lakes in the Northeast United States for decades. The result is lake ecosystems with abnormally low pH that stresses the organisms that live there. Management plans in place in the Adirondack Park have been working to remediate acidified lakes for the past few decades. Limestone (CaCO3) has been the generally accepted method for managing these lakes, in an attempt restore the lakes pre-impacted conditions. The purpose of this study was to evaluate the effectiveness of liming in reversing the effects of acidification, and to identify effective alternatives. Five alternatives were tested against limestone: Sodium carbonate (Na2CO3), Sodium bicarbonate (NaHCO3), Sodium acetate (CH3COONa), Magnesium carbonate (MgCO3), and Potassium carbonate (K2CO3). Double End-Point Titration tests were performed on all of the compounds, using both distilled water and lake water, to determine the relative alkalinity of each compound. Alkalinity is the measure of the ability of a solution to neutralize acid, also known as its "buffering capacity." Lake water was used in the titration tests in an attempt to mimic in-situ testing. The results of the titrations showed limestone proving to be the most effective in the lake water tests, with Magnesium carbonate and Potassium carbonate ranked closely behind. While limestone has proven to be an effective management method, its reliability is dependent upon the characteristics of the lake catchment, making it important to continue to look for alternative solutions.
Literary Rights: Off
Major: Environmental Sciences
File Attachments: AcidDeposition_Capstone.pptx
Changes in aquatic communities resulting from interactions between climate change and invasive aquatic plants in the Adirondacks.
Thu, 02/09/2012 - 11:26
Abstract: Global climate change can act synergistically with invasive species leading to shifts in ecosystem structure and function. We assessed how a rise in water temperature influenced the potential competitive advantage of an invasive aquatic plant, Eurasian watermilfoil, (Myriophyllum spicatum) over a co-occurring native species northern watermilfoil (M. sibiricum). We also examined the interrelationship between water temperature, watermilfoil, and the aquatic ecosystem including periphyton growth and zooplankton abundance. The study was conducted using replicated mesocosms (3785-liter), with water heaters used to provide a range of temperatures. We found that increasing water temperature promoted the likely competitive advantage of the invasive species, M. spicatum: Survival of M. sibiricum plants was lower than that of M. spicatum across all temperature treatments with a mean survival rate of 24% and 96% respectively. M. sibiricum also showed significantly slower rates of plant growth (mean growth of 3.3 cm compared to 7.6 cm for M. spicatum) and reduced vigor compared to M. spicatum, with an average of less than half the number of growing meristems. Zooplankton densities averaged over 20 times higher in mesocosms with M. sibiricum compared to those with the invasive M. spicatum. Periphyton biomass was best explained by water temperature with an increase in growth in warmer water. Our study confirms that in the face of global climate change, the invasive M. spicatum will continue to exert dominance over its native counterpart. Our results also provide compelling evidence that the combined effects of climate change and invasive aquatic plants can dramatically alter aquatic ecosystems.
Literary Rights: Off
Major: Environmental Sciences, Fisheries and Wildlife Science, Forestry, Natural Resources Management and Policy
File Attachments: Climate change and milfoil draft FINAL.doc