THE CHRISTMAS TREE PROJECT – FRIEND OR FOE OF LOUISIANA’S SALT MARSHES

According to the National Christmas Tree Association there are approximately 35 million Christmas trees currently growing in the United States, and 25 – 30 million are sold each year. The NCTA states that there are more than 4,000 recycling programs throughout the U.S., including the “Christmas Tree Project” in coastal Louisiana. The project is the annual placement of used Christmas Trees in fencing parallel to the wetlands as a restoration technique, which is said to buffer waves, slow erosion, trap sediment, and keep the trees out of landfills. However, since the program’s inception in the 1990s only one study has been done in 1997 which found that the Christmas tree fences did in fact decrease wave energy and increased marsh platform elevation, however within the three-year study plant colonization was not found at either site in the study. Although the study had some positive outcomes, there were many questions left unanswered, one for instance is, “Why weren’t there any new plants after three years?” When a Christmas tree’s roots are removed it is considered to be on “life support”, needing water every day to delay decomposition. Studies show plant debris decomposition within wetlands can potentially release excess nutrients and change the microbial community diversity. The microbial community diversity alteration may potentially increase the possibility of Eutrophication, which in turn can decrease below-ground root biomass. This loss of root biomass can then decrease the soil strength and increase the marsh’s susceptibility to erosion. This proposed project will measure salt marsh platform surface elevation, calculate the wave energy reduction of the fencing, measure sediment transport, measure erosion and/or accretion, collect water quality samples, calculate below-ground biomass, measure vegetation diversity and vegetation density. Another purpose of this study is to utilize an Unmanned Aerial Vehicle (UAV) to collect the elevation data, accretion and erosion data, and potentially the vegetation data. The main benefit of completing this study is to get a better understanding of how salt marshes are responding to the decomposing Christmas trees being placed as barriers for wave energy. The salt marsh is an important sink of atmospheric carbon and its soil is responsible for transforming biological and chemical materials. Gathering data on nutrient release from the Christmas trees over a year’s time will further the understanding of how the possible nutrient release may be altering the salt-marsh vegetation and biomass.