Dr. Meg Woller-Skar, Dr. Alexandra Locher, Joel Ball, Hannah French, Jessica DakeGrand Valley State University, Biology Department

AbstractThe rise of carbon dioxide levels (CO2) in the atmosphere has increased global temperatures and influenced changes in plant composition, distribution patterns, water use efficiency, and function of terrestrial systems. Additionally, extreme climate events such as increased precipitation and flood events, drought, hurricanes, duration of fires, introduced species, pathogen outbreaks, windstorms, ice storms and landslides have been documented more frequently than in past decades. Natural systems, such as forests, combat atmospheric carbon by sequestrating the gas and storing it within the vegetation and soil. This process lowers the amount of carbon found in the atmosphere, in turn slowing the rate of climate change and global warming. Rare ecosystems, such as wetlands, may act as a significant carbon sink. While rare ecosystems do not represent the majority of Earth’s land surface, their ability to store carbon may be significant when compared to other forested land cover. Thus, our goal was to measure and understand the importance of carbon sequestration in three rare ecosystems (oak-pine barrens, wet-mesic sand prairie, and coastal marsh) found in western Lower Michigan. Using methodology published by the US Department of Agriculture, we computed the amount of carbon is stored in the three rare ecosystems. Preliminary results reveal the importance of oak-pine barrens, wet mesic sand prairies, and coastal marshes in sequestering carbon and conservation of landscapes.

Introduction

Climate Change Current temperatures are expected to increase 1.1 o C - 6.4 o C over the next 100 years due to

the doubling of atmospheric CO2 (IPCC 2007). Global temperature trends have more than doubled over the last century. Threatens structure, composition, and function of ecosystems

Carbon Sequestration Involves processes by which atmospheric carbon is removed and stored over time. Carbon sequestration may slow or reduce the amount of CO2 in the atmosphere and slow the

rate of global warming. Wetlands (Mitra et al. 2005) and grasslands (Acharya et al. 2012) also may store a significant

amount of biological carbon. Most research investigating carbon sequestration occurs in forests, but rare ecosystems may

also represent important carbon sinks.

Carbon Sequestration Involves processes by which atmospheric carbon is removed and stored over time. Carbon sequestration

Objectives1. Quantify carbon in biomass and soil in 3 rare ecosystems and surrounding encroaching areas2. Model carbon storage in these ecosystems3. Apply results to larger spatial extents.

(Images from wwwo.commons.wikimedia.org and http://pics-about-space.com/earth-from-space-nasa-high-resolution?p=2)

Methods

Study Area Allegan State Game Area

Biomass and Soil Sampling 4-meter plots randomly positioned within each ecosystem and at paired locations in adjacent

encroaching forests. Measured DBH of trees. Harvested living biomass and dead organic matter within 0.25m2 plots. Collected soil samples to measure soil organic carbon. Measured soil moisture, temperature, pH, and air temperature, relative humidity, wind speed

and direction. Dried and weighed vegetation and soil samples. Burned off soil organic matter in muffle furnace, and weighed samples again

Modeling Acquire leaf-on 2016 imagery (available November 2016) from National Agriculture Imagery

Program (USDA). Calculate Normalized Difference Vegetation Index (NDVI) and model carbon sequestration in

each ecosystem and in the adjacent encroaching forests.

Results

Environmental Variables Principle Components Analysis explained 56% of the variability in the first 2 components. Oak-Pine Barrens and Wet Meadow Prairie: separated as a function of wind speed and air

temp. Coastal Plain Marsh: explained with higher humidity and lower soil pH.

Total Carbon Storage per Ecosystem Type Data were not normal despite transformation (Shapiro Wilk < 0.05). Comparisons made using

Mann-Whitney tests.

NDVI is an index of photosynthetic activity, or vegetation productivity. The rare ecosystems in this study generally have a lower NDVI than the surrounding encroaching forest because the tree biomass is larger. Thus, there is more carbon stored in aboveground biomass.

Assessing the Importance of Rare Ecosystems for Carbon Sequestration in WesternLower Michigan

Encroaching forest

Rare Ecosystem

Coastal Plain MarshOak-Pine BarrensWet Meadow Prairie

More total C stored within encroaching forests than within the rare ecosystems due to more tree biomass in the encroaching forests.

SOIL is more important for storing C within the 3 rare ecosystems than aboveground biomass.

Encroaching forest

Interior

Oak-Pine Barrens

Amount of Carbon (t C/ha)MEAN TREE CPM OPB WMPEncroaching 81.0 45.1 64.3Interior 0.9 10.5 5.3

SOIL ORGANICEncroaching 22.8 21.7 18.5Interior 37.1 20.0 23.2

TOTALEncroaching 100.8 67.3 78.9Interior 33.4 29.8 26.4

BELOWGROUND STORAGE OF CARBON IS CRITICAL FOR LONG-TERM SEQUESTRATION. CONSERVATION OF THESE RARE ECOSYSTEMS IS IMPORTANT FOR SLOWING THE RELEASE OF CARBON INTO THE ATMOSPHERE.