Research Results
Carbon Storage Above and Below Ground in Two Sites in Cascade Brook Watershed, Black Rock Forest, New York
Title | Introduction | Methods | Results | Discussion
A. Introduction
For the past one hundred and fifty years to two hundred years, humankind has been altering the balance of the global biogeochemical carbon cycle. Only during the past two decades have some scientists, political leaders, governments of industrialized countries, international energy corporations, environmental NGOs and the media begun to take notice of how humans have been tipping the balance.
Carbon, in its various chemical forms, is naturally cycled through the atmosphere, the terrestrial biosphere and the oceans through several processes, including photosynthesis, respiration, decomposition and combustion. Through fossil fuel emissions, land conversion, slash and burn agriculture and deforestation, human carbon emissions have been altering the carbon budget. The response of the global ecosystem to elevated atmospheric carbon dioxide has not been predictable. This study aims to elucidate the role of temperate, deciduous forest ecosystems and reduce the unpredictability of their response to the changes in the global carbon cycle.
Carbon dioxide plays a major role in determining climate. As a "greenhouse gas", CO2 helps to trap solar radiation within the troposphere, giving all the regions of the world their characteristic annual average temperature. Because carbon affects temperature, it also affects atmospheric pressure, ocean circulation and weather and storm patterns. There is great uncertainty about the degree to which different regions will experience climate change. With a better understanding of the capacity of the terrestrial biosphere sink to store anthropogenic carbon, we can improve predictions as to the magnitude and timing of anthropogenic climate change.
According to measured emissions and estimated land conversion and deforestation rates, the level and acceleration of atmospheric CO2 should be greater than it is. It seems that a component of the budget is acting to somewhat offset anthropogenic carbon emissions. The extra carbon must be stored somewhere in the oceans or the terrestrial biosphere, somewhere in the boreal, temperate or tropical biomes of the world. Because there is still so much ambiguity about this carbon storehouse, it has been called the missing carbon "sink" (Tans et al. 1990)1. The "sink" must be located and it must be quantified in order to determine its capacity.
Many researchers believe that the missing sink lies somewhere in the world's temperate forest ecosystems. However, there are currently very few studies which attempt to quantify the carbon storage in temperate forest trees and soil. Our team decided to undertake this preliminary study to determine the carbon storage in an upland and a lowland site in a typical temperate, deciduous forest ecosystem.
B. Site Description
Black Rock Forest is an example of a typical northern hemisphere, northeastern deciduous forest in terms of forest composition, tree diversity and age. The forest is located in the Hudson Highlands region of New York State, about 80 kilometers north of New York City (see Figure 1). It is a 1500 hectare natural forest ecosystem. The two sites chosen for this study are located in the southern section of Cascade Brook Watershed; one site is on a ridge near the top of the watershed (the "upland site") and one is near a wetland that lies at the lowest point in the watershed, Glycerine Hollow (the "lowland site").
Figure 1: Black Rock Forest, 80 km North of New York City. Source:blackrockforest.org
The two sites for this research were chosen in order to study how differences in topography, microclimate and vegetation might affect carbon storage over time. How different microclimates and ecosystems affect carbon storage is of particular interest since global climate change is expected to alter the conditions in many of the world's biomes and it is important to understand how a change in local climate might enhance or reduce an ecosystem's ability to store carbon and buffer anthropogenic emissions.
The Cascade Brook Watershed upland site is dominated by Quercus rubra, Quercus velutina and Carya spp. The lowland site is dominated by Quercus rubra, Acer saccharum, Fraxinus sp. and Fagus grandifolia, among others.
References
1. Tans, P.P., I.Y Fung and T. Takahashi. (1990). Observational constraints on the global atmospheric C02 budget. Science. 247:1431-1438.
Title | Introduction | Methods | Results | Discussion
