How Bedrock Nitrogen Influences Carbon Storage

The purpose of this research is to examine how trees, specifically Douglas fir (Pseudotsuga menziesii) responds at sites with high amounts of nitrogen (N) from rocks. In forests where Douglas firs are found, their growth is usually limited by the amount of N available to them. By providing the trees with more N from the rocks, the trees can consume more carbon (C) from the atmosphere. This explores carbon sequestration, capturing C from the atmosphere in the biomass of the trees and reducing the amount of CO2 in the atmosphere. My hypothesis is that trees with access to more N from the rocks, which acts like a fertilizer, will be larger and capture more C from the atmosphere storing it as biomass. We will be collecting measurements from 12 sites in northern California. The sites range from 60 to 1000 parts per million (ppm) of N in the rocks. We will use the diameter at breast height (DBH) measurements to calculate the leaf area index (LAI), which tells us how much C the trees are holding per acre. Contributing to the research will also be the counting tree rings which indicate the age of trees, so we may also see if trees are able to see if trees with more N are growing more annually. The larger amount of N taken from the bedrock resulted in more CO2 taken from the atmosphere as biomass. This resulted in more photosynthetic vegetation per unit area which means the trees are more productive. Carbon stored at these sites helps to slow the effects of increasing atmospheric CO2.