All vegetation is composed of carbon. Around 47% of the biomass is carbon. Carbon is stored in the trunk, branches, and leaves (also referred to as aboveground biomass) and the roots (belowground biomass).
Map the current status of ecosystem service (carbon storage) on the University of Twente campus using allometric equations. The focus is on above-ground biomass of trees (See Land cover map)
Pre-field preparation:
Sampling frame of 30 plots
Plots were naturally divided into strata (Coniferous, broadleaf, and Mixed) based on data attributes
Sampling type: stratified sampling with equal allocation
Sample size of 6 plots
Instruments: Locus Map, measuring tapes, DBH tape, metal pin, and field forms.
Field measurement
Attached the measurement tape to a central point and indicated a circular plot of 12.62 m radius.
Used a second measurement tape to make a ‘wedge’ to make it easier to systematically measure all trees in the plot.
For each plot, the DBH of all trees (minimal DBH 1 cm) was taken, and it was indicated if the tree is a broadleaf or conifer.
Adhered to the DBH measurement protocol by Ravindranath and Ostwald (2007).
(See gallery for pictures.)
Post Field:
Data entry and cleaning of field measurements
Calculated Above Ground Biomass (AGB) for each of the measured plots using the allometric equation by Lambert et al. (2005) for softwood (conifer) and hardwood (broadleaf) trees.
Used secondary data of existing field measurements to increase the sample size and help in extrapolation and estimation of carbon storage.
Mapping:
Mapping Approach: Remote sensing
Use vegetation indices from Sentinel-2 imagery to extrapolate the plot-level carbon storage data for the whole forest area.
Use regression analysis to establish the relation between these variables carbon and different vegetation indices (NDVI, GNDVI, SAVI, IRECI)
Vegetation indices were the explanatory variable.
Used both a linear and quadratic regression. The best vegetation was SAVI (highest R²).
Masked forest land cover and created a carbon map.
Tools used: Copernicus Sentinel Browser, ESA SNAP tool, R, Excel and ArcGIS Pro
Ecosystem Type: Regulating Service
Supply/Demand/Flow: Supply (Potential Carbon stored in Forest Biomass)
Savi R² = 0.7
Total forest area = 43.67 hectares
Total carbon stored = 590,737 tons