Hello, I would like to confirm how we should be entering carbon pool values for the water class in the biophysical table and also I am looking for geospatial data for this LULC class in particular.
1- What carbon pool value do we need for the water LULC of the biophysical table: dissolved inorganic carbon, dissolved organic carbon or else?
2- Under which column should this information be entered (below-ground or soil)?
3- What techniques did you use to differentiate the carbon found in lakes from rivers?
4- To get my carbon pool values, I have used open-access geospatial data from scientific papers and performed zonal statistics to estimate average values. I would like to know if anyone in this forum has found gridded data for carbon in aquatic environments that I could use (North America). I found it very difficult to find geospatial data on dissolved inorganic carbon or dissolved organic carbon in inland waters.
Are you referring to the Carbon Storage and Sequestration model or the Blue Carbon model? I’m guessing Carbon Storage, but just checking. Their carbon pools are similar anyway.
The Carbon Storage model is extremely simple, it just adds up the values in the 4 carbon pools and assigns them to each LULC class. Sometimes we have values for all 4 pools, sometimes not, sometimes we have aboveground biomass information combined with belowground biomass in a single value and only put that value into one of those pools and leave the other one at 0, etc. So the model itself is flexible about which pool you assign values to, they just all must have the same units (per hectare), and must have some value, even if it’s 0.
Specifically for water, we usually assign it a value of 0 for aboveground and belowground biomass, unless we know that there’s significant vegetation within the water bodies (so they’re more like wetlands). Personally, I’ve never included dissolved carbon. If you want to include dissolved carbon in the water class, I’d say that you’re welcome to if it’s important for your work, and it can be up to you to decide which form of carbon, and which column to put it under. The model doesn’t really care since it just adds the 4 pool values together.
Since I’ve never considered dissolved carbon, I don’t have any data sources to share, but perhaps someone else does.
Thanks so much for the prompt reply. Your explanations were very clear. I am indeed using the Carbon Storage and Sequestration Model. Just to confirm, I’d like to hear more about how you consider the carbon found in aquatic environments such as rivers or lakes:
Do you distinguish between the two types of ecosystems in the LULC (rivers/lakes)?
Also, from what I understand you assign the value of 0 to AGB and BGB. What about soils and dead matter?
I have never distinguished between rivers and lakes, but I’ve also not worked on a study where it might have been important to do so. Has anyone else looked into this?
It’s usually hard to find dead matter information for any land cover type, so it’s often left at 0 simply because data doesn’t exist.
For soil data, we often set that pool to 0 in the model, then add in a separate soil carbon raster in post-processing (like Soil Organic Carbon Stock from ISRIC SoilGrids). This allows us to define soil separate from vegetation classes, which is useful. However, soil maps often are missing data in water bodies, so you might still end up with no information in these places. One thing you can do as an estimate is use a little GIS processing to fill in the missing data in the soil carbon layer with the dominant value around the water bodies.
I think I understand. I should use the InVEST model for terrestrial ecosystems. Then, I could combine the model output with another raster map containing the carbon storage estimates for water bodies (in tons/pixel). Is that correct?