"We cannot manage carbon on the land without thinking about who will be doing the managing," Lisa Dilling of the University of Colorado, Boulder, US, told environmentalresearchweb. "There was a lot of research on estimating the amount of carbon that could be potentially stored in various terrestrial reservoirs, but a lack of focus on the decision makers themselves."
With this in mind, Dilling and colleague Elisabeth Failey became interested in how the potential for carbon storage based on factors such as soil and vegetation type overlapped with various types of land ownership. The pair used GPS to study these variables for the US state of Colorado.
Roughly 57% of Colorado's 27 million hectare land-area is owned by the private sector, while federal government agencies such as the US Forest Service and Bureau of Land Management hold 37%. Nearly half of the state (46%) is covered by grassland and shrubland, some of which is used to graze livestock, while forests take up 31% and agriculture covers 15%. Three-quarters of Colorado's forest area is publicly owned; this is significant because forests tend to store more carbon per hectare than grassland and agricultural land.
"While we have not investigated this pattern for the broader US, at least in Colorado there is more carbon stored in public lands proportionately compared with private lands, because of the vegetation type," said Dilling. "It is therefore important to recognize that if we want to obtain the maximum carbon potential for additional sequestration, we cannot rely only on incentives for private land owners, such as carbon offsets."
Currently, forest carbon-offset projects in the US have focused on private owners. Such schemes typically provide a payment in return for carbon storage. Although there are plans afoot to set up protocols for managing carbon on federal lands, public land owners are likely to be under pressure to focus on areas such as fire management, recreation, species preservation, reducing erosion, and resource extraction. While some of these may be compatible with carbon management, it's likely that trade-offs will need to be negotiated.
According to Dilling, achieving the land's full potential for carbon storage will "require multiple types of policies from those that target private owners to policy mandates for federal land owners and the like to add carbon storage to their portfolio".
Now Dilling and Failey are looking to gain a greater understanding of "the influences on land use decision-making and how it will affect carbon, as well as how information can be useful across various scales of decision-making".
The researchers reported their work in Environmental Research Letters.