For centuries, maps have been critical to understanding our world. In forestry and natural resource management, this is especially true.

Many efforts have been made to quantify, map, and visualize forests around the globe. Some of these efforts build on advances in remote sensing technologies, using data from sensors to model forest structures and monitor forest change. Other work has focused on using ecological information to model forest characteristics, as well as efforts to harmonize multiple maps of different parts of the globe into single, coherent datasets.

All of these efforts add to our understanding of Earth’s forests and dynamics, as well as how we can use the available tools, data, and technologies to map and estimate the current landscape and predict what changes may come. But, keeping track of all of these projects is challenging.

We’ve compiled a non-exhaustive list of forest map products, along with the inputs and data used to develop the product, resolution of the data product, what value is being mapped (treelists? Aboveground biomass? Cover type?), and what year the dataset represents. More information for each of the datasets we focused on is presented in the table below.

It can be hard to evaluate the accuracy of a dataset representing large-scale, small-area estimates of forest structure or related values, such as aboveground biomass. Data from different researchers and organizations can differ quite substantially – see A Review of Regional and Global Gridded Forest Biomass Datasets for one such assessment. Such differences motivate the creation of harmonized data products like the Avitable et al. work. Another great recent publication focuses on both comparison and validation challenges. The Importance of Consistent Global Forest Aboveground Biomass Product Validation, highlights these challenges, pointing out that there is no canonical or fiduciary dataset representing global biomass field measurements. Many maps and models exist, but independent data to evaluate and compare them is much harder to come by!

Here at NCX, our Data Science team is working on a system for reporting the performance of our Basemap dataset against field data and other available data products. As our programs grow and scale, we are collecting many thousands of field measurements each year – data that we will use to transparently assess our Basemap data product as we improve it over time. In doing so we hope to contribute to the conversation about validation and comparison of these data products as researchers work together to quantify the current state of our forests.