2023-05-04T13:11:58.897275

2025-03-10T13:45:54.548019

Administrative area

Global

Use the following credit when this data is displayed:  Accessed through Global Forest Watch on 04/10/2022. [www.globalforestwatch.org](https://www.globalforestwatch.org/). <br><br>  Use the following credit when this data is cited:  Potapov, P., Hansen, M.C., Pickens, A., Hernandez-Serna, A., Tyukavina, A., Turubanova, S., Zalles, V., Li, X., Khan, A., Stolle, F., Harris, N., Song, X-P., Baggett, A., Kommareddy, I., and Kommareddy, A. 2022. The Global 2000-2020 Land Cover and Land Use Change Dataset Derived From the Landsat Archive: First Results. Frontiers in Remote Sensing, 13, April 2022. <https://doi.org/10.3389/frsen.2022.856903>; summarized by administrative area at WRI.

UMD Net Tree Cover Change (from height, adm0)

2000-2020, global, UMD/NASA GEDI

Potapov, P., Hansen, M.C., Pickens, A., Hernandez-Serna, A., Tyukavina, A., Turubanova, S., Zalles, V., Li, X., Khan, A., Stolle, F., Harris, N., Song, X-P., Baggett, A., Kommareddy, I., and Kommareddy, A. 2022. The Global 2000-2020 Land Cover and Land Use Change Dataset Derived From the Landsat Archive: First Results. Frontiers in Remote Sensing, 13, April 2022. [https://doi.org/10.3389/frsen.2022.85690](https://doi.org/10.3389/frsen.2022.856903); summarized by administrative area at WRI 

[CC by 4.0](https://creativecommons.org/licenses/by/4.0/)

This data set, a collaboration between the GLAD (Global Land Analysis & Discovery) lab at the University of Maryland, Google, USGS, and NASA, measures areas of net tree cover change across all global land (except Antarctica and other Arctic islands) at the administrative area. The data shows how much more or less tree cover a given area (country, state/province, or county/municipality) had in 2020 compared to 2000. This is not an annual data set and is displayed as a 20-year cumulative layer with a baseline year of 2000 and end year of 2020. Tree cover change was determined using tree cover extent for the years 2000 and 2020, which are based on tree height information. Tree height was determined by the integration of the Global Ecosystem Dynamics Investigation (GEDI) lidar forest structure measurements and Landsat analysis-ready data time-series. The NASA GEDI is a spaceborne lidar instrument operating onboard the International Space Station since April 2019. It provides point-based measurements of vegetation structure, including forest canopy height between 52°N and 52°S globally. The tree cover extent maps for 2000 and 2000 were produced by attributing pixels with ≥5 m height as the tree cover extent. The tree cover gain or loss was derived from a comparison between the year 2000 and 2020 maps, with steps taken to eliminate small changes in height which are “noise” in the data. The net change corresponds to the area of gross gain minus the area of gross loss to show the overall change. The net change percent per administrative region was then derived by calculating tree cover gain or loss as a percentage of the baseline 2000 tree cover area. <br><br>  **Stable forest** – Area of tree cover that remained at or above 5m in height between 2000 and 2020. <br><br>  **Gain** – Area of tree cover that was below 5m height in 2000 but at or above 5m height in 2020. <br><br>  **Loss** – Area of tree cover that was at or above 5m height in 2000 but below 5m height in 2020. <br><br>  **Disturbed** - Represents areas that experienced both loss and gain between 2000 and 2020. <br><br> 

Identifies net tree cover change

In this data set, “tree cover” is defined as all vegetation greater than 5 meters in height, and may take the form of natural forests or plantations across a range of canopy densities.<br><br>  A direct comparison of the years 2000 and 2020 forest height products, without the application of thresholds which define forest height increase and decrease in this product, will not provide consistent and meaningful results and will not be comparable to this product. Integrated use of other products such as canopy cover density data also available on GFW should be performed with caution. <br><br>  Accuracy metrics were calculated for forest extent 2000, forest extent 2020 and for the stable forest area within that time period. Overall accuracy, User's Accuracy (based on the false positives, and calculated as 100%-Commission Error) and Producer’s error (based on the false negatives, and calculated as 100%-Omission error) were all >93%. <br><br> 

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