Understanding the current status of forest resources is essential for monitoring changes 
    in forest ecosystems and generating related statistics. In South Korea, the National Forest
    Inventory (NFI) surveys over 4,500 sample plots nationwide every five years and records 70 items,
    including forest stand, forest resource, and forest vegetation surveys. Many researchers use NFI 
    as the primary data for research, such as biomass estimation or analyzing the importance value of
    each species over time and space, depending on the research purpose. However, the large volume
    of accumulated forest survey data from across the country can make it challenging to manage and
    utilize such a vast dataset. To address this issue, we developed an R package that efficiently
    handles large-scale NFI data across time and space. The package offers a comprehensive 
    workflow for NFI data analysis. It starts with data processing, where read_nfi() function 
    reconstructs NFI data according to the researcher's needs while performing basic integrity checks
    for data quality.Following this, the package provides analytical tools that operate on the verified
    data. These include functions like summary_nfi() for summary statistics, diversity_nfi() for
    biodiversity analysis, iv_nfi() for calculating species importance value, and biomass_nfi() and
    cwd_biomass_nfi() for biomass estimation. Finally, for visualization, the tsvis_nfi() function
    generates graphs and maps, allowing users to visualize forest ecosystem changes across various
    spatial and temporal scales. This integrated approach and its specialized functions can enhance
    the efficiency of processing and analyzing NFI data, providing researchers with insights into
    forest ecosystems. The NFI Excel files (.xlsx) are not included in the R package and must be 
    downloaded  separately. Users can access these NFI Excel files by visiting 
    the Korea Forest Service Forestry Statistics Platform <https://kfss.forest.go.kr/stat/ptl/article/articleList.do?curMenu=11694&bbsId=microdataboard>
    to download the annual NFI Excel files, which are bundled in .zip archives. Please note that this 
    website is only available in Korean, and direct download links can be found in the notes section 
    of the read_nfi() function.