Primary spruce forests of Kamchatka are relatively stable in the face of global change

Repository Description This repository contains data and code accompanying the study "Primary spruce forests of Kamchatka are relatively stable in the face of global change", which assesses the ecological status, growth dynamics, and vegetation greenness trends of unique, uneven-aged boreal ecosystems on the Kamchatka Peninsula. Background and Significance On the Kamchatka Peninsula, primary spruce forests dominated by Picea jezoensis remain well-preserved, particularly within the Kronotsky State Biosphere Nature Reserve. These forests provide critical ecosystem services, yet their response to recent climate change in Northeast Asia has remained virtually unexplored. This study presents the first field-verification results of circumboreal greening estimates for this region, evaluating forest resilience and highlighting the priority for their conservation. Materials and Methods Area Increment (BAI) for Picea jezoensis, Betula ermanii, Betula platyphylla, and Larix cajanderi. This tree-ring data was integrated with 30-meter resolution Landsat time series (2000–2023/2024) across randomly distributed sampling sites to derive maximum annual NDVI and assess ecosystem greenness trends (greening, browning, or no-trend) using the LandsatTS R package. Finally, the forest response to recent climate change was evaluated by linking these growth indices and satellite-derived NDVI metrics – including lagged effects – to historical climate records and specific summer heat-supply temperature indices. Data Structure 1. Remote Sensing & Trend Data picea.gsdt.ndvi_sample_plots.csv (CSV) contains calculated annual NDVImax values for 10 the Picea jezoensis study plots over the 2000–2023 period picea.gsdt.ndvi_random_points.csv (CSV) contains calculated annual NDVImax values for 1500 random plots over the 2000–2023 period trend_ndvi_2000_2023.csv (CSV)Extracted growing season trends parameters and categorical classifications (greening, browning, no-trend) for the analyzed sampling sites over the 2000–2023 period. 2. Tree-Ring & Field Measurements RWI_BAI_ed-2.xlsx (Excel)Standardized tree-ring width measurements, including Ring-Width Index (RWI) and Basal Area Increment (BAI) series for the dominant and associated tree species. 3. Climate Data Clim_upd_2.xlsx (Excel)Updated historical climate records and derived temperature indices (e.g., summer heat-supply metrics) utilized to analyze tree growth and greenness climate responses. 4. Analysis Scripts Kam_NDVI_climate_growth_analysis_final.R (R Script)The complete statistical pipeline used for data integration, trend estimation, climate-growth response analysis, and generating the final figures/tables for the study.