Speaker
Description
Background and objectives: Boreal forests are important carbon stocks, but their stability is increasingly challenged by climate change and forest harvests. Detecting long-term harvest effects on resilience is difficult because they are mixed with changes in forest resilience due to climate change. We asked whether long-term harvest induces a detectable resilience shifting after accounting for this changing climate baseline, and whether structural and functional vegetation indicators provide consistent evidence.
Methods: We combined kNDVI, CCI, NIRv, GOSIF and GPP with ERA5-Land meteorological variables, including temperature, evapotranspiration, vapor-pressure deficit and radiation, and spatially explicit Finnish harvest records at 0.05° resolution for 2001–2020. We used lag-1 temporal autocorrelation (TAC) as a proxy for inferred resilience, with higher TAC indicating slower recovery and lower resilience. Because harvest at 0.05° scale represents cumulative management pressure, we excluded grid cells exceeding an annual clear-cut threshold, quantified long-term resilience change, and compared harvested forests with nearby non-harvested forests as a local climate baseline. Climate controls on this baseline were assessed using machine-learning attribution.
Preliminary results: Climate strongly shaped resilience dynamics in nearby non-harvested forests. Greenness-based resilience, represented by kNDVI, was mainly linked to mean temperature and trends in actual evapotranspiration, whereas photosynthesis-related resilience, represented by GOSIF, was more sensitive to vapor pressure deficit trends and mean solar radiation. After accounting for this baseline, harvest-associated resilience signals were identified, and these signals were modest and differed among vegetation indicators. Greenness and photosynthetic indicators including kNDVI, NIRv, and GOSIF, tended to show faster recovery after cumulative harvest, especially where thermal conditions favored regrowth, while GPP-based ecosystem carbon uptake suggested weaker stability in warmer regions. These divergent responses indicate that harvest may promote rapid ecosystem recovery. Overall, climate-driven resilience change formed a coherent regional background, whereas harvest-associated responses were more spatially patchy.
Keywords: boreal forest resilience, forest management, climate change, remote sensing, ecosystem stability
| Are you participating to the "AnaEE Environmental Rising Star Award "? | No |
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