Machine learning-based prediction and assessment of recent dynamics of forest net primary productivity in Romania

• Published in: Journal of environmental management Vol. 334; p. 117513
• Main Authors: Prăvălie, Remus, Niculiță, Mihai, Roșca, Bogdan, Marin, Gheorghe, Dumitrașcu, Monica, Patriche, Cristian, Birsan, Marius-Victor, Nita, Ion-Andrei, Tișcovschi, Adrian, Sîrodoev, Igor, Bandoc, Georgeta
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 15-05-2023
• Subjects: Carbon Cycle; Carbon fluxes; Climate Change; Ecosystem; Forestry; Forests; Geostatistical modelling; Machine learning; NPP; Romania; Spatio-temporal trends; Trees; Romania; Carbon fluxes; Climate change; Romania; Geostatistical modelling; Machine learning; Spatio-temporal trends; NPP
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2023.117513

While the analysis of spatio-temporal changes in the net primary productivity (NPP) of forests can provide critical information on carbon cycle and climate change, these ecological trends have remained unclear in many countries worldwide, including Romania. By using complex (satellite, forest and climate) data, many sophisticated (machine learning) algorithms and some widely applied (the Mann-Kendall test and Sen's slope estimator) statistical procedures, this study investigates, for the first time, recent forest NPP trends (1987–2018) that occurred in Romania, in relation to climate change that affected the country over the past decades. Following the modelling, mapping and assessment of NPP dynamics, results showed almost exclusively positive trends for this ecological parameter, which accounts for ∼99% of all forest NPP changes that occurred throughout the country, after 1987. Interestingly, almost three quarters (∼73%) of all NPP increasing trends are statistically significant, which indicates that Romania's forests have recently experienced a large-scale improvement in carbon fluxes and stocks. Investigations of eco-climatic relationships suggest that climate change has partially contributed to these surprising NPP dynamics observed in recent decades. All these findings can provide valuable information for forest management and for many stakeholders and policymakers who operate in the forestry and climate fields in Romania.
•Changes in the net primary productivity (NPP) of forests were explored for the first time in Romania.•NPP trends (1987–2018) were modelled using a variety of data and statistical algorithms/procedures.•Almost exclusively positive NPP trends (∼99% of all forest NPP changes) were detected countrywide.•About three quarters (∼73%) of all national NPP positive trends are statistically significant.•Climate change is a partial driving force of the observed NPP dynamics in recent decades.