English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

It is projected that forest disturbances, such as insect outbreaks, will havean increasingly negative impact on forests with a warmer climate. Thesedisturbance events can have a substantial impact on forests' ability toabsorb atmospheric CO2, and may even turn forests from carbon sinks intocarbon sources; hence, it is important to develop methods both to monitorforest disturbances and to quantify the impact of these disturbance events onthe carbon balance. In this study we present a method to monitor insect-induced defoliation in a subarctic birch forest in northern Sweden, and toquantify the impact of these outbreaks on gross primary productivity (GPP).Since frequent cloud cover in the study area requires data with high temporalresolution and limits the use of finer spatial resolution sensors such asLandsat, defoliation was mapped with remote sensing data from the MODISsensor with 250 m  ×  250 m spatial resolution. The impact on GPP wasestimated with a light use efficiency (LUE) model that was calibrated withGPP data obtained from eddy covariance (EC) measurements from 5 years withundisturbed birch forest and 1 year with insect-induced defoliation. Twomethods were applied to estimate the impact on GPP: (1) applying a GPPreduction factor derived from EC measured GPP to estimate GPP loss, and(2) running a LUE model for both undisturbed and defoliated forest andderiving the differences in modelled GPP. In the study area of 100 km2the results suggested a substantial setback to the carbon uptake: an averagedecrease in regional GPP over the three outbreak years (2004, 2012, and 2013)was estimated to 15 ± 5 Gg C yr−1, compared to the meanregional GPP of 40 ± 12 Gg C yr−1 for the 5 years withoutdefoliation, i.e. 38 %. In the most severe outbreak year (2012), 76 %of the birch forests were defoliated, and annual regional GPP was merely50 % of GPP for years without disturbances. The study has generatedvaluable data on GPP reduction, and demonstrates a potential for mappinginsect disturbance impact over extended areas

Mapping the reduction in gross primary productivity in subarctic birch forests due to insect outbreaks