Shun Hasegawa
Research Scientist
Biography
I have been assigned as the head of the Norwegian National Soil Carbon Monitoring programme at NIBIO since 2023. My role is to lead, develop and execute this very first soil carbon monitoring project in Norway.
I am a climate change biologist with broad interests in the impacts of human activities and associated climate/environmental changes on global biogeochemical processes. I completed PhD at Imperial College London in 2015 with a thesis entitled Investigation into the effects of elevated carbon dioxide and temperature on nutrient cycling and understorey vegetation in a Eucalyptus woodland. My previous work can be found here.
Previous employment:
- 2022-2023 Senior Research Engineer at Umeå University with a focus on the role of root carbon supply on oxidative decomposition in the boreal soil.
- 2018-2022 Postdoc at Swedish University of Agricultural Sciences with a focus on the long-term effects of nitrogen addition on organic matter accumulation in boreal forests.
- 2017-2018 Senior research technician at National Institute for Environmental Studies of Japan with a focus on meta-analysis on microbial immobilisation.
- 2015-2017 Postdoc at Hawkesbury Institute for the Environment, Western Sydney University with a focus on the effects of elevated CO2 and water availability on soil nutrient availability in relation to root exudates.a
Authors
Sally A. Power Manjunatha H. Chandregowda Kirk Barnett Juan Pineiro Shun Hasegawa Coline Deveautour Eleanor Gibson‐Forty Jeff Chieppa Scott N. Johnson Sarah Facey Raul Ochoa‐HuesoAbstract
Warming‐driven intensification of the hydrological cycle is altering global rainfall patterns. However, the relative importance of changes in the amount versus timing of rainfall and the role of atmospheric drivers of moisture demand in modifying relationships between rainfall, biodiversity and ecosystem functioning are currently unresolved. To address this, we undertook a 10‐year rainfall manipulation experiment in a mesic grassland in New South Wales, Australia. We used rain shelters to achieve five rainfall treatments: (i) ambient, (ii) ambient +50% (IA), (iii) ambient −50% (RA), (iv) reduced frequency (RF, cumulative ambient rainfall applied once every 3 weeks) and (v) summer drought (SD, no rain during the Austral summer). We found that inter‐annual variation in ANPP was best explained by the amount of growing season rainfall relative to potential evapotranspiration (i.e., P/PET, or aridity) (R 2 adj 0.52). Reductions in the amount of rainfall, particularly during summer, were associated with productivity decline, shifts in community composition and a loss of diversity. However, reducing the frequency of rain events had no overall effect on productivity, despite a loss of species diversity. Notably, treatment‐related declines in diversity and/or richness were associated with both increases (IA) and decreases (SD) in temporal stability of ANPP and the stabilising role of species asynchrony, thereby highlighting the importance of species identity and associated functional traits for community stability. Our study uniquely emphasises the importance of accounting for seasonal drivers of moisture demand when predicting functional responses to changes in rainfall regimes and highlights how the ecological mechanisms underpinning community stability are influenced by changes in both the amount and timing of rainfall. These mechanistic insights can enhance the predictive capacity of Earth system models and inform targeted management strategies to offset the negative effects of future, more extreme rainfall on the ecosystem services provided by global grasslands.
Authors
Bin Wang He Lyu Xueqian Zhang Mingkai Jiang Belinda E. Medlyn David Wårlind Jürgen Knauer Katrin Fleischer Daniel S. Goll Stefan Olin Xiaojuan Yang Lin Yu Sönke Zaehle Haicheng Zhang Kristian Schufft Kristine Y. Crous Yolima Carrillo Catriona A. Macdonald Ian C. Anderson Matthias M. Boer Mark Farrell Andrew Gherlenda Laura Castañeda-Gómez Shun Hasegawa Klaus Jarosch Paul Milham Raúl Ochoa-Hueso Varsha Pathare Johanna Pihlblad Juan Piñeiro Sally A. Power Peter B. Reich Markus Riegler David S. Ellsworth Benjamin SmithAbstract
The capacity of nutrient-limited forests to enhance carbon (C) sequestration under elevated CO 2 (eCO 2 ) remains a critical uncertainty in C cycle modeling. While existing evidence suggests that low phosphorus (P) bioavailability may constrain CO 2 fertilization effects on plant growth, the extent to which this limitation modulates ecosystem responses to eCO 2 in forests adapted to P-deficient soils remains poorly understood. Here, using eight P-enabled models, we simulated the magnitudes and mechanisms through which P bioavailability interacts with eCO 2 , emulating an ecosystem-scale P enrichment experiment at a P-limited Eucalyptus forest undergoing long-term Free-Air CO 2 Enrichment. While models predicted pronounced P effects on tree growth, P enrichment unexpectedly did not increase the CO 2 effects on tree growth and ecosystem C sequestration. Models prioritized either CO 2 -driven or P-driven growth, but rarely both. This tradeoff emerged due to model-specific assumptions on 1) partitioning of the extra P in soil labile versus nonlabile pools; 2) plant photosynthetic acclimation to P deficiency; 3) C and nutrient use strategies regulating plant size and allocation; and 4) microbial-driven soil decomposition processes. By generating divergent yet biologically plausible outcomes, these predictions establish critical testable hypotheses for empirical research and highlight multiple P-related pathways that may influence the future land C sink.
Authors
Shun Hasegawa Inge Stupak Kristin Baldursdóttir Hannu Ilvesniemi Carl-Fredrik Johannesson O. Janne Kjønaas Andis Lazdins Aleksi Lehtonen Jenni Nordén Ivika Ostonen David Paré Helena Marta Stefánsdóttir Johan Stendahl Iveta Varnagiryté-Kabasinskiene Lars Vesterdal Lise DalsgaardAbstract
Bakgrunn: Overvåking av karbon i skogjord gjennomføres i mange land, noe som har resultert i omfattende nasjonale datasett, også i tilfelle hvor landene har felles grenser og i stor utstrekning lignende eller tilsvarende skogs- og jordtyper. Mulighet: Internasjonalt samarbeid om data og feltmetoder kan legge til rette for integrasjon av datasett og sammenligning av overvåkingsdata til støtte for utvikling av internasjonal politikk i et multinasjonalt fremfor et nasjonalt perspektiv. Utfordring: Variasjoner i overvåkingsmetodikk mellom land må håndteres for å kunne gjennomføre en effektiv syntese av data om karbon i skogjord. Tilnærming: Hvert land har utviklet sitt eget overvåkingsprogram for å møte spesifikke og nasjonale miljømessige og institusjonelle behov, noe som har ført til omfattende datasett på nasjonalt nivå. Harmonisering kan bidra til å realisere det fulle potensialet i disse nasjonale datasettene gjennom utvikling av internasjonale referansedefinisjoner. En tilnærming med utgangspunkt i harmonisering tillater nasjonal tilpasning, samtidig med at data kan brukes i en internasjonal kontekst, i kontrast til standardisering og en «én størrelse passer alle»-tilnærming.