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Conference paper presented in XII Maaperätieteen päivät [Soil Science days], 10.-11.1.2023, Helsinki, Finland,&nbsp

Aboveground biomass (AGB) and leaf area index (LAI) are key variables of ecosystem processes and functioning. Knowledge is lacking on how well the seasonal patterns of ground vegetation AGB and LAI can be detected by satellite images in boreal ecosystems. We conducted field measurements between May and September during one growing season to investigate the seasonal development of ground vegetation AGB and LAI of seven plant functional types (PFTs) across seven vegetation types (VTs) within three peatland and forest study areas in northern Finland. We upscaled field-measured AGB and LAI with Sentinel-2 (S2) imagery by applying random forest (RF) regressions. Field-measured AGB peaked around the first week of August and, in most cases, one to two weeks later than LAI. Regarding PFTs, deciduous vascular plants had clear unimodal seasonal patterns, while the AGB and LAI of evergreen vegetation and mosses remained steady over the season. Remote sensing regression models explained 24.2–50.2% of the AGB (RMSE: 78.8–198.7 g m−2) and 48.5–56.1% of the LAI (RMSE: 0.207–0.497 m2 m−2) across sites. Peatland-dominant sites and VTs had a higher prediction accuracy. S2-predicted peak dates of AGB and LAI were one to three weeks earlier than the field-based ones. Our findings suggest that boreal ground vegetation seasonality varies among PFTs and VTs and that S2 time series data can be applied to monitor its spatiotemporal patterns, especially in treeless regions.

Peatlands form part of the boreal landscapes exhibiting diverse types and microforms that have different characteristics of topography, hydrology, vegetation, and soil. Our understanding is still limited concerning how boreal peatlands, especially their inherent heterogeneities, affect the regional biosphere-atmosphere exchange of carbon and related climate effects, and what level of detail is needed to characterize them in land cover maps. By combining remote sensing information, field measurements, and biogeochemical modeling, we estimated that the peatlands within the study area (26% of the area) contributed 22% of the landscape-scale carbon dioxide uptake and 93% of methane emissions. We also showed that, among different land cover types, peatlands played the dominant role in the variability of radiative climate effect due to carbon exchanges. Possible aggregation and misclassification of peatland types could induce significant biases in the regional balances and their radiative effect, but the distinction of non-inundated dry and inundated wet peatland types could reduce these biases effectively.

Katastrofitutkimus (disaster studies) pureutuu vaaroihin, katastrofeihin ja kriiseihin. Tutkimusalue ei ole vakiintunut yhteiskuntatieteiden osaksi Suomessa, mutta sillä on annettavaa erityisesti luonnonilmiöihin kietoutuneita katastrofeja tutkittaessa. Tämä katsausartikkeli tarkastelee, millaista suomenkielistä käsitteistöä katastrofeja tutkittaessa käytetään tai voitaisiin käyttää. Käsitteistön tarkastelu on tärkeää useasta syystä: (1) katastrofit ovat ajankohtaisia kansainvälisesti ja Suomessa, (2) aiempi kotimainen käsitteistö on osin ongelmallista luonnonilmiöihin liittyvien vaarojen yhteydessä, ja (3) käsitteistön selkeys auttaisi yhteistyötä katastrofikontekstissa, jossa aihepiirin politiikka ja tutkimus ovat kytkeytyneet toisiinsa. Artikkelissa käymme läpi avainkäsitteitä kolmelta kantilta. Ensiksi ammennamme käsitteitä kansainvälisestä katastrofitutkimuksesta. Toiseksi käymme läpi Suomen katastrofiriskien hallinnoinnin politiikkaa ja sen sanastoa. Kolmanneksi tarkastelemme suomalaista riskejä ja poikkeusoloja koskevaa tutkimusta. Keskustelussa tutkimusalueen avainkäsitteet hahmottuvat ja kirkastuvat. Haastamme esimerkiksi ”luonnononnettomuuden” käytön käsitteenä katastrofeista puhuttaessa, sekä pohdimme, kannattaako puhua ”resilienssistä” vai kantaisiko kimmoisuus oleelliset merkitykset paremmin. Vaikka painotammekin tiettyjä käsitteiden tulkintoja, emme pyri lyömään lukkoon yksittäisiä määritelmiä, sillä käsitteiden monisyisyys kuuluu tutkimukseen., Disaster studies examines the societal impacts of hazards, disasters and crises but the field is not yet well established in Finland. We review and debate Finnish disaster-related concepts and conceptualizations. The topic is timely as (1) disasters are a contemporary challenge both globally and in Finland, (2) pre-existing Finnish concepts are partly problematic in the context of natural hazards, and (3) conceptual clarity advances collaboration in the disaster context where research and practice are intertwined. We discuss the key concepts and approach the topic from three complementary perspectives. Firstly, we review selected key concepts in the international literature. Secondly, we summarize Finnish disaster risk governance and related vocabulary. Thirdly, we explore the Finnish research on disasters, risks, and crises. Although we emphasize certain interpretations of the concepts, we do not intend to give fixed definitions, as the versatility of concepts is inherent to any interdisciplinary field.