Fire and environmental change in northern Australian savannas during the Holocene

Emma Rehn studied the fire history of three wetlands in the savannas of northern Australia over thousands of years. She found that fire incidence and intensity varied greatly at each site, related to climate and humans. The methods developed in her study will improve future research reconstructing past fire records

Modelled dispersal patterns for wood and grass charcoal are different: implications for paleofire reconstruction

Sedimentary charcoal records provide useful perspectives on the long-term controls and behavior of fire in the Earth system. However, a comprehensive understanding of the nuances, biases, and limitations of charcoal as a fire proxy is necessary for reliable paleofire interpretations. Here, we use a charcoal dispersal model to answer the following questions: (1) How does the dispersal of wood and grass charcoal particles differ? (2) Do traditional conceptual models of charcoal dispersal reliably characterize grass charcoal dispersal? We find that small differences in shape (L:W) and density of grass and wood charcoal can cause substantial differences in particle dispersal and source area. Whereas the modelled dispersal of wood charcoal shows a localized deposition signal which decays with distance, grass charcoal shows more diffuse deposition lacking a localized center (for both >125 µm and >60 µm). Although paleofire research has typically not distinguished between fuel types, we show that the dispersal of charcoal derived from different fuels is unlikely to be uniform. Because differences in localization, production, and preservation could bias aggregate charcoal accumulation, caution should be taken when interpreting wood and grass-derived charcoal particles preserved in the same record. Additionally, we propose an alternative, dual background conceptual model of grass charcoal dispersal, as the traditional, two-component (peak and background) conceptual model does not accurately characterize the modelled dispersal of grass charcoal. Lastly, this mismatch of conceptualizations of dispersal mechanics implies that grass charcoal may not fit the criteria necessary for peak analysis techniques

A late-Holocene multiproxy fire record from a tropical savanna, eastern Arnhem Land, Northern Territory, Australia

Fire has a long history in Australia and is a key driver of vegetation dynamics in the tropical savanna ecosystems that cover one quarter of the country. Fire reconstructions are required to understand ecosystem dynamics over the long term but these data are lacking for the extensive savannas of northern Australia. This paper presents a multiproxy palaeofire record for Marura sinkhole in eastern Arnhem Land, Northern Territory, Australia. The record is constructed by combining optical methods (counts and morphology of macroscopic and microscopic charcoal particles) and chemical methods (quantification of abundance and stable isotope composition of pyrogenic carbon by hydrogen pyrolysis). This novel combination of measurements enables the generation of a record of relative fire intensity to investigate the interplay between natural and anthropogenic influences. The Marura palaeofire record comprises three main phases: 4600–2800 cal BP, 2800–900 cal BP and 900 cal BP to present. Highest fire incidence occurs at ~4600–4000 cal BP, coinciding with regional records of high effective precipitation, and all fire proxies decline from that time to the present. 2800–900 cal BP is characterised by variable fire intensities and aligns with archaeological evidence of occupation at nearby Blue Mud Bay. All fire proxies decline significantly after 900 cal BP. The combination of charcoal and pyrogenic carbon measures is a promising proxy for relative fire intensity in sedimentary records and a useful tool for investigating potential anthropogenic fire regimes

Multiproxy Holocene fire records from the tropical savannas of northern Cape York Peninsula, Queensland, Australia

Palaeoecology has demonstrated potential to inform current and future land management by providing long-term baselines for fire regimes, over thousands of years covering past periods of lower/higher rainfall and temperatures. To extend this potential, more work is required for methodological innovation able to generate nuanced, relevant and clearly interpretable results. This paper presents records from Cape York Peninsula, Queensland, Australia, as a case study where fire management is an important but socially complex modern management issue, and where palaeofire records are limited. Two new multiproxy palaeofire records are presented from Sanamere Lagoon (8150-6600 cal BP) and Big Willum Swamp (3900 cal BP to present). These records combine existing methods to investigate fire occurrence, vegetation types, and relative fire intensity. Results presented here demonstrate a diversity of fire histories at different sites across Cape York Peninsula, highlighting the need for finer scale palaeofire research. Future fire management planning on Cape York Peninsula must take into account the thousands of years of active Indigenous management and this understanding can be further informed by palaeoecological research

Holocene climate-fire-vegetation feedbacks in tropical savannas: Insights from the Marura sinkhole, East Arnhem Land, northern Australia

Aims: Informed management of savanna systems depends on understanding determinates of composition, structure and function, particularly in relation to woody-plant components. This understanding needs to be regionally based, both past and present. In this study, Holocene plant patterns are explored at a site within the eucalypt savannas of northern Australia. Australian savannas are the least developed globally and uniquely placed to track ecological change. LocationNorthern Territory, Australia. Methods: Palynological analyses were undertaken on a 5-m sediment core, spanning the last 10,700 calendar years. Pollen was categorised to capture vegetation type, classified further according to plant function and/or environmental response. Detrended Correspondence Analysis was used to quantify ecological dissimilarities through time. Results: At the Pleistocene transition, grasses were abundant then declined and remained low relative to increased woody cover from the mid-late Holocene. Savanna composition gradually transitioned from Corymbia to Eucalyptus dominance until significantly disturbed by a phase of repeated, extreme climate events. Highest non-savanna variability in terrestrial and wetland plant types formed mixed vegetation communities through the mid-Holocene. Conclusions: Savannas are not homogeneous but the product of plant changes in multiple dimensions. In the Northern Territory, dynamic though restricted non-eucalypt shifts are embedded within larger, slower eucalypt change processes. Primary climate-vegetation relationships determine the long-term fire regime. The role of large but infrequent disturbance events in maintaining savanna diversity are significant, in degrees of impact on tree-grass turnover, its form and the extent of vegetation recovery. People's landscape interactions were found to be interwoven within this feedback hierarchy

A common framework for using and reporting consumer purchase data (CPD) in foodborne outbreak investigations in Europe

Publisher Copyright: © 2021 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.Consumer purchase data (CPD) can be a powerful tool in the investigation of foodborne outbreaks through analyses of electronic records of food that individuals buy. The objective of this study was to develop a common framework for use of CPD in foodborne outbreak investigations using the expertise of European public health professionals from 11 European countries. We also aimed to describe barriers and limitations preventing CPD utilization. CPD are mainly gathered from supermarket loyalty programmes, smaller consortia, and independent supermarkets. Privacy legislation governing CPD was perceived as the most crucial barrier for CPD usage, but still resolvable. The main practical challenges were obtaining consumer consent for CPD usage, the associated workload, data access, format, and analysis. Harmonising methods and reporting across countries, standardised consent forms and electronic consent methods were identified as solutions. This guideline was developed to support outbreak investigators in overcoming barriers in using CPD, thereby increasing public health professionals’ application and value of this powerful investigation tool. In addition, we hope this framework will lead to more public health institutions, in collaboration with food safety authorities, making use of CPD in outbreak investigations in the future.Peer reviewe

Assessing changes in global fire regimes

PAGES, Past Global Changes, is funded by the Swiss Academy of Sciences and the Chinese Academy of Sciences and supported in kind by the University of Bern, Switzerland. Financial support was provided by the U.S. National Science Foundation award numbers 1916565, EAR-2011439, and EAR-2012123. Additional support was provided by the Utah Department of Natural Resources Watershed Restoration Initiative. SSS was supported by Brigham Young University Graduate Studies. MS was supported by National Science Centre, Poland (grant no. 2018/31/B/ST10/02498 and 2021/41/B/ST10/00060). JCA was supported by the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No 101026211. PF contributed within the framework of the FCT-funded project no. UIDB/04033/2020. SGAF acknowledges support from Trond Mohn Stiftelse (TMS) and University of Bergen for the startup grant ‘TMS2022STG03’. JMP participation in this research was supported by the Forest Research Centre, a research unit funded by Fundação para a Ciência e a Tecnologia I.P. (FCT), Portugal (UIDB/00239/2020). A.-LD acknowledge PAGES, PICS CNRS 06484 project, CNRS-INSU, Région Nouvelle-Aquitaine, University of Bordeaux DRI and INQUA for workshop support.Background The global human footprint has fundamentally altered wildfire regimes, creating serious consequences for human health, biodiversity, and climate. However, it remains difficult to project how long-term interactions among land use, management, and climate change will affect fire behavior, representing a key knowledge gap for sustainable management. We used expert assessment to combine opinions about past and future fire regimes from 99 wildfire researchers. We asked for quantitative and qualitative assessments of the frequency, type, and implications of fire regime change from the beginning of the Holocene through the year 2300. Results Respondents indicated some direct human influence on wildfire since at least ~ 12,000 years BP, though natural climate variability remained the dominant driver of fire regime change until around 5,000 years BP, for most study regions. Responses suggested a ten-fold increase in the frequency of fire regime change during the last 250 years compared with the rest of the Holocene, corresponding first with the intensification and extensification of land use and later with anthropogenic climate change. Looking to the future, fire regimes were predicted to intensify, with increases in frequency, severity, and size in all biomes except grassland ecosystems. Fire regimes showed different climate sensitivities across biomes, but the likelihood of fire regime change increased with higher warming scenarios for all biomes. Biodiversity, carbon storage, and other ecosystem services were predicted to decrease for most biomes under higher emission scenarios. We present recommendations for adaptation and mitigation under emerging fire regimes, while recognizing that management options are constrained under higher emission scenarios. Conclusion The influence of humans on wildfire regimes has increased over the last two centuries. The perspective gained from past fires should be considered in land and fire management strategies, but novel fire behavior is likely given the unprecedented human disruption of plant communities, climate, and other factors. Future fire regimes are likely to degrade key ecosystem services, unless climate change is aggressively mitigated. Expert assessment complements empirical data and modeling, providing a broader perspective of fire science to inform decision making and future research priorities.Peer reviewe

Utomhuspedagogik som undervisningmetod i årskurs F-3 : Möjligheter och hinder med utomhuspedagogik som undervisningsmetod

Syftet med studien är att undersöka i vilken utsträckning 23 grundskollärare använder utomhuspedagogik i sin undervisning samt att undersöka vilka möjligheter och hinder de ser med utomhuspedagogik som undervisningsmetod. Studien genomfördes med en enkätstudie och intervjuer. Resultaten jämfördes med varandra för att finna eventuella skillnader i svaren. Resultaten visade att majoriteten av de deltagande lärarna använder utomhuspedagogik i sin undervisning en gång i veckan. Både möjligheter och hinder med utomhuspedagogik som undervisningsmetod har kommit fram i resultaten. Slutsaten blev att det finns mestadels stora möjligheter med utomhuspedagogik som metod

”Tryggheten är A och O på förskolan, det är det viktigaste av allt” : En studie om barns trygghet på förskolan med fokus på olika anknytningsmönster

Syftet med studien är att utveckla kunskap om hur förskollärare ser på och anser sig arbeta med barns trygghet på förskolan, med fokus på barns olika anknytningsmönster. Frågeställningarna är ”Hur ser förskollärare på barns trygghet i förskolan?”, ”Hur anser förskollärare att de arbetar med barns trygghet på förskolan?” och ”Hur uppfattar förskollärare att barns olika anknytningsmönster tas hänsyn till för att skapa trygghet på förskolan?”. Den teoretiska utgångspunkten studien utgår ifrån är John Bowlbys anknytningsteori. Studien bygger på fyra förskollärares tankar och åsikter. En kvalitativ forskningsmetod har följts där halvstrukturerade intervjuer har utgjort grunden för resultatet av studien. Resultatet visar att förskollärarna ser barns trygghet som en grundläggande del i förskolans verksamhet och arbetar med olika faktorer för att alla barn ska känna sig trygg på förskolan. De mest framträdande faktorer var tydlighet, mindre grupper, närvarande pedagoger, förhållningssätt och attityd samt samverkan med vårdnadshavare. Förskollärarna hade viss kunskap om olika anknytningsmönster och kände igen de beteenden som kännetecknar en otrygg anknytning. De gav olika förslag på åtgärder både på och utanför förskolans verksamhet

”Tryggheten är A och O på förskolan, det är det viktigaste av allt” : En studie om barns trygghet på förskolan med fokus på olika anknytningsmönster

Syftet med studien är att utveckla kunskap om hur förskollärare ser på och anser sig arbeta med barns trygghet på förskolan, med fokus på barns olika anknytningsmönster. Frågeställningarna är ”Hur ser förskollärare på barns trygghet i förskolan?”, ”Hur anser förskollärare att de arbetar med barns trygghet på förskolan?” och ”Hur uppfattar förskollärare att barns olika anknytningsmönster tas hänsyn till för att skapa trygghet på förskolan?”. Den teoretiska utgångspunkten studien utgår ifrån är John Bowlbys anknytningsteori. Studien bygger på fyra förskollärares tankar och åsikter. En kvalitativ forskningsmetod har följts där halvstrukturerade intervjuer har utgjort grunden för resultatet av studien. Resultatet visar att förskollärarna ser barns trygghet som en grundläggande del i förskolans verksamhet och arbetar med olika faktorer för att alla barn ska känna sig trygg på förskolan. De mest framträdande faktorer var tydlighet, mindre grupper, närvarande pedagoger, förhållningssätt och attityd samt samverkan med vårdnadshavare. Förskollärarna hade viss kunskap om olika anknytningsmönster och kände igen de beteenden som kännetecknar en otrygg anknytning. De gav olika förslag på åtgärder både på och utanför förskolans verksamhet