Using legacy data to reconstruct the past? Rescue, rigour and reuse in peatland geochronology

There is a growing interest in the rescue and reuse of data from past studies (so-called legacy data). Data loss is alarming, especially where natural archives are under threat, such as peat deposits. Here we develop a workflow for reuse of legacy radiocarbon dates in peatland studies, including a rigorous quality assessment that can be tailored to specific research questions and study regions. A penalty is assigned to each date based on criteria that consider taphonomic quality (i.e., sample provenance) and dating quality (i.e., sample material and method used). The weights of quality criteria may be adjusted based on the research focus, and resulting confidence levels may be used in further analyses to ensure robustness of conclusions. We apply the proposed approach to a case study of a (former) peat landscape in the Netherlands, aiming to reconstruct the timing of peat initiation spatially. Our search yielded 313 radiocarbon dates from the 1950s to 2019. Based on the quality assessment, the dates—of highly diverse quality—were assigned to four confidence levels. Results indicate that peat initiation for the study area first peaked in the Late Glacial (~14,000 cal years BP), dropped during the Boreal (~9,500 cal years BP) and showed a second peak in the Subboreal (~4,500 cal years BP). We tentatively conclude that the earliest peak was mostly driven by climate (Bølling–Allerød interstadial), whereas the second was probably the result of Holocene sea level rise and related groundwater level rise in combination with climatic conditions (hypsithermal). Our study highlights the potential of legacy data for palaeogeographic reconstructions, as it is cost-efficient and provides access to information no longer available in the field. However, data retrieval may be challenging, and reuse of data requires that basic information on location, elevation, stratigraphy, sample and laboratory analysis are documented irrespective of the original research aims

Anthropogenic drivers for exceptionally large meander formation during the Late Holocene

Large-amplitude meanders may form in low-energy rivers despite generally limited mobility in theses systems. Exceptionally large meanders which even extend beyond the valley sides have developed in the Overijsselse Vecht river (the Netherlands) between ca. 1400 CE (Common Era) and the early 1900s, when channelization occurred. Previous studies have attributed the enhanced lateral dynamics of this river to changes in river regime due to increased discharges, reflecting climate and/or land-use alterations in the catchment. This paper focuses on local aspects that may explain why exceptionally large meanders developed at specific sites. Through an integrated analysis based on archaeological, historical, and geomorphological data along with optically stimulated luminescence dating, we investigated the relative impact of three direct and indirect anthropogenic causes for the local morphological change and enhanced lateral migration rates: (1) lack of strategies to manage fluvial erosion; (2) a strong increase in the number of farmsteads and related intensified local land use from the High Middle Ages onwards; and (3) (human-induced) drift-sand activity directly adjacent to the river bends, causing a change in bank stability. Combined, these factors led locally to meander amplitudes well beyond the valley sides. Lessons learned at this site are relevant for management and restoration of meandering rivers in similar settings elsewhere, particularly in meeting the need to estimate spatial demands of (restored) low-energy fluvial systems and manage bank erosion.</p

Workshop FAIR Data and Data Reuse for Environmental Science Group Researchers

We designed and organized a one-day workshop, where in the context of FAIR the following themes were discussed and practiced: scientific transparency and reproducibility; how to write a README; data and code licenses; spatial data; programming code; examples of published datasets; data reuse; and discipline and motivation. The intended audience were researchers at the Environmental Science Group of Wageningen University and Research. All workshop materials were designed with further development and reuse in mind and are shared through this dataset

Workshop FAIR Data and Data Reuse for Environmental Science Group Researchers

We designed and organized a one-day workshop, where in the context of FAIR the following themes were discussed and practiced: scientific transparency and reproducibility; how to write a README; data and code licenses; spatial data; programming code; examples of published datasets; data reuse; and discipline and motivation. The intended audience were researchers at the Environmental Science Group of Wageningen University and Research. All workshop materials were designed with further development and reuse in mind and are shared through this dataset

Data from: Quantitative visual soil observation for visual soil evaluation on dairy farms

Quantitative visual observations were collected for two studies on dairy farms in the Netherlands. Data were collected following the same methodology (Van Leeuwen et al., 2018) based on Visual Soil Assessment of Shepherd (2009)

Data from: Using legacy data to reconstruct the past? Rescue, rigor and reuse in peatland geochronology

There is a growing interest for rescue and reuse of data from past studies (so-called legacy data). Data loss is alarming, especially where natural archives are under threat, such as peat deposits. Here we develop a workflow for reuse of legacy radiocarbon dates in peatland studies, including a rigorous quality assessment that can be tailored to specific research questions and study regions. A penalty score is assigned to each date based on criteria that consider taphonomic quality (i.e. sample provenance) and dating quality (i.e. sample material and method used). The weights of quality criteria may be adjusted based on the research focus, and resulting confidence levels may be used in further analyses to ensure robustness of conclusions. We apply the proposed approach to a case study of a (former) peat landscape in the northern Netherlands, aiming to reconstruct the timing of peat initiation spatially. Our search yielded 313 radiocarbon dates from the 1950s to 2019. Based on the quality assessment the dates—of highly diverse quality—were assigned to four confidence levels. Results indicate that peat initiation for the study area first peaked in the Late Glacial, dropped during the Boreal (10640 – 9220 cal y BP) and showed a second peak in the Subboreal (5660 – 2400 cal y BP). Further spatial analysis shows that for local valleys peat initiation occurred throughout the Holocene, with age-elevation plots indicating a prominent control by Holocene sea level rise. On plains and ridges peat initiation only occurred during the Subboreal, likely controlled by groundwater rise related to sea level rise. Our study highlights the potential of legacy data for palaeogeographic reconstructions, as it is cost-efficient and provides access to information no longer available in the field. However, data retrieval may be challenging and reuse of data requires that basic information on location, elevation, stratigraphy, sample and analysis details are documented irrespective of the original research aims

History interest and history teaching : Students' and teachers' views on the subject of history

This thesis studies teachers’ and students’ conceptions of history and history teaching and aims to explain the importance of an interest in history among teachers and students of the subject. Research on teachers’ conceptions (e.g. Martin 2005) shows that the didactical question “Why?” influences the “How?” and “Why?” questions and that teachers’ thinking about their own practice is mainly influenced by their background and their experiences from teaching. Research on students’ opinions (e.g. Youth and History, 1997) shows that they enjoy history shown in films, that they appreciate museums, and that the preferred topic is 20th century history. In this thesis learning is envisaged as something individual but it is the learners’ social context that defines what is important, meaningful and interesting to learn. The research methods consist of a survey study concerning the pupils’ attitudes towards history and history education, and an interview study with their teachers about their teaching and their opinions about history in general. Nine teachers and their 217 pupils participated. It is mainly topics from 20th century that are described as interesting by both students and teachers. The teachers had different views on the didactical whyquestion, which they described either as student oriented or subject oriented. Their views on why history is important influenced their teaching methods. The student oriented teachers stated that their pupils’ needs and wishes affect their methods while the subject oriented teachers said that they give varying lessons, and have a more student active teaching, but decide for themselves what teaching methods are to be used. The subject matter is influenced by the teachers’ personal interest in history, in most cases a Eurocentric political history. This choice of content, and the teachers own interest, are explained by the historical culture of Swedish society rather than the curriculum. The teachers state that exciting stories and dramatic events related in books or films were, and still are, important to their interest in history. Their individual interpretation of what is important and meaningful in their historical culture influences teachers’ personal interest, their knowledge, and the content of their history teaching. The students’ attitudes to history are also influenced by various factors, of which history education at school is merely one

Faded landscape: unravelling peat initiation and lateral expansion at one of northwest Europe's largest bog remnants

On the mainland of northwest Europe generally only remnants of former peat landscapes subsist. Due to the poor preservation of these landscapes, alternative approaches to reconstruct peat initiation and lateral expansion are needed compared to regions with intact peat cover. Here we aim (1) to find explanatory variables within a digital soil mapping approach that allow us to reconstruct the pattern of peat initiation and lateral expansion within (and potentially beyond) peat remnants, and (2) to reconstruct peat initiation ages and lateral expansion for one of the largest bog remnants of the northwest European mainland, Fochteloërveen. Basal radiocarbon dates were obtained from the peat remnant, which formed the basis for subsequent analyses. We investigated the relationship between peat initiation age and three potential covariates: (1) total thickness of organic deposits, (2) elevation of the Pleistocene mineral surface that underlies the organic deposits, and (3) a constructed variable representing groundwater-fed wetness based on elevation of the mineral surface and current hydraulic head. Significant relationships were found with covariates (1) and (3), which were then used for subsequent modelling. Our results indicate simultaneous peat initiation at several loci in Fochteloërveen during the Early Holocene and continuous lateral expansion until 900 cal BP. Lateral expansion accelerated between 5500-3500 cal BP. Our approach is spatially explicit (i.e. results in a map of peat initiation ages), and it allows for a quantitative evaluation of the prediction using the standard deviation and comparison of predictions with validation points. The applied method based on covariate (1) is only useful where remnant peat survived, whereas covariate (3) may ultimately be applied to reconstruct peat initiation ages and lateral peatland expansion beyond the limits of peat remnants

Faded landscape: unravelling peat initiation and lateral expansion at one of northwest Europe's largest bog remnants

On the mainland of northwest Europe generally only remnants of former peat landscapes subsist. Due to the poor preservation of these landscapes, alternative approaches to reconstruct peat initiation and lateral expansion are needed compared to regions with intact peat cover. Here we aim (1) to find explanatory variables within a digital soil mapping approach that allow us to reconstruct the pattern of peat initiation and lateral expansion within (and potentially beyond) peat remnants, and (2) to reconstruct peat initiation ages and lateral expansion for one of the largest bog remnants of the northwest European mainland, Fochteloërveen. Basal radiocarbon dates were obtained from the peat remnant, which formed the basis for subsequent analyses. We investigated the relationship between peat initiation age and three potential covariates: (1) total thickness of organic deposits, (2) elevation of the Pleistocene mineral surface that underlies the organic deposits, and (3) a constructed variable representing groundwater-fed wetness based on elevation of the mineral surface and current hydraulic head. Significant relationships were found with covariates (1) and (3), which were then used for subsequent modelling. Our results indicate simultaneous peat initiation at several loci in Fochteloërveen during the Early Holocene and continuous lateral expansion until 900 cal BP. Lateral expansion accelerated between 5500–3500 cal BP. Our approach is spatially explicit (i.e. results in a map of peat initiation ages), and it allows for a quantitative evaluation of the prediction using the standard deviation and comparison of predictions with validation points. The applied method based on covariate (1) is only useful where remnant peat survived, whereas covariate (3) may ultimately be applied to reconstruct peat initiation ages and lateral peatland expansion beyond the limits of peat remnants