231 research outputs found

    The overlooked spatial dimension of climate-smart agriculture

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    Climate-smart agriculture (CSA) and sustainable intensification (SI) are widely claimed to be high-potential solutions to address the interlinked challenges of food security and climate change. Operationalization of these promising concepts is still lacking and potential trade-offs are often not considered in the current continental- to global-scale assessments. Here we discuss the effect of spatial variability in the context of the implementation of climate-smart practices on two central indicators, namely yield development and carbon sequestration, considering biophysical limitations of suggested benefits, socioeconomic and institutional barriers to adoption, and feedback mechanisms across scales. We substantiate our arguments by an illustrative analysis using the example of a hypothetical large-scale adoption of conservation agriculture (CA) in sub-Saharan Africa. We argue that, up to now, large-scale assessments widely neglect the spatially variable effects of climate-smart practices, leading to inflated statements about co-benefits of agricultural production and climate change mitigation potentials. There is an urgent need to account for spatial variability in assessments of climate-smart practices and target those locations where synergies in land functions can be maximized in order to meet the global targets. Therefore, we call for more attention toward spatial planning and landscape optimization approaches in the operationalization of CSA and SI to navigate potential trade-offs

    Perfectionistic Cognitions as Antecedents of Work Engagement : Personal Resources, Personal Demands, or Both?

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    Whereas personal resources have been established as a counterpart to external job resources in the Job Demands–Resources Theory, personal demands as a counterpart to job demands have been rather neglected. In this study, we propose that multidimensional perfectionism—in the form of daily perfectionistic cognitions—is a relevant personal characteristic for predicting daily work engagement in addition to and in its interplay with daily time pressure as a common job demand. 157 employees participated in a daily diary study for 15 workdays. As hypothesized, multilevel regression analyses yielded a positive unique effect of perfectionistic strivings cognitions and a negative unique effect of perfectionistic concerns cognitions on daily work engagement. Furthermore, we found that both unique perfectionistic strivings cognitions and perfectionistic concerns cognitions moderated a quadratic relationship between daily time pressure and daily work engagement. Building on the Job Demands–Resources Theory, we propose that the dimension of perfectionistic strivings constitutes a personal resource and the dimension of perfectionistic concerns constitutes a personal demand in the prediction of work engagement

    A global assessment of gross and net land change dynamics for current conditions and future scenarios

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    The consideration of gross land changes, meaning all area gains and losses within a pixel or administrative unit (e.g. country), plays an essential role in the estimation of total land changes. Gross land changes affect the magnitude of total land changes, which feeds back to the attribution of biogeochemical and biophysical processes related to climate change in Earth System Models. Global empirical studies on gross land changes are currently lacking. Whilst the relevance of gross changes for global change has been indicated in the literature, it is not accounted for in future land change scenarios. In this study, we extract gross and net land change dynamics from large-scale and high-resolution (30-100m) remote sensing products to create a new global gross and net change dataset. Subsequently, we developed an approach to integrate our empirically derived gross and net changes with the results of future simulation models, by accounting for the gross and net change addressed by the land use model and the gross and net change that is below the resolution of modelling. Based on our empirical data, we found that gross land change within 0.5-degree grid cells were substantially larger than net changes in all parts of the world. As 0.5- degree grid cells are a standard resolution of Earth System Models, this leads to an underestimation of the amount of change. This finding contradicts earlier studies, which assumed gross land changes to appear in shifting cultivation areas only. Applied in a future scenario, the consideration of gross land changes led to approximately 50% more land changes globally compared to a net land change representation. Gross land changes were most important in heterogeneous land systems with multiple land uses (e.g. shifting cultivation, smallholder farming, and agro-forestry systems). Moreover, the importance of gross changes decreased over time due to further polarization and intensification of land use. Our results serve as empirical database for land change dynamics that can be applied in Earth System Models and Integrated Assessment Model

    Wiederansiedlung seltener und gefĂ€hrdeter Ackerwildpflanzen auf Ökobetrieben. Teilprojekt Freising: Einfluss von Feldfrucht und Aussaatzeitpunkt

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    Intensive land use has led to a drastic decline of arable weeds in Central Europe. The objective of the project “Restoration of local populations of rare and endangered arable field plants on organic farms in Germany” is to develop methods for a successful re-establishment of arable weeds on fields where absence of herbicides provides favourable development conditions. Two complementary approaches are tested by research teams at Freising and Witzenhausen. In Freising two exact trials were set up in order to find suitable crops and dates for the initial sowing of three rare and endangered species (Consolida regalis, Legousia speculum-veneris, Lithospermum arvense). The study area is located in the Munich Plain which is characterized by limestone gravel. First results show a better establishment of all three species on plots with a reduced sowing density of the crop. Furthermore, sowing in early autumn seems to be beneficial for the establishment of the study species

    Using Smartphone Sensor Paradata and Personalized Machine Learning Models to Infer Participants' Well-being: Ecological Momentary Assessment

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    Background: Sensors embedded in smartphones allow for the passive momentary quantification of people’s states in the context of their daily lives in real time. Such data could be useful for alleviating the burden of ecological momentary assessments and increasing utility in clinical assessments. Despite existing research on using passive sensor data to assess participants’ moment-to-moment states and activity levels, only limited research has investigated temporally linking sensor assessment and self-reported assessment to further integrate the 2 methodologies. Objective: We investigated whether sparse movement-related sensor data can be used to train machine learning models that are able to infer states of individuals’ work-related rumination, fatigue, mood, arousal, life engagement, and sleep quality. Sensor data were only collected while the participants filled out the questionnaires on their smartphones. Methods: We trained personalized machine learning models on data from employees (N=158) who participated in a 3-week ecological momentary assessment study. Results: The results suggested that passive smartphone sensor data paired with personalized machine learning models can be used to infer individuals’ self-reported states at later measurement occasions. The mean R 2 was approximately 0.31 (SD 0.29), and more than half of the participants (119/158, 75.3%) had an R 2 of ≄0.18. Accuracy was only slightly attenuated compared with earlier studies and ranged from 38.41% to 51.38%. Conclusions: Personalized machine learning models and temporally linked passive sensing data have the capability to infer a sizable proportion of variance in individuals’ daily self-reported states. Further research is needed to investigate factors that affect the accuracy and reliability of the inference

    How to Capture Reciprocal Communication Dynamics: Comparing Longitudinal Statistical Approaches in Order to Analyze Within- and Between-Person Effects

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    Choosing an appropriate statistical model to analyze reciprocal relations between individuals’ attitudes, beliefs, or behaviors over time can be challenging. Often, decisions for or against specific models are rather implicit and it remains unclear whether the statistical approach fits the theory of interest. For longitudinal models, this is problematic since within- and between-person processes can be confounded leading to wrong conclusions. Taking the perspective of the reinforcing spirals model (RSM) focusing on media effects and selection, we compare six statistical models that were recently used to analyze the RSM and show their ability to separate within- and between-person components. Using empirical data capturing respondents’ development during adolescence, we show that results vary across statistical models. Further, Monte Carlo simulations indicate that some approaches might lead to wrong conclusions if specific communication dynamics are present. In sum, we recommend using approaches that explicitly model and clearly separate within- and between-person effects

    New approaches to the conservation of rare arable plants in Germany

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    Der rasante technische Fortschritt der Landwirtschaft wĂ€hrend der letzten Jahrzehnte hat einen dramatischen RĂŒckgang seltener Ackerwildpflanzen verursacht. Um diesem RĂŒckgang Einhalt zu gebieten, wurden verschiedene Artenschutzkonzepte wie das Ackerrandstreifenprogramm oder das aktuelle Programm ‘100 Äcker fĂŒr die Vielfalt’ entwickelt. FĂŒr Sand- und KalkĂ€cker sind geeignete Bewirtschaftungsmethoden zur Erhaltung seltener Arten inzwischen gut erforscht. FĂŒr saisonal vernĂ€sste AckerflĂ€chen, die ebenfalls viele seltene Arten aufweisen können, ist dagegen wenig ĂŒber naturschutzfachlich geeignet Standortfaktoren und Bewirtschaftungsmethoden bekannt. Untersuchungen an sieben zeitweise ĂŒberstauten Ackersenken bei Parstein (Brandenburg) zeigten, dass das Überstauungsregime und insbesondere die Dauer der Überstauung die Artenzusammensetzung der BestĂ€nde stark beeinflussen. Die aktuelle Bewirtschaftung zeigte dagegen weniger deutliche Auswirkungen auf Populationen der Zielarten Myosurus minimus und Elatine alsinastrum. Ein weiteres aktuelles Problem des Ackerwildpflanzenschutzes ist, dass seltene Arten oft auf FlĂ€chen vorkommen, wo ihr Überleben durch die derzeitige Bewirtschaftung akut gefĂ€hrdet ist. Da die Richtlinien der ökologischen AnbauverbĂ€nde intensive Bewirtschaftungsverfahren weitgehend einschrĂ€nken, bietet der Ökologische Landbau gĂŒnstige Voraussetzungen fĂŒr den Schutz gefĂ€hrdeter Ackerwildpflanzen. Wie deren Populationen erfolgreich in ökologisch bewirtschafteten Feldern etabliert werden können, wird in einem Feldversuch bei GrĂ€felfing in der MĂŒnchner Schotterebene untersucht. Erste Ergebnisse zu den winterannuellen Arten Legousia speculum-veneris und Consolida regalis zeigen, dass sich diese Arten erfolgreich in ökologisch bewirtschafteten Äckern etablieren lassen. FrĂŒhe Herbstsaat und eine reduzierte Kulturpflanzenkonkurrenz im Ansaatjahr erbrachten dabei die besten Erfolge. Bei reduzierter Kulturpflanzendichte fĂŒhrte Dinkel zu deutlich höheren Etablierungsraten als Roggen. Die Ergebnisse dieser Studie können einen wesentlichen Beitrag zur Erhaltung gefĂ€hrdeter Arten in der Agrarlandschaft leisten, wenn der Transfer gefĂ€hrdeter Ackerwildpflanzen in ökologisch bewirtschaftete AckerflĂ€chen umgesetzt wird.Stichwörter: Artentransfer, Bewirtschaftung, Ökologischer Landbau, ÜberstauNeue AnsĂ€tze zum Artenschutz gefĂ€hrdeter Ackerwildpflanzen in DeutschlandAbstractOver the past decades, the rapid improvement of agricultural technology has caused a dramatic decrease of rare arable plants. This process has stimulated the development of various concepts to protect these species such as the field margin program or more recently the program ‘100 fields for biodiversity’. For fields with sandy or calcareous soils, management practices to conserve the specific arable flora are well explored. For occasionally wet sites, however, which may also harbour various threatened species, little is known about suitable site conditions and conservation management. Studying seven seasonally flooded field sites close to Parstein (Brandenburg) showed that the flooding regime and particularly the duration of flooding strongly affect the composition of the apparent plant communities. Effects of different arable farming practices on the populations of the two target species Myosurus minimus and Elatine alsinastrum were less pronounced. Another urgent problem of arable plant conservation is that rare species frequently grow at sites where they are threatened by current cultivation. As management is less intense under organic farming, this system could provide suitable conditions for the conservation of threatened species. However, locally extinct species need to be actively reintroduced to overcome dispersal limitations. How these plants can be successfully established in fields under organic farming was studied in a field trial at GrĂ€felfing (Bavaria). Preliminary results on the winter annuals Legousia speculum-veneris and Consolida regalis indicate that rare arable plants can be successfully introduced to organic fields. Early autumn sowing and a low crop competition provide the most favourable conditions for their establishment. At reduced sowing rates, winter spelt allowed a much better establishment than winter rye. If the idea of transferring rare arable plants to organic farmland establishes in practice, results of this study could substantially contribute to the conservation of rare species in arable landscapes.Keywords: Arable weed, flooding, management, organic farming, species transfer, threatened species, wet fiel
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