Monitoring the spread of invasive plant species in Germany – how many species can we possibly detect by remote sensing and what data do we need?

Combining remote sensing and field data allows for the detection of some invasive alien plant species with an adequate accuracy. Especially the use of satellite data for larger areas or UAS (unmanned aerial system) data for smaller sites may provide alternatives to classical field mapping approaches. A main advantage is that satellite or UAS data is potentially more cost-efficient then the use of for example hyperspectral data, which was frequently applied in research on the detectability of invasive species in the past. This study discusses the possibilities and limitations of remote sensing to contribute to the detection of invasive alien plant species in Germany. Taking into account previous studies on the topic, we estimate the potential for a successful detection of relevant invasive plant species in Germany. Main criteria to determine the potential for detection are the species characteristics (size, detectable traits, habitat) as well as their similarity to other native species. For 19 of the 42 species examined, the use of remote sensing data is most probably successful, mainly for larger species and species with characteristic features such as colorful flowers or leaves. For another 10 species the detection might eventually be feasible. For about 13 species, especially hydrophytes living below the water surface and other species lacking any characteristic features, the detection is currently not possible. We can conclude that remote sensing remote may offer efficient solutions for a small or large scale monitoring of certain invasive plant species or to control the management success and thus support decision-making. In general, more research is needed to develop cost-efficient and user-friendly solutions

Institutionelle Workflows zum Forschungsdatenmanagement.

Institutionelle Workflows zum Forschungsdatenmanagement sind an Instituten der Leibniz-Gemeinschaft unterschiedlich ausgeprägt. Im Rahmen eines Workshops haben Mitarbeitende aus dem Bereich Forschungsdatenmanagement verschiedener Leibniz-Institute eine Bestandsaufnahme der derzeitigen Praxis vorgenommen und übertragbare Ansätze herausgearbeitet. In diesem Beitrag werden die einzelnen Erfahrungen und Berichte zusammengefasst und als Gesamtsituation skizziert. Darauf aufbauend werden erfolgreich etablierte Abläufe modellhaft als Lösungsmöglichkeiten entworfen. Der Workshopbericht differenziert dabei verschiedene Aspekte des Forschungsdatenmanagements. Klare Regelungen und Zuständigkeiten sowie eine möglichst frühzeitige und kontinuierliche Einbindung von Forschenden stellen wichtige Voraussetzungen für das Gelingen des Datenmanagements dar

Monitoring ecological change during rapid socio-economic and political transitions: Colombian ecosystems in the post-conflict era

After more than 50-years of armed conflict, Colombia is now transitioning to a more stable social and political climate due to a series of peace agreements between the government and different armed groups. Consequences of these socio-economic and political changes on ecosystems are largely uncertain, but there is growing concern about derived increases in environmental degradation. Here, we review the capacity of Colombia to monitor the state of its ecosystems and their rate of change over time. We found several important programs currently set in place by different institutions as well as by independent groups of scientists that address different aspects of environmental monitoring. However, most of the current initiatives could be improved in terms of data coverage, quality and access, and could be better articulated among each other. We propose a set of activities that would increase the capacity of Colombia to monitor its ecosystems, provide useful information to policy makers, and facilitate scientific research. These include: 1) the establishment of a national center for ecological synthesis that focuses on analyzing existing information; 2) the establishment of an ecological observatory system that collects new information, integrates remote sensing products, and produces near real-time products on key ecological variables; and 3) the creation of new platforms for dialog and action within existing scientific and policy groups

A global experiment on motivating social distancing during the COVID-19 pandemic

Finding communication strategies that effectively motivate social distancing continues to be a global public health priority during the COVID-19 pandemic. This cross-country, preregistered experiment (n = 25,718 from 89 countries) tested hypotheses concerning generalizable positive and negative outcomes of social distancing messages that promoted personal agency and reflective choices (i.e., an autonomy-supportive message) or were restrictive and shaming (i.e., a controlling message) compared with no message at all. Results partially supported experimental hypotheses in that the controlling message increased controlled motivation (a poorly internalized form of motivation relying on shame, guilt, and fear of social consequences) relative to no message. On the other hand, the autonomy-supportive message lowered feelings of defiance compared with the controlling message, but the controlling message did not differ from receiving no message at all. Unexpectedly, messages did not influence autonomous motivation (a highly internalized form of motivation relying on one’s core values) or behavioral intentions. Results supported hypothesized associations between people’s existing autonomous and controlled motivations and self-reported behavioral intentions to engage in social distancing. Controlled motivation was associated with more defiance and less long-term behavioral intention to engage in social distancing, whereas autonomous motivation was associated with less defiance and more short- and long-term intentions to social distance. Overall, this work highlights the potential harm of using shaming and pressuring language in public health communication, with implications for the current and future global health challenges

A global experiment on motivating social distancing during the COVID-19 pandemic

Finding communication strategies that effectively motivate social distancing continues to be a global public health priority during the COVID-19 pandemic. This cross-country, preregistered experiment (n = 25,718 from 89 countries) tested hypotheses concerning generalizable positive and negative outcomes of social distancing messages that promoted personal agency and reflective choices (i.e., an autonomy-supportive message) or were restrictive and shaming (i.e. a controlling message) compared to no message at all. Results partially supported experimental hypotheses in that the controlling message increased controlled motivation (a poorly-internalized form of motivation relying on shame, guilt, and fear of social consequences) relative to no message. On the other hand, the autonomy-supportive message lowered feelings of defiance compared to the controlling message, but the controlling message did not differ from receiving no message at all. Unexpectedly, messages did not influence autonomous motivation (a highly-internalized form of motivation relying on one’s core values) or behavioral intentions. Results supported hypothesized associations between people’s existing autonomous and controlled motivations and self-reported behavioral intentions to engage in social distancing: Controlled motivation was associated with more defiance and less long-term behavioral intentions to engage in social distancing, whereas autonomous motivation was associated with less defiance and more short- and long-term intentions to social distance. Overall, this work highlights the potential harm of using shaming and pressuring language in public health communication, with implications for the current and future global health challenges

Erfassung invasiver Pflanzenarten mithilfe von Hyperspektraldaten

Biological invasions are among the most important drivers of the decline in biodiversity worldwide. The assessment of invasive plant species by field mapping is tedious and expensive, especially for large or undeveloped areas. Remote sensing is an alternative method to quantify the distribution of invasive plant species. Distribution maps can be used to guide further analysis and management decisions. One of the most successful remote sensing data products for mapping invasive plant species are airborne hyperspectral remote sensing data, providing an unsurpassed spectral as well as a high spatial resolution, allowing to differentiate many invasive target species from their co-occurring vegetation with an acceptable error rate. In this dissertation, I used such airborne hyperspectral remote sensing datasets in combination with field datasets from the Isle of Sylt in Northern Germany, from three areas in Belgium, and from the Jasper Ridge Biological Preserve in Northern California to map invasive plants. In Germany and Belgium, the target species was the bryophyte Campylopus introflexus, while in California, the target species were the herb Centaurea solstitialis and the grass Phalaris aquatica. For each subproject, the first step was to create a distribution map of the species. This step was followed by an accuracy assessment, using a second independent field dataset and visually examining the results. Overall accuracy was about 76% for C. introflexus on the Isle of Sylt and between 59% and 82% for the sites in Belgium. In the Jasper Ridge Biological Preserve overall accuracy was 72% to 74% and 83% to 88% for C. solstitialis and P. aquatica, respectively. The first case study focused on the success rate of mapping small cover fractions to support early detection. Detection accuracy did not significantly drop before the cover of the target species falls below 5% in a 3 m × 3 m plot. Moreover, it was examined how widespread the species is in different biotope types. The study showed that some biotope types on the Isle of Sylt such as the dune heath are much more seriously affected by the invasion than others. The second case study aimed at comparing different methodological approaches, testing three different one-class classifiers – Maxent, boosted regression trees and biased support vector machines. Distribution patterns and overall accuracy of the resulting maps were relatively similar, but there were significant differences in the selected spectral bands and the user-friendliness of the tested approaches. The third case study examined whether it is possible to transfer models for a target species from one site to another site. This was found to be true for the majority of the tested transfers for Campylopus introflexus, but the mapping success highly depended on the characteristics of the respective study site and the remote sensing dataset. Models based on a combination of field data from different sites provided the best results.Biologische Invasionen gehören zu den Hauptfaktoren, die zum fortschreitenden Rückgang der weltweiten Biodiversität beitragen. Während konventionelle Kartierungen im Gelände für große oder schlecht zugängliche Gebiete oft zeit- und kostenintensiv sind, kann man mithilfe von Fernerkundungsdaten großflächig effizient Informationen zur Ausbreitung der Arten erhalten. Die resultierenden Verbreitungskarten können dann als Grundlage für weitere Analysen dienen oder für Managemententscheidungen herangezogen werden. Für die Kartierung invasiver Pflanzenarten sind Hyperspektraldaten aus Flugzeugüberfliegungen besonders gut geeignet, da sie sowohl eine hohe räumliche als auch eine hohe spektrale Auflösung aufweisen. Damit lassen sich viele invasive Zielarten gut von der umgebenden Vegetation unterscheiden. In dem vorliegenden Dissertationsprojekt habe ich mit Hyperspektraldaten aus Flugzeugüberfliegungen und Felddaten aus den folgenden drei Untersuchungsgebieten gearbeitet: auf der Insel Sylt, in Belgien und im Jasper Ridge Biological Preserve in Kalifornien. Dabei wurde auf Sylt und in Belgien die invasive Moosart Campylopus introflexus untersucht, während in Kalifornien die krautige Art Centaurea solsitialis und die Grasart Phalaris aquatica kartiert wurden. Für jedes der drei Teilprojekte habe ich zunächst eine Ausbreitungskarte für die genannten Arten erstellt. Diese Ausbreitungskarten wurden anschließend mit einem zweiten Felddatensatz validiert, und die Ausbreitungsmuster wurden visuell geprüft, um abzuschätzen, wie gut die Karten die tatsächliche Verbreitung darstellen. Die Gesamtgenauigkeiten der Verbreitungskarten lagen bei 76% für C. introflexus auf Sylt und zwischen 59% und 82% für die drei Gebiete in Belgien. Für C. solstitalis lagen die Gesamtgenauigkeiten der Verbreitungskarten in Jasper Ridge bei 72 - 74%, und für P. aquatica bei 83 - 88%. Die erste Fallstudie hat sich außerdem mit der Frage befasst, inwieweit sich kleinere Vorkommen mit geringen Deckungsgraden erfassen lassen. Für C. introflexus haben die Untersuchungen ergeben, dass die Erfassungsgenauigkeit erst deutlich sinkt, wenn der Flächenanteil der Zielart innerhalb der 3 m x 3 m Plots unter 5% beträgt. Weiterhin wurde analysiert, in welchen Biotoptypen die Art vorranging vorkommt: deutlich höhere Anteile wurden hierbei innerhalb der Dünenheide festgestellt. In der zweiten Fallstudie ging es darum, verschiedene methodische Ansätze zu vergleichen, insbesondere den Unterschied bei der Verwendung drei verschiedener Klassifizierungsalgorithmen (Maxent, boosted regression tree und biases support vector machines). Die Untersuchungen haben gezeigt, dass die generellen Verbreitungsmuster sich ähneln, und die Gesamtgenauigkeiten sich nur geringfügig unterscheiden. Andererseits gab es deutliche Unterschiede bei der Auswahl der spektralen Bänder und der Benutzerfreundlichkeit der Methoden. Bei der dritten Fallstudie lag der Schwerpunkt auf der Frage, ob sich lokal kalibrierte Modelle auf andere Gebiete übertragen lassen. Für die Mehrzahl der untersuchten Übertragungen konnten hier gute Ergebnisse erzielt werden, wobei der Erfolg der Übertragbarkeit stark von den Eigenschaften des jeweiligen Untersuchungsgebiets und der zugehörigen Datensätze abhing. Generell haben Modelle, in denen Kalibrierungsdaten aus mehreren Gebieten kombiniert wurden, höhere Gesamtgenauigkeiten erreicht

Institutionelle Workflows zum Forschungsdatenmanagement.

Institutionelle Workflows zum Forschungsdatenmanagement sind an Instituten der Leibniz-Gemeinschaft unterschiedlich ausgeprägt. Im Rahmen eines Workshops haben Mitarbeitende aus dem Bereich Forschungsdatenmanagement verschiedener Leibniz-Institute eine Bestandsaufnahme der derzeitigen Praxis vorgenommen und übertragbare Ansätze herausgearbeitet. In diesem Beitrag werden die einzelnen Erfahrungen und Berichte zusammengefasst und als Gesamtsituation skizziert. Darauf aufbauend werden erfolgreich etablierte Abläufe modellhaft als Lösungsmöglichkeiten entworfen. Der Workshopbericht differenziert dabei verschiedene Aspekte des Forschungsdatenmanagements. Klare Regelungen und Zuständigkeiten sowie eine möglichst frühzeitige und kontinuierliche Einbindung von Forschenden stellen wichtige Voraussetzungen für das Gelingen des Datenmanagements dar

The DIARS toolbox: a spatially explicit approach to monitor alien plant invasions through remote sensing

The synergies between remote sensing technologies and ecological research have opened new avenues for the study of alien plant invasions worldwide. Such scientific advances have greatly improved our capacity to issue warnings, develop early-response systems and assess the impacts of alien plant invasions on biodiversity and ecosystem functioning. Hitherto, practical applications of remote sensing approaches to support nature conservation actions are lagging far behind scientific advances. Yet, for some of these technologies, knowledge transfer is difficult due to the complexity of the different data handling procedures and the huge amounts of data it involves per spatial unit. In this context, the next logical step is to develop clear guidelines for the application of remote sensing data to monitor and assess the impacts of alien plant invasions, that enable scientists, landscape managers and policy makers to fully exploit the tools which are currently available. It is desirable to have such guidelines accompanied by freely available remote sensing data and generated in a free and open source environment that increases the availability and affordability of these new technologies. Here we present a toolbox that provides an easy-to-use, flexible, transparent and open source set of tools to sample, map, model and assess the impact of alien plant invasions using two high-resolution remote sensing products (hyperspectral and LiDAR images). This online toolbox includes a real case dataset designed to facilitate testing and training in any computer system and processing capacity

Transferability of species distribution models for the detection of an invasive alien bryophyte using imaging spectroscopy data

Remote sensing is a promising tool for detecting invasive alien plant species. Mapping and monitoring those species requires accurate detection. So far, most studies relied on models that are locally calibrated and validated against available field data. Consequently, detecting invasive alien species at new study areas requires the acquisition of additional field data which can be expensive and time-consuming. Model transfer might thus provide a viable alternative. Here, we mapped the distribution of the invasive alien bryophyte Campylopus introflexus to i) assess the feasibility of spatially transferring locally calibrated models for species detection between four different heathland areas in Germany and Belgium and ii) test the potential of combining calibration data from different sites in one species distribution model (SDM). In a first step, four different SDMs were locally calibrated and validated by combining field data and airborne imaging spectroscopy data with a spatial resolution ranging from 1.8 m to 4 m and a spectral resolution of about 10 nm (244 bands). A one-class classifier, Maxent, which is based on the comparison of probability densities, was used to generate all SDMs. In a second step, each model was transferred to the three other study areas and the performance of the models for predicting C. introflexus occurrences was assessed. Finally, models combining calibration data from three study areas were built and tested on the remaining fourth site. In this step, different combinations of Maxent modelling parameters were tested. For the local models, the area under the curve for a test dataset (test AUC) was between 0.57–0.78, while the test AUC for the single transfer models ranged between 0.45–0.89. For the combined models the test AUC was between 0.54–0.9. The success of transferring models calibrated in one site to another site highly depended on the respective study site; the combined models provided higher test AUC values than the locally calibrated models for three out of four study sites. Furthermore, we also demonstrated the importance of optimizing the Maxent modelling parameters. Overall, our results indicate the potential of a combined model to map C. introflexus without the need for new calibration data

Invasion by the Alien Tree Prunus serotina Alters Ecosystem Functions in a Temperate Deciduous Forest

Alien invasive species can affect large areas, often with wide-ranging impacts on ecosystem structure, function, and services. Prunus serotina is a widespread invader of European temperate forests, where it tends to form homogeneous stands and limits recruitment of indigenous trees. We hypotesized that invasion by P. serotina would be reflected in the nutrient contents of the native species' leaves and in the respiration of invaded plots as efficient resource uptake and changes in nutrient cycling by P. serotina probably underly its aggressive invasiveness. We combined data from 48 field plots in the forest of Compiegne, France, and data from an experiment using 96 microcosms derived from those field plots. We used general linear models to separate effects of invasion by P. serotina on heterotrophic soil and litter respiration rates and on canopy foliar nutrient content from effects of soil chemical properties, litter quantity, litter species composition, and tree species composition. In invaded stands, average respiration rates were 5.6% higher for soil (without litter) and 32% higher for soil and litter combined. Compared to indigenous tree species, P. serotina exhibited higher foliar N (+24.0%), foliar P (+50.7%), and lower foliar C:N (-22.4%) and N:P (-10.1%) ratios. P. serotina affected foliar nutrient contents of co-occuring indigenous tree species leading to decreased foliar N (-8.7 %) and increased C: N ratio (+9.5%) in Fagus sylvatica, decreased foliar N: P ratio in Carpinus betulus (-13.5%) and F. sylvatica (-11.8%), and increased foliar P in Pinus sylvestris (+12.3%) in invaded vs. uninvaded stands. Our results suggest that P. serotina is changing nitrogen, phosphorus, and carbon cycles to its own advantage, hereby increasing carbon turnover via labile litter, affecting the relative nutrient contents in the overstory leaves, and potentially altering the photosynthetic capacity of the long-lived indigenous broadleaved species. Uncontrolled invasion of European temperate forests by P. serotina may affect the climate change mitigation potential of these forests in the long term, through additive effects on local nutrient cycles