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Non-forest ecosystems, dominated by shrubs, grasses and herbaceous plants, provide ecosystem services including carbon sequestration and forage for grazing, and are highly sensitive to climatic changes. Yet these ecosystems are poorly represented in remotely sensed biomass products and are undersampled by in situ monitoring. Current global change threats emphasize the need for new tools to capture biomass change in non-forest ecosystems at appropriate scales. Here we developed and deployed a new protocol for photogrammetric height using unoccupied aerial vehicle (UAV) images to test its capability for delivering standardized measurements of biomass across a globally distributed field experiment. We assessed whether canopy height inferred from UAV photogrammetry allows the prediction of aboveground biomass (AGB) across low-stature plant species by conducting 38 photogrammetric surveys over 741 harvested plots to sample 50 species. We found mean canopy height was strongly predictive of AGB across species, with a median adjusted R2 of 0.87 (ranging from 0.46 to 0.99) and median prediction error from leave-one-out cross-validation of 3.9%. Biomass per-unit-of-height was similar within but different among, plant functional types. We found that photogrammetric reconstructions of canopy height were sensitive to wind speed but not sun elevation during surveys. We demonstrated that our photogrammetric approach produced generalizable measurements across growth forms and environmental settings and yielded accuracies as good as those obtained from in situ approaches. We demonstrate that using a standardized approach for UAV photogrammetry can deliver accurate AGB estimates across a wide range of dynamic and heterogeneous ecosystems. Many academic and land management institutions have the technical capacity to deploy these approaches over extents of 1–10 ha−1. Photogrammetric approaches could provide much-needed information required to calibrate and validate the vegetation models and satellite-derived biomass products that are essential to understand vulnerable and understudied non-forested ecosystems around the globe.
Refugee reception in Germany is a primarily municipal task that relies heavily on neighborhood-based volunteering. This paper asserts that there are fundamental spatial mismatches between municipal policies and neighborhood-based approaches that place additional burden on all of the stakeholders involved. Drawing from the case of Frankfurt-Rödelheim, which is a socially and ethnically mixed neighborhood in Frankfurt am Main, I show how the way the municipality accommodates refugees disregards the politically embraced work of neighborhood-based volunteers and how the ideal of neighborhood-based inclusion creates a spatial fetish that fails the living reality of the refugees. The findings are based on my ethnographic fieldwork as volunteer in a neighborhood-based welcome initiative.
The analysis of charcoal fragments in peat and lake sediments is the most widely used approach to reconstruct past biomass burning. With a few exceptions, this method typically relies on the quantification of the total charcoal content of the sediment. To enhance charcoal analyses for the reconstruction of past fire regimes and make the method more relevant to studies of both plant evolution and fire management, the extraction of more information from charcoal particles is critical. Here, I used a muffle oven to burn seven fuel types comprising 17 species from boreal Siberia (near Teguldet village), which are also commonly found in the Northern Hemisphere, and built on published schemes to develop morphometric and finer diagnostic classifications of the experimentally charred particles. I then combined these results with those from fossil charcoal from a peat core taken from the same location (Ulukh-Chayakh mire) in order to demonstrate the relevance of these experiments to the fossil charcoal records. Results show that graminoids, Sphagnum, and wood (trunk) lose the most mass at low burn temperatures (<300 ∘C), whereas heathland shrub leaves, brown moss, and ferns lose the most mass at high burn temperatures. This suggests that species with low mass retention in high-temperature fires are likely to be under-represented in the fossil charcoal record. The charcoal particle aspect ratio appeared to be the strongest indicator of the fuel type burnt. Graminoid charcoal particles are the most elongate (6.7–11.5), with a threshold above 6 that may be indicative of wetland graminoids; leaves are the shortest and bulkiest (2.1–3.5); and twigs and wood are intermediate (2.0–5.2). Further, the use of fine diagnostic features was more successful in separating wood, graminoids, and leaves, but it was difficult to further differentiate these fuel types due to overlapping features. High-aspect-ratio particles, dominated by graminoid and Sphagnum morphologies, may be robust indicators of low-temperature surface fires, whereas abundant wood and leaf morphologies as well as low-aspect-ratio particles are indicative of higher-temperature fires. However, the overlapping morphologies of leaves and wood from trees and shrubs make it hard to distinguish between high-intensity surface fires, combusting living shrubs and dead wood and leaves, and high-intensity crown fires that have burnt living trees. Distinct particle shape may also influence charcoal transportation, with elongated particles (graminoids) potentially having a more heterogeneous distribution and being deposited farther away from the origin of fire than the rounder, polygonal leaf particles. Despite these limitations, the combined use of charred-particle aspect ratios and fuel morphotypes can aid in the more robust interpretation of fuel source and fire-type changes. Lastly, I highlight the further investigations needed to refine the histories of past wildfires.
Drought is understood as both a lack of water (i.e., a deficit as compared to some requirement) and an anomaly in the condition of one or more components of the hydrological cycle. Most drought indices, however, only consider the anomaly aspect, i.e., how unusual the condition is. In this paper, we present two drought hazard indices that reflect both the deficit and anomaly aspects. The soil moisture deficit anomaly index, SMDAI, is based on the drought severity index, DSI, but is computed in a more straightforward way that does not require the definition of a mapping function. We propose a new indicator of drought hazard for water supply from rivers, the streamflow deficit anomaly index, QDAI, which takes into account the surface water demand of humans and freshwater biota. Both indices are computed and analyzed at the global scale, with a spatial resolution of roughly 50 km, for the period 1981-2010, using monthly time series of variables computed by the global water resources and the model WaterGAP2.2d. We found that the SMDAI and QDAI values are broadly similar to values of purely anomaly-based indices. However, the deficit anomaly indices provide more differentiated, spatial and temporal patterns that help to distinguish the degree of the actual drought hazard to vegetation health or the water supply. QDAI can be made relevant for stakeholders with different perceptions about the importance of ecosystem protection, by adapting the approach for computing the amount of water that is required to remain in the river for the well being of the river ecosystem. Both deficit anomaly indices are well suited for inclusion in local or global drought risk studies.
Am Beispiel des politisch-planerischen Diskurses zu ehemaligen Planungen für ein großflächiges Einkaufszentrum in der Mainzer Innenstadt wird der potenzielle Mehrwert diskurs- und gouvernementalitätstheoretischer Zugänge zu raumbezogenen Fragestellungen erörtert. Insbesondere werden die diskursiven Mechanismen der Einschreibung einer unternehmerischen und depolitisierten Konzeption urbaner Räume in scheinbar neutrale und objektive Techniken raumbezogener Wirkungsanalysen herausgearbeitet. Die damit verbundene Sichtweise auf städtische Räume als Wettbewerbseinheiten, die durch raumwirtschaftliche Gesetzmäßigkeiten determiniert sind, wird jedoch gleichzeitig durch Gegendiskurse aufgebrochen, die das Bewahren ortsspezifisch gewachsener baulicher Strukturen zum Maßstab von Stadtentwicklungspolitik machen. Die Fallstudie verdeutlicht damit, wie mithilfe diskursanalytischer Zugänge die raumbezogenen Wissensordnungen freigelegt werden können, die die politischplanerische Steuerung gegenwärtiger Stadtentwicklungsprozesse anleiten.
This article is written from the perspective of phenomenology. Its potential gain for a critical human geography is discussed in contrast to the paradigmatic frame of basic assumptions in constructivism. The example of atmospheres will illustrate another theoretical conception of space. In phenomenological view there happens not only a reality of things but also a circum-actuality is not spatially extended like a house or another material objective. Atmospheres are vital qualities (Dürckheim) we feel like a cloud in our sense perception in situations of awareness. This implies the necessity to make a difference between a material body (Körper) and a felt body (Leib). This epistemic knowledge will improve our critique of neoliberal societies, tuned by aestheticisation especially in glamour CBDs of postmodern cities. Finally there is a close link to the work of Michel Foucault, topped off in his The Hermeneutics of the Subject. References to the Critical Theory (Frankfurter Schule) are connected.
The accurate knowledge of the groundwater storage variation (ΔGWS) is essential for reliable water resource assessment, particularly in arid and semi-arid environments (e.g., Australia, the North China Plain (NCP)) where water storage is significantly affected by human activities and spatiotemporal climate variations. The large-scale ΔGWS can be simulated from a land surface model (LSM), but the high model uncertainty is a major drawback that reduces the reliability of the estimates. The evaluation of the model estimate is then very important to assess its accuracy. To improve the model performance, the terrestrial water storage variation derived from the Gravity Recovery And Climate Experiment (GRACE) satellite mission is commonly assimilated into LSMs to enhance the accuracy of the ΔGWS estimate. This study assimilates GRACE data into the PCRaster Global Water Balance (PCR-GLOBWB) model. The GRACE data assimilation (DA) is developed based on the three-dimensional ensemble Kalman smoother (EnKS 3D), which considers the statistical correlation of all extents (spatial, temporal, vertical) in the DA process. The ΔGWS estimates from GRACE DA and four LSM simulations (PCR-GLOBWB, the Community Atmosphere Biosphere Land Exchange (CABLE), the Water Global Assessment and Prognosis Global Hydrology Model (WGHM), and World-Wide Water (W3)) are validated against the in situ groundwater data. The evaluation is conducted in terms of temporal correlation, seasonality, long-term trend, and detection of groundwater depletion. The GRACE DA estimate shows a significant improvement in all measures, notably the correlation coefficients (respect to the in situ data) are always higher than the values obtained from model simulations alone (e.g., ~0.15 greater in Australia, and ~0.1 greater in the NCP). GRACE DA also improves the estimation of groundwater depletion that the models cannot accurately capture due to the incorrect information of the groundwater demand (in, e.g., PCR-GLOBWB, WGHM) or the unavailability of a groundwater consumption routine (in, e.g., CABLE, W3). In addition, this study conducts the inter-comparison between four model simulations and reveals that PCR-GLOBWB and CABLE provide a more accurate ΔGWS estimate in Australia (subject to the calibrated parameter) while PCR-GLOBWB and WGHM are more accurate in the NCP (subject to the inclusion of anthropogenic factors). The analysis can be used to declare the status of the ΔGWS estimate, as well as itemize the possible improvements of the future model development.
BIOfid is a specialized information service currently being developed to mobilize biodiversity data dormant in printed historical and modern literature and to offer a platform for open access journals on the science of biodiversity. Our team of librarians, computer scientists and biologists produce high-quality text digitizations, develop new text-mining tools and generate detailed ontologies enabling semantic text analysis and semantic search by means of user-specific queries. In a pilot project we focus on German publications on the distribution and ecology of vascular plants, birds, moths and butterflies extending back to the Linnaeus period about 250 years ago. The three organism groups have been selected according to current demands of the relevant research community in Germany. The text corpus defined for this purpose comprises over 400 volumes with more than 100,000 pages to be digitized and will be complemented by journals from other digitization projects, copyright-free and project-related literature. With TextImager (Natural Language Processing & Text Visualization) and TextAnnotator (Discourse Semantic Annotation) we have already extended and launched tools that focus on the text-analytical section of our project. Furthermore, taxonomic and anatomical ontologies elaborated by us for the taxa prioritized by the project’s target group - German institutions and scientists active in biodiversity research - are constantly improved and expanded to maximize scientific data output. Our poster describes the general workflow of our project ranging from literature acquisition via software development, to data availability on the BIOfid web portal (http://biofid.de/), and the implementation into existing platforms which serve to promote global accessibility of biodiversity data.
Anfang der 1990er Jahre haben die anglophonen Geographien damit begonnen, sich mit dem Verhältnis von Psychoanalyse und Stadt auseinanderzusetzen. Ausgehend hiervon kam es Anfang der 2000er Jahre zum Ausruf eines psychoanalytic turn und zur Etablierung von Subdisziplinen, wie den psychoanalytic geographies und der psychoanalytic planning theory, die in den letzten Jahren zu etablierten Bestandteilen der wissenschaftlichen Auseinandersetzung mit Städten im anglophonen Raum geworden sind. Da ein solcher turn hierzulande ausgeblieben ist, stellt sich dieser Beitrag die Frage nach dem Potential einer psychoanalytischen Stadtforschung im deutschsprachigen Raum. Hierzu verfolgt der Autor die These, dass die Stadt bereits in ihrer Entstehung durch das Unbewusste heimgesucht wird. Das urbane Unbewusste kennzeichnet eine Art konstitutiven Störfaktor, der sich in die Topologie der Stadt einschreibt und die Stadt als Objekt (der Stadtforschung) in letzter Instanz unmöglich macht. Ausgehend von dieser Unmöglichkeit, geht der Beitrag den Fantasien rund um die sozialen, politischen und materiellen Verhältnisse einer Stadt nach. Fantasien spielen aus Sicht der psychoanalytischen Stadtforschung eine zentrale Rolle, um der Stadt eine illusorische Konsistenz zu verleihen und das urbane Unbewusste auf Distanz zu halten. Sie ermöglichen es, sich die Stadt vorzustellen, sie zu fühlen und über sie zu sprechen. Der Beitrag endet schließlich mit ein paar Worten zu den Herausforderungen einer künftigen Erschließung der Psychoanalyse für kritische Stadtforschung.