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Precise and timely information on biomass yield and nitrogen uptake in intensively managed grasslands are essential for sustainable management decisions. Imaging sensors mounted on unmanned aerial vehicles (UAVs) along with photogrammetric structure-from-motion processing can provide timely data on crop traits rapidly and non-destructively with a high spatial resolution. The aim of this multi-temporal field study is to estimate aboveground dry matter yield (DMY), nitrogen concentration (N%) and uptake (Nup) of temperate grasslands from UAV-based image data using machine learning (ML) algorithms. The study is based on a two-year dataset from an experimental grassland trial. The experimental setup regarding climate conditions, N fertilizer treatments and slope yielded substantial variations in the dataset, covering a considerable amount of naturally occurring differences in the biomass and N status of grasslands in temperate regions with similar management strategies. Linear regression models and three ML algorithms, namely, random forest (RF), support vector machine (SVM), and partial least squares (PLS) regression were compared with and without a combination of both structural (sward height; SH) and spectral (vegetation indices and single bands) features. Prediction accuracy was quantified using a 10-fold 5-repeat cross-validation (CV) procedure. The results show a significant improvement of prediction accuracy when all structural and spectral features are combined, regardless of the algorithm. The PLS models were outperformed by their respective RF and SVM counterparts. At best, DMY was predicted with a median RMSECV of 197 kg ha(-1), N% with a median RMSECV of 0.32%, and Nup with a median RMSECV of 7 kg ha(-1). Furthermore, computationally less expensive models incorporating, e.g., only the single multispectral camera bands and SH metrics, or selected features based on variable importance achieved comparable results to the overall best models.

Mediterranean oak woodlands are currently facing unprecedented degradation threats from oak decline. The Iberian oak decline Seca, related to Phytophthora infection, causes crown defoliation that may adversely affect ecosystem services (ESs). We aim to improve our understanding of how Seca-induced declines in crown foliation affect the provision of multiple ecosystem services from understory vegetation. We selected holm (Quercus ilex) and cork oak (Q. suber) trees in a Spanish oak woodland and evaluated three proxies of canopy effects. One proxy (crown defoliation) solely captured Seca-dependent effects, one proxy solely captured Seca-independent effects (tree dimensions such as diameter and height), while the third proxy (tree vigor) captured overall canopy effects. We then used the best-performing proxies to assess canopy effects on key ecosystem services (ESs) such as aboveground net primary production (ANPP), grass and legume biomass, species diversity, litter decomposition rates, and a combined index of ecosystem multifunctionality. We found that both types of canopy effects (i.e. Seca-dependent and Seca-independent effects) were related, indicating that ANPP was disproportionally more affected by Seca when defoliated trees were large. Responses of other ESs were mostly not significant, although lower species diversity was found under trees with intermediate vigor. Our results underline that a Seca-related decline in canopy density triggered a homogenization of ecosystem service delivery on the ecosystem scale. The ecosystem functions (EFs) under trees of low vigor are similar to that in adjacent open microsites indicating that the presence of vigorous (i.e. old and vital) trees is critical for maintaining EFs at a landscape level. Our results also highlight the importance of quantifying not only defoliation but also tree dimensions as both factors jointly and interactively modify canopy effects on ecosystem multifunctionality.

The monumental tumulus Yigma Tepe is an important part of the cityscape of the ancient city of Pergamon. The tumulus construction is estimated in the Hellenistic period, the internal structure and exact purpose have been unknown so far. Its height of 32 m and diameter of 158 m make the deep interior of the tumulus practically inaccessible for excavations. Therefore, we applied a combination of geophysical measurements and archaeological sondages to explore the structure of the Yigma Tepe. The investigations centre on P-wave refraction soundings. They were carried out to clarify the stratigraphic structure and soil composition as a prerequisite for a better understanding of construction techniques, building history and soil deposition. Interactive seismic raytracing, traveltime tomography and visco-elastic forward modelling were applied to derive a three-dimensional seismic velocity model, which was validated by excavations and soil analysis, historical records and additional geoelectric measurements. Our results reveal that the tumulus is composed of three layers, each about 10 m thick, separated by first-order seismic discontinuities which were locally verified. These layers form a stack of conical disks, the interfaces of which define two internal plateaus. The analysis of soil samples showed that the seismic velocity increase at the interfaces is likely to be caused by anthropogenic compaction applied to soils showing increased fractions of silt and clay. By combining topographic data with results from seismic and geoelectric sounding on the tumulus, the surrounding trench and the unaltered surrounding area, we show that the tumulus was built almost completely from the surrounding soils and that 17% of its original volume was displaced by destruction and erosion. Based on this mass balance the strongly destroyed and eroded original surface of the tumulus and its surrounding trench is reconstructed.

Throughout human history, communication and trade have been key to society. Because maritime trade facilitated the rapid transportation of passengers and freight at relatively low cost, harbours became hubs for traffic, trade and exchange. This general statement holds true for the Pergamenian kingdom, which ruled wide parts of today's western Turkey during Hellenistic times. Its harbour, located at the city of Elaia on the eastern Aegean shore, was used extensively for commercial and military purposes. This study reconstructs the coastal evolution in and around the ancient harbour of Elaia and compares the observed environmental modifications with archaeological and historical findings. We use micropalaeontological, sedimentological and geochemical proxies to reconstruct the palaeoenvironmental dynamics and evolution of the ancient harbour. The geoarchaeological results confirm the archaeological and historical evidence for Elaia's primacy during Hellenistic and early Roman times, and the city's gradual decline during the late Roman period. Furthermore, our study demonstrates that Elaia holds a unique position as a harbour city during ancient times in the eastern Aegean region, because it was not greatly influenced by the high sediment supply associated with river deltas. Consequently, no dredging of the harbour basins is documented, creating exceptional geo-bioarchives for palaeoenvironmental reconstructions.

Paleoenvironmental studies and corresponding data are abundantly published and available in scientific records. However, paleoenvironmental data sets are comparatively rarely provided in GIS data formats. Here, we present an Open Science approach for collecting and creating GIS data, visualizing it in maps of paleoenvironments, and publishing them in a web-based Spatial Data Infrastructure (SDI), for access by the archaeology and paleoenvironment communities. The Open Science approach to the publication of data allows to properly cite the published data sets as bibliographic sources in research that builds upon these data sets. This paper has its focus on the implementation and setup of the Free and Open Source Software for Geospatial (FOSS4G)-based SDI, and on the workflow for compiling and publishing the GIS data.

The Mejillones Peninsula is thought to have one of the highest rates of tectonic uplift along the active convergent margin of northern Chile. We use exposure age dating from a flight of well-preserved marine terraces to determine the long-term tectonic history of the northern part of the Peninsula. Terrace ages suggest the area is comprised of discrete crustal blocks with differing uplift chronologies. Periods of uplift reaching rates of 0.60 +/- 0.06 m/ka over the similar to 480 ka are recorded on one block, a value that is several-fold higher than is typical for the north Chilean coastline. Subsidence of an adjacent block is suggested by the anomalously old ages of terraces currently close to sea-level, and by observations of paleo-sea cliff warping and measurements of coastal sinuosity. Opposing crustal motion between adjacent blocks is compatible with the formation of intervening normal faults and the hypothesis of ongoing extension of the forearc. Comparisons with published data suggest a contemporaneous acceleration in uplift occurred throughout the Peninsula, with higher rates of mean uplift observed after 480 ka. A.second, even more rapid period of uplift occurred sometime within the last 2001 a, most likely 40 ka ago. Uplift of the footwall due to downthrowing blocks on normal faults caused by crustal extension may be one of the mechanisms causing the pulses of accelerated uplift rates of the Mejillones Peninsula. Another hypothesis is an increase of subduction earthquake activity. Both hypotheses suggesting a more general link to plate coupling and are not mutually exclusive. (C) 2016 The Authors. Published by Elsevier B.V.

The non-destructive monitoring of crop growth status with field-based or tractor-based multi-or hyperspectral sensors is a common practice in precision agriculture. The demand is given for flexible, easy to use, and field scale systems with super-high resolution (< 20 cm) or on single plant scale to provide knowledge on in-field variability of crop status for management purposes. Satellite- and airborne systems are usually not able to provide the spatial and temporal resolution for such purposes within a low-cost approach. The developments in the area of Unmanned Aerial Vehicles (UAV) equipped with hyperspectral sensor systems may be suited to fill that niche. In this contribution, we introduce two hyperspectral full-frame cameras weighing less than 1 kg which can be mounted to low-weight UAVs (< 3 kg). The first results of a campaign in June/July 2013 are presented and the derived spectra from the hyperspectral images are compared to related spectra collected with a portable spectroradiometer. The first results are promising.