Large-scale Field Research Articles

Quickly select heliostat candidates and design pattern-free layout using geometric projection method

Central receiver system is one of the most promising solar energy harvesting technologies, which focuses sunlight onto the receiver through heliostats to generate high temperatures for thermal cycling. The optimal layout of the heliostat plays a crucial role, but the pattern-free heliostat field layout requires multiple uses of computationally intensive shadowing and blocking efficiency, which is highly time-consuming. In this work, a new geometric projection method, Projection radius method (PRM), is proposed. It includes two aspects: (i) Quickly and effectively selecting heliostat candidates with shadowing and blocking potential by the incident and reflected ray projection radius; (ii) Designing the pattern-free heliostat field layout by employing overlap radius instead of shadowing and blocking efficiency. The results indicate that, compared to traditional methods, when designing 2650 heliostats, (i) the calculation time for optical efficiency was reduced by 63%; (ii) optical efficiency increased by 1.23%, and designing a pattern-free layout took only 2.78 h. These advancements facilitate the efficient design of large-scale pattern-free heliostat field layouts.

Galaxy Assembly Bias in the Stellar-to-halo Mass Relation for Red Central Galaxies from SDSS

We report evidence of galaxy assembly bias—the correlation between galaxy properties and biased secondary halo properties at fixed halo mass (M H)—in the stellar-to-halo mass relation for red central galaxies from the Sloan Digital Sky Survey. In the M H = 1011.5–1013.5 h −1 M ⊙ range, central galaxy stellar mass (M *) is correlated with the number density of galaxies within 10 h −1 Mpc (δ 10), a common proxy for halo formation time. This galaxy assembly bias signal is also present when M H, M *, and δ 10 are substituted with group luminosity, galaxy luminosity, and metrics of the large-scale density field. To associate differences in δ 10 with variations in halo formation time, we fitted a model that accounts for (1) errors in the M H measured by the J. L. Tinker group catalog and (2) the level of correlation between halo formation time and M * at fixed M H. Fitting of this model yields that (1) errors in M H are ∼0.15 dex and (2) halo formation time and M * are strongly correlated (Spearman’s rank correlation coefficient ∼0.85). At fixed M H, variations of ∼0.4 dex in M * are associated with ∼1–3 Gyr variations in halo formation time and galaxy formation time (from stellar population fitting). These results are indicative that halo properties other than M H can impact central galaxy assembly.

Research and Application of Flexible Fracturing Manifold in Volumetric fracturing

Abstract In order to solve the problems of high pressure pipe valves in Volumetrictric fracturing, such as large demand of high pressure pipe and valve parts, high pressure manifold for fracturing complex connection, fracturing pipeline connections are complex, long fracturing construction preparation period. The economy and timeliness of pipeline connection seriously affect the speed and efficiency of Volumetrictric fracturing operations. This paper designed and developed the high pressure flexible composite pipe and carried out its performance evaluation test. Combined with Volumetrictric fracturing operation conditions, supporting functional modular manifold system, overcome flexible pipeline and rigid pipeline fast connection technology, flexible fracturing manifold system was formed. Through the large-scale field application in the unconventional reservoir Volumetric fracturing field, The flexible fracturing manifold is compared with the conventional high-pressure pipe valve connection and the single pipe universal connection, the flexible fracturing manifold can reduce the use of high-pressure pipe valves by 1/3, increase the efficiency of fracturing manifold connection by 50%, and reduce the labor intensity by 50%, enables efficient, reduce high pressure manifold connection points by 70%. The timeliness and safety of fracturing manifold connections have been greatly improved. Flexible fracturing manifold fundamentally change the connection mode of Volumetrictric fracturing high-pressure manifold, and realizes the speed and efficiency of reservoir transformation.

Characteristics of extreme hourly precipitation induced by tropical cyclones in Zhejiang, China: A comparative analysis based on two different datasets

This study investigates the characteristics of tropical cyclones (TCs) that cause extreme hourly precipitation (EXHP) in Zhejiang, China, using datasets from 67 national stations (Con-ST) and 1551 surface stations (All-ST), spanning 1973–2020 and 2011–2020, respectively. Our analysis revealed notable variations in the EXHP caused by individual TCs. The top 10 % of TCs contributed 37.2–38 % of the total TC-induced EXHP amount, while the bottom 50 % only accounted for 5.8–22.7 %. Using sparse stations may overestimate the impact of TCs causing EXHP in the lower to middle rankings. Long-term trend analysis suggested a consistent increase in TC-induced EXHP despite a decreasing trend in the number of TCs affecting Zhejiang. High-value EXHP centers tended to be concentrated in mountainous areas within 0–50 km from the coastline, where Con-ST stations are sparse and can significantly underestimate EXHP. The maximum amount of EXHP per TC increased logarithmically with the number of observation stations. In Zhejiang, EXHP predominantly occurred northeast of the TC centers (50.4–61.7 %) and within 500 km from the TC center (69.5–81.5 %). High-frequency EXHP centers exhibited a clockwise rotation with increasing distance from the TC center–a pattern resembling a “spiral rainband.” A key area where most EXHP in Zhejiang occurred when TC centers remained within this area was identified. The TC intensity within the key area was a key factor influencing EXHP occurrence in Zhejiang, whereas the duration of TC center residence within the key area and the distance of its movement were crucial predictors of significant EXHP occurrence. The analysis of large-scale environmental fields revealed that high-EXHP TCs are characterized by strong upper-level divergence, intense upward motion, and an expanded subtropical high. The southeasterly steering airflow drives these TCs northwestward, prolonging their impact on Zhejiang and resulting in significant moisture accumulation and EXHP.

Estimating the Value of Offsite Tracking Data to Advertisers: Evidence from Meta

We run a large-scale field experiment at Meta to estimate how valuable offsite tracking data are for digital ad effectiveness.

How to control nasty scarabs? Effectiveness of the generalist entomopathogenic fungus Metarhizium brunneum against garden chafer larvae

Several scarab beetles (Scarabaeidae) cause major damage in agriculture, horticulture, and forestry. Especially root feeding scarab larvae cause substantial economic losses on crops, forage plants and recreational areas. In Europe, the entomopathogenic fungi (EPF) Beauveria brongniartii and Metarhizium brunneum are applied against the most problematic, native scarabs, the common cockchafer (Melolontha melolontha) and the garden chafer (Phyllopertha horticola). While the control of cockchafer larvae with B. brongniartii is well-researched, conclusive results from field applications for the control of the garden chafer with M. brunneum remain elusive. We therefore assessed the performance of commercially available fungal strains of M. brunneum against garden chafer larvae in pot and large-scale field experiments.The application of M. brunneum significantly increased the abundance of fungal propagules in the soil by approximately a factor of ten, irrespective of high levels of naturally occurring Metarhizium spp. Furthermore, the applied strains infected and propagated on the larvae and the mortality of garden chafer larvae was slightly increased due to the fungal treatments. We found three other EPF species frequently infecting garden chafer larvae (mean infection rates: 13–25%), including B. brongniartii which is considered to be a specific pathogen of the cockchafer. Thus, the applied fungal strains were only part of a consortium of natural enemies which reduces garden chafer populations strongly as a whole. Hence, we suggest that the application of EPF may be advisable on areas with reduced natural enemies such as golf courses but is probably redundant on meadows harboring a diverse consortium of antagonists.

Efficient Fourth-Order PSTD Algorithm with Moving Window for Long-Distance EMP Propagation.

Satellite-borne electromagnetic pulse (EMP) detection technology plays an important role in military reconnaissance, space environment monitoring, and early warning of natural disasters. However, the complex ionosphere greatly distorts the waveform during propagation and poses a challenge to EMP detection. Therefore, it is necessary to conduct theoretical research on EMP propagation in the ionosphere. Conventional second-order pseudo-spectral time-domain (PSTD-2) algorithm has difficulties in keeping the stability and accuracy of waveforms in calculations over hundreds of kilometers of propagation. To overcome the difficulties, a fourth-order PSTD algorithm incorporating the moving window technique (MWPSTD-4) is proposed. In the numerical examples, the performance of MWPSTD-4 is compared with PSTD-4 and PSTD-2 in the long-distance propagation of EMP. The results show that the MWPSTD-4 improves efficiency while guaranteeing accuracy and is suitable for large-scale electromagnetic field simulation. The proposed method provides a basic algorithm to eliminate the numerical dispersion interference for calculating the long-distance propagation of EMP in complex spaces and is helpful for the design and calibration of satellite-borne EMP detectors.

Optimizing crop seeding rates on organic grain farms using on farm precision experimentation

Organic agriculture is often regarded as less damaging to the environment than conventional agriculture, though at the expense of lower yields. Field-specific precision agriculture may benefit organic production practices given the inherent need of organic farmers to understand spatiotemporal variation on large-scale fields. Here the primary research question is whether on-farm precision experimentation (OFPE) can be used as an adaptive management methodology to efficiently maximize farmer net returns using variable cover crop and cash crop seeding rates. Inputs of cash crop seed and previous-year green manure cover crop seed were experimentally varied on five different farms across the Northern Great Plains from 2019 to 2022. Experiments provided data to model the crop yield response, and subsequently net return, in response to input (seeding) rates plus a suite of other spatially explicit data from satellite sources. New, field-specific spatially explicit optimum input rates were generated to maximize net return including temporal variation in economic variables. Inputs were spatially optimized and using simulations it was found that the optimization strategies consistently out-performed other strategies by reducing inputs and increasing yields, particularly for non-tillering crops. By adopting site specific management, the average increase in net return for all fields was $50 ha−1. These results showed that precision agriculture technologies and remote sensing can be utilized to provide organic farmers powerful adaptive management tools with a focus on within-field spatial variability in response to primary input drivers of economic return. Continued OFPE for seeding rate optimization will allow quantification of temporal variability and subsequent probabilistic recommendations.

The Impact of Economic Incentives on the Purchase Behavior of Recycled Fashion and Footwear

This study investigates the impact of economic incentives on the purchase behavior of recycled fashion and footwear in Vietnam, addressing a critical gap in sustainable consumption research within emerging markets. Employing a mixed-methods approach, including a large-scale survey (n=1,023) and field experiments across 120 stores, we examine the effectiveness of various incentive types: discounts, loyalty programs, and government subsidies. Our findings reveal that while price discounts drive immediate sales increases (28.3% volume increase), loyalty programs foster superior long-term engagement (23.5% increase in repeat purchases) and higher average order values (31.7% increase). Government subsidies, particularly when combined with educational initiatives, also prove effective (27.3% sales volume increase). The study identifies key moderating factors, including environmental consciousness, age, and urban-rural location, which significantly influence the impact of these incentives. By providing empirical evidence on the nuanced effectiveness of economic incentives in promoting sustainable fashion choices, this research offers valuable insights for retailers, policymakers, and sustainability advocates. The findings contribute to bridging the intention-action gap in sustainable consumption and provide a foundation for developing targeted strategies to promote recycled fashion in emerging markets.

Mapping fine-scale carbon sequestration benefits and landscape spatial drivers of urban parks using high-resolution UAV data

Urban parks offer dual ecological benefits by increasing carbon sinks and reducing carbon emissions and are considered an important natural strategy for cities to achieve “double carbon” goals. However, rapid, efficient, and accurate quantification of the carbon sequestration benefits of urban parks poses a significant challenge. To address this, we utilized unmanned aerial vehicle (UAV) multispectral data to construct large-area, high-resolution models of urban park carbon sequestration benefits, replacing traditional, time-consuming, and laborious large-scale field surveys. Additionally, we explored the relationship between urban park landscape patterns and the benefits of carbon sequestration. First, we used data from 12 tree species to calculate the carbon storage based on tree species and compared these results with those calculated based on forest type. Second, three prediction models were constructed using multispectral vegetation index only, texture features only, and a combination of both, in conjunction with gradient boosting decision Trees (GBDT), random forest (RF), and backpropagation (BP) neural network to generate carbon sequestration benefit maps for the entire park. These maps allowed us to determine how variations in urban park landscape structures affect carbon stocks. The results show that UAV multispectral imagery provides a fast and accurate method for measuring the carbon sequestration benefits of urban parks and offers an alternative method for generating carbon sequestration benefit maps. This research reveals the benefits of urban park carbon sequestration and explores the spatial patterns within landscapes. The findings are of great significance for guiding the estimation of urban carbon sequestration benefits and achieving carbon neutrality.

ТРИ САРМАТСКИХ ПОГРЕБАЛЬНЫХ КОМПЛЕКСА ИЗ СТЕПНОГО КРЫМА

The work analyzes three recently discovered burial monuments of the 1st century BC – mid (?) 1st century AD in the Steppe Crimea. Their distinctive features are the use of an older kurgan for burial, the predominant orientation of the deceased to the northern sector, the insignificant depth of the burial, the paucity of grave goods, etc. – typical for early Sarmatian burials of the Northern Black Sea region. Therefore, the complexes under consideration should be correlated specifically with this cultural group. It is important to emphasize that, although large-scale field research in recent years has covered a significant part of the steppe space of the Crimean Peninsula, passing through it in a wide strip from east to west, Sarmatian monuments have not been identified in most of this territory. The newly opened complexes are located on the Kerch Peninsula and near it, i.e. in those areas in which Sarmatian burials were previously known. This only confirms the conclusion already made about the location of Sarmatian burials in the Steppe Crimea only in a narrow strip along the northern and north-eastern borders of the region, along the coast of the Black Sea and Sivash. This location, apparently, marks the path of the ancient nomads from the Dnieper region – one of the main areas of their settlement – to the ancient centers of the Crimean Peninsula, in particular Panticapaeum, to carry out trade and other relationships.

Multi-kilogauss magnetic field driving the magnetospheric accretion process in EX Lupi

EX Lupi is the prototype of EX Lup-type stars, which are classical T Tauri stars (cTTSs) with luminosity bursts and outbursts of 1 to 5 magnitudes that last for a few months to a few years. These events are ascribed to an episodic accretion that can occur repeatedly, but whose physical mechanism is still debated. We aim to investigate the magnetically driven accretion of EX Lup in quiescence. We include for the first time a study of the small- and large-scale magnetic field. This allows us to characterise the magnetospheric accretion process of the system completely. We used spectropolarimetric times series acquired in 2016 and 2019 with the Echelle SpectroPolarimetric Device for the Observation of Stars and in 2019 with the SpectroPolarimètre InfraRouge at the Canada-France-Hawaii telescope during a quiescence phase of EX Lup. We were thus able to perform a variability analysis of the radial velocity, the emission lines, and the surface-averaged longitudinal magnetic field in different epochs and wavelength domains. We also provide a small-scale magnetic field analysis using Zeeman intensification of photospheric lines and a large-scale magnetic topology reconstruction using Zeeman-Doppler imaging. Our study reveals that typical magnetospheric accretion is ongoing on EX Lup. A main accretion funnel flow connects the inner disc to the star in a stable fashion and produces an accretion shock on the stellar surface close to the pole of the magnetic dipole component. We also measure one of the strongest fields ever observed on cTTSs. This strong field indicates that the disc is truncated by the magnetic field close to but beyond the corotation radius, where the angular velocity of the disc equals the angular velocity of the star. This configuration is suitable for a magnetically induced disc instability that yields episodic accretion onto the star.

Environmental risk evaluation for radionuclide transport through natural barriers of nuclear waste disposal with multi-scale streamline approaches

Natural barriers, encompassing stable geological formations that serve as the final bastion against radionuclide transport, are paramount in mitigating the long-term contamination risks associated with the nuclear waste disposal. Therefore, it is important to simulate and predict the processes and spatial-temporal distributions of radionuclide transport within these barriers. However, accurately predicting radionuclide transport on the field scale is challenging due to uncertainties associated with parameter scaling. This study develops an integrated evaluation framework that combines upscaled parameters, streamline transport models, and response surface techniques to systematically assess environmental risk metrics and parameter uncertainties across different scales. Initially, upscaling methods are established to estimate the prior interval of critical transport parameters at the field scale, and streamline models are derived by considering the radionuclides transport with a variety of physicochemical mechanisms and geological characterizations in natural barriers. To assess uncertainty ranges of the risk metrics related to upscaled parameters, uncertainty quantification is performed on the ground of 5000 Monte Carlo simulations. The results indicate that the upscaled dispersivity of fractured media (αLf) has a relatively high sensitivity ranking on release dose for all nuclides, and upscaled matrix sorption coefficient (Kd) of Pu-242 strongly affects breakthrough time and release dose of Pu-242. Facilitated by robust response surface with the lowest R2 of 0.89, it is shown that the release doses of Pu-242 and Pb-210 increase under conditions of low Kd and αLf, respectively. Furthermore, statistical analysis reveals that employing limited laboratory-scale parameters results in narrower confidence intervals for risk metrics, while upscaling methods better account for the highly heterogeneous properties of large-scale field conditions. The developed risk evaluation framework provides valuable insights for utilizing upscaled parameters and modeling radionuclide transport within natural barriers under various scenarios.

Robust future projections of global spatial distribution of major tropical cyclones and sea level pressure gradients

Despite the profound societal impacts of intense tropical cyclones (TCs), prediction of future changes in their regional occurrence remains challenging owing to climate model limitations and to the infrequent occurrence of such TCs. Here we reveal projected changes in the frequency of major TC occurrence (i.e., maximum sustained wind speed: ≥ 50 m s−1) on the regional scale. Two independent high-resolution climate models projected similar changes in major TC occurrence. Their spatial patterns highlight an increase in the Central Pacific and a reduction in occurrence in the Southern Hemisphere—likely attributable to anthropogenic climate change. Furthermore, this study suggests that major TCs can modify large-scale sea-level pressure fields, potentially leading to the abrupt onset of strong wind speeds even when the storm centers are thousands of kilometers away. This study highlights the amplified risk of storm-related hazards, specifically in the Central Pacific, even when major TCs are far from the populated regions.

“Cosmic alternator” for the onset of large-scale magnetic fields

Magnetic field configurations extending over macroscopic scale distances are shown to be generated in rarefied collisionless plasmas when non-thermal and spatially inhomogeneous electron distributions in phase space emerge. The analyzed representative case is where, in the presence of a significant spatial gradient of the electron pressure and of a sheared magnetic field configuration, an alternating magnetic field reconnection process can develop associated with the anisotropy of the fluctuating electron temperature. The relevant process is intrinsically different from that known as the “Biermann Battery,” which does not involve magnetic reconnection and requires that the unperturbed spatial gradient of the (isotropic) electron temperature be misaligned relative to that of the density gradient.

High nitrate and sulfate leaching in response to wetter winters in temperate beech forests

Climate models project moderate to large increases in air temperature for most temperate ecosystems with an overall increase in winter precipitation and a shift from snow towards rain. We investigated the effects of increased winter rainfall on the ecosystem functioning of European beech forests at their north-eastern distribution range. In a large-scale field experiment we manipulated winter climate at nine forest sites by increasing the amount of rainfall and excluding snow. Nutrient availability in the topsoil and leaching in 50 cm depth as well as litter decomposition and radial growth of mature European beech trees were analysed. It was hypothesized that (1) wetter winters lead to increased nutrient deposition as well as leaching, with an overall increase in net nutrient availability, (2) decomposition decreases in response to water addition containing also additional nutrients and (3) primary production during the subsequent growing season increases as presumably not all additionally available nutrients would be leached. We found an increase in topsoil nitrate and sulfate availability during winter in response to rain addition, likely as a consequence of collecting more atmospheric deposition, and surprisingly high leaching rates of the additionally available nutrients. During the subsequent early growing season, no difference in nutrient availability could be observed anymore. Enhanced nutrient availability in the topsoil and leaching do not seem to have a strong short-term influence on forest ecosystem processes in ecosystems which are close to their critical load of N deposition. Decomposition rates during winter and early growing season as well as stem diameter growth during the following growing season were not influenced. This indicates that additional nutrients in the topsoil in response to wetter winters are not available for plant growth but pollute ground- and surface waters.

Plant-Soil Moisture Positive Feedback Maintaining Alternative Stable States in the Alpine Marsh Ecosystem.

A self-reinforcing positive feedback is regarded as a critical process for maintaining alternative stable states (ASS); however, identification of ASS and quantification of positive feedbacks remain elusive in natural ecosystems. Here, we used large-scale field surveys to search for ASS and a positive feedback mechanism under a wide range of habitats on the Tibetan Plateau. Using multiple methods, we proved that three stable states exist that accompany alpine marsh degradation. Positive feedbacks between changing soil moisture and plant community composition forced the ecosystem into another stable state, and the alteration of water use efficiency (WUE) of the component species contributed to this shift. This study provides the first empirical evidence that positive feedback loops maintain ASS in the alpine marsh ecosystem on the Tibetan Plateau. Our research revealed the powerful driving role of plants in transitions between states, which may support the conservation and restoration of global alpine marsh ecosystems.

Biochar Amendment and its Impacts on Medicinal and Aromatic Plants in Sustainable Agriculture

Introduction: Biochar application and research have experienced a significant increase in recent decades. It can produce different kinds of organic materials, and it can be employed for different purposes, such as soil conditioning, carbon sequestration and filtration of pollutants from gas and aqueous media. Biochar is a C-rich material, which can be obtained from different types of organic feedstock, such as animal manure, sewage sludge, wood and crop residues and other organic waste. It is also considered an environmentally friendly and resource-saving approach in medicinal and aromatic plants production. Biochar can lead to plant growth improvement and influence on chemical components of medicinal plants, stimulate the growth of soil microflora, increase soil carbonsequestration, bioremediation of soil, regulate carbon fluxes between atmosphere and biosphere, reduce biotic stress in plants, improve soil nutrient availability, decrease abiotic stress in plants, wastewater treatment, immobilization and sorption of soil heavy metal contaminants. Methods: Relevant literature has been obtained using the keywords “biochar”, “organic amendment”, “soil quality”, “medicinal Plants”, “natural products”, “soil quality”, “macronutrient”, and “chemical components” in scientific databases, such as “PubMed”, “SciFinder”, “Elsevier”, and “Web of Science”. Results: The aim of this literature review is to study the impact of different kinds of biochars on medicinal and aromatic plants, soil quality and soil fertility by considering case studies of successful paradigms. Conclusion: Conclusively, we consider our review article will provide an appropriate guide for practitioners and researchers for future studies as well as large-scale field applications.

Cenozoic faulting leading to petroleum escape in SW Ordos Basin, China: Evidence from fault-related calcite in situ U-Pb dating, rare earth elements and fluid inclusions

Understanding the link between fault activity and movement to petroleum escape is crucial for assessing the petroleum exploration potential in sedimentary basins. As a significant petroliferous basin in China, the Ordos Basin hosts the world-class uncompartmentalized Jingbian natural gas field within the Ordovician marine carbonate reservoirs. However, the role of the unique exhumation history and the Cenozoic faulting in the formation of such large-scale oil-gas fields remain unclear. Our study combines fault-related calcite U-Pb dating with fluid inclusions analysis offers a unique opportunity to trace petroleum leakage along the the carbonate strata brittle fault zones in the SW Ordos Basin. Calcite samples collected from the carbonate fault zone and across the Ordovician carbonate strata in the SW Ordos Basin reveal clear positive Eu anomaly, slight positive Y anomaly, the lack of positive La and Gd anomalies, and the absence of a negative Ce anomaly. The Y/Ho ratios range from 29 to 36, with an average value of 32, indicating calcite formation in a hydrothermal environment during fault activation. U-Pb dating of these fault-related calcites yields ages of 32.8 ± 3.3 Ma and 23.7 ± 7.4 Ma. Raman spectroscopy of fluid inclusions reveals the presence of CH4 gas, coeval with the fault-related calcite. The homogenization temperatures (Th) of aqueous inclusions coeval with CH4 inclusion from two calcite veins range from 140.0 to 172.4 °C (average Th = 157.8 °C, n = 16) and 127.7–154.3 °C (average Th = 142.2 °C, n = 18). Low temperature thermochronology suggest rapid uplift since 40 Ma, potentially linked to fault activity. The Cenozoic erosion rate was 0.06 mm/y during the ∼9 Myr period from 32.8 to 23.7 Ma in the SW Ordos Basin, suggesting that Cenozoic faulting may have created permeable pathways for petroleum escape. This study provides a temporal link between Cenozoic uplift, faulting, and petroleum loss in SW Ordos Basin.

Cost-effectiveness of lures in attracting mammals: a large scale camera-trapping field test on European species

The cost-effectiveness of different attractants during camera trapping surveys has been seldom evaluated. To contribute in filling this knowledge gap we (1) compare the effectiveness of a suite of attractants in detecting widely distributed mammals in Europe and (2) evaluate the cost-effectiveness of these attractants, by calculating the costs associated to reach a specific monitoring objective. We conducted a large-scale field experiment across four study areas in central and northern Italy, encompassing a variety of environments, from lowland forest to alpine beech forest. We focused on comparing the following low cost and readily available attractants: sardines, peanut butter, a commercial lure and we used a camera with no attractant as control, collecting data on a suite of small to large mammals. We found that for seven of our 13 target species detectability varied with the type of attractant used. Specifically, sardines proved to be the most effective attractant for canids and the porcupine, peanut butter was most effective for mustelids but was avoided by the roe deer, whereas the commercial lure was the most effective with red deer. Through a power analysis combined with a cost function analysis we were able to show striking differences in the cost-effectiveness of the different methods, sometimes in the order of magnitude of tens of thousands of euros, which strongly emphasizes the critical importance played by the choice of whether to use an attractant or not and the type of attractant to be used.