Lowcost(audio)recorders(LCRs)representanewopportunitytoinvestigatethesonic complexity of both natural and urban ecosystems. LCRs are inexpensive sampling audio recorders which have the external shape of a universal serial bus (USB) flash drive, and are composed of a microphone, an analog-to-digital converter, central processing unit with permanent internal non-volatile memory, rechargeable battery, and a USB connection. The reduced dimen- sions allow the device to be deployed inconspicuously within any environment, in any config- uration and for an extended time period. This investigation tested a specific type of LCR (UR-09) with a spectral range of 8 kHz - sufficient to cover the acoustic range of most western Palearctic songbirds. The reliability of the UR-09, compared with other commercial recorders (Zoom H4 and Song Meter SM1) and based on the quality of recordings quantified by the Acoustic Complexity Index (ACI), was tested and confirmed. An example of the application of LCRs is presented in an evaluation of the audio patterns occurring during dawn and dusk choruses within a forested ecosystem. Results of this investigation are encouraging and a new generation of LCR devices is currently being designed with real-time acoustic data processing capabilities, timer programmability, a larger frequency range and wireless communication compatibility. LCRs are revealed to be ideal instruments to conduct surveys in fragile or protected areas and also in urban environments. Moreover, due to their low cost, they can be used to encourage research in soundscape ecology, especially within developing countries, where large areas can be monitored by professionals or incorporating citizen science models of data collection

Capturing the variability in soil-landscape properties is a challenge for grain producers attempting to integrate spatial information into the decision process of precision agriculture (PA). Digital soil maps (DSMs) use traditional soil survey information and can be the basis for PA subfi eld delineation (e.g., management zones). However, public soil survey maps provide only general descriptions of soil-landscape features. Th erefore, improved DSMs are needed that use high-resolution data that more precisely model soil-landscape characteristics. Additionally, reliable methods are needed to validate DSM products for PA. Th e objective of this study was to validate with corn (Zea mays L.) yield data the performance of a new DSM product, termed Environmental Response Unit (ERU), compared with the USDA Soil Survey Geographic (SSURGO) soil map. Th e ERU was developed by integrating SSURGO information with highresolution elevation data. For validation, corn yield maps were collected and corrected for common data collection errors from 409 fi elds across Indiana, Iowa, Minnesota, and Nebraska in 2010 to 2012. Reductions in the area-weighted variance (R v ) of corn yield for ERU and SSURGO were calculated relative to the whole-fi eld variance. Th e average R v across all site-years for SSURGO and ERU was 16 and 25%, respectively, which equated to a 57% higher median yield variance reduction with ERU over SSURGO. Th is variance reduction technique showed the potential of ERU as an improved model better representing soillandscape properties that impact corn yield. Th is research also has application potential for determining the success of a DSM for identifying management zones in PA.

Ecoacoustic techniques using multiple acoustic sensors and two metrics of the acoustic community – the acoustic complexity index (ACI) and the chorus ratio (CR) – were successfully used to describe and characterize the morning acoustic activity of birds according to three equal temporal intervals during spring 2013: Dawn Chorus, Post Chorus 1, and Post Chorus 2.The metrics were applied across five Italian Mediterranean locations (Valenza, Madonna dei Colli, Monte Curto, Virolo, Croce di Tergagliana) that differed by land-cover typologies. Results from the ACI metrics showed a peak during the Dawn Chorus and a visible lull close to sunrise between Dawn Chorus and Post Chorus 1.The lull was evident in all localities except Valenza, where singing activity was relatively constant across the successive morning intervals. Temperature and vegetation structure were confirmed as important factors associated with morning acoustic activities. Vegetation evenness and temperature across the season was negatively correlated with ACI, whereas CR was positively correlated with temperature and vegetation diversity. Of the 33 species of birds identified during the maximum dawn chorus activity, Blackcap, Blackbird, European Robin, and Great Tit were acoustically dominant and their activity was significantly higher before sunrise except for Blackcap, whose acoustic activity showed no significant differences across time intervals. The dawn chorus is one of the most conspicuous behaviours of birds, engendering much speculation but no definitive, univocal explanations. The ecoacoustic approach opens a new perspective for investigating this complex phenomenon

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