A Range of Earth Observation Techniques for Assessing Plant Diversity

AbstractVegetation diversity and health is multidimensional and only partially understood due to its complexity. So far there is no single monitoring approach that can sufficiently assess and predict vegetation health and resilience. To gain a better understanding of the different remote sensing (RS) approaches that are available, this chapter reviews the range of Earth observation (EO) platforms, sensors, and techniques for assessing vegetation diversity. Platforms include close-range EO platforms, spectral laboratories, plant phenomics facilities, ecotrons, wireless sensor networks (WSNs), towers, air- and spaceborne EO platforms, and unmanned aerial systems (UAS). Sensors include spectrometers, optical imaging systems, Light Detection and Ranging (LiDAR), and radar. Applications and approaches to vegetation diversity modeling and mapping with air- and spaceborne EO data are also presented. The chapter concludes with recommendations for the future direction of monitoring vegetation diversity using RS

Specialization for Sound Localization in Fields A1, DZ, and PAF of Cat Auditory Cortex

Cortical deactivation studies in cats have implicated the primary auditory cortex (A1), the dorsal zone (DZ), and the posterior auditory field (PAF) in sound localization behavior, and physiological studies in anesthetized conditions have demonstrated clear differences in spatial sensitivity among those areas. We trained cats to perform two listening tasks and then we recorded from cortical neurons in off-task and in both on-task conditions during single recording sessions. The results confirmed some of the results from anesthetized conditions and revealed unexpected differences. Neurons in each field showed a variety of firing patterns, including onset-only, complex onset and long latency, and suppression or offset. A substantial minority of units showed sharpening of spatial sensitivity, particularly that of onset responses, during task performance: 44 %, 35 %, and 31 % of units in areas A1, DZ, and PAF, respectively, showed significant spatial sharpening. Field DZ was distinguished by a larger percentage of neurons responding best to near-midline locations, whereas the spatial preferences of PAF neurons were distributed more uniformly throughout the contralateral hemifield. Those directional biases also were evident in measures of the accuracy with which neural spike patterns could signal sound locations. Field DZ provided the greatest accuracy for midline locations. The location dependence of accuracy in PAF was orthogonal to that of DZ, with the greatest accuracy for lateral locations. The results suggest a view of spatial representation in the auditory cortex in which DZ exhibits an overrepresentation of the frontal areas around the midline, whereas PAF provides a more uniform representation of contralateral space, including areas behind the head. Spatial preferences of area A1 neurons were intermediate between those of DZ and PAF, sharpening as needed for localization tasks