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The hemlock woolly adelgid (HWA) (Adelges tsugae Annand) is an invasive insect in the eastern United States. Since its initial detection in Richmond, Virginia, in 1951, HWA has spread to half of the eastern hemlock (Tsuga canadensis (L.) Carr.) natural range. Detection of early infestation symptoms via remote sensing requires the knowledge of the changes in reflectance resulting from physiological changes in the host as inflicted by the insect and the selection of equipment with the appropriate sensor characteristics. Laboratory-based reflectance measurements of infested and non-infested hemlock foliage collected from four sites in southern New Hampshire and Maine occurred biweekly over 6 months in 2012 and weekly over 5 weeks in 2013. Vegetation indices (red edge inflection point (REIP), normalized difference vegetation index (NDVI), moisture stress index (MSI), and near infrared (NIR) 3/1 ratio) were associated with concurrent chlorophyll and moisture content data. Infested first-year foliage contained greater concentrations of chlorophyll and moisture, resulting in reduced visible spectral reflectance, greater REIP and NDVI values, and lower MSI and NIR 3/1 values than non-infested foliage. Furthermore, fluorescence measurements indicated greater photosystem function during the early stages of infestation, suggesting a possible compensatory response by hemlock to infestation. Significant differences in reflectance between infested and non-infested foliage were observed in late June and July in the weeks immediately following HWA settlement on new growth. Implementing these observations during remote sensing mission planning may increase the likelihood of detecting early HWA infestation symptoms at landscape scales. Key words: Adelges tsugae, hemlock woolly adelgid, remote sensing, vegetation indices, fluorescence, chlorophyll. Le puceron lanigere de la pruche (PLP) (Adelges tsugae Annand) est un insecte invasif dans l'est des Etats-Unis. Depuis qu'il a ete detecte pour la premiere fois a Richmond en Virginie, en 1951, le PLP a envahi la moitie de l'aire de repartition naturelle de la pruche du Canada (Tsuga canadensis (L.) Carr.). Pour detecter les symptomes precoces d'infestation au moyen de la teledetection il faut connaitre les changements dans la reflectance dus aux modifications physiologiques chez l'hote causees par l'insecte et choisir l'equipement dont les capteurs ont les caracteristiques appropriees. Des mesures de reflectance ont ete effectuees en laboratoire sur du feuillage de pruche infeste ou non preleve a quatre endroits dans le sud du New Hampshire et du Maine a toutes les deux semaines durant six mois en 2012 et a toutes les semaines durant cinq semaines en 2013. Des indices de vegetation (REIP, NDVI, MSI et NIR 3/1) ont ete associes aux donnees simultanees de teneur en humidite et en chlorophylle. Le feuillage d'un an infeste contenait de plus fortes concentrations de chlorophylle et d'humidite qui se traduisaient par une diminution de la reflectance spectrale dans le visible, des valeurs plus elevees de REIP et NDVI et plus fables de MSI er NIR 3/1 que dans le feuillage non infeste. De plus, des mesures de fluorescence ont montre que le photosysteme fonctionnait davantage durant les premiers stades de l'infestation, ce qui suggere possiblement une reaction compensatoire de la pruche a l'infestation. Des differences significatives de reflectance entre le feuillage infeste et non infeste ont ete observees a la fin du mois de juin et en juillet durant les semaines qui ont immediatement suivi l'etablissement du PLP sur les nouvelles pousses. L'integration de ces observations durant la planification des missions de teledetection pourrait augmenter les chances de detecter les symptomes precoces d'infestation du PLP a l'echelle du paysage. [Traduit par la Redaction] Mots-cles: Adelges tsugae, puceron lanigere de la pruche, teledetection, indices de vegetation, fluorescence, chlorophylle., 1. Introduction Eastern hemlock (Tsuga canadensis (L.) Carr.) is a foundation tree species in the northeastern United States (Ellison et al. 2005). Often found on steep slopes and in riparian [...]

A detection scheme that uses classical and spatial statistics has been developed to identify roadways with the most severe safety needs. It is based on the null hypothesis that all roadways have the same crash risk, that is, all have the same nonfatal and fatal crash rates throughout the entire study region. Fatal and nonfatal crash rates, which are assumed to be randomly distributed as Poisson processes, are modeled with a marked homogeneous Poisson process model. Since the traffic exposures are typically unknown at the crash sites, they are predicted with a geostatistical model. Locations, where the null hypothesis is rejected, are safety treatment candidates. P-value risk rankings are used to identify locations with the most severe safety needs. The results from alternative analyses--one using vehicle miles traveled and another using population as measures of traffic exposure--are conducted and compared. The state of New Hampshire is used in a case study. The effects of analyzing areas with small traffic exposures, the so-called 'small-area estimation' problem, and the aim to develop a data-driven detection scheme that meets the requirements as an objective decision-making tool are discussed. DOI: 10.1061/(ASCE)TE.1943-5436.0000048 CE Database subject headings: Traffic safety; Traffic models; Spatial analysis; Spatial data; Spatial distribution; Statistics; Stochastic processes. Author keywords: Traffic safety; Traffic models; Spatial analysis; Spatial data; Spatial distribution; Statistics; Stochastic processes.

Geographic variability in abundance can be driven by multiple physical and biological factors operating at multiple scales. To understand the determinants of larval trematode prevalence within populations of the marine snail host Littorina littorea, we quantified many physical and biological variables at 28 New England intertidal sites. A hierarchical, mixed-effects model identified the abundance of gulls (the final hosts and dispersive agents of infective trematode stages) and snail size (a proxy for time of exposure) as the primary factors associated with trematode prevalence. The predominant influence of these variables coupled with routinely low infection rates (21 of the 28 populations exhibited prevalence Key words: Bayesian statistics; Cryptocotyle lingua; dispersal; environmental forcing; hierarchical models; Larus argentatus; Littorina littorea; macroecology; nested spatially explicit analyses; reversible-jump Markov chain Monte Carlo; rocky intertidal zone; species abundance.

A physical and chemical heterogeneity study of glaciofluvial deposit in Deerfield, New Hampshire, was conducted in order to understand the processes controlling the spatial variation of sediment properties. The findings suggest that lithofacies and color information could aid the characterization and modeling of heterogeneity at similar carbon-poor glaciofluvial sites.