Palynological Analysis of a Peat Core from Imnavait Creek, the North Slope, Alaska

The pollen record of a 160 cm peat core from Imnavait Creek, a small upland basin in the northern foothills of the Brooks Range, Alaska, reveals a history of vegetation change from the early Holocene to the present. The Alnus rise within the region occurred after 8500 yr B.P. Betula and Cyperaceae are the major floristic elements throughout the diagram, and this, along with the significant levels of Salix and Ericaceae, suggest that the area was characterized by a mosaic of herb and shrub tundra communities, dependent on variations in terrain and moisture availability.Key words: palynology, Peat , North Slope, Alaska, pollen, Brooks Range, vegetation history, HoloceneMots clés: “Paleontologie”, tourbière, pente nord, Alaska, pollen, Brooks Range, histoire de la végétation, holocèn

Holocene Biogeochemical and Pollen History of a Lake Erie, Ohio, Coastal Wetland

Author Institution: Department of Biological and Environmental Sciences, Morehead State University and Byrd Polar Research Center, The Ohio State UniversityA five meter sediment core was taken from Old Woman Creek National Estuarine Research Reserve and State Natural Area and Preserve along the western basin of Lake Erie, U.S.A., to determine the historical biogeochemistry of the wetland. Analysis of pollen and sediment chemistry revealed that the area has remained a wetland since ca. 5,500 yr BP, despite changing lake levels. Pollen stratigraphy indicates a distinctive local succession, which has been divided into three zones. Sediments from sometime after glaciation to 5,500 yr BP were characterized by low concentrations of herb pollen; the next zone showed an establishment of hardwood forest vegetation. The modern local vegetation developed after deforestation (about 200 years ago), when sedimentation increased an order of magnitude, phosphorus deposition increased, and the ecosystem changed from a macrophyte dominated wetland to a plankton dominated marsh. After European settlement, the wetland retained its ability to act as a sink and biotic transformer of bioavailable phosphorus; however, abiotic processes seemed to be more important than the biotic transformations that dominated before deforestation

Modern Erosion Rates and Loss of Coastal Features and Sites, Beaufort Sea Coastline, Alaska

This study presents modern erosion rate measurements based upon vertical aerial photography captured in 1955, 1979, and 2002 for a 100 km segment of the Beaufort Sea coastline. Annual erosion rates from 1955 to 2002 averaged 5.6 m a-1. However, mean erosion rates increased from 5.0 m a-1 in 1955–79 to 6.2 m a-1 in 1979–2002. Furthermore, from the first period to the second, erosion rates increased at 60% (598) of the 992 sites analyzed, decreased at 31% (307), and changed less than ± 30 cm at 9% (87). Historical observations and quantitative studies over the past 175 years allowed us to place our erosion rate measurements into a longer-term context. Several of the coastal features along this stretch of coastline received Western place names during the Dease and Simpson expedition in 1837, and the majority of those features had been lost by the early 1900s as a result of coastline erosion, suggesting that erosion has been active over at least the historical record. Incorporation of historical and modern observations also allowed us to detect the loss of both cultural and historical sites and modern infrastructure. U.S. Geological Survey topographic maps reveal a number of known cultural and historical sites, as well as sites with modern infrastructure constructed as recently as the 1950s, that had disappeared by the early 2000s as a result of coastal erosion. We were also able to identify sites that are currently being threatened by an encroaching coastline. Our modern erosion rate measurements can potentially be used to predict when a historical site or modern infrastructure will be affected if such erosion rates persist.Cette étude présente les mesures de taux d’érosion contemporains établies en fonction de photographies aériennes verticales prises en 1955, en 1979 et en 2002 sur un segment de 100 km du littoral de la mer de Beaufort. Entre 1955 et 2002, les taux d’érosion annuels ont atteint 5,6 m a-1 en moyenne. Cependant, les taux d’érosion moyens se sont accrus pour passer de 5,0 m a-1 pendant les années 1955- 1979 à 6,2 m a-1 dans les années 1979 - 2002. Par ailleurs, de la première période à la deuxième période, les taux d’érosion ont augmenté à 60 % (598) des 992 sites analysés, ont diminué dans le cas de 31 % (307) des sites, et changé de moins de ± 30 cm à 9 % (87) des sites. Les observations historiques et les études quantitatives recueillies au cours des 175 dernières années nous ont permis de placer nos mesures des taux d’érosion dans un contexte à plus long terme. Plusieurs des caractéristiques côtières le long de cette étendue du littoral ont reçu des noms d’endroits typiques de l’Ouest dans le cadre de l’expédition de Dease et Simpson en 1837, et la majorité de ces caractéristiques avaient disparu vers le début des années 1900 en raison de l’érosion côtière. Cela laisse donc entendre que l’érosion s’est à tout le moins manifestée pendant la période visée par les données historiques. Grâce à l’utilisation d’observations historiques et d’observations contemporaines, nous avons pu déceler la perte de sites culturels et historiques de même que d’infrastructures modernes. Les cartes topographiques de l’U.S. Geological Survey révèlent un certain nombre de sites culturels et historiques connus, ainsi que des sites dotés d’infrastructures modernes datant des années 1950, sites et infrastructures qui avaient disparu vers le début des années 2000 en raison de l’érosion côtière. Nous avons également été en mesure de cerner des sites qui sont présentement menacés par un littoral qui empiète sur le terrain. Nos mesures des taux d’érosion contemporains pourraient éventuellement servir à déterminer à quel moment un site historique ou une infrastructure moderne sera touché advenant que des taux d’érosion similaires persistent

Advancing Landscape Change Research through the Incorporation of Iñupiaq Knowledge

Indigenous knowledge is a valuable but under-used source of information relevant to landscape change research. We interviewed Iñupiat elders, hunters, and other knowledge-holders in the villages of Barrow and Atqasuk on the western Arctic Coastal Plain of northern Alaska to gain further insight into the processes governing the ubiquitous lakes and the dynamics of landscape change in this region of continuous permafrost. The interviews provided a suite of information related to lakes and associated drained lake basins, as well as knowledge on landforms, environmental change, human events, and other phenomena. We were able to corroborate many observations independently and verify the timing of several large and significant lake drainage events using either aerial photography or remotely sensed time series. Data collected have been incorporated into a geodatabase to develop a multi-layer Geographic Information System that will be useful for local and scientific communities. This research demonstrates that indigenous knowledge can reveal a new understanding of landscape changes on the Arctic Coastal Plain in general and on lake processes in particular. We advocate ongoing, community-oriented research throughout the Arctic as a means of assessing and responding to the consequences of rapid environmental change.Les connaissances indigènes représentent une source d’information à la fois précieuse et sous-utilisée en matière de recherche sur les changements caractérisant le paysage. Nous avons interviewé des aînés de la nation Iñupiat, de même que des chasseurs et des personnes qui possèdent des connaissances dans les villages de Barrow et d’Atqasuk sur la plaine côtière occidentale de l’Arctique du nord de l’Alaska afin de mieux comprendre les processus qui gouvernent les lacs ubiquistes et la dynamique du changement de paysage dans cette région au pergélisol permanent. Les entrevues nous ont permis de recueillir une série de renseignements se rapportant aux lacs et aux bassins lacustres asséchés connexes de même que des connaissances sur les reliefs, le changement environnemental, les événements humains et d’autres phénomènes. Nous avons réussi à corroborer de nombreuses observations de manière indépendante et à vérifier le moment auquel plusieurs grands et importants événements d’assèchement lacustre se sont produits et ce, à l’aide de photographies aériennes ou de séries chronologiques télédétectées. Les données ainsi recueillies ont été intégrées à une banque de données cartographiques afin de permettre l’élaboration d’un système d’information géographique multicouche qui sera utile aux communautés locales et scientifiques. Cette recherche démontre que les connaissances indigènes peuvent aider à mieux comprendre les changements de paysage sur la plaine côtière de l’Arctique en général, et les processus lacustres en particulier. Nous favorisons donc la réalisation de recherches permanentes et axées sur la communauté dans l’Arctique pour évaluer les conséquences du changement environnemental rapide et les façons d’y réagir

Large-scale genome-wide association studies and meta-analyses of longitudinal change in adult lung function.

BACKGROUND: Genome-wide association studies (GWAS) have identified numerous loci influencing cross-sectional lung function, but less is known about genes influencing longitudinal change in lung function. METHODS: We performed GWAS of the rate of change in forced expiratory volume in the first second (FEV1) in 14 longitudinal, population-based cohort studies comprising 27,249 adults of European ancestry using linear mixed effects model and combined cohort-specific results using fixed effect meta-analysis to identify novel genetic loci associated with longitudinal change in lung function. Gene expression analyses were subsequently performed for identified genetic loci. As a secondary aim, we estimated the mean rate of decline in FEV1 by smoking pattern, irrespective of genotypes, across these 14 studies using meta-analysis. RESULTS: The overall meta-analysis produced suggestive evidence for association at the novel IL16/STARD5/TMC3 locus on chromosome 15 (P  =  5.71 × 10(-7)). In addition, meta-analysis using the five cohorts with ≥3 FEV1 measurements per participant identified the novel ME3 locus on chromosome 11 (P  =  2.18 × 10(-8)) at genome-wide significance. Neither locus was associated with FEV1 decline in two additional cohort studies. We confirmed gene expression of IL16, STARD5, and ME3 in multiple lung tissues. Publicly available microarray data confirmed differential expression of all three genes in lung samples from COPD patients compared with controls. Irrespective of genotypes, the combined estimate for FEV1 decline was 26.9, 29.2 and 35.7 mL/year in never, former, and persistent smokers, respectively. CONCLUSIONS: In this large-scale GWAS, we identified two novel genetic loci in association with the rate of change in FEV1 that harbor candidate genes with biologically plausible functional links to lung function

Investigating variation in replicability

Although replication is a central tenet of science, direct replications are rare in psychology. This research tested variation in the replicability of 13 classic and contemporary effects across 36 independent samples totaling 6,344 participants. In the aggregate, 10 effects replicated consistently. One effect – imagined contact reducing prejudice – showed weak support for replicability. And two effects – flag priming influencing conservatism and currency priming influencing system justification – did not replicate. We compared whether the conditions such as lab versus online or US versus international sample predicted effect magnitudes. By and large they did not. The results of this small sample of effects suggest that replicability is more dependent on the effect itself than on the sample and setting used to investigate the effect

Using MacPollen: A Computer Guide

A program is presented that can be run on most Macintosh computers. This program permits the drawing of pollen diagrams in a standard format. Pollen percentage diagrams and pollen concentration options are available within this program. The diagrams can be drawn in PICT format and transferred to various current drawing programs, where they can be enhanced to produce publication-quality pollen diagrams.Division of Polar Programs, National Science Foundation (Grant DPP-8615507

Holocene Biogeochemical and Pollen History of a Lake Erie, Ohio, Coastal Wetland

A five meter sediment core was taken from Old Woman Creek National Estuarine Research Reserve and State Natural Area and Preserve along the western basin of Lake Erie, U.S.A., to determine the historical biogeochemistry of the wetland. Analysis of pollen and sediment chemistry revealed that the area has remained a wetland since ca. 5,500 yr BP, despite changing lake levels. Pollen stratigraphy indicates a distinctive local succession, which has been divided into three zones. Sediments from sometime after glaciation to 5,500 yr BP were characterized by low concentrations of herb pollen; the next zone showed an establishment of hardwood forest vegetation. The modern local vegetation developed after deforestation (about 200 years ago), when sedimentation increased an order of magnitude, phosphorus deposition increased, and the ecosystem changed from a macrophyte dominated wetland to a plankton dominated marsh. After European settlement, the wetland retained its ability to act as a sink and biotic transformer of bioavailable phosphorus; however, abiotic processes seemed to be more important than the biotic transformations that dominated before deforestation