scholarly journals Phenology of Rock Pool Mosquitoes in the Southern Appalachian Mountains: Surveys Reveal Apparent Winter Hatching of Aedes japonicus and the Potential For Asymmetrical Stage-Specific Interactions

2020 ◽  
Vol 36 (4) ◽  
pp. 216-226
Author(s):  
Corey A. Day ◽  
Kaylin Lewandowski ◽  
James R. Vonesh ◽  
Brian D. Byrd
Keyword(s):  
Mosquito Species ◽  
Field Studies ◽  
High Elevation ◽  
Specific Interactions ◽  
Rock Pool ◽  
Egg Hatching ◽  
The North ◽  
High Elevation Site ◽  
Natural Rock ◽  
Aedes Atropalpus

ABSTRACT The North American rock pool mosquito, Aedes atropalpus, has reportedly decreased in abundance following the introduction of Ae. japonicus japonicus to the USA, but the specific mechanisms responsible for the reduction remain unclear. Thus, there is a need for field studies to improve our knowledge of natural rock pool systems where both species co-occur. We sampled rock pool invertebrates over a 12-month period along the Chattooga River at a high-elevation site (728 m) near Cashiers, NC, and at a lower-elevation site (361 m) near Clayton, GA. We identified 12 orders of macroinvertebrates representing at least 19 families and 5 mosquito species. Aedes j. japonicus was present year-round at both sites. We observed overwintering Ae. j. japonicus larvae in pools with water temperatures as cold as 3°C and detected apparent winter egg hatching in water below 10°C. Aedes atropalpus was rarely encountered at the high-elevation site but was highly abundant in the summer months at the low-elevation site. Late-stage Ae. j. japonicus larvae inhabited pools in March 2019 when Ae. atropalpus first appeared in the same pools, creating the potential for asymmetrical stage-specific interactions. Our observations provide evidence of overwintering and early hatching of Ae. j. japonicus in the southeastern climate. Further study of the importance of stage-dependent competition and winter egg hatching of diapausing Ae. j. japonicus eggs is warranted.

Stopover Site Fidelity by Tennessee Warblers at a Southern Appalachian High-elevation Site

2012 ◽  
Vol 124 (2) ◽  
pp. 366-370 ◽  
Author(s):  
David F. Vogt ◽  
Mark E. Hopey ◽  
G. Rad Mayfield ◽  
Eric C. Soehren ◽  
Laura M. Lewis ◽  
...  
Keyword(s):  
Site Fidelity ◽  
High Elevation ◽  
Stopover Site ◽  
Southern Appalachian ◽  
High Elevation Site

Landscape development in western and central Dronning Maud Land, East Antarctica

2001 ◽  
Vol 13 (3) ◽  
pp. 302-311 ◽  
Author(s):  
Jens-Ove Näslund
Keyword(s):  
Large Scale ◽  
High Elevation ◽  
Continental Margins ◽  
Landscape Development ◽  
Ice Streams ◽  
The North ◽  
Ice Stream ◽  
Dronning Maud Land ◽  
Break Up

Large-scale bedrock morphology and relief of two key areas, the Jutulsessen Nunatak and the Jutulstraumen ice stream are used to discuss glascial history and landscape development in western and central Dronning Maud Land, Antarctica. Two main landform components were identified: well-defined summit plateau surfaces and a typical alpine glacial landscape. The flat, high-elevation plateau surfaces previously were part of one or several continuous regional planation surfaces. In western Dronning Maud Land, overlying cover rocks of late Palaeozoic age show that the planation surface(s) existed in the early Permian, prior to the break-up of Gondwana. A well-develoment escarpment, a mega landform typical for passive continental margins, bounds the palaeosurface remnants to the north for a distance of at least 700 km. The Cenozoic glacial landscape, incised in the palaeosurface and escarpment, is exemplified by Jutulsessen Nunatak, where a c. 1.2 km deep glacial valley system is developed. However, the prominent Penck-Jutul Trough represents some of the deepest dissection of the palaeosurface. This originally tectonic feature is today occupied by the Jutulstraumen ice stream. New topographic data show that the bed of the Penck-Jutul Trough is situated 1.9±1.1 km below sea level, and that the total landscape relief is at least 4.2 km. Today's relief is a result of several processes, including tectonic faulting, subaerial weathering, fluvial erosion, and glacial erosion. It is probable that erosion by ice streams has deepened the tectonic troughs of Dronning Maud Land since the onset of ice sheet glaciation in the Oligocene, and continues today. An attempt is made to identify major events in the long-term landscape development of Dronning Maud Land, since the break-up of the Gondwana continent.

scholarly journals Vitality Structure of the Populations of Vegetative Motile Plants of Forest Ecosystems of the North-East of Ukraine

2019 ◽  
Vol 13 (1) ◽  
pp. 125-132
Author(s):  
Kovalenko Ihor ◽  
Skliar Iurii ◽  
Klymenko Hanna ◽  
Kovalenko Nataliia
Keyword(s):  
Quality Index ◽  
Forest Ecosystems ◽  
Morphological Structure ◽  
Field Studies ◽  
Complete Analysis ◽  
Individual Plant ◽  
North East ◽  
The North ◽  
Motile Species ◽  
Two Populations

Background: The vitality level of the populations has turned out to be statistically reliably associated with such coenotic factors: age and density of forest stand. In general, the vitality spectra vary widely: the quality index Q of the populations ranges from 0,00 to 0,50, that is, it fully covers the theoretically possible scale of the values of this coefficient, which indicates the sensitivity of the vitality structure of the populations to the ecological-coenotic conditions and determines high informative value of the vitality analysis. Objective: The aim of the study is to assess the vitality structure of the populations of vegetative motile plant species – typical representatives of the grassy layer of forest ecosystems of the North-East of Ukraine as a factor that determines their stability and dynamics. Methods: The analysis of the vitality structure is based on the field studies of the populations of 4 vegetative motile species of plants – Aegopodium podagraria L., Asarum europaeum L., Carex pilosa Scop. and Stellaria holostea L. in forest ecosystems of the North-East of Ukraine. Vitality analysis was carried out according to Yu. A. Zlobin’s methodology. Vitality analysis procedure, classically, is carried out in three stages: 1) Selection of quantitative features that characterize the vital status of the individual plant; 2) Evaluation of vitality of individual plants that were included in the sample; 3) Integral assessment of the population’s vitality. Depending on the ratio in the population of plants of classes a, b and c, the population belongs to one of three vitality types: prosperous, equilibrium or depressive. Results: The obtained estimates of the vitality structure of populations of the clone-forming plants in the grass-shrub layer of forests of the North-East of Ukraine can be considered quite reliable, because they are based, in general, on a complete analysis of the morphological structure of about 13 thousand ramets of the studied species of plants. The statistical reliability of estimates of the population’s vitality structure is predominantly between 70 and 99% and only in some cases lower than 70%. As the clone grows older, its ramet’s vitality decreases and the clone degrades. New young clones, that start to form on the basis of genets, replace old ones. Such ramets have increased vitality, greater stress and competitive resistance. Due to the mechanisms of clone substitution in the living cover, the dominance of nemoralis herbs persists for a long time. Conclusion: The vitality spectra of the populations of the studied species of plants vary widely: the quality index Q of the populations ranges from 0,00 to 0,50, that is, it covers full theoretically possible scale of the values of this coefficient, which indicates the sensitivity of the vitality structure of the populations to the ecological-coenotic conditions and determines high informative value of vitality analysis. Prosperous populations: two populations A. europaeum of the associations Quercetum (roboris) coryloso (avellanae) – convallariosum (majalis) and Quercetum (roboris) coryloso (avellanae) – convallariosum (majalis), two populations A. podagraria of the associations – Pinetum (sylvestris) vacciniosum (myrtilli) and Querceto (roboris) – Pinetum (sylvestris) convallarioso (majalis) – vacciniosum (myrtilli), one population S. holostea of the association Querceto (roboris) – Pinetum (sylvestris) vacciniosum (myrtilli) and one population C. pilosa of the association Querceto (roboris) – Pinetum (sylvestris) vaccinioso (myrtilli) – convallariosum (majalis).

scholarly journals Use of summer habitat by caribou on the north slope of a mountain near the Macmillan Pass, N.W.T.

Rangifer ◽  
1996 ◽  
Vol 16 (4) ◽  
pp. 311 ◽  
Author(s):  
James F. Quayle ◽  
G. Peter Kershaw
Keyword(s):  
Habitat Type ◽  
Indirect Evidence ◽  
High Elevation ◽  
North Slope ◽  
Habitat Types ◽  
The North ◽  
Feeding Cycle ◽  
Alpine Habitats ◽  
Pellet Density ◽  
Insect Harassment

Habitat use by woodland caribou was investigated by counting pellet-groups, sampling phytomass, and evaluating topography in nine habitat-types on the north slope of an unnamed mountain near Macmillan Pass, N.W.T. Caribou pellets were most abundant in high elevation habitat-types, and pellet density was greatest in an alpine Lichen-Grass habitat-type with a slope of <1°. The high density of pellets in alpine areas may have resulted from of the use of cool, windy, alpine habitats by caribou seeking relief from insect harassment. There were no apparent relationships between pellet abundance, and phytomass of mosses, lichens, or graminoids, possibly as a result of caribou feeding and defecating in different habitats. The occurrence of pellets with a coalesced morphology in the barren Lichen-Grass habitat-type provided indirect evidence in support of a feeding cycle, whereby caribou visit lush habitats to feed, and return to open, alpine habitats to rest and ruminate.

scholarly journals Aeolian mass flux characterization: uncertainties from a wind-tunnel perspective and implications for field studies

2014 ◽  
Author(s):  
Ate Poortinga ◽  
Joep GS Keijsers ◽  
Jerry Maroulis ◽  
Saskia M. Visser
Keyword(s):  
Wind Tunnel ◽  
Mass Flux ◽  
Shear Velocity ◽  
Field Studies ◽  
Sediment Traps ◽  
Sediment Flux ◽  
Cumulative Probability ◽  
Surface Moisture ◽  
The North ◽  
Specific Configuration

Aeolian sediment traps are widely used to estimate the total volume of wind-driven sediment transport, but also to study the vertical mass distribution of a saltating sand cloud. The reliability of sediment flux estimations from this data are dependent upon the specific configuration of the measurement compartments and the analysis approach used. In this study, we analyse the uncertainty of these measurements by investigating the vertical cumulative probability distribution and relative sediment flux derived from both wind-tunnel and field studies. Three existing datasets were used in combination with a newly acquired meteorological dataset, which was collected in combination with sediment fluxes from six different events, using three customized catchers at one of the beaches of Ameland in the north of The Netherlands. Fast-temporal data collected in a wind-tunnel shows that eq has a scattered pattern between impact and fluid threshold, but increases linearly with shear velocities above the fluid threshold. For finer sediment fractions, a larger portion of the sediment was transported closer to the surface compared to coarser sediment fractions. It was also shown that errors originating from the the distribution of the sampling compartments, specifically the location of the lowest sediment trap relative to the surface, can be identified using the relative sediment flux. In the field, surface conditions such as surface moisture, surface crusts or frozen surfaces have a more pronounced, but localized effect, than shear velocity. Uncertainty in aeolian mass flux estimates can be reduced by placing multiple compartments in closer proximity to the surface.

Roof of the World: Tibet, Pamirs

2013 ◽  
Author(s):  
Mike Searle
Keyword(s):  
Tibetan Plateau ◽  
High Elevation ◽  
Tien Shan ◽  
Palm Tree ◽  
The Tibetan Plateau ◽  
Wet Season ◽  
North West ◽  
Mountain Ranges ◽  
The North ◽  
The World

The Tibetan Plateau is by far the largest region of high elevation, averaging just above 5,000 metres above sea level, and the thickest crust, between 70 and 90 kilometres thick, anywhere in the world. This huge plateau region is very flat—lying in the internally drained parts of the Chang Tang in north and central Tibet, but in parts of the externally drained eastern Tibet, three or four mountain ranges larger and higher than the Alps rise above the frozen plateau. Some of the world’s largest and longest mountain ranges border the plateau, the ‘flaming mountains’ of the Tien Shan along the north-west, the Kun Lun along the north, the Longmen Shan in the east, and of course the mighty Himalaya forming the southern border of the plateau. The great trans-Himalayan mountain ranges of the Pamir and Karakoram are geologically part of the Asian plate and western Tibet but, as we have noted before, unlike Tibet, these ranges have incredibly high relief with 7- and 8-kilometre-high mountains and deeply eroded rivers and glacial valleys. The western part of the Tibetan Plateau is the highest, driest, and wildest area of Tibet. Here there is almost no rainfall and rivers that carry run-off from the bordering mountain ranges simply evaporate into saltpans or disappear underground. Rivers draining the Kun Lun flow north into the Takla Makan Desert, forming seasonal marshlands in the wet season and a dusty desert when the rivers run dry. The discovery of fossil tropical leaves, palm tree trunks, and even bones from miniature Miocene horses suggest that the climate may have been wetter in the past, but this is also dependent on the rise of the plateau. Exactly when Tibet rose to its present elevation is a matter of great debate. Nowadays the Indian Ocean monsoon winds sweep moisture-laden air over the Indian sub-continent during the summer months (late June–September). All the moisture is dumped as the summer monsoon, the torrential rains that sweep across India from south-east to north-west.

Morpho (Morpho) helenor (Cramer) (Lepidoptera, Nymphalidae, Morphinae) in Bolivia: Geographical distribution and ecological plasticity, with a description of a new subspecies

Zootaxa ◽  
2011 ◽  
Vol 3130 (1) ◽  
pp. 30 ◽  
Author(s):  
YUVINKA GARECA ◽  
PATRICK BLANDIN
Keyword(s):  
Geographical Distribution ◽  
Field Studies ◽  
Neotropical Region ◽  
New Subspecies ◽  
Transition Zones ◽  
Ecological Plasticity ◽  
North East ◽  
The North ◽  
Intermediate Phenotypes ◽  
Wide Range

The geographical distribution of Morpho helenor (Cramer) in Bolivia is mapped from the study of specimens preserved in Bolivian and foreign collections, and from recent field studies in various ecoregions. One subspecies, M. h. theodorus Fruhstorfer, inhabits Amazonian moist forests in the western and northern parts of the country. Another subspecies, M. h. coelestis Butler, is common in moist cloud forests (Bolivian Yungas), but also occurs to the North and North-East. We describe a new subspecies, M. h. prometa ssp. nov., from Southern Andean Yungas. Transition zones between theodorus and coelestis are highlighted, where specimens exhibiting intermediate phenotypes were collected. The pattern of geographic transition from M. h. coelestis to M. h. prometa needs to be documented. M. h. prometa inhabits sub-humid, semideciduous forests, whereas M. h. theodorus and M. h. coelestis live in rainforests. M. h. coelestis populations are found from less than 100 m to more than 1600 m a.s.l.; M. h. theodorus has been collected at more than 1000 m a.s.l.; and M. h. prometa between 500 m and 1400 m a.s.l.. Therefore, Bolivian M. helenor populations are distributed throughout a wide range of ecological contexts: we discuss the habitat plasticity of the species in light of available knowledge of its geographical distribution and habitats in the Neotropical Region.

Population Growth Rates of Aedes atropalpus (Diptera: Culicidae) Are Depressed at Lower Temperatures Where Aedes japonicus japonicus (Diptera: Culicidae) Are Naturally Abundant in Rock Pools

2020 ◽  
Author(s):  
Corey A Day ◽  
Eleanor G Armstrong ◽  
Brian D Byrd
Keyword(s):  
Growth Rate ◽  
Population Growth ◽  
Population Growth Rate ◽  
Invasion Biology ◽  
The United States ◽  
Rock Pools ◽  
Temperature Range ◽  
Natural Rock ◽  
Aedes Atropalpus ◽  
Middle Temperature

Abstract Recent studies report extensive reductions in the abundance of the North American rock pool mosquito, Aedes atropalpus (Diptera: Culicidae), following the invasion of Ae. japonicus japonicus in the United States. Although developmental temperature is recognized as an important component of the invasion biology of Ae. j. japonicus, its impacts on the population growth and fitness of Ae. atropalpus remain largely undefined. In this study we reared Ae. atropalpus larvae at three temperature ranges reflecting ecologically important temperatures in natural rock pools: a low temperature range (mean: 19°C) where Ae. j. japonicus is common and Ae. atropalpus is often rare, a middle temperature range (mean: 25°C) where both species are naturally found in similar relative abundances, and a higher temperature range (mean: 31°C) where Ae. atropalpus is the dominant species. We measured survival, development time, wing length, and fecundity to calculate a finite population growth rate at each temperature. Our results indicate that Ae. atropalpus population growth suffers in colder rock pools, which informs the perceived displacement of the species in temperate habitats. The population growth rate was highest in the middle temperature range, but not significantly higher than in the highest temperature range used in this study. The developmental success of Ae. atropalpus at the intermediate temperature range suggests that competition with Ae. j. japonicus in rock pools within that range may significantly impact natural Ae. atropalpus populations.

Environmental correlates of herpetofaunal diversity in Costa Rica

2010 ◽  
Vol 26 (5) ◽  
pp. 521-531 ◽  
Author(s):  
David Laurencio ◽  
Lee A. Fitzgerald
Keyword(s):  
Costa Rica ◽  
Species Diversity ◽  
Beta Diversity ◽  
Geographic Distance ◽  
Alpha Diversity ◽  
High Elevation ◽  
Diversity Patterns ◽  
Regional Diversity ◽  
Environmental Correlates ◽  
High Elevation Site

Abstract:Disentangling local and historical factors that determine species diversity patterns at multiple spatial scales is fundamental to elucidating processes that govern ecological communities. Here we investigated how environmental correlates may influence diversity at local and regional scales. Primarily utilizing published species lists, amphibian and reptile alpha and beta diversity were assessed at 17 well-surveyed sites distributed among ecoregions throughout Costa Rica. The degree to which regional species diversity patterns were related to environmental variables and geographic distance was determined using Canonical Correspondence Analysis and Mantel tests. Amphibian alpha diversity was highest in lowland Pacific sites (mean = 43.3 species) and lowest at the high elevation site (9 species). Reptile alpha diversity values were high for both lowland Atlantic (mean = 69.5 species) and lowland Pacific (mean = 67 species) sites and lowest for the high elevation site (8 species). We found high species turnover between local sites and ecoregions, demonstrating the importance of beta diversity in the determination of regional diversity. For both amphibians and reptiles, beta diversity was highest between the high-elevation site and all others, and lowest among lowland sites within the same ecoregion. The effect of geographic distance on beta diversity was minor. Ecologically significant climatic variables related to rain, temperature, sunshine and insolation were found to be important determinants of local and regional diversity for both amphibians and reptiles in Costa Rica.

The first meteorological observations at a tropical high elevation site: Antisana, 1846

2016 ◽  
Vol 13 (6) ◽  
pp. 1047-1055 ◽  
Author(s):  
Ana Mª M. Farrona ◽  
Fernando Domínguez-Castro ◽  
Mª Cruz Gallego ◽  
José M. Vaquero
Keyword(s):  
High Elevation ◽  
High Elevation Site ◽  
Meteorological Observations
Sign in / Sign up

Export Citation Format

Share Document