scholarly journals Growth And Phenology Of Established Tilia Cordata Street Trees In Response To Different Irrigation Regimes

2006 ◽  
Vol 32 (1) ◽  
pp. 3-9
Author(s):  
Oliver Bühler ◽  
Christian Nørgård Nielsen ◽  
Palle Kristoffersen
Keyword(s):  
Growth Period ◽  
Stem Growth ◽  
Tilia Cordata ◽  
Street Trees ◽  
Irrigation Regimes ◽  
Southern Side ◽  
Northern Side ◽  
Stem Increment

The effect of different irrigation regimes on growth and phenology of 100 established Tilia cordata street trees was investigated during the growth period of 2004. Relative stem increment increased significantly when irrigating with 280, 320, or 640 L (74, 84.5, and 169 gal) of water throughout the growth period. The length of the growth period was affected by irrigation regimes in regard to termination of growth, as the trees receiving 640 L (169 gal) had a growth period significantly longer than the control trees. These results indicate that growth and growth period of street trees are augmented by an increase in the amount of water available to them. In addition, block effects concerning the start of the growth period were observed, as trees situated on the northern side of the street initiated stem growth 7 days earlier than the trees on the southern side.

scholarly journals Chronic nitrogen addition causes a reduction in soil carbon dioxide efflux during the high stem-growth period in a tropical montane forest but no response from a tropical lowland forest in decadal scale

2009 ◽  
Vol 6 (5) ◽  
pp. 8633-8660
Author(s):  
B. Koehler ◽  
M. D. Corre ◽  
E. Veldkamp ◽  
J. P. Sueta
Keyword(s):  
Growth Period ◽  
Montane Forest ◽  
Stem Growth ◽  
Soil Co2 Efflux ◽  
Co2 Efflux ◽  
N Addition ◽  
Soil Co2 ◽  
Lowland Forest ◽  
Soil Carbon Dioxide ◽  
Decadal Scale

Abstract. Atmospheric nitrogen (N) deposition is rapidly increasing in tropical regions. We studied the response of soil carbon dioxide CO2 efflux to long-term experimental N-addition (125 kg N ha−1 yr-1) in mature lowland and montane forests in Panamá. In the lowland forest, on soils with high nutrient-supplying and buffering capacity, fine litterfall and stem-growth were neither N- nor phosphorus-limited. In the montane forest, on soils with low nutrient supplying capacity and an organic layer, fine litterfall and stem-growth were N-limited. Our objectives were to 1) explore the influence of soil temperature and moisture on the dynamics of soil CO2 efflux and 2) determine the responses of soil CO2 efflux from an N-rich and N-limited forest to elevated N input. Annual soil CO2-C efflux was larger from the lowland (15.20±1.25 Mg C ha−1) than the montane forest (9.36±0.29 Mg C ha−1). In the lowland forest, soil moisture explained the largest fraction of the variance in soil CO2 efflux while soil temperature was the main explanatory variable in the montane forest. Soil CO2 efflux in the lowland forest did not differ between the control and 9–11 yr N-addition plots, suggesting that chronic N input to nutrient-rich tropical lowland forests on well-buffered soils may not change their C balance in decadal scale. In the montane forest, first year N addition did not affect soil CO2 efflux but annual CO2 efflux was reduced by 14% and 8% in the 2- and 3 yr N-addition plots, respectively, compared to the control. This reduction was caused by a decrease in soil CO2 efflux during the high stem-growth period of the year, suggesting a shift in carbon partitioning from below- to aboveground in the N-addition plots where stem diameter growth was promoted.

scholarly journals Sensitivity of a calving glacier to ice–ocean interactions under climate change: new insights from a 3-D full-Stokes model

2019 ◽  
Vol 13 (6) ◽  
pp. 1681-1694 ◽  
Author(s):  
Joe Todd ◽  
Poul Christoffersen ◽  
Thomas Zwinger ◽  
Peter Råback ◽  
Douglas I. Benn
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Greenland Ice Sheet ◽  
Environmental Sensitivity ◽  
Predictive Capacity ◽  
Outlet Glacier ◽  
Iceberg Calving ◽  
Southern Side ◽  
Northern Side ◽  
Global Sea Level

Abstract. Iceberg calving accounts for between 30 % and 60 % of net mass loss from the Greenland Ice Sheet, which has intensified and is now the single largest contributor to global sea level rise in the cryosphere. Changes to calving rates and the dynamics of calving glaciers represent a significant uncertainty in projections of future sea level rise. A growing body of observational evidence suggests that calving glaciers respond rapidly to regional environmental change, but predictive capacity is limited by the lack of suitable models capable of simulating calving mechanisms realistically. Here, we use a 3-D full-Stokes calving model to investigate the environmental sensitivity of Store Glacier, a large outlet glacier in West Greenland. We focus on two environmental processes: undercutting by submarine melting and buttressing by ice mélange, and our results indicate that Store Glacier is likely to be able to withstand moderate warming perturbations in which the former is increased by 50 % and the latter reduced by 50 %. However, severe perturbation with a doubling of submarine melt rates or a complete loss of ice mélange destabilises the calving front in our model runs. Furthermore, our analysis reveals that stress and fracture patterns at Store's terminus are complex and varied, primarily due to the influence of basal topography. Calving style and environmental sensitivity vary greatly, with propagation of surface crevasses significantly influencing iceberg production in the northern side, whereas basal crevasses dominate in the south. Any future retreat is likely to be initiated in the southern side by a combination of increased submarine melt rates in summer and reduced mélange strength in winter. The lateral variability, as well as the importance of rotational and bending forces at the terminus, underlines the importance of using the 3-D full-Stokes stress solution when modelling Greenland's calving glaciers.

Observations of circulation and exchange processes in Jervis Bay, New South Wales

1992 ◽  
Vol 43 (6) ◽  
pp. 1487 ◽  
Author(s):  
PE Holloway ◽  
G Symonds ◽  
Vaz R Nunes
Keyword(s):  
New South ◽  
New South Wales ◽  
Additional Mechanism ◽  
Near Surface ◽  
South Wales ◽  
Circulation Current ◽  
Southern Side ◽  
Northern Side ◽  
Wind Currents ◽  
Coastally Trapped Waves

This paper discusses oceanographic observations obtained in and near Jervis Bay, a small coastal embayment of approximately 124 km2 situated on the New South Wales coast, during a series of measurement programmes spanning three years. Various mechanisms that drive water circulation within the bay and water exchange between the bay and the adjacent continental shelf are discussed. Current meter data from within the bay show surprisingly little correlation with the wind. Currents are characterized by persistent flows in one direction for periods of months, and it is suggested that influences from the shelf are responsible for driving the bay circulation. Flow through the bay entrance is weakly correlated with the wind at a period of around eight days, with near-surface inflow on the southern side of the entrance being in phase with deeper outflow on the northern side and vice versa. The shelf waters are well known for their coastally trapped waves. These have the potential to oscillate vertically the density surfaces on the shelf on a time scale of around eight days, and observations indicate that these waves are an additional mechanism driving circulation in the bay. The shelf waters are influenced by the warm East Australia Current and its eddies, and this appears to maintain a density contrast between the bay and the shelf for most of the year, with the shelf waters being less dense, which may be an additional mechanism driving bay circulation. Current-meter data from the bay entrance show a persistent northward current component in contrast to the strong southward flow of the East Australia Current on the shelf. Conductivity-temperature- depth data reveal cold, dense water flowing out of the bay during periods of strong winter cooling and the effects of warm eddies pushing warm water into the bay and displacing cold deeper water away from the bay. The heating/cooling cycle of the bay appears to be influenced by advection processes on the shelf as well as by aidsea heat and radiation exchanges.

Art. XIII.—Grammatical Sketch of the Haúsa Language

1882 ◽  
Vol 14 (2) ◽  
pp. 176-217
Author(s):  
J. F. Schön
Keyword(s):  
The North ◽  
Correct Pronunciation ◽  
Southern Side ◽  
Northern Side

The word consists of three syllables, and must not be tortured into Housa as is frequently done. Ha-ou-sa conveys the correct pronunciation. The meaning of the word itself is not quite certain. From two expressions in the writer's collection it may be inferred that it means ‘language’. The first is, “He speaks another ha-u-sa,”that is, another language; and the second, in answer to the question, “Do many people speak Haúsa?” The reply given was, “How can they be Haúsa unless they speak Ha1sa?” Barth also admits that it means ‘language,’ although it is not confined to that meaning. The word itself was probably unknown to Leo Africanus, who says that Zāria Kano and Katsena speak the language of Gober, instead of Haúsa, Gober being at Leo's time the most prominent and noble among the provinces of the North. Whether the name, Aúsa given to the northern side of “the great river” in contrast to Gurma on the southern side, has anything to do with Haúsa, is left undecided by Barth. Sultan Bello derives the Haúsa from a Bornu slave, named Bāwu. This Bāwu has a real historical existence in the traditions of the Haúsa people, though not as a slave, the Haúsa word for ‘slave’ being Bāwa not Bāwa, a fact of which Sultan Bello could not have been ignorant; and besides this, it must be argued that, if the Haúsa derived their origin from the Bornu or Kanúri, there would exist a greater similarity between these two languages than is found to be the case. Both languages have a few words in common, but the grammars are most distinct.

Effects of Planting on Different Sides of the Ridge on Emergence, Plant Growth, Yield and Quality of Potato (Solanum tuberosum) in the Sudan

1989 ◽  
Vol 25 (3) ◽  
pp. 409-415 ◽  
Author(s):  
A. M. Ali
Keyword(s):  
Solanum Tuberosum ◽  
Plant Growth ◽  
Soil Temperature ◽  
Growth Yield ◽  
Potato Tubers ◽  
Yield And Quality ◽  
Southern Side ◽  
Northern Side

SUMMARYThe effects of planting potato tubers on four different sides of two ridge orientations was investigated. Soil temperature was coolest on the northern side, followed by the western, eastern and southern sides. Fifty percent emergence took place in 24, 42 and 49 days for tubers planted on the northern, western and eastern sides, respectively. Only 22% of tubers planted on the southern side emerged. The best yield and quality was obtained by planting on the northern side, followed successively by the eastern, western and southern sides of the ridge.

scholarly journals Similarities and differences of aerosol optical properties between southern and northern sides of the Himalayas

2014 ◽  
Vol 14 (6) ◽  
pp. 3133-3149 ◽  
Author(s):  
C. Xu ◽  
Y. M. Ma ◽  
A. Panday ◽  
Z. Y. Cong ◽  
K. Yang ◽  
...  
Keyword(s):  
Optical Properties ◽  
Monsoon Season ◽  
Diurnal Variations ◽  
The Other ◽  
The Tibetan Plateau ◽  
Aerosol Optical Properties ◽  
Coarse Mode ◽  
Southern Side ◽  
Northern Side ◽  
The Himalaya

Abstract. The Himalaya mountains along the southern edge of the Tibetan Plateau act as a natural barrier for the transport of atmospheric aerosols from the polluted regions of South Asia to the main body of the Tibetan Plateau. In this study, we investigate the seasonal and diurnal variations of aerosol optical properties measured at two Aerosol Robotic Network (AERONET) sites on the southern side of the Himalaya (Pokhara, 812 m above sea level (a.s.l.) and EVK2-CNR, 5079 m a.s.l. in Nepal) and one on the northern side (Qomolangma (Mt. Everest) station for Atmospheric and Environmental Observation and Research, Chinese Academy of Sciences (QOMS_CAS) in Tibet, 4076 m a.s.l. in China). While observations at QOMS_CAS and EVK2-CNR can generally be representative of a remote background atmosphere, Pokhara is a lower-elevation suburban site with much higher aerosol load due to both the influence of local anthropogenic activities and to its proximity to the Indo-Gangetic Plains. The annual mean aerosol optical depth (AOD) during the investigated period was 0.05 at QOMS_CAS, 0.04 at EVK2-CNR and 0.51 at Pokhara, respectively. Seasonal variations of aerosols are profoundly affected by large-scale atmospheric circulation. Vegetation fires, peaking during April in the Himalayan region and northern India, contribute to a growing fine mode AOD at the three stations. Dust transported to these sites, wind erosion and hydrated/cloud-processed aerosols lead to an increase in coarse mode AOD during the monsoon season at QOMS_CAS and EVK2-CNR. Meanwhile, coarse mode AOD at EVK2-CNR is higher than at QOMS_CAS in August and September, indicating that the transport of coarse mode aerosols from the southern to the northern side may be effectively reduced. The effect of precipitation scavenging is clearly seen at Pokhara, which sees significantly reduced aerosol loads during the monsoon season. Unlike the seasonal variations, diurnal variations are mainly influenced by meso-scale systems and local topography. The diurnal pattern in precipitation appears to contribute to diurnal changes in AOD through the effect of precipitation scavenging. AOD exhibits diurnal patterns related to emissions in Pokhara, while it does not at the other two high-altitude sites. At EVK2-CNR, the daytime airflow carries aerosols up from lower-altitude polluted regions, leading to increasing AOD, while the other two stations are less influenced by valley winds. Surface heating influences the local convection, which further controls the vertical aerosol exchange and the diffusion rate of pollution to the surrounding areas. Fine and coarse mode particles are mixed together on the southern side of the Himalaya in spring, which may lead to the greater inter-annual difference in diurnal cycles of Ångström exponent (AE) at EVK2-CNR than that at QOMS_CAS.

scholarly journals A climatology of sub-seasonal temporal clustering of extreme precipitation in Switzerland and its links to extreme discharge

2021 ◽  
Vol 21 (10) ◽  
pp. 2949-2972
Author(s):  
Alexandre Tuel ◽  
Olivia Martius
Keyword(s):  
Extreme Precipitation ◽  
River Discharge ◽  
Precipitation Extremes ◽  
Spatiotemporal Pattern ◽  
High Discharge ◽  
Temporal Clustering ◽  
Extreme Precipitation Events ◽  
Southern Side ◽  
Northern Side ◽  
The Alps

Abstract. The successive occurrence of extreme precipitation events on sub-seasonal timescales can lead to large precipitation accumulations and extreme river discharge. In this study, we analyze the sub-seasonal clustering of precipitation extremes in Switzerland and its link to the occurrence and duration of extreme river discharge. We take a statistical approach based on Ripley's K function to characterize the significance of the clustering for each season separately. Temporal clustering of precipitation extremes exhibits a distinct spatiotemporal pattern. It occurs primarily on the northern side of the Alps in winter and on their southern side in fall. Cluster periods notably account for 10 %–16 % of seasonal precipitation in these two regions. The occurrence of a cluster of precipitation extremes generally increases the likelihood and duration of high-discharge events compared to non-clustered precipitation extremes, particularly at low elevations. It is less true in winter, when the magnitude of precipitation extremes is generally lower and much of the precipitation falls as snow. In fall, however, temporal clusters associated with large precipitation accumulations over the southern Alps are found to be almost systematically followed by extreme discharge.

Flexural toppling and the development of uphill-facing scarps along the Bedretto valley, Swiss Alps

2020 ◽  
Author(s):  
Masahiro Chigira ◽  
Michel Jaboyedoff ◽  
Andrea Pedrazzini ◽  
Satoru Kojima
Keyword(s):  
Rock Mass ◽  
Swiss Alps ◽  
Normal Faults ◽  
Mica Schist ◽  
Valley Bottom ◽  
Southern Side ◽  
Northern Side ◽  
Flexural Toppling ◽  
Brittle Fractures ◽  
Differential Uplift

<p>Uphill-facing scarps develop in the central Swiss Alps, particularly along the Upper Rhone valley, the Urseren valley, the Upper Rhine valley, and Bedretto valley. It has been argued whether they have gravitational origin, tectonic origin, or differential uplift after the deglaciation. We made geological survey and topographic interpretation in the Bedretto valley, in which the Ticino River flows from the west-southwest to east-northeast. The Bedretto valley slopes have shoulders on both sides of the valley at elevations of 1500 to 1900 m, below which is a lower U-shaped valley. Uphill-facing scarps develop more on the southern side slopes of the Bedretto valley, where is underlain mainly by mica schist of the Bedretto zone, than on the northern side slopes, where is underlain mainly by gneiss and slate. In addition, they develop much more on slopes higher than the slope shoulders, and the uphill-facing scarps on the lower U-shaped valley are much smaller in scale. Tributary valleys on the south side of the Bedretto valley go down into this lower U-shaped valley from the southeast with intervening ridges, and we surveyed along the valleys of Ri di Cristallina, Ri di Valleggio, and Val Cavagnolo. We found that steeply-dipping schistosity in the ridges is toppled valleyward with brittle fractures along the hinge zones, which are approximately along or slightly higher than the tributary valley bottom. Rock mass as thick as 300 m thus toppled. Flexural toppling of mica schist developed uphill-facing scarps, which were mostly along high-angle faults, some of which were recognized to have brittle crush zones. The flexural toppling generated extension field in the upper ridges, where rock mass apparently settled down along normal faults. The reason why the northern side slopes of the Bedretto valley have much smaller uphill facing scarps may be due to the rocks are mainly gneiss and also due to the numbers of faults are possibly much less than in the southern slopes . The facts that uphill facing scarps are mainly developed above the lower U-shaped valleys may be related to the longer time intervals of the exposure of slopes higher than the slope breaks to the atmosphere during the glacial age.</p>

scholarly journals Piecing together a new mosaic: Gravettian lithic resources and economic territories in the Western Pyrenees

2020 ◽  
Vol 12 (12) ◽  
Author(s):  
Aitor Calvo ◽  
Alvaro Arrizabalaga
Keyword(s):  
Raw Materials ◽  
Microscopic Analysis ◽  
Archaeological Sites ◽  
General Terms ◽  
Wide Range ◽  
Southern Side ◽  
Northern Side ◽  
Lithic Raw Materials ◽  
Surrounding Areas ◽  
Western Pyrenees

AbstractTo palliate the current scarcity of information about lithic raw materials in the Western Pyrenees during the Gravettian, the study of ten assemblages has explored the flint procurement patterns and economic organisation of the territory. The study was based on the macro- and microscopic analysis of the different lithic remains. A wide range of flint varieties were used, including some excellent rocks for knapping and others of poorer quality. This diversified catchment pattern was defined by the criteria of quality and suitability for reduction. Although procurement took place mostly at the primary outcrops, there is some evidence of limited acquisition in secondary deposits. Within the economic territory of the Western Pyrenees, divergences in the connections between the outcrops on one side of the mountains and the archaeological sites on the other may indicate different territorial or economic roles for each side. In general terms, the northern side may have been more residential with more stable habitation, while the southern side was linked with logistic tasks and more seasonal occupation. The economic connections between this territory and surrounding areas revealed by the lithic resources are the reflection of inter-group contacts and an economic mosaic imbricated with a cultural or symbolic one.

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