Uprooting in boreal spruce forests: long-term variation in disturbance rate

1993 ◽  
Vol 23 (11) ◽  
pp. 2383-2388 ◽  
Author(s):  
Bengt Gunnar Jonsson ◽  
Mats Dynesius
Keyword(s):  
Retrospective Studies ◽  
Temporal Distribution ◽  
Long Period ◽  
Term Variation ◽  
Forest Floor Disturbance ◽  
Disturbance Pattern ◽  
Fall Direction ◽  
First Time ◽  
High Winds

Uprooted trees provide many kinds of exposed and colonizable substrates and may mediate coexistence of plant species. Here we present, for the first time, the temporal forest floor disturbance pattern caused by uprooted trees over a long period of time (120 years). There was a significant correlation between the frequency of high winds and number of uprooted trees, and the fall direction was closely related to the main direction of high winds. The temporal distribution was strongly aggregated, with many uprootings in the 1890s and the 1970s, resulting in large variations in disturbance rate between different decades. This implies periods with low availability of exposed soil. To interpret traits among species dependent on the disturbance as adaptations to some mean rate may thus be strongly misleading. However, the occurrence and importance of such bottleneck periods is hard to evaluate, as studies of the process of uprooting have only documented numbers and rates of uprooted trees and not the availability of exposed soil. We recommend more retrospective studies to evaluate long-term variation in disturbance regime parameters and studies on the temporal availability of exposed and colonizable soil.

scholarly journals Radar and Rain Gauge Analysis of the Extreme Rainfall during Hurricane Danny’s (1997) Landfall

2007 ◽  
Vol 135 (5) ◽  
pp. 1869-1888 ◽  
Author(s):  
Jeffrey M. Medlin ◽  
Sytske K. Kimball ◽  
Keith G. Blackwell
Keyword(s):  
Inner Core ◽  
Temporal Distribution ◽  
Extreme Rainfall ◽  
Rain Gauge ◽  
Rainfall Amount ◽  
Mobile Bay ◽  
Maximum Rainfall ◽  
Torrential Rainfall ◽  
First Time

Abstract As a minimal hurricane, Danny moved over Mobile Bay around 0900 UTC 19 July 1997 and became stationary by midmorning, while situated within a synoptic col. Danny then evolved into an asymmetric storm with an intensely convective rainband that produced torrential rainfall through 1200 UTC 20 July 1997. Danny’s center remained <100 km from the National Weather Service (NWS) Weather Surveillance Radar-1988 Doppler (WSR-88D) in Mobile, Alabama, for over 48 h, allowing long-term surveillance of the storm’s inner core. This event marked the first time the tropical Z–R relationship was employed on an operational WSR-88D system during tropical cyclone landfall. A radar-estimated maximum rainfall accumulation of 1097 mm (43.2 in.) was analyzed over southwestern Mobile Bay. A NWS cooperative rain gauge located on Dauphin Island, Alabama, measured 896 mm (35.28 in.). An adjacent standard rain gauge measured the highest rainfall amount of 932 mm (36.71 in.). This paper investigates the spatial and temporal distribution and potential magnitude of Danny’s torrential rainfall episode over coastal Alabama. It is shown that both gauges and radar seriously underestimated event rainfall. An estimate is given for what could have been the true event rainfall amount. In the case of the radar, the WSR-88D Algorithm Testing and Display System is used to obtain a better estimate of rainfall using higher dBZ caps than the operational 50 dBZ. In the case of the tipping-bucket rain gauge, wind and mechanical error estimates were applied in order to quantify rainfall underestimation.

scholarly journals Long-term variation in an occurrence of Rhabditis orbitalis parasitic larvae (Nematoda, Rhabditidae) in the eyes of montane rodents

2006 ◽  
Vol 43 (4) ◽  
pp. 232-236
Author(s):  
M. Kocianová-Adamcová ◽  
M. Špakulová ◽  
E. Kocianová
Keyword(s):  
Weather Conditions ◽  
Clethrionomys Glareolus ◽  
Seasonal Abundance ◽  
Term Variation ◽  
Chionomys Nivalis ◽  
Tatra Mts ◽  
Vole Species ◽  
First Time ◽  
Long Term Survey

AbstractDuring a long-term survey (1999–2005) of parasitic larvae of nidicolous nematode Rhabditis orbitalis Sudhaus et Schulte, 1986 in the West Tatra Mts, the nematodes were detected in the eye orbits of snow voles Chionomys nivalis in 1999, 2004 and 2005. In the last year, R. orbitalis was detected also in another vole species Clethrionomys glareolus and Microtus tatricus both in previously studied site and in the Low Tatra Mts, however, it has never appeared at other rodent species. For the first time, an irregular occurrence of the R. orbitalis parasitic larvae has been ascertained in natural conditions of the Slovak mountains. The eye nematodes occurred only during autumn or cold and rather wet summer months, when density of the preferred host Ch. nivalis was relatively low. A hypothesis has been put forward that an occasional appearance of parasitic eye larvae in the life cycle of bacteriophagous R. orbitalis represents a strategy for surviving periods of a scarcity of bacterial food, which could be influenced by a combination of weather conditions, density of host rodents and seasonal abundance of R. orbitalis in rodent nests.

scholarly journals Influence of mid-stress on the dynamic fatigue of a light weight EPS bead foam

e-Polymers ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 349-354
Author(s):  
Jan-Hendrik Keller ◽  
Volker Altstädt
Keyword(s):  
Mechanical Properties ◽  
Mechanical Behavior ◽  
Complex Loading ◽  
Load Level ◽  
Static Compression ◽  
Long Period ◽  
First Time ◽  
Quasi Static Compression ◽  
Dynamic Fatigue

AbstractExpandable Polystyrene (EPS) is one of the most commonly used material, when it comes to protect thermal sensitive goods, since the thermal conductivity of EPS is very low. The mechanical properties in terms of long-term compression or quasi-static compression are also quite well known. But when the material is loaded with higher amplitudes over a long period of time, not much is known yet about long-term mechanical behavior. For example, as a packaging material, EPS exhibits complex loading situation ranging from small to high amplitudes over a long period of time, when e.g. it is transported in a truck, a ship or in a car. In order to characterize the mechanical behavior under such large amplitude loading, the dynamic fatigue needs to be recorded and evaluated. In this paper, the principles of the hysteresis measurements evaluation are applied on EPS for the first time to unveil long-term mechanical properties in compression. Results show, that after increasing the dynamic load level to a critical level of over 100 kPa, the mechanical behavior, in terms of compression rate, of EPS changes from a linear to a kind of exponential mode.

Spatial and temporal distribution of rainfall erosivity in New Zealand

Soil Research ◽  
2015 ◽  
Vol 53 (7) ◽  
pp. 815 ◽  
Author(s):  
Andreas Klik ◽  
Kathrin Haas ◽  
Anna Dvorackova ◽  
Ian C. Fuller
Keyword(s):  
New Zealand ◽  
Temporal Distribution ◽  
Annual Rainfall ◽  
Rainfall Erosivity ◽  
High Resolution Data ◽  
Topographic Features ◽  
Erosion Processes ◽  
Precipitation Records ◽  
First Time

Rainfall and its kinetic energy, expressed by rainfall erosivity, drives soil erosion processes by water. One of the most commonly used erosivity parameters is the rainfall-runoff erosivity factor R of the Revised Universal Soil Loss Equation. The goal of this study was to investigate for the first time the spatial distribution of annual rainfall erosivity in New Zealand. High-resolution data from 35 weather stations were used to calculate the R-factors. Based on these results, region-specific equations were developed and were applied by using long-term precipitation records from 597 stations. The values were interpolated with a geographic information system to generate a map showing spatial variations of rainfall erosivity. Annual R-values vary across both islands by a factor of 30, from <550 MJ mm ha–1 h–1 in parts of Central Otago to >16 000 MJ mm ha–1 h–1 in the Southern Alps. These large differences are related to climatic and topographic features. Nevertheless, the data show a high correlation to the precipitation. In most parts of New Zealand, highest erosivity values occurred in December and January, whereas the lowest values were observed in August.

Somatic Embryogenesis and In vitro Plant Regeneration in Vigna trilobata (L.) Verd. - A Potential Pasture Legume

1970 ◽  
Vol 19 (1) ◽  
pp. 89-99
Author(s):  
K. Choudhary ◽  
M. Singh ◽  
M. S. Rathore ◽  
N. S. Shekhawat
Keyword(s):  
Somatic Embryogenesis ◽  
Growth Regulators ◽  
Somatic Embryos ◽  
Basal Medium ◽  
Long Term Study ◽  
Continuous Application ◽  
First Time ◽  
Pasture Legume

This long term study demonstrates for the first time that it is possible to propagate embryogenic Vigna trilobata and to subsequently initiate the differentiation of embryos into complete plantlets. Initiation of callus was possible on 2,4-D. Somatic embryos differentiated on modified MS basal nutrient medium with 1.0 mg/l  of 2,4-D and 0.5 mg/l  of Kn. Sustained cell division resulted in globular and heart shape stages of somatic embryos. Transfer of embryos on to a fresh modified MS basal medium with 0.5 mg/l of Kn and 0.5 mg/l of GA3 helped them to attain maturation and germination. However, the propagation of cells, as well as the differentiation of embryos, were inhibited by a continuous application of these growth regulators. For this reason, a long period on medium lacking these growth regulators was necessary before the differentiation of embryos occurred again. The consequences for improving the propagation of embryogenic cultures in Vigna species are discussed. Key words: Pasture  legume, Vigna trilobata, Globular, Heart shape, somatic embryogenesis D.O.I. 10.3329/ptcb.v19i1.4990 Plant Tissue Cult. & Biotech. 19(1): 89-99, 2009 (June)

An Evaluation of Provincial Macroeconomic Performance in Vietnam

2017 ◽  
pp. 34-47
Author(s):  
Hoi Le Quoc ◽  
Nam Pham Xuan ◽  
Tuan Nguyen Anh
Keyword(s):  
Development Strategy ◽  
Institutional Transformation ◽  
Economic Indicators ◽  
Macroeconomic Performance ◽  
Economic Development Strategy ◽  
Socio Economic Development ◽  
The Cost ◽  
Development Objectives ◽  
First Time

The study was targeted at developing a methodology for constructing a macroeconomic performance index at a provincial level for the first time in Vietnam based on 4 groups of measurements: (i) Economic indicators; (ii) oriented economic indicators; (iii) socio-economic indicators; and (iv) economic - social – institutional indicators. Applying the methodology to the 2011 - 2015 empirical data of all provinces in Vietnam, the research shows that the socio-economic development strategy implemented by those provinces did not provide balanced outcomes between growth and social objectives, sustainability and inclusiveness. Many provinces focused on economic growth at the cost of structural change, equality and institutional transformation. In contrast, many provinces were successful in improving equality but not growth. Those facts threaten the long-term development objectives of the provinces.

Effect of Climate Change and Variety on Long-term Variation of Grain Yield and Quality in Winter Wheat in Kazakhstan

2014 ◽  
Vol 42 (1) ◽  
pp. 163-172 ◽  
Author(s):  
A. Morgounov ◽  
A. Abugalieva ◽  
S. Martynov
Keyword(s):  
Climate Change ◽  
Winter Wheat ◽  
Grain Yield ◽  
Yield And Quality ◽  
Term Variation ◽  
Grain Yield And Quality

NEW VARIETIES OF CURRANTS AND GOOSEBERRY BREEDING PLANTS

1970 ◽  
pp. 41-46
Author(s):  
O. D. Golyaeva ◽  
O. V. Kurashev ◽  
S. D. Knyazev ◽  
А. Yu. Bakhotskaya
Keyword(s):  
Powdery Mildew ◽  
Genetic Basis ◽  
Black Currant ◽  
Leaf Spots ◽  
Agricultural Sciences ◽  
Berry Crops ◽  
New Varieties ◽  
First Time ◽  
Red Currant

The main goal of the scientific institution was and remains to improve the assortment of fruit and berry crops for the development of domestic horticulture. Black currant breeding at VNIISPK was started by A.F Tamarova and continued by the doctor of agricultural Sciences T.P.Ogoltsova and doctor of agricultural Sciences S.D. Knyazev. A long-term breeding program has been developed. The main goals of the program are to create black currant cultivars with continuous resistance to diseases, first of all powdery mildew, as wells resistance to pests, i.e. bud mite. As a result of the long-term work, over 40 black currant cultivars have been developed, 14 of them are zoned. Red currant breeding was led by the candidate of agricultural Sciences L.V. Bayanova; since 2001 the work has been continued by the candidate of agricultural Sciences O.D. Golyaeva. ‘Heinemanns Rote Spӓtlese’, the descendant of R. multiflorum Kit., was involved in the red currant breeding for the first time in Russia. On its genetic basis, a series of late maturing cultivars with long and dense racemes was created. At the Institute, in total 21cultivars of red currants have been developed, 13 of them are zoned. At present, red currant cultivars make up 25.5% of the zoned assortment in Russia. The first research on gooseberries was stated by V.P. Semakin and A.F Tamarova; since 1992 the systematic gooseberry breeding has been carried out by the candidate of agricultural Sciences O.V. Kurashev. On the basis of Grossularia robusta, we have created gooseberry forms that are resistant to powdery mildew and leaf spots. These forms are highly productive, weakly thorned, having bush habit suitable for mechanized harvest. The result of breeding activities was the transfer of 6 gooseberry cultivars to State agricultural testing: ‘Solnechny Zaychik’, ‘Nekrasovsky’, ‘Yupiter’, ‘Zemlianichny’, ‘Moryachok’ and ‘Discovery’.

LONG-TERM AND SHORT-TERM VARIATION OF SEDIMENT RUNOFF CHARACTERISTICS IN A MOUNTAINOUS TORRENT EXPRESSED BY SEDIMENT RUNOFF MODEL

2018 ◽  
Vol 74 (4) ◽  
pp. I_943-I_948
Author(s):  
Kazuki YAMANOI ◽  
Hideka MURAKAMI ◽  
Masaharu FUJITA
Keyword(s):  
Sediment Runoff ◽  
Short Term ◽  
Term Variation ◽  
Runoff Model
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