Alpine Conditions Research Articles

Productivity, requirements and efficiency of feed and nitrogen utilization of grass‐fed early lactating cows exposed to high Alpine conditions

ZusammenfassungProduktivität, Bedarf und Effizienz der Futter‐ und Stickstoffverwertung von grasgefütterten, frischlaktierenden Kühen unter hochalpinen BedingungenIm vorliegenden Versuch wurden drei Gruppen zu je sechs Tieren (zwei davon in verschiedenen Saisonen geweidet, eine im Stall gehalten) nach einer 2wöchigen Talperiode (400 m über N.N.) für 8 Wochen in ein hochalpines Gebiet (2000 m über N.N.) transportiert. Der alpine Aufenthalt war in drei Meßabschnitte unterteilt (Woche 1, Wochen 2 und 3 sowie Woche 8). Futterzusammensetzung, ad libitum‐Aufnahme an Futter und Nährstoffen sowie die Verdaulichkeit der organischen Substanz wurden wiederholt unter Anwendung der doppelten Indikatormethode gemessen. Meteorologische Daten und Milchleistung wurden durchgehend, Milchzusammensetzung und Lebendmasseveränderungen (nach mehrstündiger Nüchterung) in bestimmten Abständen erfaßt.Die klimatischen Bedingungen während der alpinen Versuchszeit zeichneten sich durch eine insgesamt höhere Abkühlungsrate aus, ohne jedoch extreme Werte zu erreichen. Zwischen den beiden Saisonen bestanden gewisse Klimaunterschiede. Die Aufnahme an Futter und an verdaulicher organischer Substanz war im Tal auf der Weide etwas niedriger als im Stall. Im Gegensatz dazu lagen die Werte auf der alpinen Weide signifikant über der Aufnahme im alpinen Stall. Bei Unterstellung der üblichen Bedarfswerte für Erhaltung im Tal und in Ruhe sowie für Milchleistung lag die berechnete Zufuhr mit Nettoenergie im Tal sowie im alpinen Stall unter dem Bedarf, während die Kühe auf der alpinen Weide 31% mehr als der errechnete Bedarf aufnahmen. Die Lebendmassen waren im alpinen Bereich in allen Gruppen gleichermaßen um durchschnittlich 42 kg niedriger als im Tal. Bei Weidehaltung ging die Milchleistung während der zehn Wochen Versuch deutlich von 28,0 kg auf 13,0 kg zurück und damit noch stärker als im Stall (von 29,4 kg auf 15,7 kg). Die Veränderungen in den Milchinhaltsstoffen verliefen bei allen Gruppen gleich. Auf Basis der erhöhten freiwilligen Nettoenergieaufnahme und dem berechneten Ausmaß an Körperenergiemobilisierung der Stalltiere läßt sich abschätzen, daß der Erhaltungsbedarf mehr als das Doppelte des Ruhebedarfs im Tal betragen haben dürfte. Die Daten legen zudem nahe, daß eine gewisse Langzeitadaptation mit der Folge einer Bedarfsreduzierung stattfand. Die Futterverwertung ging nicht nur im Verlauf des Experiments zurück, sondern war bei Weide während des gesamten alpinen Aufenthalts schlechter. Im Gegensatz zur Talperiode lag die Verwertung des aufgenommenen Stickstoffs zur Milch‐N‐Bildung bei den geweideten Tieren mit im Mittel 19,3% signifikant unter den 27,3%, die bei den Tieren im Stall gemessen wurden. Dies war eine Folge der unvermeidlich höheren N‐Aufnahme zur Sicherstellung der Energieversorgung auf der Weide bei dennoch etwas geringerer Milch‐N‐Ausscheidung.

Geoecology of the Norra Storfjallet Area, Northern Sweden

The geoecology of the Norra Storfjillet region is reconstructed from the record of deglaciation beginning about 8000 yr BP with the first break-up of the Fenno-Scandian ice sheet (Stage 1). By Stage 2 valleys below 600 m a.s.1. (the Tirna Valley was an exception) had become free of ice. Stage 3 involved a retreat of small valley glaciers to about 700-800 m, major nunataks appeared on the high plateau, and outlet glaciers were considerably reduced in size. Stage 4 was characterized by a warmer and wetter climate (Mid-Atlantic chronozone, 6000-5000 yr BP) when timberline rose to about 900 m. This led to the development of Spodosols (podzols) under stands of dwarf pine in swale topography. This paleo-podzolic signature was not erased during alpine conditions that typified the Sub-Boreal (Stage 5) and Sub-Atlantic (Stage 6) chronozones that followed. These were periods of lower temperatures and with reduced precipitation initially during Stage 5. Precipitation increased during the Sub-Atlantic and, together with temperature, remained similar to the present. Human settlement began about 6000 yr BP and had a recognizable impact on the landscape. This activity accelerated during the Sub-Boreal and Sub-Atlantic, with more intensive use of the mountains for reindeer procurement. The reconstructions are based upon glacial, geomorphological, pedological, and archaeological evidence.

Some notes on the behaviour of tropical glaciers

The fact of a relatively immediate inference of tropical glacier fluctuations on a climate originating from relatively homogenous air masses makes glaciological investigations in the tropics particularly important. One peculiarity of tropical climate is the lack of any appreciable thermal seasonality. Under this general aspect, two characteristic features of the glacier - climate relationship, (a) the sensitivity of the equilibrium line altitude (ELA) on climatic perturbations and (b) the corresponding reaction of glacier tongues are discussed in comparison to the Alpine conditions. The discussion is based on a modelled vertical budget gradient (VBG). Compared to midlatitude glaciers, the ELA reacts generally less sensitively, but more strongly if forced by a change in temperature. The tongues as well as small glaciers react sensitively on increasing ablation. The reaction on long term dynamic forcing is weak.

Vivipary in Polygonum viviparum: an adaptation to cold climate?

Populations of Polygonurn viviparurn were investigated in the Swiss Alps at 14 sites, ranging from 450 m to 2530 m above sea level. The average length of stems and the mean number of reproductive organs (flowers + bulbils) decreased significantly with increasing altitude. On average, the ratio of flowers to bulbils per inflorescence also declined so that at high altitudes, bulbil production was more pronounced. Increased allocation to vegetative reproduction is discussed as an adaptation to cold climate. It is suggested that enhanced vegetative reproduction might be controlled by incornplete floral induction in high altitudes. In addition variability within and between populations was investigated by isozyme electrophoresis and the examination of bulbil colours. A considerable amount of variability was found in alpine populations. The demonstrated genetic variability showed that in P. viviparum it is likely that minor sexual reproduction is maintained even under alpine conditions. This is reflected in different enzyme phenotypes and different bulbil colours.

Alliums: the ornamental onions

With the wide range of colour and attractive flowers, Alliums (ornamental onions) are ideal for growing in the modern garden, whether in the border or under alpine conditions. This book considers 200 species of ornamental onions, providing simple botanical descriptions, cultivation guides, attributes and geographical distribution plus associated hardiness zones. Sections on the importance of Alliums in agriculture, their place in myth and folk medicine, and their culinary usage are also included.

Simulated successional characteristics of managed and unmanaged low-elevation forests in central Europe

A forest succession model of the JABOWA/FORET type was applied to simulate stand development on low-elevation sites in The Netherlands and Switzerland. The model, previously tested for alpine conditions, proved to simulate accurately the successional characteristics of forests on poor sandy soils in the Veluwe area (central Netherlands). Model runs suggested that, in this region, Scots pine ( Pinus sylvestris) is the most important species in early succession. At a simulated stand age of 200–300 years, P. sylvestris is replaced by sessile oak ( Quercus petraea). The modeling experiment for a Swiss low-elevation forest was designed to explore long-term effects of forest management schemes. A forest system that would naturally belong to the sub-alliance Eu-Fagion was subjected to a management scheme that favors spruce ( Picea abies) during the first 250 years. After 250 years, an abrupt change from a managed to an unmanaged forest is assumed. The comparison of the undisturbed vs. the disturbed model system shows that the transformation from an artificial stand dominated by spruce to a natural forest composition takes between 300 and 350 years after forest management has ceased.

Late Quaternary vegetational history of the Enga province of Upland Papua New Guinea

Late Quaternary vegetational history of the Enga province of Upland Papua New Guinea

TAXONOMY OF THE NEARCTIC SPECIES OF TWINNIA AND GYMNOPAIS (DIPTERA: SIMULIIDAE) AND A DISCUSSION OF THE ANCESTRY OF THE SIMULIIDAE

AbstractThree species of Twinnia, including hirticornis n. sp., and five species of Gymnopais, including dichopticoides n. sp., holopticoides n. sp., and fimbriatus n. sp., are described, keyed, and illustrated. The ancestral simuliid is portrayed as possessing cephalic fans, because several related nematocerous families, viz., the Ptychopteridae, Dixidae, and Culicidae, also have similar and presumably homologous structures in the larval stage which are used in the same fashion to ingest food particles suspended in water The peculiar Twinnia–Gymnopais larval type, which lacks cephalic fans, is considered to have arisen simply by a neotenic retention of the fanless condition found in the first instar of Prosimulium. Phylogenetically, Twinnia and Gymnopais are therefore considered to have been derived from a Prosimulium-like ancestor. Twinnia is intermediate phylogenetically between Prosimulium and Gymnopais, and the latter is believed to be the most recently derived, possibly as a response to the development of arctic–alpine conditions in Beringia during the Tertiary.

Soil Temperature Effects on Root Respiration and the Ecology of Alpine and Subalpine Plants

Root respiration rates of Geum rossii (R. Br.) Ser. of G. triflorum Pursh, and of populations of Achillea millefolium L. from elevations of 2,400-3,220 m were compared at 4, 10, 18, and 25 C to determine whether soil temperature is important in controlling distribution of plants relative to alpine timberlines. Respiration was measured as a function of oxygen uptake by detached roots and was determined with an oxygen electrode. Comparisons of rates of roots and caudex tissue from mature plants collected in the field before and after 3 wk of growth in cold (4-10 C) or warm (15-25 C) soils and again following reversal of conditions showed that the alpine endemic G. rossii maintained higher rates than the subalpine G. triflorum; "alpine" populations of Achillea likewise had higher rates than populations from more subalpine habitats. Aerial conditions for all plants were about the same. Similar results were obtained in comparing respiration rates of 14-day-old Achillea seedlings germinated and grown at 26 C for 20 h and 10 C for 4 h, with a 16-h photoperiod daily. No differences were observed, however, between seedlings of the two Geum species, apparently due to a strong selection for heat-resistant individuals as indicated by the differences in seedling mortality. The results suggest that there are inherent tendencies for alpine plants to have higher root respiration rates than subalpine plants, which could make them more competitive under alpine conditions but could produce a wasteful metabolic rate in the warmer conditions of the subalpine. Estimations of root and shoot growth support our conclusion that soil temperatures could be an important factor in determining plant distribution patterns about alpine timberlines.

Internal Leaf Surface and Stomatal Abundance in Arctic and Alpine Populations of Oxyria Digyna

Internal leaf surface is greater in alpine populations of Oxyria digyna than in arctic populations grown under identical conditions. Outlines of lower epidermal cells of leaves vary among 10 arctic and alpine populations. Numbers of stomata, as well as epidermal cells, per unit area in the upper epidermis increase from north to south. Such a trend is not found in the lower epidermis. An alpine population from Mt. Washington has many more stomata per unit area on the lower epidermis than the upper, suggesting a closer affinity to the European alpine populations and to arctic populations than to its western North American and alpine conditions may be due to the development of ecological races which differ in structure and metabolic potential

Leaf temperatures of alpine plants in the field

1. Leaf temperatures of Colorado alpine plants on Mount Evans (4300 m) and near the Trail Ridge Road (3800 m) were measured along with air temperature, wind velocity, maximum and zenith light intensities, net radiation, and in one study humidity. 2. When skies were clear above Mount Evans, plant temperatures were clearly dependent upon insolation, being as much as 22° C above ambient. Under uniformly cloudy skies, plant temperatures did not deviate far from air temperatures. 3. Under typically fluctuating alpine conditions, correlations between leaf temperature and certain environmental factors are imperfect. Failure of the correlation is ascribed to factors not measured, mechanics of the analysis, changing environment, and position effects. 4. Application of these findings to controlled environment (growth chamber) studies poses an interesting and inherently difficult problem.

Biostratigraphic History of Dead Man Lake, Chuska Mountains, New Mexico

Dead Man Lake (elevation 2,800 m) is one of several hundred shallow lakes on the flat, rolling crest of the Chuska Mountains. The lacustrine sediments consist of 7 to 10 m late—Pleistocene sandy silt or fine sand beneath only 0.1 to 0.3 m Holocene organic mud. Five faunal zones in the Pleistocene sediments contain distinctive assemblages of Cladocera and larval Chironomidae. The Chydoridae were the dominant Cladocera during Wisconsin glaciopluvial time, but only two or three species occurred in any of the zones. Tanytarsini and Procladius (Tanypodinae) were usually the dominant Chironomidae; populations of Orthocladiinae and Chironomini were smaller and chronologically discontinuous. The Pleistocene fauna is an impoverished as in other Pleistocene lake sediments and in modern arctic lakes. Therefore the faunal assemblages support the palynological evidence for alpine conditions on the crest of the Chuska Mountains during Wisconsin glaciopluvial time. The organic mud deposited since the end of the Pleistoc...

Photo‐electric measurements of daylight under alpine conditions

AbstractObservations have been made with vacuum sodium and with rectifier selenium photo‐electric cells, under opal flashed glass diffusing plates. The former may remain constant save when exposed to intense tropical desert heat and full sunshine for a long period. The latter are far less constant, and in time the curvature of the light‐current relation may increase; this is accompanied by a decrease in blue and green sensitivity so that the response at the long wave end of the spectrum becomes relatively greater. No serious temperature error is introduced when the current from a Ixeston selenium cell is measured with a 10 ohm galvanometer amid snowy surroundings.Sodium cell measurements at about 0.41 μ give the reflection from the snow as being from 0.74 to 1.19 times the vertical component of mixed daylight. With a selenium cell, sensitive throughout the spectrum, observations ranged from 0.68–0.88. Calculated on the maximum values for mixed daylight the snow reflections were from 0.38–0.74 and from 0.28–0.38 respectively for the sodium and selenium cells.Under Alpine conditions there is relatively less scattered light from the sky, consequently the sun/sky ratio is greater, in the violet, than in England or Ceylon for the same solar altitude; with the selenium cell the sun/sky ratio is even greater, with a maximum of 9.70, as against 3.55 for the violet, both determinations being made at Scheidegg (2,064 m.) with an absolutely cloudless very dark blue sky, solar altitude 48.1°.The vertical component of daylight is higher in the violet, under Alpine conditions, than in Ceylon, for low or moderate solar altitudes, but the difference is less at higher solar altitudes. For measurements covering the whole spectrum the Alpine values are also noticeably higher. The physiological effects of Alpine sunlight are due partly to the intensity of the reflected light.

On a new Prorhynchid Turbellarian from Tasmania

ABSTRACT 1. Prorhynehus tasmaniensis sp. nov. is found under alpine conditions in Tasmania. 2. It is allied to Prorhynehus putealis Haswell, but exhibits the following differences: (a) Larger size, (b) Posterior excretory canal does not bifurcate, (c) Female genital pore almost in line with excretory pores and below pharynx, (d) Female genital pore only one-eighth of body-length from anterior end. (Difference from all other members of the genus.) (e) Germo-vitellarium in middle line ventral to intestine. (f) Testis follicular, extending from the right side over the intestine on to the left side. (Difference from all other members of the genus.)