Autumn Air Temperature Research Articles

The sediment record of the past 200 years in a Swiss high- alpine lake: Hagelseewli (2339 ma.s.l.)

Sediment cores spanning the last two centuries were taken in Hagelseewli, a high-elevation lake in the Swiss Alps. Contiguous 0.5 cm samples were analysed for biological remains, including diatoms, chironomids, cladocera, chrysophyte cysts, and fossil pigments. In addition, sedimentological and geochemical variables such as loss-on-ignition, total carbon, nitrogen, sulphur, grain-size and magnetic mineralogy were determined. The results of these analyses were compared to a long instrumental air temperature record that was adapted to the elevation of Hagelseewli by applying mean monthly lapse rates.During much of the time, the lake is in the shadow of a high cliff to the south, so that the lake is ice-covered during much of the year and thus decoupled from climatic forcing. Lake biology is therefore influenced more by the duration of ice-cover than by direct temperature effects during the short open-water season. Long periods of ice-cover result in anoxic water conditions and dissolution of authigenic calcites, leading to carbonate-free sediments.The diversity of chironomid and cladoceran assemblages is extremely low, whereas that of diatom and chrysophyte cyst assemblages is much higher. Weak correlations were observed between the diatom and chrysophyte cyst assemblages on the one hand and summer or autumn air temperatures on the other, but the proportion of variance explained is low, so that air temperature alone cannot account for the degree of variation observed in the paleolimnological record.Analyses of mineral magnetic parameters, spheroidal carbonaceous particles and lead suggest that atmospheric pollution has had a significant effect on the sediments of Hagelseewli, but little effect on the water quality as reflected in the lake biota.

イチゴのＮＦＴ栽培におけるチャンネル液温の変化

Changes in environmental factors were investigated in NFT system where 12 strawberry cultivars were grown. While the solution temperature was regulated at three levels, transition of air temperatures, solution temperatures at the channel and plant temperatures were measured. At relatively high air temperature in autumn, the concentration of dissolved oxygen at the lower part of channel decreased a little than in the upper part. However, at low air temperature in winter, the concentrations of dissolved oxygen at the lower and upper parts were almost the same.When the daytime air temperature in the plastic house was higher than the solution temperature in the tank, the lower the part of channel, the higher the solution temperature was tend to be. On the contrary, when the daytime air temperature in the plastic house was lower than the solution temperature in the tank, the lower the part of channel, the lower the solution temperature was tend to be. These tendency became obvious as the difference between air temperature in the plastic house and solution temperature at the tank increased.

ウンシュウミカンの花芽分化に及ぼす環状はく皮と温度条件

The effects of ringing with or without hand defoliation on vegetative growth, flower bud differentiation, and physiological changes in young, container-grown satsuma mandarin (cv.Okitsu Wase) on trifoliate orange were investigated. Comparisons were made between trees grown under different temperatures in a growth chamber and those grown in the field. A ring of bark, 3 mm wide was removed 5 cm above the bud union. The wound was wrapped with a vinyl tape to prevent drying and to enhance callus development.1. Ringing in mid-June, after the spring growth flush ceased root growth within several days. After the ringing wound healed, new roots developed but the onset of the summer flush was delayed and shoot growth was depressed. Ringing in early September, after the summer flush stopped, not only depressed root growth, but it also prevented the initiation of new roots even though the girdles callused over. The absence of new roots is attributed to the lower air temperature in autumn. The autumn flush of new growth did not occur on treated trees.2. Potted trees were ringed in either mid-June, late July, or mid-September. Ringed and non-ringed trees were defoliated, and then transferred to a 25°C growth chamber at intervals of 1.5 months. Number of flowers and vegetative shoots which emerged after defoliation was observed. Defoliation in mid-June of non-ringed control trees required new growth over 10 days. When trees were defoliated in late July, bud break occurred within several days.However, trees required more days again in mid-September, and the maximum of 20 days in late October for bud break after defoliation. Trees ringed in mid-June and defoliated in late July, mid-September, or late October required 15, 9, and 17 days, respectively, to initiate regrowth. Ringed trees in July or September caused regrowth similar to that of non-ringed trees. Trees defoliated in early December, girdled in July or September, and held at 25°C produced many flowers, whereas those ringed in June produced few flowers.3. Trees, ringed on 1 September, and non-ringed trees were held at 15°, 20°, and 25°C in growth chambers or planted in the open field. The girdle produced more callus and healed faster at 25°C than at 20°C; no callus formed at 15°C. When trees at 25°C were defoliated in early December and kept at the same temperatures, bud break was delayed compared to those which were transferred to lower temperatures. Non-ringed trees held at 25°C produced few flowers, whereas ringed trees bloomed profusely. With or without girdles, trees kept at 15° and 20°C produced many flower buds; girdled trees kept at all temperatures had more flowers per sprouting node than did non-girdled ones.4. Analysis of leaves from non-girdled trees growing in the field and from those girdled on 1 September revealed that the sugar content in all samples increased in autumn. The in-crease is attributed to the low air temperatures. After ringing, leaf starch content increased to over 20% (dry weight basis) and then decreased. Nitrogen content decreased linearly until the wound callused over and then the level increased. The C/N ratio increased until the wound healed and then decreased. Transpiration resistance of the leaves was temporarily greater on ringed trees; the upward movement of the transpiration stream was, therefore, slower until the girdle healed.

ZONATION OF OPTIMUM SEEDING PERIOD OF WINTER WHEAT BASED ON AUTUMN TEMPERATURES

Seeding date is an important management factor affecting the performance of winter wheat (Triticum aestivum L.). In this study, optimum seeding date was closely related to air temperatures in autumn in various regions of Canada (R = 0.998). This relationship was used to estimate optimum seeding period (SP) and construct a zonation map for the Maritime Provinces. Seeding period ranged from 15–28 Aug. in northern New Brunswick to 10–25 Sept. in the Annapolis Valley region of Nova Scotia.Key words: Wheat (winter), climate, winter survival, zonation map

Effets of wind on the temperature in the leaf-sheath of paddy rice plant

The temperature around the young panicle in the leaf-sheath of paddy rice plants was found to rise remarkably when the weather was windy and when the plant was exposed to direct sunlight, the phenomenon was more conspicuous, the same relation was observed either under high air temperatures in summer or under lower air temperatures in autumn.