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1.
S. D. Kashenko 《Russian Journal of Marine Biology》2009,35(5):422-430
The combined effects of temperatures of 14, 17, 20, 22, and 25°C and salinities of 36–12‰ on embryos and larvae of the sand
dollar Scaphechinus mirabilis was studied. Embryonic development is the most sensitive stage in the early ontogenesis of S. mirabilis. It is completed at a temperature of 14–20°C in a salinity range of 36–24‰ and at temperature of 22°C to 26‰. The fertilization
proceeds in wider ranges of temperature and salinity. Among the swimming larvae, blastulae showed the greatest resistance
to variations of these environmental factors. All the larvae survived at a temperature of 14–22°C and a salinity of 36–20‰,
and more than 70% of them at 18‰. The pluteus I is the most vulnerable stage; probably this is related to the formation of
the larval skeleton and transition to phytoplankton feeding. The survival of larvae at the age of 20 days was 100% at 14–22°
C and a salinity of 36–24‰, most of them survived at 14–20°C and a salinity 18‰. The temperature 25 ° C is the most damaging
for early development of S. mirabilis. The duration of development of that species lasts 28.5–29 days at 20°C and a salinity of 32.2–32.6‰. At 20 and 22°C, the
larvae settled and completed metamorphosis more quickly if sand from the parental habitat was present. The larvae did not
settle during the experiment (14 days) at 14 ° C and in the absence of sand. 相似文献
2.
Climate change and sea turtles: a 150-year reconstruction of incubation temperatures at a major marine turtle rookery 总被引:1,自引:0,他引:1
GRAEME C. HAYS ANNETTE C. BRODERICK FIONA GLEN BRENDAN J. GODLEY 《Global Change Biology》2003,9(4):642-646
Sea turtles show temperature dependent sex determination. Using an empirical relationship between sand and air temperature, we reconstructed the nest temperatures since 1855 at Ascension Island, a major green turtle (Chelonia mydas) rookery. Our results show that inter‐beach thermal variations, previously ascribed to the albedo of the sand, which varies hugely from one beach to another, have persisted for the last century. Reconstructed nest temperatures varied by only 0.5 °C on individual beaches over the course of the nesting season, while the temperature difference between two key nesting beaches was always around 3 °C. Hence inter‐beach thermal variations are the main factor causing a large range of incubation temperatures at this rookery. There was a general warming trend for nests, with a mean increase in reconstructed nest temperatures for different months of between 0.36 and 0.49 °C for the last 100 years. 相似文献
3.
In some localities of the upper reaches of the Kolyma River, the narrow-headed ant (Formica exsecta Nylander, 1846) has become the dominant species instead of a rare one during the last decade. To study this phenomenon, soil
temperatures at a depth of 20 cm were measured in the winter of 2008–2009, near 11 nests of this species and in 11 more biotopes
without nests, in the same localities where similar measurements had been carried out in the 1980s. The growth of minimum
air temperatures by 2–2.5°C combined with increased snow cover since the end of the past century by the present time, has
resulted in the minimal soil temperatures at a depth of 20 cm rising by 3–7°C. Being one of the least cold-resisting species
of the genus (with limit of tolerance −12…−15°C), the narrow-headed ant has responded to winter warming of soils by increasing
the variety of inhabited biotopes by 3–4 times, from 5–6 to 20–23 out of more than 43 examined; its abundance has grown sharply,
to 130 nests per survey route 1300 m long and 20 m wide. Within the frame of the existing climate such deviations of soil
temperature may occur once every 15–20 years. Therefore the changes observed may represent regular fluctuations. The prediction
of population dynamics of F. exsecta in other parts of the subarctic belt within the permafrost zone should take into account the climatic specificity of the
region which may considerably differ from that in adjoining territories. 相似文献
4.
Two experiments were conducted to assess the response of cauliflower (Brassica oleracea L. var. botrytis) cv. “Nautilus” F1 hybrid to different constant temperatures after curd initiation by keeping the plants in six different
temperature-controlled glasshouse compartments with heating set point temperatures of 6, 10, 14, 18, 22, and 26 °C (±4 °C)
at the School of Plant Sciences, The University of Reading, UK during winter 1998–1999 and summer 1999. Many of the growth
parameters increased with increasing mean growing temperature up to an optimum temperature and then declined with further
increases in temperature. Therefore, cauliflower’s growth and development after curd initiation could be resolved into linear
or curvilinear function of effective temperatures calculated with optimum temperatures between 19 and 23 °C. It is suggested
that future warmer climates will be beneficial for winter cauliflower production rather than summer cauliflower production. 相似文献
5.
Water temperature and upstream migration of glass eels in New Zealand: implications of climate change 总被引:4,自引:0,他引:4
Glass eels migrating upstream in a New Zealand river showed a clear preference for water temperatures between 12 and 20°C,
with an optimum of 16.5°C. Water temperatures <12°C and >22°C almost completely inhibited migration, which implies that warmer
temperatures associated with global climate change might have a detrimental impact on glass eel recruitment in their current
ranges. We established this by trapping glass eels of shortfin, Anguilla australis, and longfin, A. dieffenbachii, eels nightly from September to November. Eels caught in 2001 (50,287) outnumbered those caught in 2002 (19,954); shortfin
glass eels dominated catches in both years, comprising 91–93% of the catch. Longfins were larger than shortfins, and size
and pigmentation in both species increased as the seasons progressed. Temperatures within the migratory season in 2001 showed
∼14-day intervals between maxima that appeared to be associated with the new and full moons. 相似文献
6.
Taoka Y Nagano N Okita Y Izumida H Sugimoto S Hayashi M 《Marine biotechnology (New York, N.Y.)》2009,11(3):368-374
The growth, lipid content, and fatty acid composition of Aurantiochytrium sp. strain mh0186 at different temperatures were investigated. Strain mh0186 grew well at 15–30°C, but weakly at 10°C. The
biomass at 15–30°C was significantly higher than at 10 and 35°C, and the total lipid at 15–35°C was significantly higher than
that at 10°C. The amount of DHA in the total fatty acid was highest at 10°C and decreased in response to temperature increase.
The content of DHA (mg/g-dry cell weight) at 15–30°C were significantly higher than those at 35°C and those at 15–25°C were
significantly higher than those at 10 and 35°C. The DHA yield at 15–35°C was significantly higher than those at 10 and 35°C.
Unsaturation of fatty acid was regulated by temperature and was enhanced in response to temperature decrease. The ratio of
DHA to DPA varied at different temperatures. 相似文献
7.
Regula Gehrig 《Aerobiologia》2006,22(1):27-34
A record-breaking heat wave affected the European continent in summer 2003. In Switzerland, the temperature in June, July
and August exceeded the 1961–1990 mean by about 5 °C. These extreme temperatures had significant effects on the pollen production
and on the airborne pollen loads. Especially affected was the grass pollen season, which started 1–2 weeks earlier than in
the mean. During May and the first part of June the grass pollen production and dispersion was favoured by the warm and dry
weather and many days with high pollen concentrations were registered. First water deficiencies occurred in June so that the
grasses ceased to grow. The grass pollen season ended 7–33 days earlier than normal. For many of our stations of the Swiss
pollen network this had never occurred as early as in 2003. The other herbaceous plants were not affected as much as the grasses.
We measured very high Chenopodium and Plantago pollen concentrations, about normal concentrations of Urtica and Rumex and slightly lower Artemisia pollen concentrations than normal. The summer 2003 was exceptional and its reoccurrence is at the moment statistically extremely
unlikely. But models of climatologists show that in the future, climate variations will increase and that in the period 2071–2100
about every second summer could be as warm or warmer and as dry or dryer than 2003. 相似文献
8.
Hydromedion sparsutum is a locally abundant herbivorous beetle on the sub-Antarctic island of South Georgia, often living in close association
with the tussock grass Parodiochloa flabellata. Over a 4-day period in mid-summer when the air temperature varied from 0 to 20°C, the temperature in the leaf litter 5–10 cm
deep at the base of tussock plants (the microhabitat of H. sparsutum) was consistently within the range of 5–7.5°C. Experiments were carried out to assess the ability of H. sparsutum larvae collected from this thermally stable environment to acclimate when maintained at lower (0°C) and higher (15°C) temperatures.
The mean supercooling points (freezing temperature) of larvae collected in January and acclimated at 0°C for 3 and 6 weeks
and 15°C for 3 weeks were all within the range of −2.6 to −4.6°C. Larvae in all treatment groups were freeze tolerant. Acclimation
at 0°C significantly increased survival in a 15-min exposure at −8°C (from 27 to 96%) and −10°C (from 0 to 63%) compared with
the field-fresh and 15°C-treated larvae. Similarly, survival of 0°C-acclimated larvae in a 72-h exposure at −6°C increased
from 20 to 83%. Extending the acclimation period at 0°C to 6 weeks did not produce any further increase in cold tolerance.
The concentrations of glucose and trehalose in larval body fluids increased significantly with low temperature acclimation.
Larvae maintained at 15°C for 3 weeks (none survived for 6 weeks) were less able to survive 1-h exposures between 30 and 35°C
than the 0°C-treated samples. Whilst vegetation and snow cover are an effective buffer against low winter temperatures in
many polar insects, the inability of H. sparsutum larvae to acclimate or survive at 15°C suggests that protection against high summer temperatures is equally important for
this species.
Accepted: 2 August 1999 相似文献
9.
Eliza R. Larson Justin R. Eastwood Katherine L. Buchanan Andrew T. D. Bennett Mathew L. Berg 《Ecological Management & Restoration》2018,19(1):39-48
Mean air temperatures and the frequency, intensity and duration of extreme weather events such as heatwaves are increasing due to climate change. Nest boxes experience more variable and extreme temperatures than natural cavities, which may reduce survival and reproductive success of the species which utilize them, but little is known about the factors which drive nest box temperature profiles. We quantified the potential for retrofitted insulation on nest boxes to modify internal temperatures and to mimic the thermal characteristics of natural cavities more closely. We tested three types of materials with insulative or reflective properties which were easy to retrofit to nest boxes: 3‐cm‐thick polystyrene, pleated foil batts and reflective paint. We found that polystyrene and foil batts reduced mean nest box temperatures during the day by 0.31 ± 0.01°C and 0.17 ± 0.01°C, respectively (but up to 5.84°C and 4.02°C). The effects of all insulation types were dependent on the time of day, and only polystyrene had a significant effect at night, with a greater capacity to retain heat (mean 0.21 ± 0.01°C warmer). Contrary to expectations, reflective paint caused a small increase in temperature during the late afternoon. In our study, the temperature modulation provided by insulation was able to match or exceed that due to variation in nest location and surrounding vegetation canopy cover. Our findings show that polystyrene and foil batts may offer effective and tractable means to mitigate the effects of extreme temperatures in nest boxes and thereby help achieve temperature profiles more similar to natural cavities. 相似文献
10.
Extremes of heat,drought and precipitation depress reproductive performance in shortgrass prairie passerines 下载免费PDF全文
Climate change elevates conservation concerns worldwide because it is likely to exacerbate many identified threats to animal populations. In recent decades, grassland birds have declined faster than other North American bird species, a loss thought to be due to habitat loss and fragmentation and changing agricultural practices. Climate change poses additional threats of unknown magnitude to these already declining populations. We examined how seasonal and daily weather conditions over 10 years influenced nest survival of five species of insectivorous passerines native to the shortgrass prairie and evaluate our findings relative to future climate predictions for this region. Daily nest survival (n = 870) was best predicted by a combination of daily and seasonal weather variables, age of nest, time in season and bird habitat guild. Within a season, survival rates were lower on very hot days (temperatures ≥ 35 °C), on dry days (with a lag of 1 day) and on stormy days (especially for those species nesting in shorter vegetation). Across years, survival rates were also lower during warmer and drier breeding seasons. Clutch sizes were larger when early spring temperatures were cool and the week prior to egg‐laying was wetter and warming. Climate change is likely to exacerbate grassland bird population declines because projected climate conditions include rising temperatures, more prolonged drought and more intense storms as the hydrological cycle is altered. Under varying realistic scenarios, nest success estimates were halved compared to their current average value when models both increased the temperature (3 °C) and decreased precipitation (two additional dry days during a nesting period), thus underscoring a sense of urgency in identifying and addressing the current causes of range‐wide declines. 相似文献
11.
Local variation in weather conditions influences incubation behavior and temperature in a passerine bird 下载免费PDF全文
Brittney H. Coe Michelle L. Beck Stephanie Y. Chin Catherine M. B. Jachowski William A. Hopkins 《Journal of avian biology》2015,46(4):385-394
Incubation is an important component of avian parental care and slight changes in incubation temperature can affect offspring phenotype. Although many extrinsic and intrinsic factors may generate variation in incubation temperature, they remain underexplored under natural conditions. Using a robust data set encompassing 55 nests, 22 816 behavioral observations, and > 1 million paired ambient and egg temperatures, we describe the relationships among abiotic factors, female incubation behavior, incubation temperature, and incubation period for tree swallows Tachycineta bicolor. We report a large amount of individual variation in incubation behaviors and average incubation temperatures for our study population. The average on‐bout incubation temperature was 34.1°C, with daily egg temperatures ranging from 18.0–39.2°C. Females modulated the number of times they left the nest and the amount of time they stayed off the nest according to interactions between precipitation and temperature patterns. Models generated from our observations predicted that the number of female off‐bouts was the lowest under warm and dry conditions while more off‐bouts were taken under cold and dry or warm and wet conditions. During cold and dry conditions, females stayed off their nest ~4 times longer than under warm and dry conditions. However, this pattern was reversed under periods of rainfall; females tended to take shorter off‐bouts when it was rainy and cold compared to longer off‐bouts during warmer rain events. Furthermore, variation in female behavior was associated with differences in overall incubation temperature such that females that maintained greater incubation constancy produced higher incubation temperatures at a given ambient temperature than those that displayed lower incubation constancy. Our results provide perspective on the timing of breeding, as some of the advantages of breeding early may be countered by cooler, early season temperatures and precipitation that cause reproducing females to favor self‐maintenance at a potential cost to optimal incubation temperatures for offspring development. 相似文献
12.
Zulima González-Parrado Carmen Reyes Fuertes-Rodríguez Ana M. Vega-Maray Rosa M. Valencia-Barrera F. Javier Rodríguez-Rajo Delia Fernández-González 《Aerobiologia》2006,22(1):47-53
Winter-flowering trees such as the alder (Alnus glutinosa (L.) Gaertner) can survive periods of adverse climatic conditions, entering a period of dormancy in the early fall. The end
of dormancy and the start of the pollen season require a period of low temperatures followed by another of warm temperatures.
These requirements were studied from 1995 to 2002, in order to develop a model to predict the onset of the alder pollen season
in Ponferrada (Spain). Chilling accumulation took place from late October to late December or early January. The best result
was obtained with a threshold temperature of 6.5 °C and an average of 848 chilling hours (CH). Heat requirements were calculated
at maximum temperature, an average 143 growth degree days (GDD) were needed, with a threshold temperature of 0 °C. In order
to validate models, predicted values were compared with real values for 2002–2003, 2003–2004 and 2004–2005, years not used
in developing the models. Predictions for the pollen-season start-date differed only slightly from observed dates: in 2002–2003
predicted and observed dates were the same, in 2003–2004 there was a difference of 7 days and in 2004–2005 a difference of
3 days. 相似文献
13.
The final thermal preference FTP) range in parthenogenetic females of cladoceran Daphnia magna was assessed by “acute” and “chronic” methods. The first method included 4-month acclimation to different temperatures in
the range of 14.2 ± 0.7 to 27.1 ± 0.3°C; the “chronic” method was characterized by long-term acclimation to +20°C. Two ranges
of FTP were found for D. magna, 13.3–15.4°C and 20.2–26.2°C. The thermal preference of daphnids and the temperature of acclimation were correspondingly
linearly. The range of FTP was independent of the season. The searching activity of D. magna rose in April, when the FTP range increased, and the FTP was less pronounced. 相似文献
14.
Bruce Vondracek Wayne A. Wurtsbaugh Joseph J. Cech 《Environmental Biology of Fishes》1988,21(1):45-57
The allocation of energy to growth and reproduction, in relation to temperature and food availability, was investigated in
laboratory experiments with the mosquitofish,Gambusia affinis. At constant temperature of 20, 25 and 30°C and ad libitum feeding, specific growth rates increased with increasing temperature
at 1.7, 3.1 and 3.4% dry mass day−1, respectively. Growth rates in a cycling temperature regime (20–30°C,
) were faster than in a 25°C constant temperature. As temperature increased from 20 to 30°C, mean age at first reproduction
decreased from 191 to 56 days and brood size and mass of offspring increased significantly. Interbrood interval was also temperature
dependent; estimates at 25 and 30°C for females >1000 mg were 22.6 and 18.6 days, respectively. Interbrood interval could
not be calculated at 20°C. Although fitness was highest at 30°C, females at 25°C invested a greater proportion of surplus
energy (growth and reproduction) to reproduction (38%) than at 20 (17%) or 30°C (36%) during the 32-week study. Fish at cooler
temperatures began reproduction at a smaller size.
Where rations were controlled at low, medium, and ad libitum levels, somatic and gonadal growth increased with increasing
temperatures and food availability. The proportion of energy invested in reproduction was highest at 25°C for each comparable
ration level. Calculated energy budgets indicated that over the 10-week study, 17–22% of the food energy was invested in growth,
0–7% in reproduction, and 75–83% in respiration and excretory losses, depending on feeding and temperature conditions. 相似文献
15.
In coastal waters, Antarctic rhodophytes are exposed to harsh environmental conditions throughout the year, like low water
temperatures ranging from −1.8°C to 2°C and high light during the summer season. Photosynthetic performance under these conditions
may be affected by slowed down enzymatic reactions and the increased generation of reactive oxygen species. The consequence
might be a chronic photoinhibition of photosynthetic primary reactions related to increased fragmentation of the D1 reaction
centre protein in photosystem II. It is hypothesized that changes in lipid composition of biomembranes may represent an adaptive
trait to maintain D1 turnover in response to temperature variation. The interactive effects of high light and low temperature
were studied on an endemic Antarctic red alga, Palmaria decipiens, sampled from two shore levels, intertidal and subtidal, and exposed to mesocosm experiments using two levels of natural
solar radiation and two different temperature regimes (2–5°C and 5–10°C). During the experimental period of 23 days, maximum
quantum yield of photosynthesis decreased in all treatments, with the intertidal specimens exposed at 5–10°C being most affected.
On the pigment level, a decreasing ratio of phycobiliproteins to chlorophyll a was found in all treatments. A pronounced decrease
in D1 protein concentration occurred in subtidal specimens exposed at 2–5°C. Marked changes in lipid composition, i.e. the
ratio of saturated to unsaturated fatty acids, indicated an effective response of specimens to temperature change. Results
provide new insights into mechanisms of stress adaptation in this key species of shallow Antarctic benthic communities. 相似文献
16.
Simulated climate change impacts on fluxes of carbon in Norway spruce ecosystems along a climatic transect in Sweden 总被引:2,自引:0,他引:2
Per-Erik Jansson Magnus Svensson Dan Berggren Kleja David Gustafsson 《Biogeochemistry》2008,89(1):81-94
A simulation study based on recent regional climate scenarios for Sweden investigated possible changes in carbon (C) dynamics
and net ecosystem exchange (NEE) of Swedish Norway spruce forest ecosystems. Four sites, representative of well-drained soils
in four regions, were included. Stand development was simulated for a 100-year rotation period using a coupled model describing
abiotic and biotic processes in the soil-plant-atmosphere system. Two IPCC climate change scenarios, corresponding to a mean
annual temperature increase of about 2°C (A2) or 3°C (B2) from the reference period 1961–1990 to a new period 2061–2090, were
considered. Annual maximum snow depth decreased with the increase in air temperature, whereas maximum soil frost depth and
mean annual soil temperature showed only small changes, especially for the sites in northern Sweden. Simulations suggested
that in the warmer climate, gross primary production (GPP) increased by 24–32% in northern Sweden and by 32–43% in the south.
In the north, the increase was related to the combined effect of air and soil temperature extending the growing season, whereas
in the south it was mainly governed by increased N availability due to increased soil temperature. NEE increased by about
20% (A2) or 25% (B2) at all sites, more or less solely due to increased accumulation of C in the tree biomass (including harvest
residues), since changes in soil C were small compared with the current climate. Both light use efficiency and water use efficiency
were improved in the future climate scenarios, despite increases in atmospheric CO2 not being considered. 相似文献
17.
The west coast of Spitsbergen is influenced by water masses of Atlantic and Arctic origin. During the winter of January–April
2006, water temperatures on the West Spitsbergen Shelf were ∼3°C warmer than typical winter conditions, leading to a coastal
sea ice cover of reduced thickness, extent and duration. A sediment trap deployed from September 2005 to May 2006 in the outer
basin of Kongsfjorden (NW Spitsbergen) at a depth of 115 m has provided a continuous winter time-series of zooplankton during
a period of rapid increase in water temperatures. Prior to an anomalous and prolonged influx of warm Atlantic water (AW) starting
at the end of January, the trap samples were dominated by the boreo-Arctic copepod Metridia longa. Species that increased in abundance during the influx included late stages of Calanus finmarchicus, C. glacialis, C. hyperboreus and Paraeuchaeta norvegica. The early introduction of shelf populations into the fjord, and thus increased copepod biomass relative to typical winter
conditions with little advection, has implications for the marine pelagic food web and pelagic-benthic coupling. 相似文献
18.
The final preferable temperature (FPT) and avoidance temperature (AT) were determined in parthenogenetic females of the crustacean
Daphnia magna Strauss. The animals were preliminary acclimated to constant temperature of 23.4°C followed by keeping them in a thermo-gradient
device for 24 days. It was revealed that daphnia select FPT with overshoot. In the first four days, daphnia selected temperatures
0.6–1.6°C higher than the acclimation temperature and 4–7.4°C higher than FPT. Two zones of FPT are revealed: the first zone
by the time of 5–13 days (17.6 ± 1.2°C); the second, by 16–24 days (20 ± 1.5°C). The dynamics of AT diapason followed the
dynamics of FPT. Two zones of the AT plateau were observed: over five to 17 days (temperatures <14°C and >25.8°C were avoided)
and for 21–24 days (<8.5°C and >26°C). 相似文献
19.
Acclimation of chlorophyll biosynthetic reactions to temperature stress in cucumber (Cucumis sativus L.) 总被引:1,自引:0,他引:1
The adaptive responses of the greening process of plants to temperature stress were studied in cucumber (Cucumis sativus L. cv. Poinsette) seedlings grown at ambient (25 °C), low (7 °C) and high (42 °C) temperatures. Plastids isolated from these
seedlings were incubated at different temperatures and the net syntheses of various tetrapyrroles were monitored. In plastids
isolated from control seedlings grown at 25 °C, the optimum temperature for synthesis of Mg-protoporphyrin IX monoester or
protochlorophyllide was 35 °C. Temperature maxima for Mg-protoporphyrin IX monoester and protochlorophyllide syntheses were
shifted to 30 °C in chill-stressed seedlings. The net synthesis of total tetrapyrroles was severely reduced in heat-stressed
seedlings and the optimum temperature for Mg-protoporphyrin IX monoester or protochlorophyllide synthesis shifted slightly
towards higher temperatures, i.e. a broader peak was observed. To further study the temperature acclimation of seedlings with
respect to the greening process, tetrapyrrole biosynthesis was monitored at 25 °C after pre-heating the plastids (28–70 °C)
isolated from control, chill- and heat-stressed seedlings. In comparison to 28 °C-pre-heated plastids the percent inhibition
of protochlorophyllide synthesis in 40 °C-pre-heated plastids was higher than for the control (25 °C-grown) in chill-stressed
seedlings and lower than for the control in heat-stressed seedlings. Maximum synthesis of total tetrapyrroles and protoporphyrin
IX was observed when chloroplasts were heated at 50 °C, which was probably due to heat-induced activation of the enzymes involved
in protoporphyrin IX synthesis. Prominent shoulders towards lower or higher temperatures were seen in chill-stressed or heat-stressed
seedlings, respectively. The shift in optimum temperature for tetrapyrrole biosynthesis in chill- and heat-stressed seedlings
was probably due to acclimation of membranes possibly undergoing desaturation or saturation of membrane lipids. Proteins synthesized
in response to temperature-stress may also play an important role in conferring stress-tolerance in plants.
Received: 8 October 1998 / Accepted: 19 November 1998 相似文献
20.
Rattan Lal 《Plant and Soil》1974,40(3):589-606
Summary The effect of constant and fluctuating soil temperature and two soil moisture regimes on the growth, development, transpiration
and nutrient uptake by maize seedlings was studied in a greenhouse investigation. The constant root temperatures were maintained
at 30, 34, 35, 36, 37, and 38°C for both 250 and 750 cm of soil moisture suctions. The fluctuating root temperature, for 250
cm of soil moisture suction only, of 30–35, 30–39, 30–40, 30–45 and 30–48°C were maintained to simulate the soil temperature
regime under field conditions. The constant root temperature of 35°C and fluctuating temperature between 30–40°C significantly
decreased the shoot and root growth and transpiration rate. On the average, there was 1.3 and 0.7 g decrease in fresh shoot
weight and 0.36 and 0.30 g in fresh root weight per degree increase in root temperature for 250 and 750 soil moisture suction,
respectively. In general, the effect of high soil moisture suction on maize seedlings was more severe when at high root temperature.
The shoot and root concentration of N, P, and K decreased while that of B increased with increase in root temperature. The
root concentration of Zn also decreased with increase in root temperature. 相似文献