设施番茄果实生长与环境因子的关系

在设施环境下,研究环境因子与番茄果实生长的关系,以期为设施番茄精准管理提供参考。以1h为步长,记录设施内温度、光照强度及空气湿度,每7d进行1次果径测定,将采集的环境数据细分为7个变量,分析7个变量与果实日增量随时间的变化,采用DPS软件进行逐步回归,建立显著环境因子与果实日增量的回归模型。春茬两个棚环境因子随时间动态变化规律较一致,秋茬日光温室与其有所不同。番茄品种'粉冠’和'金棚’果实日增量呈现先升高后降低的趋势,品种'珍琪’果实日增量变化波动较大。3个设施内影响果实日增量的显著环境因子有所不同,7个环境变量之间相互影响、相互制约。剔除不显著的环境变量后,建立了3个番茄品种果实日增量与显著环境变量的回归模型,确定了7个环境因子对果实生长的影响及果实生长适宜的环境变量范围。     

Spatiotemporal variability in activity patterns of urban street cattle as function of environmental factors

ABSTRACT

In the current study, we studied behavioral patterns, such as foraging, activity, standing, and laying in a population of cattle wandering on streets of Raipur city. We also determined the effects of four environmental factors (temperature, humidity, light, and noise intensities) on these behaviors. We recorded all four behavioral variables at four time points each day over a period of three consecutive days at 10 randomly selected locations using on-site human observation method, digital video, and still camera. We used Cosinor rhythmometry to analyze the time series data on all four behavioral variables. One-way ANOVA was performed to determine the impact of the factor “time of the day” on all observed behavioral variables. Pearson correlation was also employed to evaluate the relationship between the environmental and behavioral variables. Cosinor analyses revealed statistically significant 24-h rhythms in all observed behavioral variables, at the group level, with peaks of foraging, activity, standing, and laying located at 11.54 h, 14.54 h, 18.66 h, and 23.88 h, respectively. Factor “time of the day” had statistically significant effect on all observed behavioral variables. Foraging and activity were found to be positively correlated with temperature, light, and noise intensities; and negatively correlated with humidity. The laying behavior was found to be negatively associated with temperature, light, and noise intensities; and positively correlated with humidity. The findings of this study might be helpful in the management of cattle menace that has become an annoying phenomenon on the streets and highways of almost all Indian cities.     

Diurnal flight behavior of Ichneumonoidea (Insecta: Hymenoptera) related to environmental factors in a tropical dry forest

The biology and behavior of insects are strongly influenced by environmental conditions such as temperature and precipitation. Because some of these factors present a within day variation, they may be causing variations on insect diurnal flight activity, but scant information exists on the issue. The aim of this work was to describe the patterns on diurnal variation of the abundance of Ichneumonoidea and their relation with relative humidity, temperature, light intensity, and wind speed. The study site was a tropical dry forest at Ría Lagartos Biosphere Reserve, Mexico; where correlations between environmental factors (relative humidity, temperature, light, and wind speed) and abundance of Ichneumonidae and Braconidae (Hymenoptera: Ichneumonoidea) were estimated. The best regression model for explaining abundance variation was selected using the second order Akaike Information Criterion. The optimum values of temperature, humidity, and light for flight activity of both families were also estimated. Ichneumonid and braconid abundances were significantly correlated to relative humidity, temperature, and light intensity; ichneumonid also showed significant correlations to wind speed. The second order Akaike Information Criterion suggests that in tropical dry conditions, relative humidity is more important that temperature for Ichneumonoidea diurnal activity. Ichneumonid wasps selected toward intermediate values of relative humidity, temperature and the lowest wind speeds; while Braconidae selected for low values of relative humidity. For light intensity, braconids presented a positive selection for moderately high values.     

Time‐series models to quantify short‐term effects of meteorological conditions on bumblebee forager activity in agricultural landscapes

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Microevolutionary dynamics of a community of Drosophilids

The microevolutionary dynamics of a community of Drosophilids has been analysed in a western-Mediterranean locality (Bordils, NE of Spain) by comparing the daily and seasonal activities of the nine most abundant Drosophila species: D. subobscura , D. melanogaster , D. simulans , D. immigrans , D. phalerata , D. testacea , D. cameraria , D. hydei and D. picta collected during two periods widely distant in time. The resemblance between samples obtained in different months (seasonal component) has been determined and a clear-cut clustering of the collections according to the season is observed. A possible relationship between the environmental variables temperature and humidity, and the frequencies of the most abundant species in each seasonal cluster has been analysed by a correspondence analysis. This study allows to characterize each species according to its activity in definite intervals of temperature and humidity. Finally, daily and monthly activity patterns of the different species have been compared and found to be equivalent in the first and second periods. The results obtained allow the characterization of the species according to the environmental variables.     

Chronobiological background to cathemerality: circadian rhythms in Eulemur fulvus albifrons (Prosimii) and Aotus azarai boliviensis (Anthropoidea)

Cathemeral activity, in which the animals' motor activity is almost evenly distributed throughout the dark and the light portion of the day, has been described in various lemur genera (Eulemur, Hapalemur) and in the owl monkey Aotus azarai of the Argentinean Chaco. Proximate and ultimate factors responsible for this behaviour are still being debated. However, the chronobiological background of the behaviour has largely been ignored. We studied E. fulvus albifrons and A. a. boliviensis under controlled laboratory conditions to assess whether their activity rhythm is endogenously regulated by a circadian timing system that obeys general rules found in other mammals, or whether there are characteristic differences. To this end, we carried out long-term activity recordings on individuals of both subspecies kept under constant light and various light-dark cycles (LDs) using a PC-controlled electro-acoustic device in combination with telemetric body temperature measurements. Both subspecies developed free-running circadian activity and body temperature rhythms with periods deviating from 24 h in constant light, and LDs turned out to be the most efficient Zeitgeber synchronizing this endogenous rhythmicity to the external 24-hour day. The luminosity prevailing during the dark time of the LD had a decisive effect on levels of activity in the lemurs and induced strong masking effects on their circadian activity pattern. The results indicate that, from a chronobiological viewpoint, both species should be considered as dark active primates. Their diel activity rhythm is regulated by a normally responding circadian timing system and strong activity inhibiting or enhancing direct effects of light intensity. Thus, hypotheses on proximate and/or ultimate factors of cathemerality in primates must also consider its circadian background.     

Circadian variation of flight activity in colonies of Apis mellifera ligustica

The circadian oscillation of the intensity of flight activity (number of honeybees returning to the hive each minute) was registered during springtime.Bees arriving at the hive were captured, dissected, and their gut content was analysed. Three conclusions were reached from the present work. (1) Daily flight activity is confined to the warm hours when the temperature is higher than a certain threshold. (2) Flight activity shows two intensity maximums: one in the morning correlated with an increased nectar flow in the hive and another in the afternoon between 15 and 16 hr (solar time) not correlated with nectar flow (correlated with photoperiod). (3) Bees captured during the afternoon maximum were engaged in brood nursing activity. The possible significance of this photoperiodically released activity in the afternoon is discussed.     

Effects of twilights on circadian entrainment patterns and reentrainment rates in squirrel monkeys

Entrainment patterns of the circadian rhythms of body temperature and locomotor activity were compared in 6 squirrel monkeys (Saimiri sciureus) exposed to daily illumination cycles with abrupt transitions between light and darkness (LD-rectangular) or with gradual dawn and dusk transitions simulating natural twilights at the equator (LD-twilight). Daytime light intensity was 500 lux, and the total amount of light emitted per day was the same in the two conditions. Mean daytime body temperature levels were stable in LD-rectangular but increased gradually in LD-twilight, reaching peak levels during the dusk twilight. Locomotor activity showed a similar pattern, but with an additional, secondary peak near the end of dawn. Activity duration was about 0.5 h longer in LD-twilight than in LD-rectangular, but the time of activity midpoint was similar in the two conditions. Reentrainment of the body temperature rhythm was faster following an 8-h advance of the LD cycle than following an 8-h delay, but did not differ significantly between the two LD conditions. These results provide no evidence that the inclusion of twilight transitions affected the strength of the LD Zeitgeber, and suggest that the observed differences in the daily patterns reflected direct effects of light intensity on locomotor activity and body temperature rather than an effect of twilights on circadian entrainment mechanisms.Abbreviation LD light-dark     

Daily biphasic behaviour in keratin-feeding desert trogid beetles in relation to climate

Abstract. 1. Patterns of daily activity of two ectothermic species of the trogid genus Omorgus were studied in the Kalahari of southern Africa in summer. The relationship between time and type of activity, and environmental temperature, relative humidity and light intensity, was investigated.
2. Beetle activity was biphasic, with peaks in activity at sunset and sunrise in both species.
3. Afternoon activity coincided with high temperatures and low humidity and morning activity with minimum daily temperature and maximum humidity.
4. Afternoon activity, which peaked at about 34°C and 25% r.h., consisted predominantly of complex breeding behaviour and dispersal. High temperatures are necessary for these activities.
5. In the morning feeding predominated. At this time temperature was about 27°C and r.h. above 60%. High r.h. is important because it restricts respiratory loss of water, improves food (moist hair and skin keratin) quality and may compensate for faecal water loss.
6. No evidence of competition between the two species was found.     

生态因子对滇重楼花药开裂的影响

滇重楼为延龄草科重楼属植物,具有极高的药用价值,由于重楼传统药用部位生长缓慢、繁殖力低下,以及人们对野生重楼资源的过度采挖使其资源日趋枯竭。滇重楼的花药在整个花期中存在开裂－关闭的现象,花药的有效闭合应是保护花粉、延长花粉寿命、增强雄性适合度的一种适应机制。该研究以滇重楼为对象,通过设计正交实验和对比实验,观测其花药开裂过程中的光照强度、温度、湿度的变化,探究光照强度、温度、湿度等生态因子对滇重楼花药开裂的影响以及滇重楼花药开裂与生态因子变化的关系。结果表明：(1)在滇重楼花药开裂的过程中,光照强度增强、温度升高、相对湿度下降;(2)温度是影响滇重楼花药开裂时间的主导因子,升温促进花药开裂,降温促进花药关闭;(3)高湿度及黑暗推迟花药开裂,但并不能阻止花药开裂;(4)低温可使滇重楼花药持续关闭,而光照强度越高,花药持续关闭所需的温度越低。该研究有利于解释滇重楼花药白天开裂夜晚关闭的现象与环境因子的关系,对滇重楼的栽培育种提供理论指导。     

Some factors influencing the sensitivity of body temperature to activity in neonates

In adult humans, core temperature is influenced by activity; the sensitivity of core temperature to such effects shows a phase dependence and is also influenced by the environment and whether the individual is asleep or awake. We have investigated if similar effects are evident in neonates, in whom thermoregulation and the circadian rhythm of core temperature are not fully developed. Eleven full-term, healthy babies were studied singly (light 07:00-19:00) at 2 days of age and again 4 weeks after birth; between these times, they were tended routinely on a communal ward. On study days, 10-minute recordings were made of rectal and skin (abdominal) temperature, heart rate (HR), and behavioral state. Sensitivities of the temperatures to activity (“arousal”) were assessed throughout the 24h by measuring the gradient of (temperature/HR). Sensitivities measured at 01:00, 05:00, 09:00, 13:00,17:00, and 21:00 were used as dependent variables in stepwise regression and linear regression analyses, with “subjects” “light versus dark”, “behavioral state”, and “difference between time of measurement and the acrophase of the endogenous component of the temperature rhythm” (ignoring sign) as possible predictors. (Acrophases of the temperature rhythms had been estimated from 24h data purified using the behavioral state record.) Light versus dark acted as a significant predictor of the sensitivity of rectal temperature to arousal on day 2 and week 4, the sensitivity increasing in the light, and there was limited evidence for behavioral state acting as a predictor on day 2. Neither factor was a significant predictor when the sensitivity of the babies' skin temperatures to arousal was investigated. There was also some evidence that the difference between the time of measurement and the temperature acrophase acted as a predictor of sensitivity to arousal in both rectal (day 2) and skin (week 4) temperature, with larger differences decreasing the sensitivity. These results indicate that there are masking effects on body temperature due to arousal in neonates, the size of which depends on both internal and external factors. However, this sensitivity of temperature to arousal shows differences from the sensitivity of temperature to physical activity in both adult humans and adult mice. One possible explanation of this result is that temperature regulation and the circadian system are not fully developed in humans at this age. (Chronobiology International, 17(5), 679-692, 2000)     

意大利蜜蜂和小峰熊蜂在温室桃园的传粉行为及其影响因素

意大利蜜蜂Apis mellifera ligustica和小峰熊蜂Bombus hypocrita是我国设施农业中的两种主要授粉昆虫, 二者的传粉方式和传粉效率因不同作物而各有不同。为了选用最理想的蜂种为温室作物授粉, 提高作物的授粉效率, 我们于2008-2010年连续3年在北京的温室桃园进行了意大利蜜蜂和小峰熊蜂的传粉行为及其影响因素的研究。结果表明, 两种蜂的日活动规律不同, 和意大利蜜蜂相比, 小峰熊蜂的活动起点温度低、 日工作时间长、 单花访问时间长, 采集蜂在温室内距离蜂巢不同距离之间扩散比较均匀。而意大利蜜蜂采集蜂的数量随授粉半径的增大而明显减少。温室内环境因子对两种蜂传粉活动的影响基本一致, 温度对两种蜂的传粉活动影响最大, 其次是湿度、 单花花蜜浓度和光照强度, 而单花花蜜体积对蜂活动无明显影响。本研究认为对于温室桃授粉应优先选用授粉性能稳定的小峰熊蜂, 并且适当调节温室内环境条件, 以提高其授粉效率。     

A Quantitative Analysis of Secretion-Grooming Behaviour in the Water Bug Plea minutissima Leach (Heteroptera,Pleidae): Control by Abiotic Factors

The pigmy backswimmer, Plea minutissima, from time to time leaves the water to apply its antimicrobial metathoracic gland secretion to its water-repellent ventral pubescence (“secretion-grooming”) which is enclosed by an air sheath when submerged and has a respiratory function. Secretion-grooming keeps the hairs free of microbial contamination and thus hydrophobous and functional. The grooming behaviour is regulated by abiotic factors. It is released by an increase in light intensity or water temperature, with a sudden rise in temperature being particularly effective. The higher the temperature and light intensity, the faster the grooming act is performed and completed. The grooming motivation is higher at a higher ambient temperature, but declines once the behaviour has been brought to completion. As a consequence the highest grooming activity in the field is observed in summer on the first sunny day after a prolonged period of overcast days. The tying of secretion-grooming to abiotic factors probably serves to destroy epizoic microorganisms before they begin to multiply more rapidly at higher temperatures. The mechanisms regulating the secretion-grooming behaviour of Plea may be of significance also for the regulation of certain other insect behaviours (e.g., flight behaviour).     

Extrinsic and intrinsic factors influencing the emergence and return of the Asian particolored bat Vespertilio sinensis to the summer roost

Circadian rhythms play a crucial role in the health and survival of organisms. However, little is known concerning how intrinsic and extrinsic factors affect animal daily rhythms in the field, especially in nocturnal animals. Here, we investigated the first emergence, mid‐emergence, and return times of Vespertilio sinensis, and also integrated environmental conditions (temperature, humidity, and light intensity) and biotic factors (reproductive status and predation risk) to determine causes of variation in the activity rhythms of the bats. We found that variation in the first emergence time, the mid‐emergence time, and the final return time were distinct. The results demonstrated that the emergence and return times of bats were affected by light intensity, reproductive status, and predation risk in a relatively complex pattern. Light intensity had the greatest contribution to activity rhythms. Moreover, we first investigated the effects of actual predators on the activity rhythms of bats; the results showed that the mid‐emergence time of bats was earlier as predators were hunting, but the final return time was later when predators were present. Finally, our results also highlighted the importance of higher energy demands during the lactation in bats to variation in activity rhythms. These results improve our understanding of the patterns and causes of variation in activity rhythms in bats and other nocturnal animals.     

Experimental study of indoor and outdoor airborne bacterial concentrations in Tempe, Arizona, USA

Indoor and outdoor airborne bacterialconcentrations were examined in an occupiedoffice building equipped with an airconditioning (HVAC) system, in Tempe, Arizona,USA. A two-stage microbial air sampler wasused to collect bacteria both inside andoutside the office at fixed locations in space,and at regular time intervals from August toDecember, 2000. Simultaneous measurement ofbacterial concentrations, temperature, relativehumidity, light intensity and wind speed wereperformed to explore the effects ofenvironmental factors on bacteria levels. Tengenera and twenty species of airborne bacteriawere found in our samples. AirborneGram-positive bacteria were most abundant, withmore than 90% of the measured population. Theparticle sizes of most outdoor and indoorairborne bacterial aerosols were larger than8.0 μm. According to the measurements ofeither a typical day or three consecutive days,the concentrations of outdoor airborne bacteriawere highest in the morning, but declined inthe afternoon and reached the lowest point inthe evening. With regard to the effects offour environmental factors – temperature,relative humidity, light intensity, and windspeed, the relative humidity had the mostpronounced influence on the outdoor bacterialconcentration, with the number of bacteriaincreasing sharply on a day of high relativehumidity.     

SOME FACTORS INFLUENCING THE SENSITIVITY OF BODY TEMPERATURE TO ACTIVITY IN NEONATES

In adult humans, core temperature is influenced by activity; the sensitivity of core temperature to such effects shows a phase dependence and is also influenced by the environment and whether the individual is asleep or awake. We have investigated if similar effects are evident in neonates, in whom thermoregulation and the circadian rhythm of core temperature are not fully developed. Eleven full-term, healthy babies were studied singly (light 07:00–19:00) at 2 days of age and again 4 weeks after birth; between these times, they were tended routinely on a communal ward. On study days, 10-minute recordings were made of rectal and skin (abdominal) temperature, heart rate (HR), and behavioral state. Sensitivities of the temperatures to activity (“arousal”) were assessed throughout the 24h by measuring the gradient of (temperature/HR). Sensitivities measured at 01:00, 05:00, 09:00, 13:00,17:00, and 21:00 were used as dependent variables in stepwise regression and linear regression analyses, with “subjects” “light versus dark”, “behavioral state”, and “difference between time of measurement and the acrophase of the endogenous component of the temperature rhythm” (ignoring sign) as possible predictors. (Acrophases of the temperature rhythms had been estimated from 24h data purified using the behavioral state record.) Light versus dark acted as a significant predictor of the sensitivity of rectal temperature to arousal on day 2 and week 4, the sensitivity increasing in the light, and there was limited evidence for behavioral state acting as a predictor on day 2. Neither factor was a significant predictor when the sensitivity of the babies' skin temperatures to arousal was investigated. There was also some evidence that the difference between the time of measurement and the temperature acrophase acted as a predictor of sensitivity to arousal in both rectal (day 2) and skin (week 4) temperature, with larger differences decreasing the sensitivity. These results indicate that there are masking effects on body temperature due to arousal in neonates, the size of which depends on both internal and external factors. However, this sensitivity of temperature to arousal shows differences from the sensitivity of temperature to physical activity in both adult humans and adult mice. One possible explanation of this result is that temperature regulation and the circadian system are not fully developed in humans at this age. (Chronobiology International, 17(5), 679–692, 2000)     

Effects of diazepam on the behaviour of weaned pigs in three putative models of anxiety

The present study examined the effects of diazepam (a widely used anxiolytic benzodiazepine) on the behavioural response of pigs to three novel experimental situations used to measure anxiety-related behaviour in rodents. Twelve weaned pigs (two pairs from each of the three litters) were tested in an elevated plus-maze at the age of 6 weeks, a light/dark test at the age of 7 weeks and an open-field test at the age of 8 weeks. Six of the pigs were pre-treated with diazepam (valium) and the other six with saline (control). In the elevated plus-maze, diazepam-treated pigs had a higher number of entries into open arms (P=0.04), spent more time on open arms (P=0.07), and had a higher number of total arm entries (P=0.05) than pigs from the control group. However, diazepam had no significant effects on behaviour in the light/dark test (i.e., latency to enter lit compartment, number of entries into lit compartment and the time spent in lit compartment) or the open-field test (i.e., number of lines crossed, number of entries into centre). In summary, the anxiolytic effects of diazepam on the pigs' behaviour were only demonstrated in the elevated plus-maze, where the time spent on open arms and the number of entries into open arms could be interpreted as measures of anxiety in pigs.     

Effects of meteorological factors on defensive behaviour of honey bees

The defensive behaviour of honey bee colonies (Apis mellifera L.) was quantitated in the field throughout a three month season by the use of a standardized test in which numbers of stings in a leather target were counted after single colonies were opened and exposed to alarm pheromone. The main results show how the defensive behaviour of honey bees is highly dependent on weather factors. Eliminating genetic variance, the following meteorological variables account for 92.4% of the variation in defensive behaviour: air temperature, solar radiation intensity, wind velocity, relative humidity, and barometric pressure.     

Effect of formic acid formulations on honey bee (Hymenoptera: Apidae) colonies and influence of colony and ambient conditions on formic acid concentration in the hive

The interaction between the effects of varroa, Varroa destructor Anderson & Trueman, and formic acid treatments on colonies of honey bees, Apis mellifera L., were examined in two field experiments. In experiment 1, colonies with low varroa levels were exposed to two different slow-release formulations and compared with untreated colonies. In experiment 2, colonies inoculated with varroa and uninoculated colonies were exposed to a slow-release formulation, a pour-on formulation, or were left untreated. The effects of treatments, hive temperature, and hive relative humidity on formic acid concentration in hive air also were examined. Slow-release formic acid application improved colony development in colonies that had been inoculated with varroa. However, in uninoculated colonies where the mean abundance of varroa was low, slow-release formic acid application suppressed colony development. The pour-on application did not have a negative impact on worker population growth in uninoculated colonies, but also it was not as effective as the slow-release treatment in improving population growth in varroa-inoculated colonies. Equivalent volumes of acid applied in pour-on and slow-release formulations provided the same cumulative dose in hive air but differed in the daily pattern of formic acid release. Colonies that were not inoculated with varroa had higher concentrations of formic acid in hive air than colonies that were inoculated with varroa on three of the five pour-on application dates. The data suggest that reductions in worker population and/or activity caused by varroa can interact with ambient conditions to affect the volatilization or sorption of formic acid in the hive.     

Anthesis and pollen dispersal of holcus lanatus L. and Festuca rubra L. in relation to climate factors

Anthesis and pollen dispersal of H. lanatus and F. rubra were related to climate factors during a field investigation on Schiermonnikoog. In both species the anthesis showed a diurnal periodicity and could be connected to air temperature, relative air humidity, and light intensity. In the pollen release of both species no daily periodicity was found. This pollen release appears to be dependent on neither the temperature nor the light intensity. It could be related to only one of the measured climate factors, viz. the relative air humidity. It was discussed that anthesis is an active process based on physiological and ecological properties of the plant, whereas the pollen dispersal is only a mechanical process.