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1.
Meteorological weather station data are often used in climate matching studies to predict potential distributions of biological control agents, yet, this does not take into account the effects of microclimates experienced by the agents. Comparisons of the number of generations that the mirid, Eccritotarsus catarinensis, a biological control agent of water hyacinth, Eichhornia crassipes (Mart.) Solms-Laub (Pontederiaceae), was predicted to complete using meteorological weather station data, on site air temperature and water hyacinth canopy microclimate temperatures recorded over two years showed that there were no significant differences between the temperature data sources. Therefore, meteorological weather station data used in degree-day models of biological control agents are useful in explaining broad establishment patterns.  相似文献   

2.
Evaluation of several degree-day estimation methods in California climates   总被引:1,自引:0,他引:1  
 Procedures for estimating degree-day accumulations are frequently employed instead of the more accurate method of calculating degree-days from hourly temperature data because on-site temperature data are commonly restricted to daily minimum and maximum temperature records. Data from seven methods of estimating degree-days at each of nine locations during 2 years in California were compared by month to degree-day values calculated by hourly summation. Methods included three sine-wave approaches, three triangulation approaches and the averaging (i.e., rectangle) method. Results of the double-sine and corrected-sine (i.e., corrected for day length) methods were nearly identical to those of the single-sine method. The double triangulation and corrected triangulation methods produced very similar results to the single triangulation method. The averaging method and sine-wave methods deviated to a greater extent from degree-day accumulations calculated from hourly temperatures from November through February than did the triangulation methods. Degree-day estimations from the late spring and summer months were more similar to one another for all estimation methods than during the cooler months of the year. Since no advantages were noted in the more complicated double and corrected methods, the single triangulation method or the sine-wave method is preferred as they are less complicated procedures. Of the various temperature threshold cut-off methods evaluated, error levels were unaffected when estimating degree-days using the sine-wave method. The employment of a horizontal cut-off with the triangulation method did not significantly increase the amount of error in the estimation of degree-days. However, an increase in error was observed when employing the intermediate cut-off and vertical threshold cut-off techniques with the triangulation method for computing degree-days. Received: 26 May 1998 / Accepted: 28 October 1998  相似文献   

3.
有效积温Sine函数拟合模型及其应用   总被引:2,自引:0,他引:2  
阐述了昆虫物候分析的SSPM模型(single sine phonological model)计算方程和过程,该模型采用Sine函数拟合每天温度变化,并利用积分,获取每天有效积温和一定时间内日度累积值.SSPM重要的参数有发育起点温度和上限温度,参与模型计算包括日最高气温和日最低气温2个输入值,在输入值和参数值组合条件下,模型有6个不同计算方程.以棉铃虫(Helicoverpa armigera)为例,介绍了SSPM在昆虫发育历期分析过程,简单表述了模型预测功能.随自动化气象站分布密度增加和Internet技术的发展,模型在区域化害虫管理中有着重要的应用前景.  相似文献   

4.
Scirpophaga incertulas (Walker) (Lepidoptera: Pyralidae) is autochthonous and monophagous on rice, Oryza spp., which favors the development of a physiological time model using degree-days (degrees C) to establish a well defined window during which adults will be present in fields. Model development of S. incertulas adult flight phenology used climatic data and historical field observations of S. incertulas from 1962 through 1988. Analysis of variance was used to evaluate 5,203 prospective models with starting dates ranging from 1 January (day 1) to 30 April (day 121) and base temperatures ranging from -3 through 18.5 degrees C. From six candidate models, which shared the lowest standard deviation of prediction error, a model with a base temperature of 10 degrees C starting on 19 January was selected for validation. Validation with linear regression evaluated the differences between predicted and observed events and showed the model consistently predicted phenological events of 10 to 90% cumulative flight activity within a 3.5-d prediction interval regarded as acceptable for pest management decision making. The degree-day phenology model developed here is expected to find field application in Guandong Province. Expansion to other areas of rice production will require field validation. We expect the degree-day characterization of the activity period will remain essentially intact, but the start day may vary based on climate and geographic location. The development and validation of the phenology model of the S. incertulas by using procedures originally developed for pecan nut casebearer, Acrobasis nuxvorella Neunzig, shows the fungibility of this approach to developing prediction models for other insects.  相似文献   

5.
Developmental models that account for the metabolic effect of temperature variability on poikilotherms, such as degree-day models, have been widely used to study organism emergence, range and development, particularly in agricultural and vector-borne disease contexts. Though simple and easy to use, structural and parametric issues can influence the outputs of such models, often substantially. Because the underlying assumptions and limitations of these models have rarely been considered, this paper reviews the structural, parametric, and experimental issues that arise when using degree-day models, including the implications of particular structural or parametric choices, as well as assumptions that underlie commonly used models. Linear and non-linear developmental functions are compared, as are common methods used to incorporate temperature thresholds and calculate daily degree-days. Substantial differences in predicted emergence time arose when using linear versus non-linear developmental functions to model the emergence time in a model organism. The optimal method for calculating degree-days depends upon where key temperature threshold parameters fall relative to the daily minimum and maximum temperatures, as well as the shape of the daily temperature curve. No method is shown to be universally superior, though one commonly used method, the daily average method, consistently provides accurate results. The sensitivity of model projections to these methodological issues highlights the need to make structural and parametric selections based on a careful consideration of the specific biological response of the organism under study, and the specific temperature conditions of the geographic regions of interest. When degree-day model limitations are considered and model assumptions met, the models can be a powerful tool for studying temperature-dependent development.  相似文献   

6.
Field observations at three locations in the Texas High Plains were used to develop and validate a degree-day phenology model to predict the onset and proportional emergence of adult Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae) adults. Climatic data from the Texas High Plains Potential Evapotranspiration network were used with records of cumulative proportional adult emergence to determine the functional lower developmental temperature, optimum starting date, and the sum of degree-days for phenological events from onset to 99% adult emergence. The model base temperature, 10 degrees C (50 degrees F), corresponds closely to known physiological lower limits for development. The model uses a modified Gompertz equation, y = 96.5 x exp (-(exp(6.0 - 0.00404 x (x - 4.0), where x is cumulative heat (degree-days), to predict y, cumulative proportional emergence expressed as a percentage. The model starts degree-day accumulation on the date of corn, Zea mays L., emergence, and predictions correspond closely to corn phenological stages from tasseling to black layer development. Validation shows the model predicts cumulative proportional adult emergence within a satisfactory interval of 4.5 d. The model is flexible enough to accommodate early planting, late emergence, and the effects of drought and heat stress. The model provides corn producers ample lead time to anticipate and implement adult control practices.  相似文献   

7.
The objective of this work was to develop and evaluate agrometeorological models to simulate the production of Guineagrass. For this purpose, we used forage yield from 54 growing periods between December 2004–January 2007 and April 2010–March 2012 in irrigated and non-irrigated pastures in São Carlos, São Paulo state, Brazil (latitude 21°57′42″ S, longitude 47°50′28″ W and altitude 860 m). Initially we performed linear regressions between the agrometeorological variables and the average dry matter accumulation rate for irrigated conditions. Then we determined the effect of soil water availability on the relative forage yield considering irrigated and non-irrigated pastures, by means of segmented linear regression among water balance and relative production variables (dry matter accumulation rates with and without irrigation). The models generated were evaluated with independent data related to 21 growing periods without irrigation in the same location, from eight growing periods in 2000 and 13 growing periods between December 2004–January 2007 and April 2010–March 2012. The results obtained show the satisfactory predictive capacity of the agrometeorological models under irrigated conditions based on univariate regression (mean temperature, minimum temperature and potential evapotranspiration or degreedays) or multivariate regression. The response of irrigation on production was well correlated with the climatological water balance variables (ratio between actual and potential evapotranspiration or between actual and maximum soil water storage). The models that performed best for estimating Guineagrass yield without irrigation were based on minimum temperature corrected by relative soil water storage, determined by the ratio between the actual soil water storage and the soil water holding capacity.irrigation in the same location, in 2000, 2010 and 2011. The results obtained show the satisfactory predictive capacity of the agrometeorological models under irrigated conditions based on univariate regression (mean temperature, potential evapotranspiration or degree-days) or multivariate regression. The response of irrigation on production was well correlated with the climatological water balance variables (ratio between actual and potential evapotranspiration or between actual and maximum soil water storage). The models that performed best for estimating Guineagrass yield without irrigation were based on degree-days corrected by the water deficit factor.  相似文献   

8.
The phenology of oriental fruit moth, Grapholita molesta (Busck), on apple (Malus spp.) in North Carolina was studied using pheromone traps and egg sampling in abandoned and commercial orchards in 2000 and 2001, with subsequent development of an oviposition degree-day model and management studies in relation to codling moth, Cydia pomonella (L.), phenology. Oriental fruit moth eggs were found in greater numbers on leaves early and on fruit later in the growing season, on the top versus the bottom of the leaf surface, and on the calyx area versus the side or stem end of the fruit. A degree-day (DD) model to predict oriental fruit moth oviposition was developed based on temperature accumulations from peak moth trap capture of the first (overwintering) generation, by using 7.2 and 32.2 degrees C as the temperature limits. The model predicted four ovipositing generations of oriental fruit moth with the second beginning 507 DD after peak moth catch. Using predictions of the oriental fruit moth and codling moth degree-day oviposition models, an experiment was conducted to determine the level of second generation oriental fruit moth control with methoxyfenozide applied under different scenarios for first generation codling moth. Methoxyfenozide was equally effective in managing codling moth and oriental fruit moth for all treatment timings.  相似文献   

9.
Although using hourly weather data offers the greatest accuracy for estimating growing degree-day values, daily maximum and minimum temperature data are often used to estimate these values by approximating the diurnal temperature trends. This paper presents a new empirical model for estimating the hourly mean temperature. The model describes the diurnal variation using a sine function from the minimum temperature at sunrise until the maximum temperature is reached, another sine function from the maximum temperature until sunset, and a square-root function from then until sunrise the next morning. The model was developed and calibrated using several years of hourly data obtained from five automated weather stations located in California and representing a wide range of climate conditions. The model was tested against an additional data-set at each location. The temperature model gave good results, the root-mean-square error being less than 2.0 °C for most years and locations. The comparison with published models from the literature showed that the model was superior to the other methods. Hourly temperatures from the model were used to calculate degree-day values. A comparison between degree-day estimates determined from the model and those obtained other selected methods is presented. The results showed that the model had the best accuracy in general regardless of the season. Received: 25 October 2000 / Revised: 2 July 2001 / Accepted: 2 July 2001  相似文献   

10.
A degree-day model was derived to predict egg hatch for Criconemella xenoplax. Eggs collected from gravid females were incubated in distilled water at constant temperatures of 10-35 C. Sixty-six percent of all eggs hatched between 13 and 32 C, and 42% hatched at 10 C. All eggs aborted above 32.5 C. Between 25 and 32 C, 8.5 ± 0.5 days were required for egg hatch. Degree-day requirement for egg hatch at 10-30 C was estimated to be 154 ± 5 with a base of 9.03 ± 0.04 C. This base of 9 C was adopted in studies of the relationship between degree-days and nematode population increase on Prunus seedlings grown 9-11 weeks in a greenhouse. Degree-day accumulations were based upon daily averages from maximum and minimum air temperatures. Ratios of final to initial population densities exhibited an exponential pattern in relation to degree-day accumulations with proportionate doubling increment of 0.100 ± 0.049 every 139 ± 8 degree-days. These results provide a means of predicting nematode population increase under greenhouse conditions and a basis for choosing sampling intervals when evaluating nematode multiplication.  相似文献   

11.
To address the lack of physiological approaches in current models assessing the potential distribution of the Argentine ant, we used data on brood development from distinct sources to evaluate a series of degree-day models for Catalonia (NE Iberian Peninsula), and data on the brood survival and oviposition rates to develop a worker production model. The degree-day model generated using data from Newell and Barber (1913) and Benois (1973) indicated that the number of degree-days required for the complete development from egg to adult worker was 445.4 degree-days above a threshold of 15.9 °C, while the model calibrated using data from Abril et al. (2008, in press) suggested 599.5 degree-days above 18.4 °C. Comparisons between the degree-day model predictions and the currently known distribution of the Argentine ant suggested that the one generated using data from Newell and Barber (1913) and Benois (1973) overestimated the presence of the species, while the one calibrated using data from Abril et al. (2008; in press) underestimated it. On the other hand, the predicted daily net production of Argentine ant workers generated by the worker production model predicted more accurately the distribution of the Argentine ant than the degree-day models. Our results show the utility of incorporating physiological data in models to assess the distribution limits of the Argentine ant, which up to date have taken little account of the physiological needs of the species in terms of its establishment and dispersion in its introduced ranges.  相似文献   

12.
The phenology of Lacanobia subjuncta (Grote & Robinson) (Lepidoptera: Noctuidae) was investigated in 30 apple orchards in central Washington state and northeastern Oregon from 1998 to 2001 (57 total orchard-yr). Adult captures in pheromone-baited traps were fit to a Weibull distribution to model emergence of the first and second generations. Initial capture of first generation adults was observed at 216.2 +/- 2.6 degree-days (DD) (mean +/- SEM) from 1 March by using a base temperature of 6.7 degrees C. The model predicted that flight was 5 and 95% complete by 240 and 700 degree-days (DD), respectively. Monitoring of oviposition and hatch was used to establish a protandry plus preoviposition degree-day requirement of 160.0 +/- 7.7 DD, as well as to provide data to describe the entire hatch period. Egg hatch was 5 and 95% complete by 395 and 630 DD, respectively. The start of the second flight was observed at 1217.1 +/- 8.3 DD by using an upper threshold for development of 32 degrees C and a horizontal cutoff. The model indicated that the second flight was 5 and 95% complete by 1220 and 1690 DD, respectively. Second generation hatch was 5 and 95% complete by 1440 and 1740 DD, respectively. A discussion of the potential uses of these detailed phenology data in optimizing management strategies is presented.  相似文献   

13.
在温带和寒冷地区,春季植被物候的变化普遍受温度影响。然而,在寒冷地区的干旱/半干旱生态系统中,温度对物候的影响仍难以捉摸,因为土壤水分状况有调节物候的重要作用。利用生长度日(growing degree day, GDD)和生长季节指数(growing season index, GSI)模型,对最低温度(minimum daily temperature, Tmin)与土壤水分(daily soil moisture, SM)进行耦合,探索热量需求和水文气候交互作用对青藏高原(QTP)两个不同降水状况的高寒草甸生态系统碳吸收期开始日期(start of carbon uptake period, SCUP)和净生态系统初级生产力(net ecosystem productivity, NEP)的影响。其中,一种是水分限制的高寒草原草甸生态系统,另一种是温度限制的高寒灌丛草甸生态系统。GDD模型和GSI模型与SCUP明显相关联:在湿润的高寒灌丛草甸生态系统中,SCUP对生长季前GDD和GSI的变化同样敏感;而在半干旱高寒草原草甸生态系统中,与GDD相比,SCUP对生长季前GSI的变化更敏感。这些不同模式表明,限制SCUP的气候因子由温度和水分有效性的平衡来决定。在湿润的高寒草甸生态系统中,在不受干旱胁迫的情况下,较高的SCUP温度敏感性可以最大化热效益,正如观察到的SCUPs与GDD模型模拟具有较高的线性相关系数(R2)和AIC。而在半干旱的草原化草甸中,较高的SCUP水分敏感性可以最大化水分效益,正如观测到的SCUPs与GSI模型模拟具有较高的R2和AIC。此外,虽然在高寒灌丛草甸生态系统中SCUPs由GDD决定,但两个高寒草甸生态系统NEP均受累积GSI控制。本研究重点强调湿润和半干旱高寒草甸生态系统水文气候交互作用对春季碳通量物候和植被生产力的影响;揭示半干旱地区高寒草甸生态系统物候和碳平衡模型中应该包括温度和水分条件。这些结果对改善植被物候模型具有重要意义,从而加深我们对将来植被物候、生产力和气候变化相互作用的理解。  相似文献   

14.
通过对祁连山中部葫芦沟流域的祁连圆柏连续采集微树芯,对其形成层活动和径向生长动态进行了连续两年的监测研究。结果表明,2012年细胞壁加厚和细胞成熟阶段开始时间分别发生在6月26日和7月24日,比2013年细胞壁加厚(6月22日)和细胞成熟阶段(6月26日)开始时间分别晚5 d和28 d。2012年细胞扩大、细胞壁加厚和细胞成熟阶段结束时间分别为7月16日、8月9日和9月8日,比2013年各阶段结束时间分别晚7、28 d和24 d。2012年最大细胞分裂速率为0.33细胞/d,共形成20.9个细胞,细胞分裂速率和木质部细胞总数均高于2013年。通过与附近气象站记录的气象数据进行对比,发现祁连圆柏生长开始时间在温暖年份显著早于寒冷年份,说明祁连圆柏的径向生长开始时间与温度有关。但2013年春季和夏初的高温导致区域干旱程度加剧,使祁连圆柏生长结束时间显著早于2012年,并导致2013年的木质部细胞总量和生长速率都小于2012年。研究表明,在寒冷干旱地区,尽管升温会使生长季提前,但升温导致的干旱胁迫可能对树木的生长速率和木质部细胞总量产生重要影响。  相似文献   

15.
Dakota skipper (Hesperia dacotae Skinner) and Poweshiek skipperling (Oarisma poweshiek Parker) (Lepidoptera: Hesperiidae) are endemic prairie species that are threatened in Canada. Surveys during the brief adult flight period are necessary to quantify population sizes, but dates of adult emergence vary widely from year to year (up to 24 days) and populations are geographically distant from one another (150–250 km). To predict adult emergence of H. dacotae and O. poweshiek, we used local weather station data to calculate the number of degree days accumulated between March 1 and adult emergence using two different models in seven different years between 2002 and 2013. We also compared the number of degree days accumulated at the soil surface where larvae and pupae reside to those accumulated using weather station data. We recommend that surveys for Dakota skipper begin when degree day accumulations (from weather stations) reach a threshold of 575 (standard model) or 600 (double sine model) in the south central portion of Manitoba and 550 (standard model) or 575 (double sine model) in the southwest region of Manitoba. For Poweshiek skipperling surveys should be considered after degree day accumulations reach 575 (standard model) or 625 (double sine model). Degree days accumulated at the soil surface were 20–30 % greater than those calculated using weather station data in Dakota skipper sites, and 1–12 % greater in Poweshiek skipperling sites. Using our models, we predicted adult emergence to within 48 h of emergence in 2011, 2012 and 2013.  相似文献   

16.
Synopsis Successful production of young in smallmouth bass,Micropterus dolomieui, nests varied between 33 and 88 percent over two years. Six variables were measured at each successful smallmouth bass nest. Discriminant analysis indicated that the combined influences of these variables differed between years. Canonical coefficients determined that hours of strong wind followed by degree-days contributed to the observed difference. Nest success was higher when the total hours of wind stronger than Beaufort force 4 was low during offspring development. Higher degree-day values during offspring development were recorded in the more successful year.  相似文献   

17.
Developmental thresholds, degree-days for development, larval weights, and head capsule widths for each larval instar and the pupal stage of Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae) were studied at eight constant temperatures (5, 10, 15, 20, 25, 30, 35, and 40°C) for two source populations (Ravenswood, Chicago, IL [IL], and Bayside, Queens, NY [NY]). The estimated lower threshold temperature for development of instars 1-5 and the pupal stage was near 10°C and was near 12°C for the higher instars. Developmental rate was less temperature sensitive for instars 5-9 compared with instars 1-4. Development for all but the first instar was inhibited at constant temperatures >30°C, and all instars failed to develop at 40°C. Although the two source populations had similar responses to temperature, IL larvae were heavier than those from NY. Temperature and its influence on larval weight had profound impacts on whether a larva proceeded to pupation. Based on the temperature effects detailed here, larval development and pupation should be possible in most of the continental United States where suitable hosts are available. These data can be used to develop a degree-day model to estimate beetle phenology; however, at least 2°C should be added to air temperatures to adjust for the mediation of temperature by the wood. These data provide a basis for predicting the potential geographical range of this species and for developing phenological models to predict the timing of immature stages, both of which are important for management programs.  相似文献   

18.
Leaf phenology dictates the time available for carbon assimilation, transpiration and nutrient uptake in plants. Understanding the environmental cues that control phenology is therefore vital for predicting climate‐related changes to plant and ecosystem function. In contrast to temperate systems, and to a lesser degree, tropical forest systems, the cues initiating leaf drop in tropical savannas are poorly studied. We investigated the cues for leaf fall in a tropical monodominant arid savanna species, Colophospermum mopane, using an irrigation experiment. We tracked soil moisture, solar radiation, air temperature, leaf water status, leaf health and leaf carbon balance through the dry season in both irrigated and control plants. Water was the primary cue driving leaf loss of C. mopane rather than temperature or light. Trees watered throughout the dry season retained their canopies. These leaves remained functional and continued photosynthesis throughout the dry season. Leaf carbon acquisition rates did not decline with leaf age but were affected by soil moisture availability and temperature. Leaf loss did not occur when leaf carbon gain was zero, or when a particular leaf carbon threshold was reached. Colophospermum mopane is facultatively deciduous as water availability determines leaf drop in this widespread arid savanna species. Obligate deciduosity is not the only successful strategy in climates with a long dry season.  相似文献   

19.
Phenological models based on degree-day accumulation have been developed to support the integrated pest management of many insects. Most of these models are based on linear relationships between temperature and development, and on daily time step simulations using daily minimum and maximum temperatures. This approach represents an approximation that does not take into account the insect physiological response to temperature, and daily temperature fluctuations. The objective of this work has been to develop a phenological model for the European corn borer (ECB) based on the insect physiological response to temperature and running at an hourly time step. Two modeling solutions based on the same generic compartmental system have been compared: the first based on a physiologically based relationship between temperature and development, and using hourly derived temperatures as input (HNL modeling solution); and the second based on a linear relationship between temperature and degree-day accumulation and using daily temperature (DL modeling solution). The two approaches have been compared using ECB moth capture data from the Piemonte region in Northern Italy. The HNL modeling solution showed the best results for all the accuracy indicators. The DL modeling solution showed a tendency to anticipate ECB phenological development too early. This tendency is attributable to the linear relationship between temperature and development, which does not take into account (1) the decline of this relationship at high temperatures, and (2) the daily fluctuation of temperature. As a consequence, degree-days accumulation is accelerated in the DL modeling solution and the phenological development anticipated.  相似文献   

20.
Global warming has created a need for studies along climatic gradients to assess the effects of temperature on ecological processes. Altitudinal and latitudinal gradients are often used as such, usually in combination with air temperature data from the closest weather station recorded at 1.5–2 m above the ground. However, many ecological processes occur in, at, or right above the soil surface. To evaluate how representative the commonly used weather station data are for the microclimate relevant for soil surface biota, we compared weather station temperatures for an altitudinal (500–900 m a.s.l.) and a latitudinal gradient (49–68°N) with data obtained by temperature sensors placed right below the soil surface at five sites along these gradients. The mean annual temperatures obtained from weather stations and adjusted using a lapse rate of ?5.5°C km?1 were between 3.8°C lower and 1.6°C higher than those recorded by the temperature sensors at the soil surface, depending on the position along the gradients. The monthly mean temperatures were up to 10°C warmer or 5°C colder at the soil surface. The within‐site variation in accumulated temperature was as high as would be expected from a 300 m change in altitude or from a 4° change in latitude or a climate change scenario corresponding to warming of 1.6–3.8°C. Thus, these differences introduced by the decoupling are significant from a climate change perspective, and the results demonstrate the need for incorporating microclimatic variation when conducting studies along altitudinal or latitudinal gradients. We emphasize the need for using relevant temperature data in climate impact studies and further call for more studies describing the soil surface microclimate, which is crucial for much of the biota.  相似文献   

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