Phenological development studies with Lupinus angustifolius and L. albus in Victoria

1977 ◽  
Vol 17 (87) ◽  
pp. 637 ◽  
Author(s):  
TG Reeves ◽  
KA Boundy ◽  
HD Brooke
Keyword(s):  
Global Radiation ◽  
Field Measurements ◽  
Lupinus Angustifolius ◽  
Floral Initiation ◽  
Flowering Period ◽  
Large Area ◽  
North Eastern ◽  
Highly Correlated ◽  
Developmental Phases ◽  
Field Plots

The effect of serial planting on the phenological development of Lupinus angustifolius (cvv. Uniwhite, Uniharvest and Unicrop) and L. albus (cv. Ultra) was investigated in field plots at north-eastern Victoria. In 1973, Uniwhite was sown at 16 weekly intervals from May to September at one site: in 1974 Uniharvest, Unicrop and Ultra were planted at four locations, from early April to late September. Duration of the developmental phases-emergence to floral initiation, initiation to first flower, and first flower to last flower-was related to field measurements of temperature, photoperiod, and global radiation. Development of all cultivars from emergence to flowering was highly correlated with temperature and photoperiod (coefficients of determination from 49.5 per cent to 98.5 per cent). Our results suggested that photoperiod contributed to the duration of the flowering period. Unicrop and Ultra were quicker to initiate and flower than Uniharvest and Uniwhite, particularly from early plantings. Later planting reduced the duration of the post-initiation phases, particularly duration of flowering. The range of developmental adaptability exhibited by the four cultivars indicates that lupins could be grown over a large area of Victoria.

The effect of grass transpiration on the air temperature

Biologia ◽  
2014 ◽  
Vol 69 (11) ◽  
Author(s):  
Miloslav Šír ◽  
Miroslav Tesař ◽  
Ľubomír Lichner ◽  
Henryk Czachor
Keyword(s):  
Air Temperature ◽  
Root Zone ◽  
Sunshine Duration ◽  
Global Radiation ◽  
Maximum Intensity ◽  
Vegetative Cover ◽  
Brown Forest Soil ◽  
Large Area ◽  
Avenella Flexuosa ◽  
Daily Total

AbstractOscillations of the air temperature and tensiometric pressure of the soil water were measured in the experimental slope Tomšovka (Czech Republic, Jizera Mts, 822 m a.s.l.). The brown forest soil (Dystric Cambisols) is covered with Calamagrostis villosa, Avenella flexuosa and Vaccinium myrtilus. Thermometers were placed at a height of 5 and 200 cm above the grassland. The tensiometer was installed in the root zone of grass at a depth of 15 cm. Oscillations in a cloudless day, August 24, 2001, (sunshine duration 12.1 hour/day, daily total of global radiation 22.4 MJ/m2/day, maximum intensity of global radiation 1008 W/m2, transpiration 13.7 MJ/m2/day) were analysed in detail. The oscillations with a period of about 30 to 60 minutes were recorded in the air temperature course taken from 11 am to 5 pm. At the height of 200 cm oscillations ranged from 24 to 28°C. Concurrently, in the depth of 15 cm, the oscillations of tensiometric pressure in the range of −6 to −11 kPa were recorded from 8 am to 4 pm. It was concluded that the oscillations in the air temperature resulted from autonomous and self-regulated oscillations in the intensity of transpiration. It is evident that the 2-m air temperature was significantly influenced by transpiration of plants around the large area. The fact that the air temperature oscillated sharply confirms that the rate of transpiration was synchronized in this area. Vegetative cover thus created a self-regulated superorganism that substantially affected the temperature of the near-ground atmosphere layer.

Predicting dry weights of pigeon-pea plants from non-destructive measurements

1977 ◽  
Vol 88 (2) ◽  
pp. 449-454 ◽  
Author(s):  
J. L. Hammerton
Keyword(s):  
Multiple Regression ◽  
Field Measurements ◽  
Dry Weight ◽  
Pigeon Pea ◽  
Stem Diameter ◽  
Predictive Equation ◽  
Plant Type ◽  
Highly Correlated ◽  
Non Destructive ◽  
Number Of Branches

SUMMARYSeven non-destructive field measurements were made on 1270 pigeon-pea plants varying widely in age, size and plant type, before determining their dry weight. The non-destructive measurements were generally highly correlated with one another, and were all significantly correlated with total, total above-ground and structural dry weights. In one experiment dry weights were best predicted by a multiple regression using stem diameter, length of longest branch and number of branches as predictors. Field height and stem diameter were the best predictors in a second trial. It is suggested that dry weights can be estimated by taking certain measurements at regular intervals, simultaneously sampling a number of plants to determine the best predictive equation. Where it is unnecessary or impracticable to do this, stem diameter appears to be the best single index of dry weight.

scholarly journals A novel injection technique: using a field-based quantum cascade laser for the analysis of gas samples derived from static chambers

2020 ◽  
Vol 13 (11) ◽  
pp. 5763-5777
Author(s):  
Anne R. Wecking ◽  
Vanessa M. Cave ◽  
Lìyĭn L. Liáng ◽  
Aaron M. Wall ◽  
Jiafa Luo ◽  
...  
Keyword(s):  
Quantum Cascade Laser ◽  
Field Measurements ◽  
Fast Response ◽  
Injection Technique ◽  
N2o Emissions ◽  
Orthogonal Regression ◽  
Quantum Cascade ◽  
The Mean ◽  
Highly Correlated ◽  
Methods Of Measurement

Abstract. The development of fast-response analysers for the measurement of nitrous oxide (N2O) has resulted in exciting opportunities for new experimental techniques beyond commonly used static chambers and gas chromatography (GC) analysis. For example, quantum cascade laser (QCL) absorption spectrometers are now being used with eddy covariance (EC) or automated chambers. However, using a field-based QCL EC system to also quantify N2O concentrations in gas samples taken from static chambers has not yet been explored. Gas samples from static chambers are often analysed by GC, a method that requires labour and time-consuming procedures off-site. Here, we developed a novel field-based injection technique that allowed the use of a single QCL for (1) micrometeorological EC and (2) immediate manual injection of headspace samples taken from static chambers. To test this approach across a range of low to high N2O concentrations and fluxes, we applied ammonium nitrate (AN) at 0, 300, 600 and 900 kg N ha−1 (AN0, AN300, AN600, AN900) to plots on a pasture soil. After analysis, calculated N2O fluxes from QCL (FN2O_QCL) were compared with fluxes determined by a standard method, i.e. laboratory-based GC (FN2O_GC). Subsequently, the comparability of QCL and GC data was tested using orthogonal regression, Bland–Altman and bioequivalence statistics. For AN-treated plots, mean cumulative N2O emissions across the 7 d campaign were 0.97 (AN300), 1.26 (AN600) and 2.00 kg N2O-N ha−1 (AN900) for FN2O_QCL and 0.99 (AN300), 1.31 (AN600) and 2.03 kg N2O-N ha−1 (AN900) for FN2O_GC. These FN2O_QCL and FN2O_GC were highly correlated (r=0.996, n=81) based on orthogonal regression, in agreement following the Bland–Altman approach (i.e. within ±1.96 standard deviation of the mean difference) and shown to be for all intents and purposes the same (i.e. equivalent). The FN2O_QCL and FN2O_GC derived under near-zero flux conditions (AN0) were weakly correlated (r=0.306, n=27) and not found to agree or to be equivalent. This was likely caused by the calculation of small, but apparent positive and negative, FN2O when in fact the actual flux was below the detection limit of static chambers. Our study demonstrated (1) that the capability of using one QCL to measure N2O at different scales, including manual injections, offers great potential to advance field measurements of N2O (and other greenhouse gases) in the future and (2) that suitable statistics have to be adopted when formally assessing the agreement and difference (not only the correlation) between two methods of measurement.

scholarly journals A novel injection technique: using a field-based quantum cascade laser for the analysis of gas samples derived from static chambers

2020 ◽  
Author(s):  
Anne R. Wecking ◽  
Vanessa M. Cave ◽  
Lìyĭn L. Liáng ◽  
Aaron M. Wall ◽  
Jiafa Luo ◽  
...  
Keyword(s):  
Quantum Cascade Laser ◽  
Field Measurements ◽  
Fast Response ◽  
Injection Technique ◽  
N2o Emissions ◽  
Orthogonal Regression ◽  
Quantum Cascade ◽  
The Mean ◽  
N2o Fluxes ◽  
Highly Correlated

Abstract. The development of fast-response analysers for the measurement of nitrous oxide (N2O) has resulted in exciting opportunities for new experimental techniques beyond commonly used static chambers and gas chromatography (GC) analysis. For example, quantum cascade laser absorption spectrometers (QCL) are now being used with eddy covariance (EC) or automated chambers. However, using a field-based QCL EC system to also quantify N2O concentrations in gas samples taken from static chambers has not yet been explored. Gas samples from static chambers are commonly analysed by GC that often requires labour and time consuming procedures off-site. Here, we developed a novel, field-based injection technique that allowed the use of a single QCL for: (1) micrometeorological EC; and (2) immediate manual injection of headspace samples taken from static chambers. To test this approach across a range of low to high N2O fluxes, we applied ammonium nitrate (AN) at 0, 300, 600 and 900 kg N ha−1 (AN0, AN300, AN600, AN900) to plots on a pasture soil. After analysis, calculated N2O fluxes from QCL (FN2O_QCL) were compared with fluxes determined by a standard method, i.e. here laboratory-based GC (FN2O_GC). Subsequent comparison of QCL and GC derived data was tested using orthogonal regression, Bland Altman and bioequivalence statistics. For the AN treated plots, the mean cumulative N2O emissions across the seven day campaign were 0.97 (AN300), 1.26 (AN600) and 2.00 (AN900) kg N2O-N ha−1 for FN2O_QCL and 0.99 (AN300), 1.31 (AN600) and 2.03 (AN900) kg N2O-N ha−1 for FN2O_GC. These FN2O_QCL and FN2O_GC were highly correlated (r = 0.996, n = 81) based on orthogonal regression, in agreement following the Bland Altman approach (i.e. within ± 1.96 standard deviations of the mean) and shown to be for all intents and purposes the same (i.e. bioequivalent). The FN2O_QCL and FN2O_GC derived under near-zero flux conditions (AN0) were weakly correlated (r = 0.306, n = 27) and not found to agree or to be bioequivalent. This was likely caused by the calculation of small but apparent positive and negative FN2O when in fact the actual flux was zero, i.e. below the detection limit of static chambers. Our study demonstrated (1) that the capability of using one QCL to measure N2O at different scales, including manual injections, offered a great potential to advance field measurements of N2O (and other greenhouse gases) in future; and (2) that suitable statistics have to be adopted when formally assessing the agreement and difference (not only the correlation) between two methods of measurement.

scholarly journals Uncertainty Problems in Image Change Detection

2019 ◽  
Vol 12 (1) ◽  
pp. 274 ◽  
Author(s):  
Wenyu Wang ◽  
Mryka Hall-Beyer ◽  
Changshan Wu ◽  
Weihua Fang ◽  
Walter Nsengiyumva
Keyword(s):  
Change Detection ◽  
Random Sampling ◽  
Stratified Sampling ◽  
Accuracy Evaluation ◽  
Commission Error ◽  
Large Area ◽  
Trade Offs ◽  
Analysis Of Results ◽  
Image Change Detection ◽  
Highly Correlated

Image Change Detection (ICD) methods are widely adopted to update large area land use/cover products. Uncertainty problems, however, are well known in such techniques, and a transparent assessment is necessary. In this study, a framework was proposed for evaluating binary land change utilizing remote sensing images. First, two widely adopted ICD methods were used to establish change maps. Second, binary decisions on Change (C) and Non-Change (NC) classes were reached through thresholding on change maps. Then, results were evaluated using two sampling designs: random sampling and stratified sampling. Analysis of results suggests that (1) for random sampling, with an increasing threshold on change variables, the overall accuracy increases and shows a large variance, which is highly correlated with the C omission error; and (2) comparatively, for stratified sampling, in which two strata (i.e., C and NC) were set, the overall accuracy shows a smaller variance and is highly associated with the NC commission error. The significant trends in accuracy assessments indicate the trade-offs between the C and NC classification errors in a binary decision and can present superficial or perfunctory accuracy evaluation in certain circumstances that the causes of error sources and uncertainty problems in ICD are not fully understood.

Field environment studies on lupins. I. Developmental patterns in Lupinus angustifolius L., the effects of cultivar, site and planting time

1975 ◽  
Vol 26 (1) ◽  
pp. 81 ◽  
Author(s):  
MW Perry ◽  
ML Poole
Keyword(s):  
Moisture Stress ◽  
Lupinus Angustifolius ◽  
Floral Initiation ◽  
Growth Phases ◽  
Developmental Patterns ◽  
Field Environment ◽  
Cool Environment ◽  
Determinate Growth ◽  
Lateral Branches ◽  
Western Australian

The development of early (Unicrop) and late (Uniharvest) flowering cultivars of Lupinus angustifolius was studied with eight planting times at two climatically contrasting sites representing the main lupin-producing areas in Western Australia. Differences in time from planting to floral initiation and from initiation to first flower, in duration of flowering, and in time of maturity were measured. The major differences in phasic development between the cultivars for the different planting times and sites were for the period from planting to initiation. This is explained in terms of the known vernalization requirement of Uniharvest. As a consequence, initiation of the two cultivars was closest with midwinter planting in the cool environment and farthest apart with eariy planting at the warmer site. For comparable planting times the differences between cultivars for the period from initiation to first flower were small. Duration of flowering and final maturity were mainly influenced by the definite end to the growing season brought on by moisture stress and high temperatures. Differences in photoperiod exerted little influence on development. Growth of the plant was indeterminate, but the presence of terminal inflorescences on the main axis and branches produced a series of easily identified orders of lateral branches. Inflorescences flowered in sequence, extending the duration of flowering as successively higher orders of laterals were formed. Late planting reduced the length of all growth phases but drastically reduced the duration of flowering. The results are discussed in relation to the Western Australian environment, and it is argued that, in such environments, indeterminate growth has potential adaptive advantage over the determinate growth pattern of the cereals.

Estimating Safe Carrying Capacities of Extensive Cattle-Grazing Properties Within Tropical, Semi-Arid Woodlands of North-Eastern Australia.

1994 ◽  
Vol 16 (1) ◽  
pp. 64 ◽  
Author(s):  
JC Scanlan ◽  
GM Mckeon ◽  
KA Day ◽  
JJ Mott ◽  
AW Hinton
Keyword(s):  
Resource Use ◽  
Carrying Capacity ◽  
Cattle Grazing ◽  
Resource Information ◽  
Eastern Australia ◽  
North Eastern ◽  
Highly Correlated ◽  
Objective Basis ◽  
Semi Arid

A methodology is presented to estimate the safe carrying capacity of properties in extensive cattle- grazing regions within tropical, semi-arid woodlands of north-eastern Australia. Carrying capacities for 45 properties were calculated from resource information collected from the properties. These calculated carrying capacities were then compared with graziers' estimates and with Queensland Department of Lands' ratings. The rated carrying capacities were not correlated with either the calculated values or the graziers' estimates, and in general were much lower than both other values. The graziers' estimates and the calculated values were highly correlated with a slope not significantly different from 1 (p>0.1). This methodology could form the basis of a review of rated carrying capacities on an objective basis. Refinements would be necessary to improve the determination of individual cases with particular emphasis on spatial variability of resource use and fine scale variability in soil fertility and tree and shrub density.

An allometric area-based approach—a cost-effective method for stand volume estimation based on ALS and NFI data

2019 ◽  
Vol 93 (3) ◽  
pp. 344-358 ◽  
Author(s):  
Jarosław Socha ◽  
Paweł Hawryło ◽  
Marcin Pierzchalski ◽  
Krzysztof Stereńczak ◽  
Grzegorz Krok ◽  
...  
Keyword(s):  
Forest Management ◽  
Scots Pine ◽  
Point Cloud ◽  
Field Measurements ◽  
Point Clouds ◽  
Volume Estimation ◽  
Linear Regression Method ◽  
Maximum Height ◽  
Stand Volume ◽  
Field Plots

Abstract Reliable information concerning stand volume is fundamental to making strategic decisions in sustainable forest management. A variety of remotely sensed data and different inventory methods have been used for the estimation of forest biometric parameters. Particularly, airborne laser scanning (ALS) point clouds are widely used for the estimation of stand volume and forest biomass using an area-based approach (ABA) framework. This method relies on the reference measurements of field plots with the necessary prerequisite of a precise co-registration between ground reference plots and the corresponding ALS samples. In this research, the allometric area-based approach (AABA) is proposed in the context of stand volume estimation of Scots pine (Pinus sylvestris L.) stands. The proposed method does not require detailed information about the coordinates of the field plots. We applied Polish National Forest Inventory data from 9400 circular field plots (400 m2) to develop a plot level stand volume allometric model using two independent variables: top height (TH) and relative spacing index (RSI). The model was developed using the multiple linear regression method with a log–log transformation of variables. The hypothesis was that, the field measurements of TH and RSI could be replaced with corresponding ALS-derived metrics. It was assumed that TH could be represented by the maximum height of the ALS point cloud, while RSI can be calculated based on the number of tree crowns delineated within the ALS-derived canopy height model. Performance of the developed AABA model was compared with the semi-empirical ABASE (with two predictors: TH and RSI) and empirical ABAE (several point cloud metrics as predictors). The models were validated at the plot level using 315 forest management inventory plots (400 m2) and at the stand level using the complete field measurements from 42 Scots pine dominated forest stands in the Milicz forest district (Poland). The AABA model showed a comparable accuracy to the traditional ABA models with relatively high accuracy at the plot (relative root mean square error (RMSE) = 22.8 per cent; R2 = 0.63) and stand levels (RMSE = 17.8 per cent, R2 = 0.65). The proposed novel approach reduces time- and cost-consuming field work required for the classic ABA method, without a significant reduction in the accuracy of stand volume estimations. The AABA is potentially applicable in the context of forest management inventory without the necessity for field measurements at local scale. The transportability of the approach to other species and more complex stands needs to be explored in future studies.

Correlation and comparison of magnetic and electric detection of small intestinal electrical activity

1997 ◽  
Vol 272 (5) ◽  
pp. G1159-G1167 ◽  
Author(s):  
L. A. Bradshaw ◽  
S. H. Allos ◽  
J. P. Wikswo ◽  
W. O. Richards
Keyword(s):  
Magnetic Fields ◽  
Quantum Interference ◽  
Rabbit Model ◽  
Field Measurements ◽  
Squid Magnetometer ◽  
Electrical Insulator ◽  
Electrode Recording ◽  
Electric Potentials ◽  
Small Intestinal ◽  
Highly Correlated

The small intestinal basic electrical rhythm (BER) was detected simultaneously with serosal electrodes and a transabdominal superconducting quantum interference device (SQUID) magnetometer in anesthetized rabbits. We induced mesenteric ischemia to correlate serosal electrode recording of changes in BER with the SQUID magnetometer. The BER frequency was obtained by spectral analysis of the data using Fourier and autoregressive techniques. There was a high degree of correlation (r = 0.96) between the BER frequency determined using the serosal electrodes and the BER frequency ascertained from SQUID data. Additionally, the effects of an electrical insulator on the external electric and magnetic fields were studied in the rabbit model. The presence of an insulator profoundly attenuates external electric potentials recorded by cutaneous electrodes but does not significantly affect external magnetic fields or serosal potentials. We conclude that SQUID magnetometers could noninvasively record small intestinal BER that was highly correlated with the activity recorded by invasive serosal electrodes. The advantages of magnetic field measurements have encouraged us to investigate clinical applications.

scholarly journals Remontant Flowering Potential of Ten Hydrangea macrophylla (Thunb.) Ser. Cultivars

HortScience ◽  
2003 ◽  
Vol 38 (7) ◽  
pp. 1337-1340 ◽  
Author(s):  
Jeffrey A. Adkins ◽  
Michael A. Dirr
Keyword(s):  
Floral Development ◽  
Floral Induction ◽  
Shoot Length ◽  
Floral Initiation ◽  
Hydrangea Macrophylla ◽  
Landscape Plants ◽  
Harvest Dates ◽  
Meristem Development ◽  
Extended Day ◽  
Highly Correlated

Floral induction of 10 Hydrangea macrophylla (Thunb.) Ser. cultivars (`All Summer Beauty', `Dooley', `Endless Summer', `Générale Vicomtesse de Vibraye', `Lilacina', `Mariesii Variegata', `Mme. Emile Mouillère', `Nikko Blue', `Penny Mac', and `Veitchii') was evaluated to determine the remontant flowering potential. Cultivars exhibiting superior flowering potential could facilitate year-round production of florist s hydrangea and expand the geographic adaptation of hydrangeas in the landscape. Plants were tested under either 8-hour inductive short-day (SD) or 24-hour noninductive extended-day (ED) photoperiods at 24 ± 2 °C. Floral induction of H. macrophylla occurred under both SD and ED but was more rapid under SD than under ED. Shoot length and total number of nodes were significantly different for cultivars, photoperiods, and harvest dates. Significant differences in the floral initiation and development were observed among cultivars. `Penny Mac', `Endless Summer', `Lilacina', `Mme. Emile Mouillère', and `Nikko Blue' displayed significantly greater floral meristem development under SD than all other cultivars. Over the nine-week period, only `Dooley', `Endless Summer', and `Penny Mac' floral development was affected significantly greater by SD photoperiods than ED photoperiods. All others cultivars showed similar floral development under SD and ED. Stage of meristem development was highly correlated with number of nodes, but not with shoot length.

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