Comparison of canonical correlation and regression based focal point seed zones of white spruce

2006 ◽  
Vol 36 (6) ◽  
pp. 1572-1586 ◽  
Author(s):  
Mark R Lesser ◽  
William H Parker
Keyword(s):  
Canonical Correlation ◽  
Focal Point ◽  
White Spruce ◽  
Biological Traits ◽  
Climate Variables ◽  
Climate Data ◽  
Statistical Efficiency ◽  
Seed Sources ◽  
Seed Zone ◽  
Point Seed

The focal point seed zone methodology determines spatially explicit areas of adaptive similarity for any selected geographic point and is used to match seed sources and planting sites. A total of 127 seed sources (provenances) of white spruce (Picea glauca (Moench) Voss) from Ontario and western Quebec were established at a greenhouse and in six field trials throughout Ontario. Growth and phenological variables were measured over three growing seasons. Two focal point seed zone methodologies were employed: (i) using models derived from principal components analysis (PCA) of biological response variables followed by multiple linear regression against climate variables and (ii) using models derived from canonical correlation analysis (CANCOR). While both approaches use climate data to model adaptive variation, CANCOR reduces the number of steps in the analysis by simultaneously finding the relationships of biological and climatic variables that maximize the covariance between the two data sets. Although more of the variation in adaptive biological traits was actually described by climate variables using the PCA–regression approach, this method produced intuitively less realistic patterns. Both methods showed similar overall geographic trends, but the CANCOR method had a finer resolution, especially in southern Ontario, presumably due to statistical efficiency; growth was modeled by all climate variables.

Provisional breeding zone determination modeled as a maximal covering location problem

2005 ◽  
Vol 35 (5) ◽  
pp. 1173-1182 ◽  
Author(s):  
Kevin A Crowe ◽  
William H Parker
Keyword(s):  
Pinus Banksiana ◽  
Location Problem ◽  
Focal Point ◽  
Genetic Material ◽  
Common Garden ◽  
Zone Method ◽  
Maximal Covering ◽  
Trade Offs ◽  
Seed Zone ◽  
Point Seed

This study was a first attempt to model the problem of delineating breeding zones as a maximal covering location problem. The method involves two steps. First, a comprehensive set of candidate breeding zones is generated for a region using the focal point seed zone method. This method allows for control over the adaptive difference of genetic material within each zone. A grid of points is used to create the set of candidate breeding zones: one zone per point. Next, candidate zones are entered into a maximal covering location model formulated to suit this problem. The objective of this model is to select a subset of candidate zones that maximally covers the area of the region, given a limit on the number of zones to be selected and on the adaptive dissimilarity allowed within zones. Through use of this method, decision-makers can gain insight into how many breeding zones are needed to cover the region. Using different inputs from the focal point seed zone method, it is also possible to explore the trade-offs between the quantity and the quality of breeding zones. The method was tested on data from a series of jack pine (Pinus banksiana Lamb.) common garden trials of 102 seed sources from northwestern Ontario.

Focal point seed zones: site-specific seed zone delineation using geographic information systems

1992 ◽  
Vol 22 (2) ◽  
pp. 267-271 ◽  
Author(s):  
William H. Parker
Keyword(s):  
Information Systems ◽  
Geographic Information Systems ◽  
Focal Point ◽  
Geographic Information ◽  
Growth And Yield ◽  
Site Specific ◽  
Seed Zones ◽  
Individual Site ◽  
Seed Zone ◽  
Point Seed

A new site-specific approach to defining seed zones in North American conifers is described. Using focal point seed zones, an individual site to be reforested becomes the focal point, and a unique seed zone is established for that site as needed. This approach depends upon (i) obtaining good comparative data in adaptive characteristics from throughout the range to beregenerated based upon a series of short-term growth tests in a common garden and (or) greenhouse and (ii) graphic analysis of multivariate summary scores by geographic information systems software to delimit boundaries of unique seed zones for any location to be reforested. A sample focal point seed zone is delineated for jack pine (Pinusbanksiana Lamb.) reforestation of a site in northern Ontario. This approach has considerable potential to help prevent decreased growth and yield due to the planting of maladapted seed.

Regression-based focal point seed zones for Picea mariana from northwestern Ontario

1996 ◽  
Vol 74 (8) ◽  
pp. 1227-1235 ◽  
Author(s):  
William H. Parker ◽  
Annette van Niejenhuis
Keyword(s):  
Picea Mariana ◽  
Focal Point ◽  
Black Spruce ◽  
Biological Data ◽  
Adaptive Variation ◽  
Contour Maps ◽  
Seed Sources ◽  
Northwestern Ontario ◽  
Seed Zones ◽  
Point Seed

The results of a recent study of adaptive variation of black spruce in northwestern Ontario, together with additional freezing damage data, were used to produce regression-based focal point seed zones for this species. The procedure required two data bases as follows: (i) the biological data derived from two common garden growth trials, one greenhouse trial, and freezing trials of 75 black spruce seed sources and (ii) climatic data for the period 1951 – 1980. Principal components analysis (PCA) was used to summarize the main components of growth and freezing variation, and the PCA axis scores for the seed sources were regressed against climatic variables. The regression equations were used to model the patterns of adaptive variation, and these patterns were graphically reproduced as contour maps by a geographic information system (GIS). A series of focal point seed zone maps for black spruce was produced by GIS intersection of the regression-based contour maps. Focal point seed zones were more restricted in the south near Lake Superior, reflecting the more rapidly changing climate in this part of the study area. Since black spruce is closely adapted to local climate, these results will be useful to formulate successful seed transfers in this area. There are additional potential applications for matching seed sources to changing climates and for the identification of genetically unique populations. Keywords: black spruce, Picea mariana, adaptive variation, focal point seed zones.

scholarly journals Onboard Radio Frequency Interference as the Origin of Inter-Satellite Biases for Microwave Humidity Sounders

2019 ◽  
Vol 11 (7) ◽  
pp. 866 ◽  
Author(s):  
Imke Hans ◽  
Martin Burgdorf ◽  
Stefan A. Buehler
Keyword(s):  
Time Series ◽  
Radio Frequency ◽  
Time Dependent ◽  
Radio Frequency Interference ◽  
Climate Variables ◽  
Compelling Evidence ◽  
Climate Data ◽  
The Earth ◽  
Correction Scheme

Understanding the causes of inter-satellite biases in climate data records from observations of the Earth is crucial for constructing a consistent time series of the essential climate variables. In this article, we analyse the strong scan- and time-dependent biases observed for the microwave humidity sounders on board the NOAA-16 and NOAA-19 satellites. We find compelling evidence that radio frequency interference (RFI) is the cause of the biases. We also devise a correction scheme for the raw count signals for the instruments to mitigate the effect of RFI. Our results show that the RFI-corrected, recalibrated data exhibit distinctly reduced biases and provide consistent time series.

scholarly journals Modeling Seasonal Influenza Transmission and Its Association with Climate Factors in Thailand Using Time-Series and ARIMAX Analyses

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Sudarat Chadsuthi ◽  
Sopon Iamsirithaworn ◽  
Wannapong Triampo ◽  
Charin Modchang
Keyword(s):  
Relative Humidity ◽  
Moving Average ◽  
Arima Model ◽  
Southern Region ◽  
Climate Variables ◽  
Climate Data ◽  
Average Temperature ◽  
Minimum Relative Humidity ◽  
Average Maximum ◽  
Influenza Transmission

Influenza is a worldwide respiratory infectious disease that easily spreads from one person to another. Previous research has found that the influenza transmission process is often associated with climate variables. In this study, we used autocorrelation and partial autocorrelation plots to determine the appropriate autoregressive integrated moving average (ARIMA) model for influenza transmission in the central and southern regions of Thailand. The relationships between reported influenza cases and the climate data, such as the amount of rainfall, average temperature, average maximum relative humidity, average minimum relative humidity, and average relative humidity, were evaluated using cross-correlation function. Based on the available data of suspected influenza cases and climate variables, the most appropriate ARIMA(X) model for each region was obtained. We found that the average temperature correlated with influenza cases in both central and southern regions, but average minimum relative humidity played an important role only in the southern region. The ARIMAX model that includes the average temperature with a 4-month lag and the minimum relative humidity with a 2-month lag is the appropriate model for the central region, whereas including the minimum relative humidity with a 4-month lag results in the best model for the southern region.

Spatially-explicit modelling of grassland classes – an improved method of integrating a climate-based classification model with interpolated climate surfaces

2014 ◽  
Vol 36 (2) ◽  
pp. 175 ◽  
Author(s):  
Xiaoni Liu ◽  
Hongxia Wang ◽  
Jing Guo ◽  
Jingqiong Wei ◽  
Zhengchao Ren ◽  
...  
Keyword(s):  
Environmental Management ◽  
Classification Model ◽  
Spatially Explicit ◽  
Forest Steppe ◽  
Climate Variables ◽  
Climate Data ◽  
Humid Forest ◽  
Cool Temperate ◽  
Total Study Area

Spatially-explicit modelling of grassland classes is important to site-specific planning for improving grassland and environmental management over large areas. In this study, a climate-based grassland classification model, the Comprehensive and Sequential Classification System (CSCS) was integrated with spatially interpolated climate data to classify grassland in Gansu province, China. The study area is characterised by complex topographic features imposed by plateaus, high mountains, basins and deserts. To improve the quality of the interpolated climate data and the quality of the spatial classification over this complex topography, three linear regression methods, namely an analytic method based on multiple regression and residues (AMMRR), a modification of the AMMRR method through adding the effect of slope and aspect to the interpolation analysis (M-AMMRR) and a method which replaces the inverse distance-weighted approach for residue interpolation in M-AMMRR with an ordinary kriging approach (I-AMMRR), for interpolating climate variables were evaluated. The interpolation outcomes from the best interpolation method were then used in the CSCS model to classify the grassland in the study area. Climate variables interpolated included the annual cumulative temperature and annual total precipitation. The results indicated that the AMMRR and M-AMMRR methods generated acceptable climate surfaces but the best model fit and cross validation result were achieved by the I-AMMRR method. Twenty-six grassland classes were classified for the study area. The four grassland vegetation classes that covered more than half of the total study area were ‘cool temperate-arid temperate zonal semi-desert’, ‘cool temperate-humid forest steppe and deciduous broad-leaved forest’, ‘temperate-extra-arid temperate zonal desert’, and ‘frigid per-humid rain tundra and alpine meadow’. The vegetation classification map generated in this study provides spatial information on the locations and extents of the different grassland classes. This information can be used to facilitate government agencies’ decision-making in land-use planning and environmental management, and for vegetation and biodiversity conservation. The information can also be used to assist land managers in the estimation of safe carrying capacities, which will help to prevent overgrazing and land degradation.

Effects of inter-annual climate variability on grape harvest timing in rainfed hilly vineyards of Piedmont (NW Italy)

2020 ◽  
Author(s):  
Danilo Rabino ◽  
Marcella Biddoccu ◽  
Giorgia Bagagiolo ◽  
Guido Nigrelli ◽  
Luca Mercalli ◽  
...  
Keyword(s):  
Climate Variability ◽  
Weather Data ◽  
Maximum Temperature ◽  
Data Series ◽  
Positive Trend ◽  
Climate Variables ◽  
Climate Data ◽  
Historical Series ◽  
Nw Italy ◽  
Level Of Significance

<p>Historical weather data represent an extremely precious resource for agro-meteorology for studying evolutionary dynamics and for predictive purposes, to address agronomical and management choices, that have economic, social and environmental effect. The study of climatic variability and its consequences starts from the observation of variations over time and the identification of the causes, on the basis of historical series of meteorological observations. The availability of long-lasting, complete and accurate datasets is a fundamental requirement to predict and react to climate variability. Inter-annual climate changes deeply affect grapevine productive cycle determining direct impact on the onset and duration of phenological stages and, ultimately, on the grape harvest and yield. Indeed, climate variables, such as air temperature and precipitation, affect evapotranspiration rates, plant water requirements, and also the vine physiology. In this respect, the observed increase in the number of warm days poses a threat to grape quality as it creates a situation of imbalance at maturity, with respect to sugar content, acidity and phenolic and aromatic ripeness.</p><p>A study was conducted to investigate the relationships between climate variables and harvest onset dates to assess the responses of grapevine under a global warming scenario. The study was carried out in the “Monferrato” area, a rainfed hillslope vine-growing area of NW Italy. In particular, the onset dates of harvest of different local wine grape varieties grown in the Vezzolano Experimental Farm (CNR-IMAMOTER) and in surrounding vineyards (affiliated to the Terre dei Santi Cellars) were recorded from 1962 to 2019 and then related to historical series of climate data by means of regression analysis. The linear regression was performed based on the averages of maximum and minimum daily temperatures and sum of precipitation (1962–2019) calculated for growing and ripening season, together with a bioclimatic heat index for vineyards, the Huglin index. The climate data were obtained from two data series collected in the Experimental farm by a mechanical weather station (1962-2002) and a second series recorded (2002-2019) by an electro-mechanical station included in Piedmont Regional Agro-meteorological Network. Finally, a third long-term continuous series covering the period from 1962 to 2019, provided by Italian Meteorological Society was considered in the analysis.</p><p>The results of the study highlighted that inter-annual climate variability, with a general positive trend of temperature, significantly affects the ripening of grapes with a progressive anticipation of the harvest onset dates. In particular, all the considered variables excepted precipitation, resulted negatively correlated with the harvest onset date reaching a high level of significance (up to P< 0.001). Best results have been obtained for maximum temperature and Huglin index, especially by using the most complete dataset. The change ratios obtained using datasets including last 15 years were greater (in absolute terms) than results limited to the period 1962-2002, and also correlations have greater level of significance. The results indicated clearly the relationships between the temperature trend and the gradual anticipation of harvest and the importance of having long and continuous historical weather data series available.</p>

The use of mitotic index in seedling assessments

1994 ◽  
Vol 24 (11) ◽  
pp. 2222-2234 ◽  
Author(s):  
Marek J. Krasowski ◽  
John N. Owens
Keyword(s):  
Mitotic Index ◽  
Treatment Effects ◽  
White Spruce ◽  
Good Alternative ◽  
Day Length ◽  
Late Winter ◽  
Bud Break ◽  
Nursery Culture ◽  
Red Cedar ◽  
Seed Sources

The daytime pattern of mitotic index (MI) (percent of apical cells undergoing mitosis) in the shoot apex of Piceaglauca (Moench) Voss (white spruce) containerized seedlings was examined and compared for five cultural treatments. From sowing in March until mid-July, all seedlings were grown under an extended, 23-h photoperiod in a common nursery culture. In mid-July, an array of photoperiod treatments was created, ranging from ambient photoperiod and temperature to different levels of short day length and ambient or controlled, constant temperature. Consistency of MI comparisons among the treatments at different specimen collection times was emphasized rather than treatment effects on MI. Specimens were collected four times a day on two dates: when most seedlings in all treatments were initiating bud scales and when most seedlings were initiating leaf primordia. Patterns of MI were different on each of these dates. It is shown that conclusions about treatment effects on MI can be influenced by the sampling protocol and analytical approach. End of the growing season studies of white spruce and P. glauca × Piceasitchensis (Bong.) Carr. (white × Sitka spruce hybrid) seedlings grown in a greenhouse culture showed that MI below 1% was well correlated with low (<25%) foliage damage, reasonably correlated with stem tissue damage, and not correlated with bud damage resulting from controlled freezer tests to −18 °C. It is concluded that the MI technique could be useful in lifting-date determination, but different MI thresholds must be established for southern, northern, or coastal seed sources. Monitoring MI was not a good alternative to using days to bud break (testing under forcing conditions) to determine bud dormancy status. However, mitotic reactivation of the apical meristem in seedlings overwintering in a nursery bed occurred earlier in the spring than visible signs of growth reactivation (bud swelling and bud break). Studies of growth resumption of western red cedar (Thujaplicata Donn) seedlings in winter revealed that this species would be considered quiescent if tested under a long photoperiod, while under a short photoperiod growth resumption was much slower in early than in mid- and late winter.

Geographic patterns of variation in allozymes and height growth in white spruce

1991 ◽  
Vol 21 (5) ◽  
pp. 707-712 ◽  
Author(s):  
Glenn R. Furnier ◽  
Michael Stine ◽  
Carl A. Mohn ◽  
Merlise A. Clyde
Keyword(s):  
White Spruce ◽  
Allozyme Variation ◽  
Allozyme Data ◽  
Evolutionary Forces ◽  
Seed Sources ◽  
Genotype Frequencies ◽  
Provenance Test ◽  
Hardy Weinberg Equilibrium ◽  
Allozyme Loci ◽  
Height Data

Variation in height at ages 9 and 19 years and at six polymorphic allozyme loci was examined for 22 seed sources (populations) in a range-wide white spruce (Piceaglauca (Moench) Voss) provenance test planted in Minnesota. There were strong differences among populations for height, with 48.0 and 54.1 % of the genetic variation for height at ages 9 and 19, respectively, due to differences among populations. Mean observed and expected estimates of allozyme heterozygosity were 0.306 and 0.290, respectively, with little deviation from genotype frequencies expected under a Hardy–Weinberg equilibrium. In contrast with the height data, an average of only 3.8% of this variation was due to differences among populations. Geographic trends were apparent in the height data, with northern and western sources performing the poorest. Neither univariate nor multivariate analyses revealed any geographic trends in the allozyme data. The very different distributions for height and allozyme variation suggest that evolutionary forces are acting in different ways on the genes controlling these traits, and that allozyme data will have limited value in developing sampling strategies for gene conservation programs, where the preservation of germ plasm adapted to many sites throughout a species range is important.

scholarly journals Local topography increasingly influences the mass balance of a retreating cirque glacier

2018 ◽  
Author(s):  
Caitlyn Florentine ◽  
Joel Harper ◽  
Daniel Fagre ◽  
Johnnie Moore ◽  
Erich Peitzsch
Keyword(s):  
Mass Loss ◽  
Mass Balance ◽  
Regional Climate ◽  
Glacier Mass Balance ◽  
Climate Variables ◽  
Climate Data ◽  
Local Effects ◽  
Surface Mass ◽  
Average Mass ◽  
Measured Mass

Abstract. Local topographically driven processes such as wind drifting, avalanching, and shading, are known to alter the relationship between the mass balance of small cirque glaciers and regional climate. Yet partitioning such local effects apart from regional climate influence has proven difficult, creating uncertainty in the climate representativeness of some glaciers. We address this problem for Sperry Glacier in Glacier National Park, USA using field-measured surface mass balance, geodetic constraints on mass balance, and regional climate data recorded at a network of meteorological stations. Geodetically derived mass changes between 1950–1960, 1960–2005, and 2005–2014 document average mass loss rates during each period at −0.22±0.12 m w.e. yr−1, −0.18±0.05 m w.e. yr−1, and −0.10±0.03 m w.e. yr−1. A correlation of field-measured mass balance and regional climate variables closely predicts the geodetically measured mass loss from 2005–2014. However, this correlation overestimates glacier mass balance for 1950–1960 by +1.18±0.92 m w.e. yr−1. This suggests that local effects, not represented in regional climate variables, have become a more dominant driver of the net mass balance as the glacier lost 0.50 km2 and retreated further into its cirque.

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