Leaf Variability in Yellow Birch (Betulaalleghaniensis) in Relation to Environment

1975 ◽  
Vol 5 (2) ◽  
pp. 149-159 ◽  
Author(s):  
Bruce P. Dancik ◽  
Burton V. Barnes
Keyword(s):  
Leaf Morphology ◽  
Climatic Conditions ◽  
Canonical Variate ◽  
Multivariate Techniques ◽  
Yellow Birch ◽  
Phenotypic Characters ◽  
Wide Range ◽  
Canonical Variates ◽  
Leaf Variation ◽  
Prim Network

Four multivariate techniques were used to analyze 13 characteristics of standard leaves of 809 yellow birches in 112 populations on selected site types in the western upper Great Lakes region to determine the variability in leaf morphology of yellow birch and to elucidate patterns of leaf variation related to differences in the sites on which the birches grew. There were significant among-population differences for each of the leaf characters, but there were no consistent groupings of the populations based on several single-character analyses. There was a significant canonical correlation between leaf morphology and the site conditions of the populations. Principal components and Prim network analysis indicated groupings of the populations that were related to ecological conditions of the sites. Of all methods used, canonical variates were the most biologically meaningful and revealed the strongest relationship between morphology and environment. The populations were arranged on canonical variate axes along natural gradients of soil pH, relative drainage, or climatic conditions of the site. The phenotypic characters may be under genetic control and probably have evolved in response to complex environmental factors. Mass collections of standard leaves of yellow birch growing over a wide range of sites appear to be useful in determining patterns of genetic differentiation in the species.

Leaf diversity in yellow birch (Betula alleghaniensis)

1974 ◽  
Vol 52 (11) ◽  
pp. 2407-2414 ◽  
Author(s):  
Bruce P. Dancik ◽  
Burton V. Barnes
Keyword(s):  
Principal Components ◽  
Canonical Variate ◽  
Betula Alleghaniensis ◽  
Yellow Birch ◽  
Short Shoot ◽  
Population Comparisons ◽  
Canonical Variates ◽  
Long Shoots

Analysis of leaves from several crown positions of a single yellow birch (Betula alleghaniensis Britton) indicated that particular short-shoot leaves from the middle and lower inside crown were more uniform than those from other crown positions. The short-shoot leaves typically occur in pairs. Each pair consists of two distinctly different leaves, termed here the A and B leaves. The A leaf is consistently larger, with more veins and teeth and a more inequilateral base than the B leaf. Because of their relative uniformity, lower inside crown A leaves would be useful as "standard" leaves for among-tree and among-population comparisons. Late leaves, borne on long shoots in exposed portions of the upper crown, were smaller than the short-shoot leaves in all dimensions. Principal components and canonical variates of the short-shoot leaves from the lower and middle inside crown exhibited the most compact and least variable groupings of all of the leaf types. The first canonical variate separated the leaves of the lower and middle crown from those of the upper crown. The second canonical variate separated A and B leaves. Observations of emerging leaves indicated no systematic differences in position of the A and B leaf.

Morphological discrimination of a tobacco-feeding form from Myzus persicae (Sulzer) (Hemiptera: Aphididae), and a key to New World Myzus (Nectarosiphon) species

1987 ◽  
Vol 77 (4) ◽  
pp. 713-730 ◽  
Author(s):  
R. L. Blackman
Keyword(s):  
Myzus Persicae ◽  
Taxonomic Status ◽  
Canonical Variate ◽  
Multivariate Techniques ◽  
Cell Nuclei ◽  
Canonical Variates ◽  
Dark Green ◽  
North And South America ◽  
North And South ◽  
Autosomal Translocation

AbstractMultivariate techniques, principally the method of canonical variates, were used to investigate morphological variation within and between populations of the group of Myzus persicae (Sulzer) from North and South America, Europe, Africa and Asia. The scores on the first canonical variate of samples from tobacco in North America, the Mediterranean region, the Middle East, Africa and Sri Lanka all grouped consistently when compared with samples from other host-plants, even after aphids from tobacco had been reared for up to seven years on a non-tobacco host. Thus there is a widely-distributed tobacco-adapted form, closely related to M. persicae but with its own characteristic morphology. Morphological discriminants are given for the recognition of apterous and alate viviparae of this tobacco form, which is given the name M. nicotianae sp. n. Both M. persicae and M. nicotianae have 2n = 12, and both are frequently heterozygous for apparently the same autosomal translocation, which they must have acquired independently. M. nicotianae is presumably isolated from M. persicae by being permanently parthenogenetic. In Japan and Central Asia, however, aphids of the M. persicae group on tobacco can produce sexual morphs; the taxonomic status of these latter populations is still unclear. Multivariate comparison of European and North American populations of dark green aphids of the M. persicae group with 13 or 14 chromosomes in somatic cell nuclei instead of the normal 12, led to the conclusion that these all belong to one morphologically variable taxon, M. antirrhinii (Macchiati). Keys are provided to the apterous and alate virginoparae of the species of the M. persicae group in America.

scholarly journals Environmental Drivers and Age Trends in Site Productivity for Oak in Southern Poland

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 209
Author(s):  
Luiza Tymińska-Czabańska ◽  
Jarosław Socha ◽  
Marek Maj ◽  
Dominika Cywicka ◽  
Xo Viet Hoang Duong
Keyword(s):  
Nitrogen Deposition ◽  
Management Practices ◽  
Additive Model ◽  
Climatic Conditions ◽  
Environmental Indicators ◽  
Environmental Drivers ◽  
Site Productivity ◽  
Site Factors ◽  
Wide Range ◽  
Si Model

Site productivity provides critical information for forest management practices and is a fundamental measure in forestry. It is determined using site index (SI) models, which are developed using two primary groups of methods, namely, phytocentric (plant-based) or geocentric (earth-based). Geocentric methods allow for direct site growth modelling, in which the SI is predicted using multiple environmental indicators. However, changes in non-static site factors—particularly nitrogen deposition and rising CO2 concentration—lead to an increase in site productivity, which may be visible as an age trend in the SI. In this study, we developed a geocentric SI model for oak. For the development of the SI model, we used data from 150 sample plots, representing a wide range of local topographic and site conditions. A generalized additive model was used to model site productivity. We found that the oak SI depended predominantly on physicochemical soil properties—mainly nitrogen, carbon, sand, and clay content. Additionally, the oak SI value was found to be slightly shaped by the topography, especially by altitude above sea level, and topographic position. We also detected a significant relationship between the SI and the age of oak stands, indicating the long-term increasing site productivity for oak, most likely caused by nitrogen deposition and changes in climatic conditions. The developed geocentric site productivity model for oak explained 77.2% of the SI variation.

scholarly journals Soil Nitrogen Dynamics in a Managed Temperate Grassland Under Changed Climatic Conditions

Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 931
Author(s):  
Mona Giraud ◽  
Jannis Groh ◽  
Horst H. Gerke ◽  
Nicolas Brüggemann ◽  
Harry Vereecken ◽  
...  
Keyword(s):  
Nitrogen Uptake ◽  
Inorganic Nitrogen ◽  
Nitrogen Concentration ◽  
Nitrogen Dynamics ◽  
Climatic Conditions ◽  
Undisturbed Soil ◽  
Nitrogen Emissions ◽  
Growing Period ◽  
Grassland Type ◽  
Wide Range

Grasslands are one of the most common biomes in the world with a wide range of ecosystem services. Nevertheless, quantitative data on the change in nitrogen dynamics in extensively managed temperate grasslands caused by a shift from energy- to water-limited climatic conditions have not yet been reported. In this study, we experimentally studied this shift by translocating undisturbed soil monoliths from an energy-limited site (Rollesbroich) to a water-limited site (Selhausen). The soil monoliths were contained in weighable lysimeters and monitored for their water and nitrogen balance in the period between 2012 and 2018. At the water-limited site (Selhausen), annual plant nitrogen uptake decreased due to water stress compared to the energy-limited site (Rollesbroich), while nitrogen uptake was higher at the beginning of the growing period. Possibly because of this lower plant uptake, the lysimeters at the water-limited site showed an increased inorganic nitrogen concentration in the soil solution, indicating a higher net mineralization rate. The N2O gas emissions and nitrogen leaching remained low at both sites. Our findings suggest that in the short term, fertilizer should consequently be applied early in the growing period to increase nitrogen uptake and decrease nitrogen losses. Moreover, a shift from energy-limited to water-limited conditions will have a limited effect on gaseous nitrogen emissions and nitrate concentrations in the groundwater in the grassland type of this study because higher nitrogen concentrations are (over-) compensated by lower leaching rates.

Fire regime shift linked to increased forest density in a piñon–juniper savanna landscape

2014 ◽  
Vol 23 (2) ◽  
pp. 234 ◽  
Author(s):  
Ellis Q. Margolis
Keyword(s):  
Regime Shift ◽  
Fire History ◽  
Fire Regime ◽  
Fire Regimes ◽  
Fire Frequency ◽  
Climatic Conditions ◽  
Tree Density ◽  
High Severity ◽  
Wide Range ◽  
In Fire

Piñon–juniper (PJ) fire regimes are generally characterised as infrequent high-severity. However, PJ ecosystems vary across a large geographic and bio-climatic range and little is known about one of the principal PJ functional types, PJ savannas. It is logical that (1) grass in PJ savannas could support frequent, low-severity fire and (2) exclusion of frequent fire could explain increased tree density in PJ savannas. To assess these hypotheses I used dendroecological methods to reconstruct fire history and forest structure in a PJ-dominated savanna. Evidence of high-severity fire was not observed. From 112 fire-scarred trees I reconstructed 87 fire years (1547–1899). Mean fire interval was 7.8 years for fires recorded at ≥2 sites. Tree establishment was negatively correlated with fire frequency (r=–0.74) and peak PJ establishment was synchronous with dry (unfavourable) conditions and a regime shift (decline) in fire frequency in the late 1800s. The collapse of the grass-fuelled, frequent, surface fire regime in this PJ savanna was likely the primary driver of current high tree density (mean=881treesha–1) that is >600% of the historical estimate. Variability in bio-climatic conditions likely drive variability in fire regimes across the wide range of PJ ecosystems.

scholarly journals A reliable rainfall–runoff model for flood forecasting: review and application to a semi-urbanized watershed at high flood risk in Italy

2016 ◽  
Vol 48 (3) ◽  
pp. 726-740 ◽  
Author(s):  
Daniele Masseroni ◽  
Alessio Cislaghi ◽  
Stefania Camici ◽  
Christian Massari ◽  
Luca Brocca
Keyword(s):  
Flood Risk ◽  
Climatic Conditions ◽  
Rainfall Runoff ◽  
Number Of Factors ◽  
Wide Range ◽  
Median Volume ◽  
Flood Estimation ◽  
High Flood ◽  
Rainfall Runoff Model ◽  
Flooding Events

Many rainfall–runoff (RR) models are available in the scientific literature. Selecting the best structure and parameterization for a model is not straightforward and depends on a broad number of factors, including climatic conditions, catchment characteristics, temporal/spatial resolution and model objectives. In this study, the RR model ‘Modello Idrologico Semi-Distribuito in continuo’ (MISDc), mainly developed for flood simulation in Mediterranean basins, was tested on the Seveso basin, which is stressed several times a year by flooding events mainly caused by excessive urbanization. The work summarizes a compendium of the MISDc applications over a wide range of catchments in European countries and then it analyses the performances over the Seveso basin. The results show a good fit behaviour during both the calibration and the validation periods with a Nash–Sutcliffe coefficient index larger than 0.9. Moreover, the median volume and peak discharge errors calculated on several flood events were less than 25%. In conclusion, we can be assured that the reliability and computational speed could make the MISDc model suitable for flood estimation in many catchments of different geographical contexts and land use characteristics. Moreover, MISDc will also be useful for future support of real-time decision-making for flood risk management in the Seveso basin.

scholarly journals A multivariate analysis of subline divergence in the shape of the mandible in C57BL/Gr mice

1973 ◽  
Vol 21 (2) ◽  
pp. 121-132 ◽  
Author(s):  
Michael Festing
Keyword(s):  
Multivariate Analysis ◽  
Distance Function ◽  
Canonical Variate ◽  
Multivariate Techniques ◽  
Graphical Display ◽  
Classification Analysis ◽  
Variate Analysis ◽  
Pedigree Relationship ◽  
Highly Correlated ◽  
Generalized Distance

SUMMARYThe shape of the mandible in. nine sublines of C57BL/Gr, seven other strains of ‘C57 ancestry’ and four unrelated strains was studied by multivariate techniques. The generalized distance function was used to classify individuals in the groups which they most closely resembled. The degree of misclassification depended on the pedigree relationship between strains and sublines. The generalized distance between pairs of subline centeroids was also highly correlated (r = 0·60) with the number of generations between them. A canonical variate analysis was used to reduce the dimensionality so that a graphical display of the relationships between strains and sublines could be made. The results agreed closely with the classification analysis. It was concluded that the shape of the mandible could be used for subline identification though the accuracy of this technique depends on how closely the sublines are related.

Exploring the Recruitment Dynamics of Sugar Maple and Yellow Birch Saplings into Merchantable Stems Following Harvesting in the Acadian Forest Region of New Brunswick, Canada

2021 ◽  
Author(s):  
Alex Noel ◽  
Jules Comeau ◽  
Salah-Eddine El Adlouni ◽  
Gaetan Pelletier ◽  
Marie-Andrée Giroux
Keyword(s):  
New Brunswick ◽  
Sugar Maple ◽  
Basal Area ◽  
Stem Density ◽  
Yellow Birch ◽  
Probability Of Occurrence ◽  
Silvicultural Treatment ◽  
Forest Region ◽  
Wide Range ◽  
Acadian Forest

The recruitment of saplings in forest stands into merchantable stems is a very complex process, thus making it challenging to understand and predict. The recruitment dynamics in the Acadian Forest Region of New Brunswick are not well known or documented. Our objective was to draw an inference from existing large scale routine forest inventories as to the different dynamics behind the recruitment from the sapling layer into the commercial tree size layer in terms of density and occurrence of sugar maple (Acer saccharum Marsh.) and yellow birch (Betula alleghaniensis Britt.) following harvesting, by looking at many factors on a wide range of spatial and temporal scales using models. Results suggest that the variation in density and probability of occurrence is best explained by the intensity of silvicultural treatment, by the merchantable stem density in each plot, and by the proportion of merchantable basal area of each group of species. The number of recruits of sugar maple and yellow birch stems tend be higher when time since last treatment increases, when mid to low levels of silvicultural treatment intensity were implemented, and within plots having intermediate levels of merchantable stem density. Lastly, our modeling efforts suggest that the probability of occurrence and density of recruitment of both species tend to increase while its share of merchantable basal area increases.

scholarly journals Evolved phenological cueing strategies show variable responses to climate change

2018 ◽  
Author(s):  
Collin B. Edwards ◽  
Louie Yang
Keyword(s):  
Climate Change ◽  
Climatic Conditions ◽  
Similar Response ◽  
Climate Data ◽  
Global Pattern ◽  
Continental Scale ◽  
Fitness Consequences ◽  
Wide Range ◽  
Correlation Structures ◽  
Phenological Shifts

AbstractSeveral studies have documented a global pattern of phenological advancement that is consistent with ongoing climate change. However, the magnitude of these phenological shifts is highly variable across taxa and locations. This variability of phenological responses has been difficult to explain mechanistically. To examine how the evolution of multi-trait cueing strategies could produce variable responses to climate change, we constructed a model in which organisms evolve strategies that integrate multiple environmental cues to inform anticipatory phenological decisions. We simulated the evolution of phenological cueing strategies in multiple environments, using historic climate data from 78 locations in North America and Hawaii to capture features of climatic correlation structures in the real world. Organisms in our model evolved diverse strategies that were spatially autocorrelated across locations on a continental scale, showing that similar strategies tend to evolve in similar climates. Within locations, organisms often evolved a wide range of strategies that showed similar response phenotypes and fitness outcomes under historical conditions. However, these strategies responded differently to novel climatic conditions, with variable fitness consequences. Our model shows how the evolution of phenological cueing strategies can explain observed variation in phenological shifts and unexpected responses to climate change.

scholarly journals Climate structuring of Batrachochytrium dendrobatidis infection in the threatened amphibians of the northern Western Ghats, India

2018 ◽  
Vol 5 (6) ◽  
pp. 180211 ◽  
Author(s):  
Christopher J. Thorpe ◽  
Todd R. Lewis ◽  
Matthew C. Fisher ◽  
Claudia J. Wierzbicki ◽  
Siddharth Kulkarni ◽  
...  
Keyword(s):  
Western Ghats ◽  
Batrachochytrium Dendrobatidis ◽  
Coastal Region ◽  
First Record ◽  
Climatic Conditions ◽  
Ecological Traits ◽  
Temperature Changes ◽  
Reverse Pattern ◽  
Wide Range ◽  
The Western Ghats

Batrachochytrium dendrobatidis ( Bd ) is a pathogen killing amphibians worldwide. Its impact across much of Asia is poorly characterized. This study systematically surveyed amphibians for Bd across rocky plateaus in the northern section of the Western Ghats biodiversity hotspot, India, including the first surveys of the plateaus in the coastal region. These ecosystems offer an epidemiological model system since they are characterized by differing levels of connectivity, edaphic and climatic conditions, and anthropogenic stressors. One hundred and eighteen individuals of 21 species of Anura and Apoda on 13 plateaus ranging from 67 to 1179 m above sea level and 15.89 to 17.92° North latitude were sampled. Using qPCR protocols, 79% of species and 27% of individuals tested were positive for Bd . This is the first record of Bd in caecilians in India, the Critically Endangered Xanthophryne tigerina and Endangered Fejervarya cf. sahyadris . Mean site prevalence was 28.15%. Prevalence below the escarpment was 31.2% and 25.4% above. The intensity of infection (GE) showed the reverse pattern. Infection may be related to elevational temperature changes, thermal exclusion, inter-site connectivity and anthropogenic disturbance. Coastal plateaus may be thermal refuges from Bd . Infected amphibians represented a wide range of ecological traits posing interesting questions about transmission routes.

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