Asymmetric, two-sided competition in even-aged monocultures of red pine

1988 ◽  
Vol 18 (7) ◽  
pp. 901-910 ◽  
Author(s):  
David G. Brand ◽  
Steen Magnussen
Keyword(s):  
Stand Density ◽  
Red Pine ◽  
Stem Volume ◽  
Large Trees ◽  
Relative Production ◽  
Competition Process ◽  
Using Data ◽  
The Individual ◽  
Individual Trees ◽  
Relative Production Rate

A framework for analysis of even-aged plant monocultures was developed and used to examine hypotheses on the process of competition, using data obtained from three independently established red pine (Pinusresinosa Ait.) stand-density experiments. Growth rate and relative production rate (a measure of tree vigour) were computed for the individual trees in stands of differing density at points in time when these stands had the same mean stem volume. Competition is shown to be both asymmetric (small trees lose vigour more rapidly than large trees as density increases) and two-sided (not only do larger trees affect smaller trees, but to some degree small trees also cause growth reduction in larger neighbours). Increasing density results in increased size inequality as smaller trees lose vigour and become suppressed. The asymmetric, two-sided competition process in red pine stands is considered ecologically inherent for a species adapted to existence in even-aged monocultures.

A model of stand allometry and biomass allocation during the self-thinning process

1986 ◽  
Vol 16 (5) ◽  
pp. 990-995 ◽  
Author(s):  
N. J. Smith
Keyword(s):  
Biomass Allocation ◽  
Stand Density ◽  
Maximum Size ◽  
Red Pine ◽  
Stem Volume ◽  
Allometric Relationships ◽  
Red Alder ◽  
Number Of Stems ◽  
Thinning Process ◽  
The Relationship

A growth model is developed to describe the relationship between any measure of size and number of stems in even-aged, monospecific plant populations during self-thinning. The model is tested on red alder (Alnusrubra Bong.) seedlings and red pine (Pinusresinosa Ait.) stands grown over a range of site qualities and initial spacings. Allometric relationships between plant dimensions are shown to change over time, finally approaching a stable value defined by a generalized self-thinning rule. Because of unique intraspecific plant geometry, allometric relationships appear to be more consistent within than between species. The priorisation for red alder biomass allocation with stand development was as follows (P < 0.05): branches > stem ≥ leaves ≥ root ≥ 2 nodules. For red pine the slope and intercept of the maximum size–density line were greater (P < 0.05) for merchantable versus total stem volume. A new approach for constructing stand density programs is presented.

Stand structure and growing space efficiency following thinning in an even-aged Douglas-fir stand

1988 ◽  
Vol 18 (7) ◽  
pp. 859-866 ◽  
Author(s):  
K. L. O'Hara
Keyword(s):  
Stand Structure ◽  
Volume Growth ◽  
Basal Area ◽  
Stand Density ◽  
Douglas Fir ◽  
Stem Volume ◽  
Projection Area ◽  
Individual Tree ◽  
Space Efficiency ◽  
Individual Trees

The growth of individual trees from four thinning treatments in a 64-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stand was analyzed to determine desirable residual stand structures after thinning. Dominant and codominant trees had the highest individual tree stem volume growth rates over the previous 5 years, and accounted for most stand volume growth in thinned and unthinned stands. Two measures of growing space, crown projection area and sapwood basal area (a surrogate for leaf area), were used to measure how efficiently individual trees used their growing space. Crown classes were useful in characterizing growing space efficiency (volume growth per unit of growing space) only in the unthinned treatment. In thinned treatments, tall trees with medium-sized crowns were most efficient, while in the unthinned treatment, tall trees with relatively large crowns were most efficient. A large crown in an unthinned stand was comparable in size to a medium-sized crown in a thinned stand. Results suggest growing space is not limiting individual tree growth in thinned stands and that thinning to a particular stand structure is more appropriate than thinning to a particular level of stand density.

Individual-tree diameter growth models for quantifying within-stand response to nitrogen fertilization

1990 ◽  
Vol 20 (8) ◽  
pp. 1149-1155 ◽  
Author(s):  
Bahman Shafii ◽  
James A. Moore ◽  
James D. Newberry
Keyword(s):  
Growth Models ◽  
Stand Density ◽  
Simulation Models ◽  
Diameter Growth ◽  
Individual Tree ◽  
Diameter Increment ◽  
Prognosis Model ◽  
Using Data ◽  
Individual Trees ◽  
Northern Idaho

Diameter-increment models for nitrogen-fertilized stands were developed using data from permanent research plots in northern Idaho. The equations partially resembled PROGNOSIS model diameter growth formulations. Results indicated that both initial tree size and initial stand density produced significant interactions with treatment to explain an individual tree's response to fertilization. Larger trees in a stand showed more fertilization response than smaller trees. Furthermore, individual trees in low-density stands showed more fertilization response than those growing in high-density stands. These diameter increment predictive equations were formulated to be compatible with individual-tree distance-independent simulation models.

Predicting the future diameter of stems in Norway spruce stands subjected to different thinning regimes

2005 ◽  
Vol 35 (6) ◽  
pp. 1331-1341 ◽  
Author(s):  
Kjell Karlsson ◽  
Lennart Norell
Keyword(s):  
Standard Deviation ◽  
Norway Spruce ◽  
Stand Density ◽  
Logistic Function ◽  
Management Regime ◽  
The Future ◽  
The Mean ◽  
Using Data ◽  
Stand Density Management ◽  
Individual Trees

The future diameter of stems in even-aged Norway spruce (Picea abies (L.) Karst.) stands subjected to different thinning regimes was modelled, using data from a thinning experiment established in 25 localities in southern Sweden. Separate models were developed for stands thinned from below, stands thinned from above, and unthinned stands. A bivariate approach was used to construct the models, based on DBH data from the initial stand and from the same trees at future points in time. The approach entails that the dependency between initial and future DBHs can be directly used to predict the future DBH. Also, the modelling used stand and site characteristics together with information about the stand density management regime. The initial stands were assumed to be unthinned, and the dominant height was assumed to be 12–18 m. A logistic function was used to predict which individual trees would remain at future points in time. The mean and standard deviation of the differences between observed and predicted future diameters were used to validate the models. When the prediction period was approximately 33 years, the mean was typically underestimated by 4 mm, and the standard deviation was approximately 40 mm.

Accent Policy and Accent Modification Enterprises as Potential Indicators of Intercultural Power Relations: A Call for an Updated Research Agenda

2013 ◽  
Vol 3 (1) ◽  
pp. 22-33 ◽  
Author(s):  
Brynne D. Ovalle ◽  
Rahul Chakraborty
Keyword(s):  
International Relations ◽  
Identity Construction ◽  
Social Theory ◽  
Power Relations ◽  
Linguistic Diversity ◽  
Cultural Organization ◽  
Using Data ◽  
The Individual ◽  
The Impact ◽  
The Relationship

This article has two purposes: (a) to examine the relationship between intercultural power relations and the widespread practice of accent discrimination and (b) to underscore the ramifications of accent discrimination both for the individual and for global society as a whole. First, authors review social theory regarding language and group identity construction, and then go on to integrate more current studies linking accent bias to sociocultural variables. Authors discuss three examples of intercultural accent discrimination in order to illustrate how this link manifests itself in the broader context of international relations (i.e., how accent discrimination is generated in situations of unequal power) and, using a review of current research, assess the consequences of accent discrimination for the individual. Finally, the article highlights the impact that linguistic discrimination is having on linguistic diversity globally, partially using data from the United Nations Educational, Scientific and Cultural Organization (UNESCO) and partially by offering a potential context for interpreting the emergence of practices that seek to reduce or modify speaker accents.

Calculation of Predictive Odds for Possible Carriers of Haemophilia

1975 ◽  
Vol 34 (03) ◽  
pp. 740-747 ◽  
Author(s):  
C. R. M Prentice ◽  
C. D Forbes ◽  
Sandra Morrice ◽  
A. D McLaren
Keyword(s):  
Biological Activity ◽  
Factor Viii ◽  
Factor Viii Related Antigen ◽  
Using Data ◽  
The Individual ◽  
Betting Odds

SummaryBetting odds for possible carriers of haemophilia have been calculated using data derived from normal and known carrier populations. For each possible carrier the concentration of factor VIII-related antigen and factor VIII biological activity was measured and used to determine the probability of the individual being a carrier. The calculations indicated that, of the 32 possible carriers, 11 were likely to be normal (odds of more than 5:1) while 11 were likely to be haemophilia carriers (again odds of more than 5:1).

Evaluation of the sensitivity of faecal sampling for detection of monophasic Salmonella Typhimurium and other Salmonella in cattle and pigs

2014 ◽  
Vol 143 (8) ◽  
pp. 1681-1691 ◽  
Author(s):  
M. E. ARNOLD ◽  
R. J. GOSLING ◽  
F. MARTELLI ◽  
D. MUELLER-DOBLIES ◽  
R. H. DAVIES
Keyword(s):  
Faecal Sample ◽  
Management Practices ◽  
Age Groups ◽  
Farm Animals ◽  
Infection Prevalence ◽  
Sample Type ◽  
Sample Data ◽  
Using Data ◽  
The Individual ◽  
Positive Groups

SUMMARYThere has been a rapid rise in the prevalence of cases of monophasic Salmonella Typhimurium (mST) in both humans and farm animals, and it has been found in pigs, cattle and poultry. It is therefore vital to have a good understanding of how to efficiently detect infected farms. The objective of this project was to determine sample type sensitivity in the detection of Salmonella to detect infected groups of animals on both pig (breeder, grower and finisher sites) and cattle (beef and dairy) farms, using data collected from a study investigating farms that were positive for mST, and to explore any variation between different age groups and management practices. A Bayesian approach in the absence of a gold standard was adopted to analyse the individual and pooled faecal sample data collected from each epidemiological group on each of the farms. The sensitivity of pooled sampling depended on the prevalence of infection in the group being sampled, with a higher prevalence leading to higher sensitivity. Pooled sampling was found to be more efficient at detecting positive groups of animals than individual sampling, with the probability of a random sample from a group of animals with 5% prevalence testing positive being equal to 15·5% for immature pigs (3·6% for an individual faecal sample, taking into account the sensitivity and infection prevalence), 7·1% for adult pigs (1·2% for individual sampling), 30% for outdoor cattle (2% for individual sampling) and 34% for indoor cattle (1% for individual sampling). The mean prevalence of each epidemiological group was higher in outdoor farms than indoor for both pigs and cattle (mean within-farm prevalence of 29·4% and 38·7% for outdoor pigs and cattle, respectively, compared to 19·8% and 22·1% for indoor pigs and cattle)

Are Religious Parents More Satisfied Parents? Individual- and Couple-Level Religious Correlates of Parenting Satisfaction

2017 ◽  
Vol 39 (7) ◽  
pp. 1770-1796 ◽  
Author(s):  
Justin J. Nelson ◽  
Jeremy E. Uecker
Keyword(s):  
Family Life ◽  
Religious Communities ◽  
Lower Odds ◽  
Parenting Satisfaction ◽  
Strong Emphasis ◽  
Research Findings ◽  
Evangelical Protestants ◽  
Using Data ◽  
The Individual ◽  
The Relationship

Using data from the 2014 Baylor Religion Survey, we examine the relationship between various aspects of religion and parenting satisfaction. Results confirm prior research findings that personal religiosity is positively associated with parenting satisfaction. We also find that religious heterogamy among couples is associated with lower odds of being a satisfied parent. Furthermore, parents who view their parenting as holy or sacred have much higher odds of reporting being satisfied as parents, and the observed relationships between religiosity and parenting satisfaction at both the individual and couple levels are no longer statistically significant in models controlling for parenting sanctification. The religiously unaffiliated have higher odds than evangelical Protestants of having high parenting satisfaction, suggesting the possible presence of parenting pressures within religious communities with a strong emphasis on family life.

Assyrian sacred trees in the Brooklyn Museum

Iraq ◽  
1994 ◽  
Vol 56 ◽  
pp. 123-133 ◽  
Author(s):  
Pauline Albenda
Keyword(s):  
Present Author ◽  
Ninth Century ◽  
Palm Tree ◽  
The West ◽  
Individual Tree ◽  
Sacred Tree ◽  
The Individual ◽  
Individual Trees ◽  
Brooklyn Museum ◽  
Tree Type

The Brooklyn Museum houses twelve stone slabs with carved decoration from the Northwest Palace of Ashurnasirpal II. The motif of a stylized tree — the so-called Sacred Tree (see Figs. 1, 4, 6) — appears on seven of those slabs which come from rooms F, I, L, S, T of the ninth century palace at Nimrud. These tree renderings are representative of the sacred tree-type found in ten rooms of the royal residence and the west wing. Approximately 96 sacred trees, in two-register arrangement, appeared on the pictorial decorations in room I; the same motif occurred about 75 times in one-register arrangement on the reliefs of the other rooms. The abundance of the sacred tree motif on the wall decorations of the Northwest Palace attests to the significance of this plant. Its design deserves investigation; in Layard's words, “the tree, evidently a sacred symbol, is elaborately and tastefully formed.”In his study of the Ashurnasirpal II reliefs in American collections, Stearns did not attempt to list the sacred trees, because “variations in the sacred tree occur only in minor details,” and “the tree in itself is rarely useful in identifying the location of the reliefs.” These statements make clear Stearns' belief that the sacred trees were nearly alike. Other scholars, notably Weidner and Reade, have pointed out that on a number of slabs now in American and European museums are carvings of matching half trees, therefore indicating that when paired, these trees belonged to adjoining slabs originally. In trying to match half trees, one finds that individual sacred trees do differ in the rendering of specific details. Bleibtreu, in her analysis of the sacred tree-type, lists three variants of the flower found on the palmette-garland framing the individual tree on three sides. The present author, after examining the sacred trees carved on the slabs in The Brooklyn Museum, concludes that the design of the tree-type is more varied than heretofore presumed, and that its construction is more complex than indicated in previous descriptions of the subjects. An analysis of the Assyrian sacred tree-type may lead to possible conclusions regarding its intended image: a stylized palm tree, a cult object, an emblem of vegetation or “tree of life”, an imperial symbol, or a combination of those forms. In addition, one may consider to what extent the rendering of individual trees was the consequence of artistic inventiveness.

scholarly journals Automatic Extraction of Grasses and Individual Trees in Urban Areas Based on Airborne Hyperspectral and LiDAR Data

2020 ◽  
Vol 12 (17) ◽  
pp. 2725
Author(s):  
Qixia Man ◽  
Pinliang Dong ◽  
Xinming Yang ◽  
Quanyuan Wu ◽  
Rongqing Han
Keyword(s):  
Urban Areas ◽  
Three Dimensional ◽  
Hyperspectral Data ◽  
Classification Method ◽  
Urban Vegetation ◽  
Individual Tree ◽  
Cloud Data ◽  
Random Forest Classification ◽  
The Individual ◽  
Individual Trees

Urban vegetation extraction is very important for urban biodiversity assessment and protection. However, due to the diversity of vegetation types and vertical structure, it is still challenging to extract vertical information of urban vegetation accurately with single remotely sensed data. Airborne light detection and ranging (LiDAR) can provide elevation information with high-precision, whereas hyperspectral data can provide abundant spectral information on ground objects. The complementary advantages of LiDAR and hyperspectral data could extract urban vegetation much more accurately. Therefore, a three-dimensional (3D) vegetation extraction workflow is proposed to extract urban grasses and trees at individual tree level in urban areas using airborne LiDAR and hyperspectral data. The specific steps are as follows: (1) airborne hyperspectral and LiDAR data were processed to extract spectral and elevation parameters, (2) random forest classification method and object-based classification method were used to extract the two-dimensional distribution map of urban vegetation, (3) individual tree segmentation was conducted on a canopy height model (CHM) and point cloud data separately to obtain three-dimensional characteristics of urban trees, and (4) the spatial distribution of urban vegetation and the individual tree delineation were assessed by validation samples and manual delineation results. The results showed that (1) both the random forest classification method and object-based classification method could extract urban vegetation accurately, with accuracies above 99%; (2) the watershed segmentation method based on the CHM could extract individual trees correctly, except for the small trees and the large tree groups; and (3) the individual tree segmentation based on point cloud data could delineate individual trees in three-dimensional space, which is much better than CHM segmentation as it can preserve the understory trees. All the results suggest that two- and three-dimensional urban vegetation extraction could play a significant role in spatial layout optimization and scientific management of urban vegetation.

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