Influence of stand density on log quality of lodgepole pine

1988 ◽  
Vol 18 (7) ◽  
pp. 911-916 ◽  
Author(s):  
Louis A. Ballard ◽  
James N. Long
Keyword(s):  
Lodgepole Pine ◽  
Stand Density ◽  
Quality Characteristics ◽  
Exponential Relationship ◽  
Stem Quality ◽  
Rotation Age ◽  
Negative Exponential ◽  
Branch Size ◽  
The Relationship

We examined the relationship between stand density and stem quality characteristics for lodgepole pine (Pinuscontorta). The influence of initial stand density on end of rotation log quality was inferred by analyzing data from unmanaged, rotation-age stands. Quality characteristics examined included first log branch diameters, taper, wood density, and the proportion of sapwood. After differences in diameter at breast height were accounted for, only branch size was strongly influenced by stand density. A strong negative exponential relationship was found between the mean of the five largest branches per first log and number of trees per hectare.

Modeling trends in stem quality characteristics of loblolly pine trees in unthinned plantations

2008 ◽  
Vol 38 (6) ◽  
pp. 1446-1457 ◽  
Author(s):  
Jungkee Choi ◽  
Harold E. Burkhart ◽  
Ralph L. Amateis
Keyword(s):  
Loblolly Pine ◽  
Stand Density ◽  
The United States ◽  
Quality Characteristics ◽  
Tree Level ◽  
Stand Age ◽  
Insect Damage ◽  
Relative Height ◽  
Stem Quality ◽  
Pine Trees

Trends in stem quality characteristics of loblolly pine trees were investigated by using data from unthinned control plots established in plantations across 12 southern states in the United States and measured at 3 year intervals. At each measurement, the stem quality was classified into (i) single stem or forked, (ii) normal top or broken top, (iii) straight or sweep (bole sweep, butt sweep, short crook), and (iv) no disease or disease. Data through the first 15 years of observation showed that, on average, 4% of the trees were forked, 5% had broken tops, 41% had sweep, and 12% had disease or insect damage; 48% exhibited single stem, normal top, straight, and no disease or insect damage. Recovery rates out of forked, broken top, sweep, and disease classes were 37%, 83%, 30%, and 11%, respectively, over the 15 years. Multicategorical logit models were developed to predict stem quality characteristics from stand-and tree-level variables. Forked trees were related with tree diameter; broken tops were related with stand density, DBH, and relative height; sweep was related with stand age. Significant predictor variables for the incidence of disease or insect attack were not found. The occurrence of undamaged and disease-free trees can be predicted from DBH and relative height.

The effect of stand structure and stand density on the leaf area–sapwood area relationship of lodgepole pine

1989 ◽  
Vol 19 (3) ◽  
pp. 392-396 ◽  
Author(s):  
Dan C. Thompson
Keyword(s):  
Leaf Area ◽  
Stand Structure ◽  
Lodgepole Pine ◽  
Habitat Type ◽  
Ring Width ◽  
Stand Density ◽  
Habitat Types ◽  
Sapwood Area ◽  
Relationship Of ◽  
The Relationship

The relationship of sapwood area to leaf area in lodgepole pine was examined across a variety of habitat types and stand densities in northwest Montana. No statistical differences were found between plots with regard to either habitat type or stand density. A nonlinear relationship was found between leaf area and sapwood area. Increasing amounts of sapwood were associated with a decrease in the leaf area–sapwood area ratio. A large amount of within-plot variation in the sapwood area–leaf area relationship was explained by differences between dominant trees and trees of other crown classes. Leaf area (LA) was best estimated by the equation LA = 0.12 × S − 0.0003 × S2 + 0.06 × S × D, where LA is leaf area, S is sapwood area, and D is the crown class (dominant). Differences between dominant and subdominant trees appear to be related to ring width and its associated permeability. Differences in sapwood area–leaf area equations among different studies may be due in part to differences in stand structure.

scholarly journals Ablation Patterns of the Debris Covered Tongue of Halong Glacier Revealed by Short Term Unmanned Aerial Vehicle Surveys

2021 ◽  
Vol 9 ◽  
Author(s):  
Wanqin Guo ◽  
Xiaojun Guo ◽  
Yushuo Liu ◽  
Jing Li ◽  
Donghui Shangguan ◽  
...  
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Limited Area ◽  
Short Term ◽  
Exponential Relationship ◽  
Glacier Tongue ◽  
Mass Losses ◽  
Surface Models ◽  
Aerial Vehicle ◽  
Negative Exponential

Debris-covered glaciers are an important glacier type and have attracted more and more attention. This study presents the results of ablation patterns of debris-covered tongue of the Halong Glacier in the northeastern Tibetan Plateau, by using two repeated unmanned aerial vehicle (UAV) surveys performed on August 11 and September 15, 2019. The results show that the tongue of Halong Glacier has experienced strong ablation during the surveyed period, with an overall ice loss amount to 4.17 × 105 metric tons Among all the briefly classified surface types, supraglacial debris has the largest area (80.9%) and also mass losses (58.6%) comparing to others. However, ice cliffs show the strongest and the most significant ablation rates (averagely 1.36 and 1.22 m w.e. for supraglacial and lateral ice cliffs, respectively), followed by clean ice regions (1.01 m w.e.). The backwastes of ice cliffs also resulted in up to 7.8 m horizontal back-off at different parts of Halong Glacier, lead to fast terminal retreat and narrowing down of the glacier tongue, and may result in the break off of Halong Glacier tongue into separated parts in the future. The surface ablation rates show a clear negative exponential relationship with the measured debris thicknesses, well in accordance with previous studies. Regions in cutting and flushing by supraglacial and lateral rivers have the largest surface elevation decreases but are not significant due to their limited area and the relatively lower quality of UAV digital surface models (DSMs) in those covered regions.

scholarly journals Stand density-a factor affecting stem quality of young hardwoods

1985 ◽  
Author(s):  
David L. Sonderman ◽  
David L. Sonderman
Keyword(s):  
Stand Density ◽  
Stem Quality

scholarly journals Statistical user behavior detection and QoE evaluation for thin client services

2015 ◽  
Vol 12 (2) ◽  
pp. 587-605 ◽  
Author(s):  
Mirko Suznjevic ◽  
Lea Skorin-Kapov ◽  
Iztok Humar
Keyword(s):  
User Behavior ◽  
Evaluation Studies ◽  
Resource Planning ◽  
Working Environment ◽  
Exponential Relationship ◽  
Network Resource ◽  
Machine Learning Approach ◽  
Logarithmic Relationship ◽  
The Relationship

Remote desktop connection (RDC) services offer clients the ability to access remote content and services, commonly in the context of accessing their working environment. With the advent of cloud-based services, an example use case is that of delivering virtual PCs to users in WAN environments. In this paper, we aim to detect and analyze common user behavior when accessing RDC services, and use this as input for making Quality of Experience (QoE) estimations and subsequently providing input for effective QoE management mechanisms. We first identify different behavioral categories, and conduct traffic analysis to determine a feature set to be used for classification purposes. We propose a machine learning approach to be used for classifying behavior, and use this approach to classify a large number of real-world RDCs. We further conduct QoE evaluation studies to determine the relationship between different network conditions and subjective end user QoE for all identified behavioral categories. Results show an exponential relationship between QoE and delay and loss degradations, and a logarithmic relationship between QoE and bandwidth limitations. Obtained results may be applied in the context of network resource planning, as well as in making QoE-driven resource allocation decisions.

Response of leaf area index to density for two contrasting tree species

1991 ◽  
Vol 21 (12) ◽  
pp. 1760-1764 ◽  
Author(s):  
Steven B. Jack ◽  
James N. Long
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Tree Species ◽  
Lodgepole Pine ◽  
Stand Density ◽  
Area Index ◽  
Subalpine Fir ◽  
Wide Range ◽  
Stable Leaf ◽  
The Relationship

It is commonly assumed that mature forest stands with closed canopies support constant amounts (weight or area) of foliage, independent of stand density. For stand leaf area to be constant, mean leaf area must be plastic with respect to density. We examined the relationship between density and both leaf area index and mean leaf area for two contrasting tree species, lodgepole pine (Pinuscontorta var. latifolia Engelm.) and subalpine fir (Abieslasiocarpa (Hook.) Nutt.). In lodgepole pine, leaf area index tended to be constant over a wide range of absolute and relative densities, but in subalpine fir, leaf area index increased with density. Consistent with these results, mean leaf area of lodgepole pine was more plastic with respect to density than mean leaf area of subalpine fir. The presumption of stable leaf area index independent of stand density, therefore, may not be as general as usually assumed owing to differential responses of mean leaf area to density. Differences in plasticity between the two species were attributed to differences in relative shade tolerance and the effect of shade on competitive interactions at high densities.

scholarly journals QUALITY OF SERVICE AND HOMESTAY CUSTOMER SATISFACTION USING THE SERVQUAL MODEL

2021 ◽  
Vol 3 (7) ◽  
pp. 59-74
Author(s):  
Najwa Karmila Othman ◽  
Nor Aishah Buang
Keyword(s):  
Customer Satisfaction ◽  
Service Quality ◽  
Quantitative Methods ◽  
Early Stage ◽  
Quality Characteristics ◽  
Quality Of Services ◽  
Five Dimensions ◽  
Tourism Services ◽  
The Relationship

The homestay industry is part of the tourism services industry. It is important for homestay operators to provide services that can meet the needs and satisfaction of customers. However, there are some problems related to the quality of services provided by homestay operators that affect customer satisfaction. Problems arise due to a lack of knowledge of the dimensions that can be used to provide quality services. There are five dimensions of the SERVQUAL model that are associated with service quality characteristics and are able to influence homestay customer satisfaction, namely tangible, empathy, responsiveness, reliability, and assurance. This study was conducted with the aim of finding out the relationship between the five dimensions of SERVQUAL service quality with homestay customer satisfaction and identifying the dimensions that most affect customer satisfaction. This study uses quantitative methods and distributed a total of 384 questionnaires to respondents who are local tourists staying at the Hulu Selangor homestay. The results of the study found that the dimensions of tangible, empathy, responsiveness, reliability, and assurance have a positive relationship to customer satisfaction. There are two main dimensions that most affect the satisfaction of homestay customers, namely reliability and assurance. This customer satisfaction is influenced by the treatment received while dealing with homestay employees. Friendly and courteous homestay workers make customers happy and comfortable to get help when needed. Homestay's that provide services efficiently without any errors from the early stage is also able to affect the level of customer satisfaction. Each homestay operator who are concerned with five dimensions and implement them in homestay services will strive to enhance and maintain the quality of the image as the best homestay.

scholarly journals HUBUNGAN ANTARA KANDUNGAN PATI RESISTEN DAN KUALITAS TANAK BERAS SIGER (TIWUL MODIFIKASI)

2018 ◽  
Vol 18 (1) ◽  
pp. 7
Author(s):  
Beni Hidayat ◽  
M. Muslihudin ◽  
Syamsul Akmal
Keyword(s):  
Resistant Starch ◽  
Digestive Enzymes ◽  
Room Temperature ◽  
Cooking Quality ◽  
Starch Content ◽  
Quality Characteristics ◽  
Eating Quality ◽  
Cycling Treatment ◽  
The Relationship

Resistant starch is a starch fraction that can not be hydrolyzed by digestive enzymes in the small intestine and classified as a prebiotic compound. Increasing the content of resistant starch to a certain amount in Siger Rice (modified tiwul) will decrease the cooking quality. The objective of this research was to study the relationship between resistant starch content and cooking quality of Siger Rice (eating quality, texture, and taste). The increase of resistant starch content in siger rice was done by the application of autoclaving-cooling cycling treatment, through steam stages, cooling to room temperature, followed by cooling at 4°C for 0 hours/control, 12 hours, 24 hours, 36 hours and 48 hours. The results showed that the increase of resistant starch content ≤ 10% (9.85%) will improve the quality characteristics of Siger Rice for all organoleptic scores, i.e., eating quality (7,15 to 8,2), texture (7.05 to 8.35), and flavor (6.95 to 8.15); on the contrary, the increase of resistant starch content more than 10% (14.25%) will decrease the cooking quality characteristics of Siger Rice for all organoleptic scores, i.e., eating quality (7.15 to 6.8), texture (7.05 to 6.6), and taste (6.95 to 6.4).

Endemism in Recently Diverged Angiosperms Is Associated With Chromosome Set Duplication

2021 ◽  
Author(s):  
Sara Villa ◽  
Matteo Montagna ◽  
Simon Pierce
Keyword(s):  
Endemic Species ◽  
Decay Constant ◽  
Molecular Dating ◽  
Exponential Relationship ◽  
Ploidy Levels ◽  
Key Driver ◽  
Negative Exponential ◽  
And Shifts ◽  
The Relationship ◽  
Upper Boundary

Abstract Chromosome set duplication (polyploidy) drives instantaneous speciation and shifts in ecology for angiosperms, and is frequently observed in neo-endemic species. However, the extent to which chromosome set duplication is associated with endemism throughout the flowering plants has not been determined. We hypothesised that across the angiosperms polyploidy is more frequent and more pronounced (higher evident ploidy levels) for recent endemics. Data on chromosome counts, molecular dating and distribution for 4210 species belonging to the major clades of angiosperms were mined from literature-based databases. As all clades include diploid taxa, with polyploids representing a possible ‘upper limit’ to the number of chromosomes over evolutionary time, upper boundary regression was used to investigate the relationship between the number of chromosomes and time since taxon divergence, both across clades and separately for families, with endemic and non-endemic species compared. A significant negative exponential relationship between the number of chromosomes and taxon age was evident across angiosperm clades (R2adj=0.48 with endemics and non-endemics considered together, R2adj=0.46 for endemics; R2adj=0.44 for non-endemics; p ≤0.0001 in all cases), which was three times stronger for endemics (decay constant=0.12, cf. 0.04 for non-endemics). The majority of families exhibited this relationship, with a steeper regression slope for endemic Campanulaceae, Compositae, Leguminosae, Poaceae, Caryophyllaceae and Rosaceae, cf. non-endemics. In conclusion, chromosome duplication is more frequent and extensive in recent angiosperms, particularly young endemics, supporting the hypothesis of polyploidy as a key driver of neo-endemism. However, as young endemics may also be diploid, polyploidy is not an exclusive driver of neo-endemism.

Predicting branch diameters on second-growth Douglas-fir from tree-level descriptors

1999 ◽  
Vol 29 (12) ◽  
pp. 1829-1840 ◽  
Author(s):  
Douglas A Maguire ◽  
Stuart R Johnston ◽  
James Cahill
Keyword(s):  
Stand Density ◽  
Douglas Fir ◽  
Tree Level ◽  
Basal Diameter ◽  
Tree Diameter ◽  
Crown Length ◽  
Second Growth ◽  
Regression Techniques ◽  
Branch Size

The quality of lumber and veneer recovered from logs of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) is directly influenced by the maximum limb size attained on the crop tree. Because limb sizes are influenced by stand-density regimes, a need has arisen for quantitative tools that link a wide array of silvicultural regimes to wood-product quality by accounting for silvicultural effects on crown development. An equation for estimating maximum branch size at a given level within the live crown was developed from data collected on 96 felled sample trees in the Coast Ranges and Cascade foothills of Oregon and Washington. Height and basal diameter of the largest branch within each live whorl were measured on each felled tree, and a predictive equation was developed by various regression techniques. The final mixed-effects nonlinear model estimates maximum branch size as a function of depth into crown and tree diameter at breast height, height, and live crown length.

Sign in / Sign up

Export Citation Format

Share Document