Use of index lines and damage assessments to estimate population densities of snowshoe hares

1983 ◽  
Vol 61 (1) ◽  
pp. 163-167 ◽  
Author(s):  
Thomas P. Sullivan ◽  
Druscilla S. Sullivan
Keyword(s):  
Lodgepole Pine ◽  
Demographic Variables ◽  
Survey Method ◽  
Grid System ◽  
Demographic Information ◽  
Population Densities ◽  
Density Estimates ◽  
Snowshoe Hares ◽  
Standard Set ◽  
Pine Stands

This study reports on the use of index lines to estimate the abundance of snowshoe hares in lodgepole pine stands in central British Columbia, Canada. Density estimates and related demographic information from the index lines were compared with a standard set of lines superimposed on a 9-ha grid. During the summer of a peak year in abundance, index line trapping provided reasonably accurate estimates of hare densities on a grid system. There was little variation in the demographic variables of reproduction, body weight, and sex ratio between line- and grid-sampled populations. Hare abundance and barking damage (feeding injuries to trees) were greater in heavily stocked stands of lodgepole pine than in lightly stocked stands. Index lines provide a rapid and economical survey method for censusing snowshoe hares in lodgepole pine stands.

Barking damage by snowshoe hares and red squirrels in lodgepole pine stands in central British Columbia

1982 ◽  
Vol 12 (2) ◽  
pp. 443-448 ◽  
Author(s):  
Thomas P. Sullivan ◽  
Druscilla S. Sullivan
Keyword(s):  
British Columbia ◽  
Animal Species ◽  
Lodgepole Pine ◽  
Red Squirrels ◽  
Control Programs ◽  
Snowshoe Hares ◽  
Average Proportion ◽  
Pine Stands

Barking damage by snowshoe hares (Lepusamericanus Erxleben) and red squirrels (Tamiasciurushudsonicus Erxleben) is common in overstocked stands of juvenile lodgepole pine (Pinusconforta Dougl.) in central British Columbia. Average proportion of potential crop trees damaged by hares was 30.0% and by squirrels was 37.7%. Most hare feeding injuries occurred in heavily stocked (> 20 000 stems/ha) stands, whereas squirrel damage was most common in less dense stands. Both animal species damaged trees in thinned stands, and hence may have a serious impact on stocking control programs in lodgepole pine.

scholarly journals Degree of Practicing Administrative Creativity by Education District Managers as Perceived by Department Heads and Administrators in the Districts of Mafraq Governorate

2021 ◽  
Vol 12 (22) ◽  
pp. 19-34
Author(s):  
Salwa Ayed Al-Salihi
Keyword(s):  
Statistical Methods ◽  
Training Programs ◽  
Educational Leaders ◽  
Demographic Variables ◽  
Survey Method ◽  
Department Heads ◽  
Male And Female ◽  
Female Employees ◽  
Standard Deviations ◽  
Descriptive Survey

The study aimed to assess the perceptions of department heads and administrators regarding the degree to which Educational District Managers practice administrative creativity in the districts of Mafraq governorate. To achieve this objective, the study followed the descriptive survey method, and used a questionnaire to collect data from the study sample which was selected from a population of 240 male and female employees (40 heads and 200 employees in education districts of Mafraq governorate). The sample consisted of (150) participants (25 department heads and 125 male and female employees). The data was analyzed by the use of statistical methods, such as means, standard deviations, the analysis of multiple variance and the method of Scheffe.  The study findings revealed that the participants' degree of perception was moderate, and that there were differences in their perceptions according to their different demographic variables. The study recommended preparing and designing training programs to develop the performance of educational leaders in education districts to implement the requirements of administrative innovation and creativity.

Study on Scientific Attitude and Academic Achievement among B.Ed. Trainees

2021 ◽  
pp. 51-58
Author(s):  
Rajendran P. ◽  
Anandarasu R.
Keyword(s):  
Academic Achievement ◽  
Sampling Technique ◽  
Simple Random Sampling ◽  
Demographic Variables ◽  
Survey Method ◽  
First Year ◽  
Scientific Attitude ◽  
The Arts ◽  
Significant Difference ◽  
Science Subject

The study was intended to find out the level of Scientific Attitude and academic achievement of B.Ed., trainees. This study involves a survey method. The size of the sample in the study was 941 B.Ed., trainees who were selected through the simple random sampling technique. The main objectives of the study are to the level of Scientific Attitude and academic achievement of B.Ed., trainees. To find out the significant difference in the Mean Scores of the level of scientific attitude and academic achievement of B.Ed., trainees with respect to the Demographic variables such as Gender, Year of Study, Subject, Locality of College. To find out whether there is any significant relationship between the Scientific Attitude and Academic Achievement of B.Ed., Trainees. The Statistical procedures used in this study were; Mean, Standard Deviation, ‘t’ test, and correlation to analyze the data. The Major findings of the study were; i) The level of Scientific Attitude and academic achievement of B.Ed., trainees is above average. ii) Female B.Ed., Trainees are a significantly higher level of Scientific Attitude and Academic Achievement than the Male B.Ed., Trainees. iii) Second-year B.Ed., Trainees are a significantly higher level of Scientific Attitude and Academic Achievement than the First-year B.Ed., Trainees. iv) The B.Ed., Trainees of Language Subject is significantly Higher Scientific Attitude than the Science Subject and Arts Subject. At the same time, the Science Subject is significantly having a higher level of Scientific Attitude than the Arts Subject. v) Urban B.Ed., Trainees are significantly higher levels of Scientific Attitude than the Rural B.Ed., Trainees. vi) There is a significant indifferent or negligible positive relationship between the Scientific Attitude and Academic Achievement. It's my conclusion that the present study reveals that there is several B.Ed., trainees who are having an above-average of the scientific attitude. However, the Academic Achievement of B.Ed., trainees are quite high.

Snag Densities in Managed Stands of the South Carolina Coastal Plain

1983 ◽  
Vol 7 (4) ◽  
pp. 224-229 ◽  
Author(s):  
Richard F. Harlow ◽  
David C. Guynn
Keyword(s):  
South Carolina ◽  
Coastal Plain ◽  
Avian Species ◽  
National Forest ◽  
Population Densities ◽  
Bird Populations ◽  
Cavity Nesters ◽  
Minimum Number ◽  
Pine Stands ◽  
Avian Populations

Abstract The availability of pine and hardwood snags was determined in managed pine and nonpine stands on the Francis Marion National Forest in the Coastal Plain of South Carolina. An estimate was made of snags required for nesting by avian cavity nesters indigenous to the region and of the density of cavity nesters currently provided for on the forest. Avian species that use snags 5 to 9 in. d.b.h. were apparently provided with more than 100 percent of the minimum number of suitable-size snags for average bird populations in the nonpine stands, which encompassed about 30 percent of the area. In pine stands, by contrast, there were enough snags of this size for only 20 percent of the average avian populations. For species using larger snags (≥10 in. d.b.h.), nonpine stands provided enough for approximately 27 percent of average bird populations, while pine stands provided snags for only about 6 percent of average population densities.

Density-dependent responses of mountain pine beetle to its pheromones and host volatiles in naïve lodgepole pine stands

2020 ◽  
Vol 472 ◽  
pp. 118257
Author(s):  
Jennifer G. Klutsch ◽  
Gail Classens ◽  
Caroline Whitehouse ◽  
James F. Cahill ◽  
Nadir Erbilgin
Keyword(s):  
Mountain Pine Beetle ◽  
Lodgepole Pine ◽  
Host Volatiles ◽  
Density Dependent ◽  
Mountain Pine ◽  
Pine Beetle ◽  
Pine Stands

scholarly journals Estimating Detection Probability and Density from Point-Count Surveys: A Combination of Distance and Double-Observer Sampling

The Auk ◽  
2006 ◽  
Vol 123 (3) ◽  
pp. 735-752 ◽  
Author(s):  
Michelle L. Kissling ◽  
Edward O. Garton
Keyword(s):  
Detection Probability ◽  
Survey Methods ◽  
Effective Area ◽  
Survey Method ◽  
Density Estimates ◽  
Point Count ◽  
Detection Probabilities ◽  
Fixed Radius ◽  
Count Surveys ◽  
Double Observer

Abstract Point counts are the method most commonly used to estimate abundance of birds, but they often fail to account properly for incomplete and variable detection probabilities. We developed a technique that combines distance and double-observer sampling to estimate detection probabilities and effective area surveyed. We applied this paired-observer, variable circular-plot (POVCP) technique to point-count surveys (n = 753) conducted in closed-canopy forests of southeast Alaska. Distance data were analyzed for each species to model a detection probability for each observer and calculate an estimate of density. We then multiplied each observer's density estimates by a correction factor to adjust for detection probabilities <1 at plot center. We compared analytical results from four survey methods: single-observer fixed-radius (50-m) plot; single-observer, variable circular-plot (SOVCP); double-observer fixed-radius (50-m) plot; and POVCP. We examined differences in detection probabilities at plot center, effective area surveyed, and densities for five bird species: Pacific-slope Flycatcher (Empidonax difficilis), Winter Wren (Troglodytes troglodytes), Golden-crowned Kinglet (Regulus satrapa), Hermit Thrush (Catharus guttatus), and Townsend's Warbler (Dendroica townsendi). Average detection probabilities for paired observers increased ≈8% (SE = 2.9) for all species once estimates were corrected for birds missed at plot center. Density estimators of fixed-radius survey methods were likely negatively biased, because the key assumption of perfect detection was not met. Density estimates generated using SOVCP and POVCP were similar, but standard errors were much lower for the POVCP survey method. We recommend using POVCP when study objectives require precise estimates of density. Failure to account for differences in detection probabilities and effective area surveyed results in biased population estimators and, therefore, faulty inferences about the population in question. Estimaciones de la Densidad y de las Probabilidades de Detección a Partir de Muestreos Utilizando Conteos en Puntos: Una Combinación de Muestreos de Distancia y de Doble Observador

Reduction of mountain pine beetle (Coleoptera: Scolytidae) attacks by verbenone in lodgepole pine stands in British Columbia

1989 ◽  
Vol 19 (1) ◽  
pp. 65-68 ◽  
Author(s):  
B. S. Lindgren ◽  
J. H. Borden ◽  
G. H. Cushon ◽  
L. J. Chong ◽  
C. J. Higgins
Keyword(s):  
British Columbia ◽  
Mountain Pine Beetle ◽  
Lodgepole Pine ◽  
Management Tool ◽  
Mountain Pine ◽  
Pine Beetle ◽  
The Mean ◽  
Pine Stands ◽  
Release Devices

The effect of the aggregation-inhibiting pheromone verbenone on mountain pine beetle attacks in lodgepole pine stands was assessed by affixing verbenone release devices on trees on a 10 × 10 m grid. In one experiment, aggregation to trees baited with an attractive combination of trans-verbenol, exo-brevicomin, and myrcene was reduced in verbenone-treated blocks compared with control blocks (attractive baits only). The mean number of trees with mass attacks (≥31.3 attacks/m2), mean percentage of available trees mass attacked, and mean total number of trees infested were reduced by 74.3, 66.7, and 58.5%, respectively. The ratio of 1987 attacks to 1986 attacks was reduced from 14.0 to 2.6. In a second experiment, using no attractive baits, verbenone caused similar but nonsignificant reductions. The mean number of trees with mass attacks, mean percentage of available trees mass attacked, and mean total number of trees infested were reduced by 75.2, 53.5, and 62.1%, respectively. The 1987 to 1986 attack ratio was reduced from 13.2 in control blocks to 0.2 in the verbenone-treated blocks, and the percentage of trees that were infested but not mass attacked was significantly increased, from 45.7% in the control blocks to 63.2% in the verbenone-treated blocks. We conclude that verbenone shows promise as a management tool for controlling the mountain pine beetle.

Long-term responses of mammalian herbivores to stand thinning and fertilization in young lodgepole pine (Pinus contorta var. latifolia) forest

2010 ◽  
Vol 40 (12) ◽  
pp. 2302-2312 ◽  
Author(s):  
Thomas P. Sullivan ◽  
Druscilla S. Sullivan ◽  
Pontus M.F. Lindgren ◽  
Douglas B. Ransome
Keyword(s):  
Habitat Use ◽  
Pinus Contorta ◽  
Large Scale ◽  
Stand Structure ◽  
Lodgepole Pine ◽  
South Central ◽  
Commercial Thinning ◽  
Snowshoe Hares ◽  
Understory Shrubs

Snowshoe hares (Lepus americanus Exrleben, 1777), mule deer (Odocoileus hemionus (Rafinesque, 1817)), and moose (Alces alces (L., 1758)) commonly occur in young coniferous forests. This study was designed to test the hypothesis that large-scale pre-commercial thinning (PCT) and repeated fertilization 15–20 years after the onset of treatments in young lodgepole pine (Pinus contorta var. latifolia Engelm. ex S. Wats.) stands would enhance relative habitat use by hares, deer, and moose compared with unmanaged stands. Study areas were located in south-central British Columbia, Canada. Habitat use was measured by fecal pellet and pellet-group counts. Understory vegetation and coniferous stand structure were measured in all stands. Habitat use by deer and moose was highest in heavily thinned stands, probably due to the higher levels of forage and cover provided by understory shrubs and conifers in thinned stands. Habitat use by snowshoe hares was highest in high-density stands, but also in lower-density (≤1000 stems·ha–1) stands where an increase in understory conifers provided essential cover for hares. Managers should consider the long-term nature of understory development in young stands managed for timber production. Heavy thinning (≤1000 stems·ha–1) will generate suitable understory habitat for these herbivores sooner than conventional PCT at higher stand densities.

Influence of repeated fertilization on forest ecosystems: relative habitat use by snowshoe hares (Lepus americanus)

2006 ◽  
Vol 36 (9) ◽  
pp. 2080-2089 ◽  
Author(s):  
Thomas P Sullivan ◽  
Druscilla S Sullivan ◽  
Pontus MF Lindgren ◽  
Douglas B Ransome
Keyword(s):  
Habitat Use ◽  
Pinus Contorta ◽  
Large Scale ◽  
Lodgepole Pine ◽  
Structural Diversity ◽  
Lepus Americanus ◽  
Volume Index ◽  
South Central ◽  
Crown Volume ◽  
Snowshoe Hares

This study was designed to test the hypothesis that large-scale precommercial thinning (PCT) and repeated fertilization of lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) would enhance relative habitat use by snowshoe hares (Lepus americanus Erxleben) in managed stands. Study areas were located near Summerland, Kelowna, and Williams Lake in south-central British Columbia, Canada. Each study area had nine treatments: four pairs of stands thinned to densities of 250, 500, 1000, and 2000 stems/ha, with one stand of each pair fertilized five times at 2-year intervals, and an unthinned stand. Understory vegetation and relative habitat use by snowshoe hares were measured annually from 1999 to 2003, 6–10 years after the onset of treatments. Mean crown volume index of herbs was significantly higher in fertilized than unfertilized stands, but density had no effect. Shrub volume was not affected by either treatment. Mean crown volume index of trees was significantly greater in the fertilized and high-density stands. Mean total richness of vascular plants was significantly reduced by fertilization. Mean total structural diversity of vegetation was highest in the low-density stands but was not affected by fertilization. Relative habitat use by hares, based on fecal pellet counts, was highest in the 2000 stems/ha and unthinned stands in summer. This pattern also occurred in winter when hare use was higher in fertilized than unfertilized stands. Overall, fertilized 2000 stems/ha stands provided habitat for hares to a degree comparable with unthinned stands of lodgepole pine.

Predicting survival of lodgepole pine stands infected with western gall rust

2006 ◽  
Vol 36 (4) ◽  
pp. 878-885 ◽  
Author(s):  
J M Wolken ◽  
P V Blenis ◽  
I Duncan
Keyword(s):  
Pinus Contorta ◽  
Management Strategy ◽  
Tree Mortality ◽  
Lodgepole Pine ◽  
Main Stem ◽  
Iteratively Reweighted Least Squares ◽  
Risk Of Mortality ◽  
Endocronartium Harknessii ◽  
Stem Gall ◽  
Pine Stands

The probability of lodgepole pine (Pinus contorta Dougl. ex Loud.) having main-stem galls caused by western gall rust, Endocronartium harknessii (J.P. Moore) Y. Hiratsuka, surviving to rotation is unknown. To evaluate survival, 400 galled trees with at least one stem gall and 400 trees without stem galls were measured in 1992 in two precommercially thinned stands approximately 20 years old. The survival of trees was assessed in 2003. Nonlinear regression using iteratively reweighted least squares was employed to estimate the survival of galled trees as a function of the proportion of the main stem encircled by galls. Galls encircling >79% and >91% of the stem in the two stands increased the risk of mortality relative to non-galled trees, with the risk increasing steeply with percent gall encirclement; smaller stem galls did not cause tree mortality. The 11-year pattern of survival of galled trees was similar for infections that occurred on the main stem and those that had reached the stem from a nearby branch infection. Based on an earlier model of gall expansion, 38%–43% of stem-galled trees would be expected to survive until age 80. Scribing of stem galls to prevent their expansion does not appear to be a feasible management strategy.

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