• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 16
  • 4
  • 3
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 36
  • 17
  • 14
  • 10
  • 9
  • 8
  • 8
  • 7
  • 6
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

An Evaluation of Browse Silage Production as a Feed Component for Zoo Herbivores

Lachance, Thierry 17 September 2012 (has links)
Browse is an essential part of many zoo animals’ diet. Exotic zoo animals cannot always be provided with sufficient browse due to limitations caused by climate. This is where the use of browse silage comes in. The production of silage from browse is not well developed and though used worldwide, it is done predominantly by hand. The speed of the ensiling process had to be increased. This was done by the development of the browse press. Apple browse was as the browse species for this study. Leafy stems were placed in 30L drums and subsequently compressed with the browse press. A total of 62 drums, with an average weight of 16kg, were made. Apple browse silage averaged 41.6% DM as well as 7.6% CP, 44.9% NDF, 36.3% ADF, 14.0% lignin, 2.6% starch, 1.46% calcium, 0.13% phosphorus, 2.06% fat and 6.33% ash. The nutritional values obtained from the analysis are generally comparable to those found for browse silage in the literature.
2

The correlation between available deer browse, forest cover type, and forest site /

Whelan, James Baird, January 1962 (has links)
Thesis (M.S.)--Virginia Polytechnic Institute, 1962. / Vita. Abstract. Includes bibliographical references (leaves 121-124). Also available via the Internet.
3

Snowshoe hare browse in North West Quebec : an estimation of its nutrient composition and use.

Ramsay, Timothy J. January 1980 (has links)
No description available.
4

Snowshoe hare browse in North West Quebec : an estimation of its nutrient composition and use.

Ramsay, Timothy J. January 1980 (has links)
No description available.
5

Fire - Herbivory Interactions in an East African Savanna: Effects on Acacia Drepanolobium Trees

LaMalfa, Eric M. 01 May 2019 (has links)
Globally, changes in plant community structure have occurred in ecosystems where humans have altered natural disturbance regimes. Many plants have adaptive life histories and morphological traits that have coevolved with fire and herbivory, which allows them to thrive despite repeated tissue losses. Therefore, altering the type, frequency, or severity of disturbance affects individual plant growth and competition among species. When these changes benefit or disadvantage different plant functional groups (i.e., grasses, shrubs, trees) it alters ecosystem structure and function. Understanding and predicting these vegetation changes, is critical for conservation and management of biodiversity, wildlife habitat, livestock forage, and water. Savannas are characterized by the codominance of grasses and trees, but the proportion of tree cover responds dynamically to changes in precipitation, fire, and herbivory. These factors often cause a ‘demographic bottleneck,’ which delays transitions from sapling size (1 m). In this dissertation, I investigated several fire × herbivory interactions to gain a mechanistic understanding of sapling recruitment processes that ultimately affect savanna structure. I made use of a long-term experiment that used semi-permeable fencing to manipulate presence and absence of different types of herbivores, to explore how fire and different combinations of domestic cattle, meso-wildlife, and megaherbivores (elephant and giraffe) affect sapling recruitment. First, I found clear evidence that a wide range of tree height classes resprout after being top-killed by fire, but they were all subsequently kept short by meso-wildlife browsing. Elephants played a key role in suppressing the largest resprouts after fire possibly because fire had reduced the presence of ant mutualists that defend the trees. Second, I found that in the absence of fire, cattle and wildlife indirectly affected saplings by altering competition with neighboring vegetation. Saplings competed with grass and trees during above-average rainfall years. Bare ground—a condition often caused by overgrazing—was positively associated with sapling growth. The highest sapling growth, however, occurred where large neighbor trees were absent, a condition maintained primarily by elephants browsing and damaging large neighbor trees. Finally, I found that saplings conditioned by pre-fire wildlife “browsing legacies” had high tolerance to combined fire and wildlife browsing. These results help explain how saplings tolerate repeated tissue loss to disturbance. Understanding how interactions between fire and herbivory affect sapling recruitment will help managers effectively use natural disturbance processes to manage savanna structure and function.
6

Effects of temperature on germination of selected browse species

McCleery, Dick Ray, 1948- January 1974 (has links)
No description available.
7

Estimation of browse biomass production of Salix SPP. and Betula blandulosa using multiple linear regression

Habgood, Helen Leslie January 1985 (has links)
Browse biomass production of Salix spp. and Betula glandulosa on a wetland in central British Columbia is estimated. Based on an extensive review of much of the literature pertaining to shrub biomass and shrub density estimation, a technique combining regression estimates of average stem biomass with a density estimate obtained using the corrected point distance method was applied. It was found that the best regression relationships were obtained using natural logarithmic transformations of the dimension and biomass variables. It was possible to obtain acceptable biomass equations for the four Salix species encountered without differentiating between the species. More accurate predictions of biomass were achieved using site specific equations and equations based on pooled site data than with general equations. It was concluded that the value of the approach taken is limited if site specific equations are required because of the considerable time required for sample collection and preparation. / Forestry, Faculty of / Graduate
8

THE EFFECT OF DEER BROWSE ON ACHYRANTHES JAPONICA

Seaton, Nicholas R 01 December 2020 (has links)
AN ABSTRACT OF THE THESIS OFNicholas Seaton, for the Master of Science degree in Plant Biology, presented on December 4, 2019 at Southern Illinois University Carbondale. TITLE: THE EFFECT OF DEER BROWSE ON ACHYRANTHES JAPONICAMAJOR PROFESSOR: Dr. David GibsonPlants respond in many ways to damage. These responses vary between sites depending on the severity and duration of the incident. One common form of damage in the forest understory is herbivory or browse. White tailed deer (Odocoileus virginianus) have been observed to change the dominant species of forests by selectively browsing palatable species in the understory. These changes in species dominance can lead to unwanted consequences, sometimes resulting in a proliferation of weedy or invasive plants or a reduction in performance and competitive abilities based on morphological traits. Understanding the changes that occur to undesirable species after deer browse can help land managers in their prioritization of sites for land management and understand the driving forces behind a species’ success or failure. Using deer exclosure plots, this study looks at the effects of white-tailed deer on Achyranthes japonica, an herbaceous invasive species in the Ohio River floodplain of Illinois and surrounding states. White tailed deer have been observed to browse A. japonica throughout the invaders range, but little is known about the plant’s response. Deer browse data were collected in the summer of 2018 from May to August. Estimated deer densities among six study sites ranged from 8 to 22 deer per km2. Plants that were browsed during the growing season were morphologically different to those that were not browsed. Browsed plants were 11.5 ± 0.1 cm shorter (F1,218=11.658; p<0.001) on average and produced 0.33 ± 0.09 fewer nodes (F1,216= 4.045; p<0.05). Browsed plants also produced 2.7 ± 0.32 fewer flowering spikes and were similar in length to those of un-browsed plants. These morphological differences showed significant variation between sites. Floristic Quality Indices of the herbaceous plant communities (Ȳ =3.5) ranged from 3.2 to 3.9 among study sites. This study shows that site conditions can impact the response of A. japonica growth as it continues to invade across its current introduced range and that the species is adaptive and grows along-side other similar weedy species such as Microstegium vimineum and Parthenocissus quinquefolia. This study also indicated that deer browse has little to no impact on the growth of Achyranthes japonica.Keywords: Achyranthes japonica, Odocoileus virginianus, herbivory, browse, deer density, site quality
9

The Role of White-tailed Deer (Odocoileus virginiana) in Long-distance Seed Dispersal of Amur Honeysuckle (Lonicera maackii)

Guiden, Peter W. 26 June 2014 (has links)
No description available.
10

The correlation between available deer browse, forest cover type, and forest site

Whelan, James B. 07 April 2010 (has links)
This study is one phase of a ten-year project designed to evaluate forest-wildlife relationships. The project was initiated in 1958 on the Jefferson National Forest, Broad Run Wildlife Management Area, Craig County, Virginia. The objective of the study was to determine if correlations existed between quantities of available deer browse in the understory of a particular forest cover type and several site quality measurements. The purpose of the study was to determine if weights of browse per acre could be estimated reliably by utilizing easily obtained site quality measurements instead of clipping and weighing browse. Eight site quality measurements (variables) were tested. These were: site index, depth of the A₁ soil horizon, position on slope, basal area per acre, aspect (exposure), percent of slope, elevation, and the number of clipped stems per sampling unit. Fieldwork was conducted in two major forest cover types; the oak, hickory, poplar, white pine type (cove hardwoods type), and the mixed oak-pine type. Sampling units were located randomly, in pairs, within each of these two forest cover types. Each sampling unit consisted of a circular 1/4 acre plot and a square 1/100 acre plot located at the center of the circular plot. A system of double sampling was used to obtain browse weight data and site quality data for comparisons. Data on eight variables recorded at each 1/4 acre sampling unit were compared with the quantity of browse clipped from the 1/100 acre sampling unit located at the center of that particular 1/4 acre plot. A multiple regression analysis was used to determine the degree of correlation between quantities of browse (available browse) clipped from sampling units and all measurements of the eight independent variables (site quality measurements) recorded on sampling units. The final analysis of the oak, hickory, poplar, white pine cover type data indicated that the variables significantly related to browsing weights per acre were the number of stems clipped per sampling unit and the depth of the A₁ soil horizon. These two significant variables explained 48,63 percent of the total variation in browse weights occurring between sampling units. Using only the two significant site quality measurements (independent variables), the final estimating equation was: Y (pounds of browse per acre) = -0.14 + 0.06 (number of stems clipped per sampling unit) + 0.61 (depth of the A₁ horizon, inches). The final estimating equation should not be used for reliable estimates of browse production in the oak, hickory, poplar, white pine forest cover type. A total of 51.37 percent of the variation in browse weights occurring between sampling units is unaccounted for in this equation. The final analysis of the mixed oak-pine cover type data indicated that the only variable significantly related to browsing weights per acre was the number of stems clipped per sampling unit. However, this significant variable explained only 17.97 percent of the total variation in browse weights occurring between sampling units. Using only the one significant site quality measurement (independent variable), the final estimating equation was: Y (pounds of browse per acre) = 2.24 + 0.07 (number of stems clipped per sampling unit). The final estimating equation should not be used for reliable estimates of available browse production in the mixed oak-pine forest cover type. A total of 82.03 percent of the variation in browse weights occurring between sampling units was unexplained in this equation. More research is necessary to determine other easily measured environmental factors (variables) which might bear a significant relationship to quantities of available deer browse produced in the two forest cover types sampled. When several more of these significant variables are discovered, the addition of these variables to the estimating equations for the two cover types might account for a large enough percent of the explained variation to enable the game biologist to use the equations for reliable estimates of browse production. / Master of Science

Page generated in 0.037 seconds