Typescript (photocopy). / Digitized by Kansas Correctional Industries

Linear strips of vegetation set within a less-hospitable matrix are common features of landscapes throughout the world. Depending on location, form and function, these linear landscape elements include hedgerows, fencerows, shelterbelts, roadside or streamside strips and wildlife corridors. In many anthropogenically-modified landscapes, linear strips are important components for conservation because they provide a large proportion of the remaining wooded or shrubby habitat for fauna. They may also function to provide connectivity across the landscape. In some districts, the linear strips form an interconnected network of habitat. The spatial configuration of remnant habitat (size, shape and arrangement) may influence habitat suitability, and hence survival, of many species of plant and animal in modified landscapes. Near Euroa in south-eastern Australia, the clearing and fragmentation of temperate woodlands for agriculture has been extensive and, at present, less than 5% tree cover remains, most of which (83%) occurs as linear strips along roads and streams. The remainder of the woodland occurs as relatively small patches and single isolated trees scattered across the landscape. As an assemblage, arboreal marsupials are woodland dependent and vary in their sensitivity to habitat loss and fragmentation. This thesis focusses on determining the conservation status of arboreal marsupials in the linear network and understanding how they utilise the landscape mosaic. Specifically, the topics examined in this thesis are: (1) the composition of the arboreal marsupial assemblage in linear and non-linear woodland remnants; (2) the status and habitat preferences of species of arboreal marsupial within linear remnants; and (3) the ecology of a population of the Squirrel Glider Petaurus norfolcensis in the linear network, focusing on population dynamics, spatial organisation, and use of den trees. The arboreal marsupial fauna in the linear network was diverse, and comprised seven out of eight species known to occur in the district. The species detected within the strips were P. norfolcensis, the Sugar Glider Petaurus breviceps, Common Brushtail Possum Trichosums vulpecula, Common Ringtail Possum Pseudocheirus peregrinus, Brush-tailed Phascogale Phascogale tapoatafa, Koala Phascolarctos cinereus and Yellow-footed Antechinus Antechinus flavipes. The species not detected was the Feathertail Glider Acrabates pygmaeus. Survey sites in linear remnants (strips of woodland along roads and streams) supported a similar richness and density of arboreal mammals to sites in non-linear remnants (large patches or continuous tracts of woodland nearby). Furthermore, the combined abundance of all species of arboreal marsupials was significantly greater in sites in the linear remnants than in the non-linear remnants. This initial phase of the study provided no evidence that linear woodland remnants support a degraded or impoverished arboreal marsupial fauna in comparison with the nonlinear remnants surveyed. Intensive trapping of arboreal marsupials within a 15 km linear network between February 1997 and June 1998 showed that all species of arboreal marsupial (except A. pygmaeus) were present within the linear strips. Further analyses related trap-based abundance estimates to measures of habitat quality and landscape structure. Width of the linear habitat was significantly positively correlated with the combined abundance of all arboreal marsupials, as well as with the abundance of P. norfolcensis and T. vulpecula. The abundance of T. vulpecula was also significantly positively correlated with variation in overstorey species composition, Acacia density and the number of hollow-bearing trees. The abundance of P. norfolcensis was positively correlated with Acacia density and canopy width, and negatively correlated with distance to the nearest intersection with another linear remnant. No significant variables were identified to explain the abundance of P. tapoatafa, and there were insufficient captures of the remaining species to investigate habitat preferences. Petaurus norfolcensis were resident within the linear network and their density (0.95 -1.54 ha-1) was equal to the maximum densities recorded for this species in continuous forest elsewhere in south-eastern Australia. Rates of reproduction were also similar to those in continuous forest, with births occurring between May and December, a mean natality rate of 1.9, and a mean litter size of 1.7. Sex ratios never differed significantly from parity. Overall, the population dynamics of P. norfolcensis were comparable with published results for the species in contiguous forest, clearly suggesting that the linear remnants currently support a self-sustaining, viable population. Fifty-one P. norfolcensis were fitted with radio transmitters and tracked intermittently between December 1997 and November 1998. Home ranges were small (1.3 - 2.8 ha), narrow (20 - 40 m) and elongated (322 - 839 m). Home ranges were mostly confined to the linear remnants, although 80% of gliders also utilised small clumps of adjacent woodland within farm paddocks for foraging or denning. Home range size was significantly larger at intersections between two or more linear remnants than within straight sections of linear remnants. Intersections appeared to be important sites for social interaction because the overlap of home ranges of members of adjacent social groups was significantly greater at intersections than straight sections. Intersections provided the only opportunity for members of three or more social groups to interact, while still maintaining their territories. The 51 gliders were radiotracked to 143 different hollow-bearing trees on 2081 occasions. On average, gliders used 5.3 den trees during the study (range 1-15), and changed den trees every 4.9 days. The number of den trees used by each glider is likely to be conservative because the cumulative number of den trees continued to increase over the full duration of the study. When gliders shifted between den trees, the mean distance between consecutive den sites was 247 m. Den trees were located throughout a glider's home range, thereby reducing the need to return to a central den site and potentially minimising energy expenditure. Dens were usually located in large trees (mean diameter 88.5 cm) and were selected significantly more often than expected based on their occurrence within the landscape. The overall conclusion of this thesis is that the linear network I studied provides high quality habitat for resident populations of arboreal marsupials. Important factors influencing the suitability of the linear remnants appear to be the high level of network connectivity, the location on soils of high nutrient status, the high density of large trees and an acacia understorey. In highly fragmented landscapes, linear habitats as part of the remaining woodland mosaic have the potential to be an integral component in the conservation of woodland-dependent fauna. The habitat value of linear strips of vegetation should not be underestimated.

Thesis (Ph. D.)--Oregon State University, 1984. / Typescript (photocopy). Includes bibliographical references (leaves 97-99). Also available on the World Wide Web.

Large-extent ice storms have received relatively little attention from researchers. This research investigates the effects of abiotic and biotic factors on the spatial patterns of ice storm disturbance on a forested landscape. This investigation provides a landscape-level perspective on the impacts of ice storm disturbance, clarifies the effects on ecosystem dynamics, and will aid future forest management plans. The study was conducted in Ouachita National Forest (ONF) in west-central Arkansas and southeastern Oklahoma and examined approximately 6000 km2 of forest between 150 and 800 m elevation. Normalized Difference Vegeation Index (NDVI) difference values were calculated using two Landsat 7 ETM+ scenes to identify NDVI changes that potentially were associated with ice storm damage to the forests. Forty-six geolocated field sites were used to determine the relationship of NDVI difference to actual forest damage caused by the ice storm by counting the number of downed tree boles intersecting a 100 m transect. These field sites encompassed a broad range of each of the physical variables (i.e. elevation, slope, and aspect), forest type, and degree of damage. The linear regression model determined the relationship between NDVI difference and ice storm damage. Elevation, slope, and aspect were calculated based on individual pixels from the DEM. Categories of forest damage were based on NDVI difference values. A chi-square test of correspondence and Cramer’s V test were then used to analyze relationships of damage to abiotic and biotic variables. The strong, negative relationship observed in the linear regression model suggested that NDVI was representative of ice storm damage in the study area. The chi-square test of correspondence indicated the abiotic and biotic variables all had associations with NDVI difference results (p<0.001). The Cramer’s V test established that elevation had the strongest influence on the degree of ice storm damage followed closely by slope and aspect. Moderate elevations, moderate slopes, and windward aspects received the highest percentage of major storm damage. Forest type displayed a weak relationship with the extent of damage. The topographic patterns of ice storm damage are similar to patterns found in previous research. Topography influenced spatial patterns of ice storm damage. Elevation, slope, and aspect were all found to be important variables influencing the degree of ice storm damage. Knowledge concerning these spatial patterns is critical for future studies of ecosystem dynamics and forest management practices.

No description available.

There is a great deal of vegetation literatures about vegetation of forest and alpine grass in Taiwan, but the weed vegetation survey often investigates the species only. As the study of vegetation in Taiwan is for away from completeness, and weed is important to biodiversity is imperative, therefore the study of weed vegetation. The study selected weed vegetation in Daliau Township as study area, and surveyed floristic composition and environmental factors. The study used Branu-Blanquet method, and set up 304 plots. Classification of the vegetation types was conducted by cluster analysis and tabular comparison method, and following the treatment of Taiwan vegetation classification system. Detrended correspondence analysis (DCA) and nonmetric multidimentional analysis (NMDS) used to clarify the relationship between vegetation composition and environmental factors. The lower two levels of the hierarchy, alliance and association, were based on floristic composition according to the floristic-sociological concept of diagnostic species. The relationships of floristic composition and environmental factors were not significant, and this might be caused by that the composition of weed communities can quickly responsed to weather and human disturbances. The resultant system consisted of 2 classes, 3 formations, 21 alliances, 37 associations, 6 tentative vegetation types and 10 intermediate vegetation types. It may supply some misgiving of study of vegetation in Taiwan.

Large-extent ice storms have received relatively little attention from researchers. This research investigates the effects of abiotic and biotic factors on the spatial patterns of ice storm disturbance on a forested landscape. This investigation provides a landscape-level perspective on the impacts of ice storm disturbance, clarifies the effects on ecosystem dynamics, and will aid future forest management plans. The study was conducted in Ouachita National Forest (ONF) in west-central Arkansas and southeastern Oklahoma and examined approximately 6000 km2 of forest between 150 and 800 m elevation. Normalized Difference Vegeation Index (NDVI) difference values were calculated using two Landsat 7 ETM+ scenes to identify NDVI changes that potentially were associated with ice storm damage to the forests. Forty-six geolocated field sites were used to determine the relationship of NDVI difference to actual forest damage caused by the ice storm by counting the number of downed tree boles intersecting a 100 m transect. These field sites encompassed a broad range of each of the physical variables (i.e. elevation, slope, and aspect), forest type, and degree of damage. The linear regression model determined the relationship between NDVI difference and ice storm damage. Elevation, slope, and aspect were calculated based on individual pixels from the DEM. Categories of forest damage were based on NDVI difference values. A chi-square test of correspondence and Cramer’s V test were then used to analyze relationships of damage to abiotic and biotic variables. The strong, negative relationship observed in the linear regression model suggested that NDVI was representative of ice storm damage in the study area. The chi-square test of correspondence indicated the abiotic and biotic variables all had associations with NDVI difference results (p<0.001). The Cramer’s V test established that elevation had the strongest influence on the degree of ice storm damage followed closely by slope and aspect. Moderate elevations, moderate slopes, and windward aspects received the highest percentage of major storm damage. Forest type displayed a weak relationship with the extent of damage. The topographic patterns of ice storm damage are similar to patterns found in previous research. Topography influenced spatial patterns of ice storm damage. Elevation, slope, and aspect were all found to be important variables influencing the degree of ice storm damage. Knowledge concerning these spatial patterns is critical for future studies of ecosystem dynamics and forest management practices.

Trail is a common outdoor recreation facility. The construction of trail often changes space structures of the nature and affect the vegetation of the trailside. Many studies indicated that the impact of outdoor recreation directly and indirectly change the plant species coverage and composition. A few new trails were recently established in Panping-Shan, Kaohsiung, and there is a need of environmental data for the management . However, the vegetation structure along the trail and the degree of trail construction impact were unclear. This study sampled vegetation and environmental factors along the trails in Panping-Shan, Kaohsiung. The trail in Panping-Shan has three patterns, footpath, plank and macadam. 35 large plots ¡]10*10m2¡^and 132 small plots ¡]1*1m2¡^ have been established along the trail. The data were analyzed with Two-way indicator species analysis ¡]TWINSPAN¡^and Canonical correspondence analysis ¡]CCA¡^ to seek the correlation of the vegetation composition, species distribution and the trailside environment gradient. The results show that the dominant species in Panping-Shan are Broussonetia papyrifera and Macarange tanarius, and the vegetation could be divided into four subtypes according to the indicator species; the understory vegetation could be divided into six types by TWINSPAN. The CCA result shows that the canopy coverage and the edaphic factors, soil depth and soil moisture, are the major environment factors influencing the understory vegetation. Between the different patterns of trail, there were no significant difference, but the environment of the footpath is more heterogeneous. It is suspected that the current light recreation activities and the unique geological structures made no obvious understory vegetation difference between the trailside and the forest interior.

Predictive vegetation mapping was employed to predict the distribution of vegetation communities and physiognomies in the portion of the Scandinavian mountains in Sweden. This was done to address three main research questions: (1) what environmental variables are important in structuring vegetation patterns in the study area? (2) how well does a classification tree predict the composition of mountain vegetation in the study area using the chosen environmental variables for the study? and (3) are vegetation patterns better predicted at higher levels of physiognomic aggregation? Using GIS, a spatial dataset was first developed consisting of sampled points across the full geographic range of the study area. The sample contained existing vegetation community data as the dependent variable and various environmental data as the independent variables thought to control or correlate with vegetation distributions. The environmental data were either obtained from existing digital datasets or derived from Digital Elevation Models (DEMs). Utilizing classification tree methodology, three model frameworks were developed in which vegetation was increasingly aggregated into higher levels of physiognomic organization. The models were then pruned, and accuracy statistics were obtained. Results indicated that accuracy improved with increasing aggregation of the dependent variable. The three model frameworks were then applied to the Abisko portion of the study area in northwestern Sweden to produce predictive maps which were compared to the current vegetation distribution. Compositional patterns were critically analyzed in order to: (1) assess the ability of the models to correctly classify general vegetation patterns at the three levels of physiognomic classification, (2) address the extent to which three specific ecological relationships thought to control vegetation distribution in this area were manifested by the model, and (3) speculate as to possible sources of error and factors affecting accuracy of the models.

Thesis (M.S.)--Eastern Illinois University, 2009. / Includes bibliographical references (leaves 29-35).