Landscape architects and designers have the ability to construct plantings in a landscape with native or non-native plants, or a combination of both plant types. The question at hand is, why choose one over the other? This study explores what might impact the plant choice decisions of practicing landscape architects in the southeast United States. A survey is utilized to understand how respondents make plant choice decisions and perceive native plants. Comparisons between previous studies are made focusing on their distribution methods, survey populations and major findings. The findings of this study are not conclusive due to a small response rate; however, they can be applied to the survey population. The results may indicate that the most common obstacles when using native plants are limited availability of natives and difficulty sourcing them, aesthetics and negative client perception, and the maintenance requirements and lack of maintenance knowledge of native plants.

Efficient and environmentally responsible tree planting is crucial to sustainable land management. Tree planting processes involve significant machinery and labor, impacting efficiency and ecosystem health. In response, Södra Skogsägarna introduced the BraSatt initiative to develop an autonomous planting vehicle called E-Beaver. This vehicle aims to simultaneously address efficiency and ecological concerns by autonomously planting saplings in clear-felled areas. BIT ADDICT, partnering with Södra Skogsägarna, is re- sponsible for developing the control system for E-Beaver’s autonomous navigation and perception.  In this thesis work, we examine the possibility of using the computer vision models YOLO and U-Net for detecting and segmenting newly planted saplings in a clear felled area. We also compare the models’ performances with and without augmenting the dataset to see if that would yield better-performing models. RGB and RGB-D images were gath- ered with the ZED 2i stereo camera. Two different models are presented, one for detecting saplings in RGB images taken with a top-down perspective and the other for segmenting saplings trunks from RGB-D images taken with a side perspective. The purpose of this the- sis work is to be able to use the models for evaluating the plating of newly planted saplings so that autonomous tree planting can be done.  The outcomes of this research showcase that YOLOv8s has great potential in detecting tree saplings from a top-down perspective and the YOLOv8s-seg models in segmenting sapling trunks. The YOLOv8s-seg models performed significantly better on segmenting the trunks compared to U-Net models.  The research contributes insights into using computer vision for efficient and ecologi- cally sound tree planting practices, poised to reshape the future of sustainable land man- agement. / BraSatt

In western North America, winterfat (Krascheninnikovia lanata (Pursh) A. Meeuse & Smit) is a valuable protein-rich subshrub whose restoration has been limited by poor seed flowability and low rates of seedling establishment. Seed flowability can be limited by a dense covering of hairs on winterfat fruits that can cause them to clog in mechanized equipment. Seedling establishment can be limited by premature germination of fall-sown seeds that can cause over-winter seedling mortality from freezing, pathogen attack, and winter drought. Seed coatings may provide a way to overcome both of these barriers to winterfat restoration. Coatings can compress hairs against the fruit and improve seed flowability, and a hydrophobic polymer within seed coatings can repel water and delay germination of fall-sown seeds until spring, when winter hazards have subsided, and conditions are more conducive to seedling establishment. With the advent of this technology, there is a need to establish cultural practices, such as optimal planting depth, for coated winterfat fruits. In chapter 1 of this thesis, we evaluated the influence of planting depth, seed coatings, and their interactions on winterfat seedling emergence under laboratory and field conditions. We predicted that seedling emergence would be greatest from shallow planting depths, and that coatings would not affect emergence. Results generally supported our hypothesis, with seedling emergence being highest from surface-sown and shallow-planted seeds for both non-coated (control) and coated winterfat fruits in laboratory and field conditions. Emergence from surface-sown seeds was more than two-fold greater than from the deepest planting depth (12.7 mm). Seed coatings improved emergence of surface-sown seeds compared to the control by 52 – 168% in the laboratory but had no effect in the field. As predicted, emergence was similar between coated and non-coated fruits when sown below the soil surface in both laboratory and field conditions. These results suggest that seed coatings may improve winterfat restoration success by improving flowability without inhibiting emergence, allowing the species to be used in more seeding projects. Winterfat seed coatings may be improved with the use of a hydrophobic polymer to delay germination of fall-sown seeds until spring. In chapter 2 of this thesis, we compared seedling emergence from non-coated seeds, calcium carbonate coated seeds (blank-coated), and seeds coated with calcium carbonate plus an exterior hydrophobic coating. We counted the number of live seedlings and those that had died after emerging, and calculated mortality percentages for each treatment. We hypothesized that emergence would be greatest from hydrophobic-coated seeds, and the results supported our hypothesis. Seedling emergence from hydrophobic-coated seeds was three-fold greater than the control, and five-fold greater than blank-coated seeds. Mortality percentages were highest for the control, lower for blank-coated seeds, and lowest for hydrophobic-coated seeds. Thus, hydrophobic seed coatings can improve winterfat seedling emergence, and so could be instrumental restoring this valuable species to degraded rangelands.

No description available.

Lina och Ronna, strax utanför Södertälje i Stockholm, har i en undersökning påvisat hög kriminalitet och en otrygg befolkning. Områdena har trots sitt knappa avstånd stora socioekonomiska olikheter. Min ambition med projektet är att förena stadsdelarna på en bondgårdsinspirerad social mötesplats belägen på en åker strax utanför staden. Genom allt från en föreläsningssal i en lada, ett ekologiskt café, en restaurang och en uteservering i en silo, till växthus och odlingsytor samt en inbjudande marknadsplats som byggs upp av invånarna själva, engageras befolkningen till att bli mer självförsörjande, att börja odla och att finna en gemenskap i odlingen som aktivitet. De traditionella bondgårdshusen som återfinns på platsen för tanken tillbaka i tiden och ut mot landsbygden. Mötesplatsen ligger i anknytning till kolonilotter på åkern som dels bidrar till det visuella lärandet av att besöka platsen, men som också tillåts få sälja sina varor där. Slutligen är förslaget ett initiativ att se på varandra bortom social och ekonomisk status som jämlika. Ett sätt att öppna ögonen för varandra och inse att vi har mer gemensamt än vad vi tror, men också att det finns otroligt mycket som vi fortfarande kan lära av varandra. / Lina and Ronna, outside of Södertälje, Stockholm, have demonstrated high levels of criminality and insecurity in studies. The regions have, despite minimal distance, great differences in socio-economic standards. My ambition with this project is to unite the districts on a farm-inspired meeting place located outside the town. With everything from a lecture hall in a barn, an organic café, a restaurant and outdoor seating in a silo, to greenhouses and farming fields as well as an inviting marketplace built by the inhabitants, the visitors are encouraged to become more self-sufficient, cultivate, and build community via cultivating. The traditional farmhouses found on the location brings the visitor back in time and towards the countryside. The meeting place is closely connected with allotments, which partly contributes to the visual learning of visiting the place, but which also allows the cultivators to sell fresh produce at the market. Lastly, the proposition is an initiative to invite people to see beyond social and economical status and see each other as equals. A way of opening our eyes up to each other, discovering that we have more in common than previously thought, and realising there is much we have yet to learn from each other.

No description available.

Diameter distributions of juvenile loblolly pine (Pinus taeda L.) with different planting densities were characterized utilizing a two-parameter Weibull distribution. Trend analysis was employed to describe the effects of planting density, age, relative spacing, and rectangularity on the estimated diameter distributions for juvenile loblolly pine. A reparameterization of the two-parameter Weibull distribution was sought to reduce the dispersion of the estimated shape parameter. Methods that quantify the amount of inter-tree spatial dependency in a particular stand were applied. Empirical semivariograms were derived for each plot over all ages to enable spatial trend recognition. Moran's I and Geary's C coefficients were estimated for ground-line diameters from ages 2 to 5, and for breast height diameters from ages 5 to 11. Though there was no discernable trend in the presence of significant spatial autocorrelation with planting density, an initial negative trend with age was present, but leveled off by age 5. A conditional autoregressive model was utilized to evaluate the amount of spatial influence stems in a stand have on one another. The occurrence of significant spatial influences was positively associated with age through age 8, the trend then leveled off; no recognizable trend was detected with planting density. These indices help to describe stand dynamics that are influenced by the spatial distribution of stems. Models to predict the parameters of the two-parameter Weibull distribution were developed to aid in forecasting and simulation of juvenile loblolly pine. Simulations were conducted where a spatial dependency was imposed on the diameters within a stand. The spatial structure simulation enables accurate representations of stem characteristics when simulating forest stands that include spatially-explicit information. / Ph. D.

The study was undertaken as a part of the research program of the Agricultural Engineering Department of the Virginia Agricultural Experiment Station to determine a method of planting corn in a vegetative residue mulch seedbed which would result in stand and yields as good as obtained in planting in a conventionally prepared seedbed. Yields obtained in the first experiments in Virginia were very low because methods used in preparing the mulch seedbed, which had proven successful in other locations in the United States, proved unsuited in that they did not kill the perennials and legumes in the vegetative residue. This factor was overcome in 1947 when the “double-cut plow” was introduced for preparing the residue mulch seedbed. However, the initial stands and yields were still not as good as for corn grown on a mulch seedbed in experiments conducted since that time. This experiment was conducted on eight main plots. Mulch seedbeds were prepared on four of the plots using the “double-cut plow” method, and on the other four the seedbeds were prepared by the conventional turn-plow method. The plots were arranged to conform to a randomised split-plot design. Six planting methods were devised by modifying a conventional two-row, tractor-mounted corn planter with fertilizer attachment. The plots were planted, using six treatments randomized in each of the eight plots, on May 10, under fair conditions. The performance of the planting equipment was good except in the planting of the first three plots in treatment P3, the first treatment planted. Stand counts and apparent vigor data were taken before each of the three cultivations. A stand count, without apparent vigor observations, was taken just prior to silking. A study was made at the time of the initial stand count in an effort to determine the causes of germination failures of seed planted. An application of 500 pounds of nitrate of soda as a side dressing was made at the time of the second cultivation. Commercial 4-12-4 fertilizer was applied to the corn at planting at a rate of 500 pounds per acre. The second plowing was delayed because of rain and resulted in weed growth in the rows. These weeds were head out just prior to the silking period. Silking dates of the corn, as an index of maturity, were determined for each planting and seedbed preparation treatment. The samples for yield were gathered in early October and placed in an artificial drier. They were shelled and weighed, and yield data were recorded in mid-October. The general condition of the harvested grain was good. There was almost a total absence of lodging when the harvest was made. The most successful, in providing initial stands and yields of grain, were those planting treatments in which mechanical means were used for pushing the mulch aside in the path of the planter. Glods, in the mulch plots where mechanical means were not employed to push the vegetative residue mulch layer away from the path of the planter, were found to interfere with young plants coming to the surface. Results of this study indicate that corn grown in a residue mulch seedbed was at a slight disadvantage in apparent vigor during the early part of the growing season, but at no appreciable disadvantage in maturing. The data did show that there was a larger loss in stand in mulch plots than in check. While the statistical analysis of variance of the initial stand count and yield data showed no significant differences, the variations did indicate definite trends. / Master of Science

The objective of this study was to develop diameter/basal area increment equations for loblolly pine trees in thinned and unthinned plantations on cutover, site-prepared areas. Results indicated that one set of coefficients was sufficient to estimate individual tree growth (for the three year period following thinning) on lightly thinned and heavily thinned plots. However, unthinned plots required a separate set of coefficients and therefore a separate equation to estimate growth. Diameter growth was adequately explained by some form of the following regressor variables: pine basal area, hardwood basal area, initial age, initial diameter, average height of the dominant and codominant trees, and crown ratio ( optional). Transforming the dependent variable from a function of diameter to a similar function of basal area had no apparent effect on the precision of the predicted results. Two alternative methods of predicting diameter growth were evaluated: (1) direct fitting of diameter growth, and (2) fitting a potential diameter growth equation and a modifier function. Even though the potential times modifier approach performed slightly better in terms of fitting the data, it provided unrealistic results at ages beyond the upper range of the data. After additional data are obtained at older ages, the potential times modifier approach may surpass the direct approach. However, at present, the direct diameter growth model was chosen as the final model form. / M.S.

Several crops are being touted as a renewable energy source. Sweet sorghum is adapted to many areas, grows relatively rapidly, has moderate water and nutrient requirements, and develops high levels of fermentables. A long term supply of fermentables is needed to make ethanol production economically feasible. Short term availability of fermentables results in unfavorable returns from investments in equipment and crop production. Two planting dates (15 May and 1 June) and eight harvest dates (30 Sep. to 15 Mar.) were used in efforts to to extend the availability of sweet sorghum fermentables. Respiration of sweet sorghum tissue was measured with an infrared gas analyzer before and after freezing to quantify loss of fermentables associated with delayed harvests. Vital stains were used before and after freezing to estimate cell mortality. No significant difference was found in the level of fermentables in sorghum from the two planting dates. Delay-ing harvest caused fermentables to decline significantly (30%) by mid-November and to continue to drop through March. Respiration dropped 90% after exposure to -8 C, but resumed the same rate after 1 week. Vital stai!1ing showed cells die upon freezing. Relatively high respiration rates in the dead tissue suggests saprophytic microbes are responsible for the large decline in fermentables after freezing. Eleven cultivars and lines were tested for yield of fermentables. Wray was superior in yield of fermentables, while Sumac and Sugardrip were inferior. / Master of Science