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1
Walmesley, Timothy James. „Factors influencing the establishment of amenity trees“. Thesis, University of Liverpool, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.237509.
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2
Yeung, Ka-ming. „The establishment and survival of roadside trees in Hong Kong /“. [Hong Kong : University of Hong Kong], 1993. http://sunzi.lib.hku.hk/hkuto/record.jsp?B13474583.
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3
Yeung, Ka-ming, und 楊家明. „The establishment and survival of roadside trees in Hong Kong“. Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1993. http://hub.hku.hk/bib/B31233326.
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4
Bryan, Donita Lynn. „Influence of planting depth on landscape establishment of container-grown trees“. [College Station, Tex. : Texas A&M University, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-3179.
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5
Thuesen, Kevin (Kevin Andrew). „The Effects of Organic Surface Amendments on Soil Nutrients and Initial Tree Establishment“. Thesis, University of North Texas, 1999. https://digital.library.unt.edu/ark:/67531/metadc277585/.
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This study examined the effects of replicating woodland soil surface horizonation on the nutrient status of underlying soils and the initial establishment and growth of trees. A total of 283 container grown trees were planted in a bufferzone around a future landfill site. Control amendments consisted of an 8 cm layer (0.5 m3) of wood chips applied in a circular area of 4.6 m2 around the trees' planting pit. For the treatment, a 2.5 cm layer of composted biosolids (0.15 m3 or 80 Mg/ha) was applied in a circular area of 4.6 m2 around the trees' planting pit followed by an 8 cm layer (0.5 m3) of wood chips. The results indicate that the replication of woodland soil surface attributes using composted biosolids can significantly improve the nutrient status of underlying soil. Some significant effects were seen under control conditions, too. However, the effects on tree establishment and growth parameters were, for the most part, not statistically significant.
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Hau, Chi-hang. „The establishment and survival of native trees on degraded hillsides in Hong Kong /“. Hong Kong : University of Hong Kong, 1999. http://sunzi.lib.hku.hk/hkuto/record.jsp?B21827400.
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7
Bellett-Travers, David Marcus. „Water relations and soil moisture requirements of transplanted amenity trees during establishment“. Thesis, University of Hertfordshire, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251544.
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8
Hau, Chi-hang, und 侯智恆. „The establishment and survival of native trees on degraded hillsides in Hong Kong“. Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B29799612.
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9
Wells, E. Doyle. „The establishment and early growth of trees planted on drained peatlands in Newfoundland, Canada“. Thesis, University of Aberdeen, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295584.
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One part of the afforestation programme consisted of the establishment of an afforestation trial on a bog and fen site in central Newfoundland to determine growth and nutrient response of newly-planted black spruce (Picea mariana (Mill.) B.S.P.) and eastern larch (Larix laricina ((Du Roi) K.Koch). The experimental design was a split-split-plot consisting of surface treatments (untilled, tilled) as main-plot treatments, fertilization (unfertilized, PK) as split-plot treatments and four ditch spacings ( 3 m, 5 m, 7 m, and 15 m) as split-split-plot treatments. A total of 3,960 25-week old container seedlings of each species were planted on each site at spacings of 0.50 m in rows of nine trees, each row being situated at a distance of 1.0 m apart. Surfaces were tilled at 0-200 mm depth using a farm rotovater attached to the back of a tractor. Ditches were made at depths of 0.50-0.75 m with a Dondi ditcher attached to the back of a tractor, and fertilizers were broadcast at the rate of 60 kg/ha P and 50 kg/ha K. The second part of the afforestation programme was a refertilization trial of 1) Japanese larch (Larix leptolepis Seib and Zucc.) and black spruce trees planted on Stephenville bog in western Newfoundland in 1968; and 2) black spruce, white spruce (Picea glauca (Moench) Voss) and lodgepole pine (Pinus contorta Dougl.) planted on Millertown fen in central Newfoundland in 1973. Both sites had been ploughed with a Parkgate-Tyne plough at 1.8 m spacings 1-2 years prior to planting. Following planting of the Stephenville site in 1968, the black spruce and Japanese larch were spot-fertilized (around each tree) with a top-dressing of 57 g of ground mineral rock phosphate. This procedure was repeated in 1970 with 128 g of a mixture of phosphate and potassium (20% P2O2, 20% K2O). On the Millertown site, all trees were spot-fertilized in 1973 with a mixture of 71 g urea, 99 g rock phosphate and 41 g potassium sulfate.
10
Witmer, Robert K. „Water Use of Landscape Trees During Pot-In-Pot Production and During Establishment in the Landscape“. Diss., Virginia Tech, 2000. http://hdl.handle.net/10919/30199.
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Water conservation and pollution concerns from nutrient runoff will very likely dictate precise irrigation regimes for nursery managers in Virginia. Maximum plant growth with minimum input of water and fertilizer is becoming increasingly important. Therefore, water use and growth of red and sugar maple (Acer rubrum L. 'Franksred' and Acer saccharum Marsh.) were studied during two years of pot-in-pot (P+P) production and during three years after transplanting to field soil. Three major experiments were completed. The first experiment studied the effect of frequent irrigation (three-times-a-day) versus standard once-a-day irrigation and found that frequent irrigation increased trunk diameter growth of sugar maples in the second production cycle and for red maples in both production cycles. Height growth of neither species was affected by frequent irrigation. A study of sap flow pattern indicated that late day water stress of red maples was partially alleviated by frequent irrigation. In the second experiment, red and sugar maples were transplanted to field soil after one (1-yr) or two (2-yr) years of P+P production. Irrigation frequency requirement decreased as the trees grew and depended on environmental conditions, size at planting, source of water (rainfall versus irrigation) and species. Height and trunk diameter of 1-yr red maple was equal to that of 2-yr trees after only one year. Height and trunk diameter differences between 1-yr and 2-yr sugar maple trees persisted three years after transplanting. In the third experiment water use of 1-yr and 2-yr red and sugar maple while in P+P production was investigated. Four models of daily water-use were developed. A simple model that is suitable for growers includes species, trunk cross-sectional area (BA) and air temperature (TA) observations. An environmental model was developed using the Penman-van Bavel estimate of evapotranspiration (ET). ET required modifications based on tree characteristics, air temperature, windspeed and relative humidity to be an effective predictor of water-use. A complex model was based on a sine-cosine function of day-of-the-year. This model fits water-use data well for each species and production cycle and includes BA, ET and TA. An alternate simpler model requires only day-of-the-year, TA and BA, offering growers a relatively simple and accurate model of water use.Ph. D.
11
Pareliussen, Ingar. „Natural and experimental establishment of trees in the edges of a fragmented forest,Ambohitantely Forest Reserve, Madagascar“. Doctoral thesis, Norwegian University of Science and Technology, Department of Biology, 2004. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-1895.
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12
Ghaui, Mark. „Grass root gaps : an establishment bottleneck limits trees in savannas and excludes them in South Africa's highveld grasslands“. Bachelor's thesis, University of Cape Town, 2010. http://hdl.handle.net/11427/25930.
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The Highveld grasslands of South Africa are climatically capable of supporting trees, yet no trees occur. The fact that no fire adapted savanna trees occur in these grasslands confounds the suggestion that fires maintain these ecosystems. This study addresses the question of what prevents savanna trees from surviving. It was hypothesized that grass root competition for space eliminates the availability of suitable 'gaps' for tree establishment under high rainfall conditions. Demographic bottlenecks on Acacia species populations were determined by examining the ratio of juvenile plants to adult carrying capacity. Below-ground root biomass was quantified in 10cm layers to a depth of 40cm at six sites along an elevation and rainfall gradient. The δ¹²C/δ¹³C ratio was determined for roots collected. High rainfall sites were limited at the tree seedling establishment phase. Fine root biomass to 40cm depth increased with rainfall from 613 g/m³ (Standard deviation = 235.1) to about 1326 g/m³ (Standard deviation = 573.1). The surface layer had significantly higher fine root biomass than other layers, with site mean biomass in the surface layer increasing with rainfall (p<0.00001, F₃.₄₂₃= 18.621). Available gaps for tree establishment decreased with increasing rainfall/elevation; no gaps were found at the Highveld grassland site. The findings of this study point to a strong savanna tree demographic bottleneck exerted, at the seedling establishment phase, by below ground grass competition for space. The Highveld grasslands receive to high rainfall for grass roots gaps to occur and permit seedling establishment.
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Scholtz, Theo. „The evaluation of the establishment and growth of indigenous trees to restore deforested riparian areas in the Mapungubwe National Park, South Africa / Theo Scholtz“. Thesis, North-West University, 2007. http://hdl.handle.net/10394/1842.
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The deforestation of riparian areas is a major concern in southern Africa. These areas are characterized as fragile ecosystems which contribute largely to the regional and global biodiversity of the world. It is therefore important to restore these degraded areas along the natural rivers of South Africa to ensure the sustainability and biodiversity of riparian corridors. Riparian areas inside the National Parks of South Africa, and especially in Mapungubwe National Park, have a high esthetical value and should be preserved for future generations. The study was conducted in the Mapungubwe National Park, which is listed as a cultural world heritage site. Plans are in place to convert it into one of Africa's biggest Transfrontier Parks, called the Limpopo/Shashe Transfrontier Conservation Area (TFCA), which will be situated between neighbouring countries Zimbabwe, Botswana and South Africa. The main purpose of this project was to establish a demonstration site for the restoration of degraded, previously cultivated lands in the deforested riparian areas in the Mapungubwe National Park, Limpopo Province. Another aim of the project was to evaluate the theoretical assumption that the growth of trees on so called "activity lines" in the environment due to geological and soil characteristics is enhanced. "Activity lines" were identified by Mr. Lynn van Rooyen of South African National Parks (SANParks) and trees of which the growth was tested, were planted both on and off "activity lines". The selection of the right type of trees for the restoration of the deforested riparian areas during active restoration applications is very important and depends on a multitude of factors. These factors include aspects such as the location with its specific vegetation, soil type and climatic conditions, the historical background of the management practices such as previous land uses, as well as other environmental impacts that previously occurred in the area to be restored. The latter can be gained through interviews with previous and present managers of the area, as well as maps, reports and aerial photographs. Ten different indigenous tree species that previously occurred in the area were planted in an experimental demonstration site of approximately 70ha, which was enclosed by an electrical game fence. The ten tree species that were evaluated included: Faidherbia albida (Ana tree), Acacia nigrescens (Knob thorn), Acacia tortilis (Umbrella thorn), Schotia brachypetala (Weeping boer-bean), Acacia xanthophloea (Fever tree), Lonchocarpus capassa, recently renamed Philenoptera violacea (Apple-leaf), Salvadora australis (Narrow-leaved mustard tree), Adansonia digitata (Baobab), Combretum imberbe (Leadwood) and Xanthocercis zambesiaca (Nyala tree). With the aid of aerial photographs, phytosociological studies, interviews with previous and present land users and managers, as well as existing surrounding vegetation, four different zones within the enclosure were identified according to ecotones. The establishment, growth and survival rate of the different tree species were monitored using morphological and physiological vegetation sampling techniques, as well as leaf component analyses on individuals of selected species. Soil physical and chemical analyses were carried out in the four different blocks identified within the experimental site. Data analysis was carried out on both the soil and leaf component analyses using the CANOCO-package. The establishment of the experimental site was successful, and important information was collected on various aspects of restoration activities. Positive growth effects were also observed in certain indigenous tree species concerning the "activity line" effect, especially with regard to Acacia tortilis and Combretum imberbe. However, the preliminary results obtained through this pilot study showed no conclusive evidence to what exactly stimulated the enhanced growth phenomena observed in certain individual tree species planted on "activity lines". Additional watering was identified as the most important factor contributing to successful establishment and growth of indigenous tree species in this semi-arid area. Various results showed a multiplying effect when a combination of additional watering and "activity lines" was applied. It was concluded that, should any further restoration work be conducted in the degraded areas of the Mapungubwe National Park, the planting of trees should be done on "activity lines" and with the addition of water. This will result in higher establishment rates of transplanted trees and speed up the succession processes involved in the natural "healing process" of degraded areas. Parameters that should be used for monitoring tree growth include the trunk thickness at the base, trunk thickness at 30cm from the base, and the length of the tree in its natural growth form. Recommendations were also made as reference for future restoration practices to ensure better and more successful and sustainable outcomes in the planting of trees. These include the use of nurse plants such as Acacia tortilis and Salvadora australis to establish a more favourable microclimate for climax species, as well as the establishment of a preferred herbaceous layer. Care should be taken in the period required for the cultivation of indigenous trees before they are transplanted into the field, as a prolonged cultivation period could lead to a circular growth form of the root system, preventing sufficient penetration ability of the roots into deeper, more nutrient rich soils. Before trees can be planted into the field, a hardening period must be applied to all seedlings for at least a three week period. This entails the exposure to more direct sunlight for longer periods as well as a reduction in the water applied weekly. Special attention should be paid to the stresses caused by herbivory, especially that of termites and porcupines. The maintenance of the exclosure is a critical factor contributing to the successful outcomes of this particular restoration project. Problem animals, especially elephants, should be kept out of the exclosure at all costs. The results of this project can be used in this ongoing restoration program, as well as in other related projects in semi-arid, degraded savannah areas over the long-term.Thesis (M.Sc. (Botany))--North-West University, Potchefstroom Campus, 2008.
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Casselman, Chad N. „Effects of Silvicultural Treatments and Soil Properties on the Establishment and Productivity of Trees Growing on Mine Soils in the Appalachian Coalfields“. Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/32909.
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Coal has been and will continue to be an important energy source in the U.S. for the foreseeable future. Surface mining for coal is one of the methods employed to extract this resource from below the ground. The process of surface mining removes native topsoils and any native vegetation that was support by these native soils. In the Appalachian coal-producing region of the United States, the pre-mining landscape is predominantly forested. Prior to the Surface Mining and Reclamation Act of 1977 (SMCRA), surface mined lands were commonly reclaimed to forests. Subsequent to the passage of SMCRA, reforestation of surface mined lands has decreased. As a result, thousands of hectares of land that were forested prior to mining are being reclaimed using grasses and legumes. This is done in spite of the fact that the SMCRA requires that land be reclaimed to an â equal or higher land use.â The decline of reforestation stems from two main issues, namely: (1) reclaiming land to pasture is an easy and low-risk way for mining companies to obtain bond release; and (2) SMCRA reclamation requirements have led to unfavorable conditions for tree establishment and growth. Recent interest has been shown in reverting these surface mined lands that have been reclaimed to pasture back to forests for reasons related to the environmental, economic, and carbon sequestration benefits that forests are believed to have when compared to pasture land. It is believed that forests can be established on existing reclaimed pasture land through the use of silvicultural treatments, that mature stands of trees growing on surface mines will respond to treatment similarly to stands growing on native soils, and that mature stands growing on relcaimed surface mines have different soil properties controlling their growth than those that have been found for younger stands. The purpose of this investigation was to understand the biological feasibility of restoring forests on post-SMCRA surface mined lands in the Appalachian coalfields reclaimed to pasture and to understand the productive potential and factors governing the productive potential of pre-SMCRA surface mines supporting mature forests in an attempt to show the benefits of reclaiming these lands with forests.
A 3x3x3 factor random complete block design was used to assess first-year survival and growth of three species assemblages under three levels of silvicultural treatment intensity at each of three study sites having different site characteristics. The native hardwood species assemblage was found to have the best survival across all three sites, with 80 and 85% survival for sites with spoils derived from shale and oxidized sandstone, respectively. White pine generally had the lowest survival of all species and ranged from 27% across treatments on siltstone spoils to 58% across treatments on oxidized sandstone spoils. Hardwood and white pine grew little over the first year, ranging from -3.7 to 8.9cm in height compared to hybrid poplar, whose height growth ranged from 22.4cm to 126.6cm. Response to silvicultural treatment was variable by site and species, but weed control in combination with tillage generally resulted in the highest survival. Greatest height growth (126.6cm) occurred on the oxidized sandstone spoil, where hybrid poplar was treated with weed control plus tillage in combination with fertilization. Hybrid poplar was found to have the greatest growth after one year compared with the hardwood and white pine and also had the greatest height growth at each level of silvicultural intensity for all sites. This superior growth should give hybrid poplar an advantage over the others used to revert these grass lands back to forests, as the amount of height growth observed (>50cm over one year in the weed control plus tillage treatment at all sites) may be enough to ensure that these trees will not succumb to aggressive competing vegetation without further weed control. The results of this study show that based on first-year data, reforestation of these lands does appear to be biologically feasible, given the species and treaments used.
In an attempt to quantify the productivity of a 26-year-old white pine stand established pre-SMCRA, a random complete block experiment was used to compare the response to a thinning that occurred in this stand at age 17. Site index of the stand was found to be 32.3m at base age 50, indicating that this is a very productive stand. Neither stand volume nor stand value was statistically different at age 26 between treatments with volumes and values ranging from 290m3ha-1 and $5639 ha-1 to 313 m3ha-1 and $5478 ha-1 for the thinned and unthinned treatments, respectively. The difference in mean breast-height diameter, however, was significant at age 26, and this was confirmed by a significant difference in a repeated measures analysis of annual diameter data for these treatments (P < 0.0001). Projection to age 30 revealed that both stand volume and value would be significantly higher in the thinned treatment by margins of 8.7 m3 ha-1 and $2457 ha-1. Regression analysis of soil data within the observed rooting depth of the trees from this stand indicated that nitrogen mineralization index, bulk density, sand percentage of the fine soil fraction, and percentage of oxidized sandstone in the soil profile were the most important variables in determining the standâ s productive capacity (R2 = 0.7174). It was also found that of the five different spoil types encountered in the stand, the oxidized sandstone spoil had the most favorable physical and chemical properties for tree growth. Common root-restricting layers were found to have high soil density or increased levels of soluble salts.
It has been shown that reclaimed surface mines can grow productive forests if the appropriate spoil materials are returned to the surface in sufficient depth. It has also been shown that surface mined lands reclaimed to pasture can be successfully reforested using silvicultural treatments to ameliorate unfavorable conditions for tree establishment and growth, though these treaments may not be cost-effective, and the success of these treatments was variable based on the soil characteristics of each site.Master of Science
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Stedingk, Henrik von. „History of Picea abies in west central Sweden : applications of pollen analysis to reveal past local presence of trees /“. Umeå : Dept. of Forest Vegetation Ecology, Swedish University of Agricultural Sciences, 2006. http://epsilon.slu.se/200692.pdf.
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Hans, Ralston Ronald. „Initial growth responses to controlled release fertilizer application at establishment of commercial forestry species in South Africa“. Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/85609.
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Thesis (MScFor)--Stellenbosch University, 2013.ENGLISH ABSTRACT: In South Africa fertilizer applications at establishment is a common practice in the forestry industry. Recommendations are based on past research with conventional sources (CV) and as a result there have only been slight improvements in additional plantation production over recent years. The objective of this study was to investigate initial stand responses in terms of leaf are index (LAI), foliar nutrient content, biomass index (BI) and volume growth to the application of controlled release fertilizers (CRF) at re-establishment. Nitrogen (N), phosphorus (P) and potassium (K) were applied in a three way factorial combination to Pinus radiata at planting on a site in the Western Cape. The design was replicated five times across the study area. N (CRF) and P (CV) were applied in a two way factorial combination at planting to two Eucalyptus grandis x urophylla hybrids and Eucalyptus dunnii across three sites, one ex-agricultural and two re-establishment sites, on the Zululand coastal plain and the Midlands region. The design was replicated nine times on each study site. Harvesting residues were burnt on the eucalypt sites prior to establishment and may have had an impact on the responses found. An outbreak of Fusarium circinatum on the P. radiata site resulted in unexpected and extremely variable responses. An attempt to quantify the effect of the disease had limited success. The mean BI of the control treatment reached 25. The best CV and CRF treatments yielded improvements of 42 % and 83 % in BI over the control respectively, with only the CRF treatment difference being significant. Foliar analysis results revealed marginal to deficient concentrations of P and Mg being alleviated by the treatments in question. On the KZN Zululand sites there was a marked response of the hybrids to N with P having an additive effect on volume growth, LAI and foliar N content. Application of 120 g N and 20 g P per tree on the ex-agriculture site produced a volume of 8 m3 ha-1 at one year of age, a significant increase of 118 % and 80 % over the control and best CV treatment respectively. Application of 80 g N and 20 g P per tree, on the re-establishment site, yielded a volume of 24.6 m3 ha-1 at one year which equates to a significant 39 % and insignificant 7 % additional volume at one year over the control and best CV treatment respectively. A non-significant suppressive effect was found with 20 g CV P application only. At the KZN Midlands site, the major early response in height were to P application. Applications of 20 g CV P per tree, resulted in a mean height of 162.6 cm at seven months of age, a significant 28 % higher than the control. There was no significant effect of 80 g CRF N and 20 g CV P per tree respectively. CRF N applications up to 120 g per tree provide additional growth over recommended CV applications on coastal Zululand sites with low organic carbon (OC) content. On the KZN Midlands site with higher OC and clay content, early responses were limited to P fertilization only regardless of the fertilizer source.
AFRIKAANSE OPSOMMING: Dit is algemene praktyk in die Suid Afrikaanse bosbou industrie om kunsmis tydens aanplanting toe te dien. Hierdie aanbeveling is gebasseer op navorsing resultate met konvensionele bronne (CV), gevolglik was slegs ‘n klein toename in bykomende plantasie produksie gemeet die afgelope paar jaar. Die doelwit tydens hierdie studie is om die aanvanklike reaksie van die bome in terme van blaar oppervlak indeks (LAI), blaar-voedingstof inhoud, biomassa indeks (BI) en volume op die toediening van beheerde vrylating kunsmis (CRF) tydens aanplanting vas te stel. Stikstof (N), fosfor (P) en kalium (K) is in drie-ledige kombinasie aan Pinus radiata op ’n plantasie in die Weskaap toegedien. Die ontwerp is vyf keer in die studiegebied herhaal. N en P is in twee-ledige kombinasie aan twee Eucalyptus grandis x urophylla hibriede en Eucalyptus dunnii op drie groeiplekke, een eks-landbou en twee eks-bosbou, op die Zoeloeland kusvlakte en in die Natalse Middellande toegedien. Die ontwerp is nege keer in elke studiegebied herhaal. Oesreste is voor aanplanting op die Eucalyptus groeiplekke verbrand. Die voorkoms van Fusarium circinatum op die P. radiata groeiplek het onverwagte en hoogs uiteenlopende reaksies tot gevolg gehad. ’n Poging om die effek van die siekte te kwantifiseer, was slegs gedeeltelik suksesvol. Die gemiddelde BI van die kontrole behandeling, was 25. Die beste CV en CRF behandeling het onderskeidelik 42 % en 83 % hoër BI as die kontrole groep gehad, waarvan slegs die CRF behandeling beduidend was. Blaarontleding het gewys dat daar marginale of ontoereikende konsentrasies van P en Mg was. In Zoeloeland het die Eucalyptus hibriede ’n beduidende reaksie op N en P getoon met meer volume groei, LAI en N inhoud. Die toediening van 120 g N en 20 g P per boom op die eks-landbou groeiplek het ’n volume van 8 m3 ha-1 op eenjarige ouderdom tot gevolg gehad. Dis beduidend beter met 118 % en 80 % onderskeidelik vir die kontrole en beste CV behandeling. Die toediening van 80 g N en 20 g P per boom op die hervestigde eks-bosbou groeiplek, het ’n volume van 24.6 m3 ha-1 op eenjarige ouderdom tot gevolg gehad. Dit is 39 % beduidend en 7 % onbeduidend addisionele volume op eenjarige ouderdom vir onderskeidelik die kontrole groep en beste CV behandeling. ’n Onbeduidende depressie effek is met die alleen toediening van 20 g CV P gevind. In die Natalse Middellande groeiplek het die toediening van P ‘n vroeë reaksie in hoogte groei veroorsaak. Die toediening van 20 g CV P per boom, het ’n gemiddelde hoogte van 162.6 cm op die ouderdom van sewe maande tot gevolg gehad. Dit is 28 % beduidend hoër as die kontrole. Die toediening van 80 g CRF N en 20 g CV P per boom was onbeduidend. Toedienings van CRF N tot en met 120 g per boom het in die kusgebiede van Zoeloeland met ‘n lae organiese koolstof (OC) inhoud, groter groei as die aanbevole CV toedienings gehad. Die Middellande groeiplek met ’n hoër OC en klei inhoud, was die vroeë reaksie alleenlik beperk tot P bemesting.
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Van, Wilgen Nicola Jane. „Alien invaders and reptile traders : risk assessment and modelling of trends, vectors and traits influencing introduction and establishment of alien reptiles and amphibians“. Thesis, Stellenbosch : Stellenbosch University, 2010. http://hdl.handle.net/10019.1/5468.
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Thesis (PhD)--Stellenbosch University, 2010.ENGLISH ABSTRACT: Biological invasions are a growing threat to biodiversity, trade and agriculture in South Africa. Though alien reptiles and amphibians (herpetofauna) are not currently a major issue, escalating problems worldwide and increased trade in South Africa suggest a possible increase in future problems. In this thesis I explore practical measures for risk assessment implementable under national legislation. I began by documenting record-keeping and legislative differences between provinces in South Africa. This revealed some serious deficiencies, complicating attempts to compile accurate inventories and discern import trends. International trade data, however, revealed an exponential increase in the number of imports to South Africa over the last 30 years. Characterising the abundance of species in this trade is important as species introduced in large numbers pose a higher establishment risk. In South Africa, I found a tendency for venomous and expensive species to be traded in low numbers, whereas species that are easy to breed and handle, or that are colourful or patterned are traded in higher numbers. Unlike South Africa, California and Florida have had a large number of well-documented herpetofaunal introductions. These introductions were used to verify the role of several key predictors in species establishment. I first evaluated the role of each variable separately. I examined different approaches for bioclimatic modelling, the predictive power of different sources of distribution data, and methods of assigning a climate-match score. I also present the first test of Darwin’s naturalization hypothesis for land vertebrates using two new phylogenies inferred for native and introduced reptiles in California and Florida. I then used boosted regression trees (BRT) to infer the relative contribution of each factor to species establishment success. Results from the BRTs were incorporated into a user-friendly spreadsheet model for use by assessors inexperienced in complex modelling techniques. Introduction effort was found to be the strongest contributor to establishment success. Furthermore, species with short juvenile periods were more likely to establish than species that started breeding later, as were species with more distant relatives in regional biotas. Average climate match and life form were also important. Of the herpetofaunal groups, frogs and lizards were most likely to establish, while snakes and turtles established at much lower rates, though analysis of all recorded herpetofaunal introductions shows slightly different patterns. Predictions made by the BRT model to independent data were relatively poor, though this is unlikely to be unique to this study and can be partially explained by missing data. Though numerous uncertainties remain in this field, many can be lessened by applying case by case rules rather than generalising across all herpetofaunal groups. The purpose for import and potential trade volume of a species will influence the threat it poses. Considering this in conjunction with a species’ environmental tolerances and previous success of species with similar life histories, should provide a reasonable and defendable estimate of establishment risk. Finally, a brief summary of the potential impacts of introduced alien herpetofauna is provided in the thesis.
AFRIKAANSE OPSOMMING: Indringer spesies hou ‘n al groter bedreiging in vir die biodiversiteit, handel en landbou van Suid- Afrika. Alhoewel uitheemse reptiele en amfibieërs (herpetofauna) tans nie ‘n groot bedreiging in Suid-Afrika is nie, dui groeiende probleme wêreldwyd asook 'n toename in plaaslike handel op moontlike toekomstige probleme. In hierdie tesis, ondersoek ek praktiese metodes vir risikobepaling wat onder nasionale wetgewing toegepas kan word. Ek begin deur die verskille in stoor van rekords en wetgewing tussen provinsies te dokumenteer. Hierdie proses het ernstige tekortkominge uitgewys, wat pogings om akkurate inventarisse saam te stel en invoertendense te bepaal, bemoeilik. Internasionale handelsdata het egter getoon dat daar ‘n eksponensiële toename in die hoeveelheid invoere na Suid-Afrika oor die laaste 30 jaar was. Die hoeveelheid spesies in hierdie handel is belangrik omdat spesies wat in groot hoeveelhede ingevoer word, ‘n hoër vestigingsrisiko het. In Suid-Afrika is ‘n tendens gevind vir handel in giftige en duur spesies teen lae hoeveelhede, terwyl spesies wat maklik teel, maklik hanteer kan word en kleurvol is of mooi patrone het, in groter hoeveelhede mee handel gedryf word. Kalifornië and Florida, in teenstelling met Suid-Afrika, het ‘n hoë aantal goed-gedokumenteerde gevalle van herpetofauna wat in die natuur vrygestel is. Hierdie introduksies was gebruik om die rol van verskeie belangrike faktore in die vestiging van populasies te bepaal. Eerstens het ek die rol van elke faktor apart ondersoek. Ek het verskillende benaderinge vir bioklimatiese model-bou ondersoek, die akuraatheid van verskillende bronne van distribusiedata getoets en drie metodes om ‘n “climate match score” te bereken, voorgestel. Ek bied ook die eerste toets van Darwin se naturalisasie-hipotese vir landwerveldiere aan, deur gebruik te maak van twee nuwe filogenieë wat ek gebou het vir inheemse en ingevoerde reptiele in Kalifornië en Florida. Ek het verder gebruik gemaak van “boosted regression trees” (BRT) om die relatiewe bydrae van elke faktor tot die vestigings-potensiaal van spesies te bepaal. Resultate van hierdie BRTs was ingekorporeerd in ‘n gebruikersvriendelike ontledingstaat wat deur bestuurders, onervare in komplekse modelboutegnieke, gebruik kan word. Invoer-hoeveelheid was die faktor wat die sterktste bygedra het tot suksesvolle vestiging. Verder is spesies met kort jeugperiodes en dié met verlangse familie in streeks-biotas, meer geskik om suksesvol te vestig. Gemiddelde klimaatooreenstemming en lewensvorm was ook belangrik. Paddas en akkedisse was die mees waarskynlikste van die herpetofauna groepe om populasies te vestig, terwyl slange en skilpaaie teen laer tempo’s populasies gevestig het, alhoewel analise van alle gedokumenteerde gevalle van herpetofauna-invoerings wêreldwyd effens verskillende tendense toon. Voorspellings wat deur die BRT-model vir onafhangklike data gemaak is was redelik swak, alhoewel hierdie resultaat onwaarskynlik nie uniek aan die studie is nie, en word gedeeltelik verduidelik deur die gebrek aan data. Alhoewel talle onsekerhede steeds bestaan, kan dié verminder word deur geval-tot-geval reëls toe te pas eerder as om vir herpetofauna as ‘n groep te veralgemeen. Die doel van invoer en potensiële handel-volumes van ‘n spesie, sal die bedreiging wat die spesie toon, bepaal. Hierdie faktore moet saam met omgewingstoleransie en voorafgaande sukses van spesies met soortgelyke lewenswyses oorweeg word, om ‘n aanvaarbare en verdedigbare beraming van vestigingsrisiko te gee. Laastens, word ‘n kort opsomming van die effekte wat uitheemse herpetofauna mag hê, verskaf.
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Abod, Sheikh Ali. „Growth and establishment of woody perennials“. Thesis, Imperial College London, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.364051.
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Alvey, Alexis A. „Efficacy and Effect of Tree Stabilization Systems On Landscape Tree Growth and Establishment“. Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/33160.
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Various forms of staking, guying, and root ball anchoring are used to prevent post-transplant tree destabilization in the landscape, but little scientific evidence exists to support this practice. This experiment tested the efficacy of three generic tree stabilization systems (TSS) and their effect on tree growth and establishment. In spring 2006, 48 balled and burlapped, 6.4 cm (2.5 inch) diameter, white ash (Fraxinus americana L. â Autumn Purpleâ ) were transplanted to a field site in Blacksburg, VA. At planting, one of four TSS treatments (staking, guying, root ball anchoring, or non-stabilized) was installed on each tree. After five weeks, tree pulling tests were conducted on 24 trees to simulate a strong wind load using a cable winch mounted to a skid-steer loader. After one growing season, change in tree height, trunk diameter, and trunk taper were compared among the 24 remaining trees. Soil cores were taken and the length, diameter, and dry weight of roots within the cores were analyzed. TSS were then removed and tree pulling tests were conducted using the same method.
The five week tests showed that destabilization was significantly greater for non-stabilized trees (mean of 16 degrees from vertical) than for trees with TSS (all means less than 3 degrees from vertical). Yet after one growing season, there were no significant differences among any treatments in tree stability. We conclude that in locations with high wind speeds, TSS may be necessary for trees similar to those in our study, but only for a very short period of time.
Results also indicated that staking, guying, and root ball anchoring were equally effective, very robust, very durable, caused no tree injuries, and did not impact tree growth or establishment after one growing season. Practical considerations may therefore play a more important role when choosing which TSS to use. Although the time required for TSS installation was similar for each system, staking was more than twice as expensive as guying or root ball anchoring.
Master of Science
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Whitbread-Abrutat, Peter Hans. „The improvement of tree establishment on metalliferous mine wastes“. Thesis, University of Exeter, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282670.
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Houx, James H. Kallenbach Robert L. „Recommendations for tree establishment in tall fescue-based silvopasture“. Diss., Columbia, Mo. : University of Missouri--Columbia, 2008. http://hdl.handle.net/10355/6631.
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Title from PDF of title page (University of Missouri--Columbia, viewed on Feb 25, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Dissertation advisor: Dr. Robert L. Kallenbach. Vita. Includes bibliographical references.
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Baumer, Marilyn Cabrini. „Tree Seedling Establishment Under the Native Shrub, Asimina Triloba“. Wright State University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=wright1183587955.
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Dutton, Richmond Anthony. „An Analysis of the Critical Stages in Urban Tree Establishment“. Thesis, University of Liverpool, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.507713.
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Botha, Susan. „The influence of rainfall variability on savanna tree seedling establishment“. Master's thesis, University of Cape Town, 2006. http://hdl.handle.net/11427/6238.
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Includes bibliographical references (leaves 111-114).My thesis investigates the rainfall requirements necessary for tree seedling survival of different savanna species in the first year of growth. Results from a field drought experiment showed that dry season survival for seedlings of Acacia nigrescens and Philenaptera vialacea was not related to wet season length. Instead mortality was highest immediately after germination despite irrigation to minimize dry spells. Furthermore there was no relationship between seedling size and the length of the dry spell seedlings of Acacia nigrescens and Philenaptera vialacea grown in basalt clay in the greenhouse, could survive. This was in contrast to seedlings of Scleracarya birrea and Terminalia sericea grown in granite sand, where number of dry days survived increased with number of growth days received. There was no significant differences in rainfall variability (t-test: tL III = 1.56, P = 0.121, F-ratio = 1.13) between a semi-arid (Satara) and semi-mesic (Pretoriuskop) site within the Kruger National Park despite significant differences in rainfall totals (t-test: tl, III = 4.40, P < 0.000, F-ratio 3.41). Results from a soil-water model show that seedling recruitment can occur at least twice a decade in the Satara area, which should be frequent enough to allow a transition to a woodland state over time. These results suggest that a mechanism other than the effect of rainfall variability on seedling establishment is required to explain the co-existence of trees and grasses at Satara. The lack of field germination, the absence of a seed bank and the germination of added seed at the field experiment site after rainfall emphasizes seed limitation as an important bottleneck at Satara. Higher herbivore biomass at Satara compared to Pretoriuskop may limit seedling establishment opportunities by destroying seed and seedlings of tree species.
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Olah, Peter. „Analysis of Tree Establishment on Stripmined Land in Southeastern Ohio“. The Ohio State University, 1990. http://rave.ohiolink.edu/etdc/view?acc_num=osu1392649024.
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Gordon, Phoebe E. „Greening Ohio Highways: Factors and Practices that Affect Tree Establishment“. The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1417687987.
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Rocha, Kortz Alessandra. „Biodiversity change in the Cerrado following invasive pine tree establishment“. Thesis, University of St Andrews, 2017. http://hdl.handle.net/10023/12220.
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How do newly established species interact with existing assemblage members to alter local biodiversity? This question is especially topical given growing concerns about increased temporal turnover levels relative to background rates. My PhD thesis concerns young, isolated pines Pinus elliottii invading the Cerrado (Brazilian savanna) as a study system to test the hypothesis that the impact of newly established individuals varies across habitat layers. I sampled both vegetation layers (shrub and grass) of two distinct habitats, the shrub-dominated campo sujo and the grass-dominated campo úmido. My results show that the pine is changing α diversity in the dominant vegetation layer of each habitat: the shrub layer of campo sujo and the grass layer of campo úmido. The shape of the diversity v. establishment time relationship is habitat dependent; there is a hump shaped relationship between diversity and pine size in the grass layer but a linear one in the shrub layer. β diversity metrics – which take species composition into account - reveal marked differences in species composition between the habitats in the shrub layer, whereas the corresponding pair of invaded and control sites of the same habitat and layer is more similar than expected (in both vegetation layers). The degree of similarity between sites also changes as the invasion proceeds. In the campo sujo habitat, sites become more compositionally distinct, whereas in the grass layer of campo úmido sites get more similar. This suggests that the timing of changes in species composition is habitat-dependent and reinforces the need to remove the invader individuals from the area. My results show that, though complex, the consequences for local biodiversity of non-native species establishment are not haphazard. As such they contribute to the understanding of species coexistence and help explain why species invasion can lead to very different biodiversity outcomes.
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Ashkenazi, Rafael 1958. „Influence of herbicides on establishment of tree seedlings in northern Israel“. Thesis, The University of Arizona, 1991. http://hdl.handle.net/10150/277933.
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The influence of the herbicides sulfometuron and simazine on the establishment of 8 species of tree seedlings was studied in northern Israel. The experiment included three treatments and a control. The first treatment applied simazine at a rate of 5 kg/ha, and second treatment applied simazine at a rate of 5 kg/ha and sulfometuron at a rate of 0.03 kg/ha. Sulfometuron was applied alone at a rate of 0.03 kg/ha in the third treatment. Statistical analyses showed significant effects on the survival of some species treated with sulfometuron. To ensure earlier season survival, the rate of sulfometuron applied should be kept at a minimum level to allow both weed control and adequate establishment of seedling. Low-rate applications are particularly important in arid and semi-arid areas.
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Ziegler, Susy Svatek, Evan R. Larson, Julia Rauchfuss und Grant P. Elliott. „Tree Establishment During Dry Spells At An Oak Savanna In Minnesota“. Tree-Ring Society, 2008. http://hdl.handle.net/10150/622571.
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Recent research has challenged the long-standing hypothesis that forests in the Upper Midwest
of the United States developed during wetter periods and retreated during dry periods. We explored this debate by examining patterns of tree establishment on an oak savanna in east-central Minnesota within the context of variable moisture availability and fire suppression. We used superposed epoch analyses (SEA) to evaluate the mean moisture conditions for a 21-year window surrounding tree establishment dates. Before effective fire suppression (1809–1939), 24 of 42 trees with pith dates (62%) grew to 30-cm height during dry years (Palmer Drought Severity Index < -1), versus only 5 of 42 (12%) that established in wet years (PDSI > 1). Significantly more trees established during dry periods (negative PDSI values) than would be expected with the proportion of wet-to-dry years (x²= 10.738, df = 1, p-value = 0.001). Twenty of the complete sample of 74 trees with pith dates (27%) established during drought in the 1930s. We hypothesize that dry conditions limited plant productivity, which in turn decreased competition between grasses and tree seedlings and reduced rates of accumulation of fine fuels, enabling seedlings to grow tall enough to resist subsequent fires. We recommend SEA as a methodological approach to compare historical climate conditions with the timing of regeneration success in other regions of forest expansion.
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Layman, Rachel Montgomery. „Rehabilitation of Severely Compacted Urban Soil to Improve Tree Establishment and Growth“. Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/76910.
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Land development restricts tree growth by damaging soil structure and removing organic matter. Mechanical loosening and organic amendment may improve soil physical properties and tree establishment and growth. Effects of typical post-construction practice and improved methods of soil restoration on tree growth and soil properties were evaluated over two years. Treatments included undisturbed soil (UN); minimum effort (ME) (10 cm topsoil); enhanced topsoil (ET) (ME + rototilling); and profile rebuilding (PR) (compost, subsoiling, topsoil and rototilling). Pretreatment included removing topsoil and compacting subsoil to 1.95 g/cm3 bulk density. Acer rubrum L. (red maple), Quercus bicolor Willd. (swamp white oak), Ulmus 'Morton' (Ulmus japonica (Rehd.) Sarg. x Ulmus wilsoniana Schneid.) (Accolade® elm), Prunus 'First Lady' (Prunus xincam x Prunus campanulata) L. and Quercus macrocarpa Michx. (bur oak) were planted in each plot. The PR treatment reduced soil bulk density at 15-20 cm depth and increased soil C/N ratio, pH, and CEC. Mean canopy projection and cross-sectional trunk area in PR plots ranged from 32% to 226% and 16% to 71% greater, respectively, than those in ME plots. PR treatment increased Q. bicolor photosynthesis rates. Greater root presence was observed in deeper soil layers of ET and PR treatments for A. rubrum and of UN and PR for Q. bicolor; root distribution was not measured for other species. Rehabilitation improved soil physical properties and tree growth after two years. Species variation in growth rate and environmental tolerance appeared to influence early growth treatment effects. Long-term data is needed to fully understand effects of soil rehabilitation.Master of Science
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Burcham, Daniel C. „Urban forest management for multiple benefits an analysis of tree establishment strategies used by community tree planting programs /“. Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 214 p, 2009. http://proquest.umi.com/pqdweb?did=1885755681&sid=4&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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Norberg, Gisela. „Steam treatment of forest ground vegetation to improve tree seedling establishment and growth /“. Umeå : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 2000. http://epsilon.slu.se/avh/2000/91-576-6054-9.pdf.
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West, Lee. „Effects of Soil Fungi on Tree Seedling Establishment in a Southeastern Coastal Plain Forest“. Thesis, Virginia Tech, 1998. http://hdl.handle.net/10919/46180.
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Effects of fungi and overstory composition on tree seedling survival and growth were investigated in closed canopy upland forests in the coastal plain of South Carolina. Seedlings of Quercus alba, Cornus florida and Pinus taeda were planted in the understory of two forest types -naturally regenerated hardwood and planted pine. Fungal species composition and biomass were experimentally manipulated with a treatment of the fungicide captan.
In contrast with other studies conducted in different systems (sand dune, grassland, and old field), the effects of soil fungi were minor in a closed canopy forest. Only Q. alba showed a significant response to the fungicide (p < 0.05) treatment with increased growth.
Overstory composition had no significant effect on growth or survival for any of the species. Both of the commercially desirable species (Q. alba and P. taeda) had reasonable survival ( @ 60%). Both also maintained positive, though modest, growth. This suggests that an advance regeneration pool could be established successfully by artificial regeneration.Master of Science
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Lett, Signe. „Mosses as mediators of climate change : implications for tree seedling establishment in the tundra“. Doctoral thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-130942.
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Alpine and arctic tree line expansion depends on the establishment of tree seedlings above the current tree line, which is expected to occur with climate warming. However, tree lines often fail to respond to higher temperatures. Other environmental factors are therefore likely important for tree seedling establishment. Above the tree line, establishing seedlings encounter existing vegetation such as bryophytes, which often dominate in arctic and alpine tundra. Bryophytes modify their environment in various ways and may mediate climate change effects on establishing tree seedlings, and with that tree line expansion. The aim of this thesis was to understand if and how the environment, in particular bryophytes, mediates the impact of climate change on tree seedling establishment at the alpine and arctic tree line. This was explored by reviewing literature on tree seedling establishment at alpine and arctic tree lines globally. In addition, tree seedling survival and growth of Betula pubescens and Pinus sylvestris were assessed experimentally. Here, individuals were planted into mono-specific mats of different bryophytes species and exposed to warming and different precipitation regimes. The literature review revealed that besides from temperature, tree seedling establishment is affected by a wide range of abiotic and biotic factors including water, snow, nutrients, light, disturbance and surrounding vegetation. Furthermore the review revealed that for example vegetation can change tree seedling responses to climate change. The experiments showed that especially tree seedling survival was adversely affected by the presence of bryophytes and that the impacts of bryophytes were larger than those of the climate treatments. Seedling growth, on the other hand, was not hampered by the presence of bryophytes, which is in line with earlier findings that seedling survival, growth and seed germination do not respond similarly to changes in environmental conditions. Moreover, we found several indications that vegetation above the tree line, including bryophytes, mediated tree seedling responses to warming and precipitation or snow cover. This thesis shows that temperature alone should not be used to predict future tree seedling establishment above the alpine and arctic tree line and that extrapolations from climate envelope models could strongly over or under estimate tree line responses to warming. This underlines the value of multi-factorial studies for understanding the interplay between warming and other environmental factors and their effects on tree seedling establishment across current tree lines.
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Järnevi, Sara. „Lyckad trädflytt : Förberedande åtgärder och efterskötsels inverkan på trädets etablering efter flytt“. Thesis, Högskolan i Gävle, Avdelningen för elektronik, matematik och naturvetenskap, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-23776.
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Syftet med denna rapport är att sammanställa fakta kring hur åtgärder före och efter trädflytt kan påverka trädets etablering. Rapporten behandlar även vilken inverkan rotbeskärning har på träd och hur nybildning av rötter kan främjas. Rapporten besvarar frågor kring hur ett träd reagerar på att bli flyttat och hur trädart, växtplats och tidigare åtgärder kan påverka resultatet av en trädflytt. Rapporten besvarar även frågor angående vilka åtgärder som kan genomföras, innan och efter trädflytt, för att förbättra trädets etablering på sin nya växtplats, vilken inverkan rotbeskärning har på det flyttade trädet och hur nybildning av finrötter kan främjas. Rapporten är skriven som en traditionell akademisk rapport och är baserad på litteratur som har samlats in från vetenskapliga artiklar, böcker och uppslagsverk. Vid trädflytt förlorar ett träd stora delar, cirka 90 procent, av sitt rotsystem och drabbas av stressymptom. Ett friväxande, sådd i naturen och icke-rotbeskuret, träd kan förlora ännu större delar av sitt rotsystem. Det är viktigt att undersöka om det är ett plantskoleträd eller ett friväxande träd och även vilken trädart som ska flyttas då det kan ha betydelse för hur lyckad trädflytten blir. Genom att utföra rotbeskärning skapas ett kompakt rotsystem som ger en minskad rotförlust. Rotbeskärning främjar även tillväxten av finrötter i rotklumpen, vilket gynnar trädet vid etablering och ger minskad vattenstress. Ofta genomförs en kronreducering för att reducera obalansen mellan krona och rötter. En måttlig kronreducering, mellan 10 och 30 procent, kan gynna trädet. Om trädet ska kunna etablera sig och överleva flytten måste det övervinna stressymptomen. Om ett träd ska kunna bilda nya rötter och ha tillväxt av grenar och skott behöver trädet ha god vitalitet. Bevattning spelar en essentiell roll för trädets överlevnad och etablering. Mulch kan ge god tillväxt av finrötter och bidra till en förbättrad etablering. Rapportens slutsats är att både förberedande åtgärder och efterskötsel har inverkan på trädets etablering och hur väl trädet klarar av att bli flyttat. En korrekt genomförd rotbeskärning bör utföras, en måttlig kronbeskärning av 10-30 procent av kronan bör utföras, träd ska flyttas under sin viloperiod och träd som flyttas bör ha hög vitalitet. Nybildning av rötter främjas av god markfukt, varm jord, jämn bevattning och att mulch läggs på.The purpose of this report was to put together facts regarding how the measures before and after tree transplanting can affect the establishment of the tree. The report also dealt with the impact that root pruning might have on trees and how regeneration of roots can be promoted. The report answers questions concerning how tree transplanting affects a tree and how tree species, locality and previous measures can influence the effect of a tree transplanting. The reports also answers a question concerning which measures could be performed, before and after tree transplanting, to improve the tree’s establishment in it’s new locality. The last question that this report answers is what impact root pruning has on the tree and how regeneration of fine roots can be favoured. The report is written as a traditional academic report and is based on literature that was collected from scientific articles, books and encyclopedias. A tree loses a large amount, approximately 90 percent, of its root system during the tree transplanting. This causes stress symptoms in the tree. A tree, sown and grown in nature, that has never been root pruned will lose even larger amounts of its root system when it’s transplanted. It’s important to do investigations before tree transplanting. Investigations should be done before tree transplanting to determine what kind of tree, nursery-grown or grown in nature, and what species is about to be transplanted. Both of these aspects may have an influence on how successful the transplanting is. Root pruning can make the root system more compact which reduces root loss during transplanting. Root pruning also increases the amount of fine roots in the root ball which is beneficent during establishment and also reduces water stress. The high amount of root loss causes an imbalance between crown and roots. The crown is often reduced to correct this imbalance and in this report it was proven that a moderate crown reduction is beneficial for the tree. The tree must overcome the stress symptoms to be able to survive and to establish itself. Trees need good vitality to be able to regenerate roots, shoots and branches. Irrigation plays an important part in the establishment and the survival of the tree. Mulch can promote regeneration of fine roots and contribute to an improved establishment. The conclusion of the report is that both preparatory measures and after care has an impact on the establishment and on how successful the transplanting of a tree will be. A correctly executed root pruning and a moderate crown pruning (10 to 30 percentage of the crown) should be carried out. Trees should be transplanted during their dormant season and trees, that are going to be transplanted, should have high vitality. Regeneration of roots is promoted by having good soil moisture, warm soil, even watering and applying mulch.
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Panter, Jonathan Paul. „Effects of drought and vegetation management on the establishment of 3 tree species in Northamptonshire, England“. Thesis, Cranfield University, 2006. http://dspace.lib.cranfield.ac.uk/handle/1826/8541.
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Water is a limiting factor in the distribution and growth of trees. Changing climatic
conditions are likely to significantly effect tree species development. The planting and
establishment of trees needs to take into account these changing factors in terms of
design and species selection. This study looked at survival and growth of newly planted
trees under field scale conditions and the effects of soil water availability and ground
treatments. The experiment followed a blocked plan allowing a line source design to
irrigate three tree species, ash, Douglas fir and oak. Each plot of 90 trees was divided
into 5 irrigation subplots with varying levels of water application. Two ground
treatments, bare ground and vegetated were also applied. Over a three year period,
there was a significant effect of species (P<0.001) and herbicide application (P<0.01)
on tree survival. Tree height and diameter were significant (P<0.01) between species
and herbicide. Irrigation had a significant effect on growth rates of all species with no
effect on survival. Ground vegetation biomass significantly increased in high irrigation
subplots (P<0.01), with increasing festuca rubra dominance decreasing plant diversity
(R2=0.8533). The results suggest that soil moisture availability increases tree growth
but does not significantly improve survival rates of the tree species studied. Water is a
key factor in the establishment of trees with maintained soil moisture increasing growth
development of individuals. Therefore site and species selection are essential in the
design of woodland plantings for conservation, recreation and commercial activities.
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Li, Fui Yee. „Factors affecting tree seedling establishment following rehabilitation management in logged-over tropical rain forest in Sabah, Malaysia“. Thesis, Imperial College London, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.429982.
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Francis, Robert Aaron. „Riparian tree establishment and river island formation within the active zone of the River Tagliamento, Northeast Italy“. Thesis, University of Birmingham, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.409027.
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Within the active zone of rivers, riparian vegetation dynamics are controlled by ecological and hydro geomorphological processes and their interactions. Within Europe, understanding of natural riparian tree establishment has been limited by a lack of unregulated, natural river systems. This thesis examines key biotic and abiotic factors influencing the establishment of three riparian tree species, Populus nigra, Salix elaeagnos and Alnus incana, that grow within the active zone of the River Tagliamento, a morphologically-intact alpine/mediterranean river in Northeast Italy. Field observation, field experimentation and greenhouse experiments indicate: (i) Interspecific and propagule form variations in survival and growth response to hydrogeomorphic conditions: P. nigra cuttings performed best in low free-draining sites with a small proportion of fine sediment but which were not subject to prolonged inundation, while seedlings preferred fine sediments and higher elevations. Salix elaeagnos cuttings performed best at lower elevations, with a preference for mixed sediments, and proved tolerant to drought and inundation. S. elaeagnos seedlings grew best at higher elevations and in coarse/mixed substrates. Alnus incana cuttings only grew in fine sediments under stable water levels in greenhouse experiments; mortality was total in field experiments. Deposited trees of an species survived better at lower elevations. (ii) Differences in growth rates according to propagule type: cuttings grew twice as fast as seedlings in the first year but not in the second, and whole deposited trees produced far higher levels of shoot growth and biomass. (iii) Timing of deposition in the growing season and size of propagule also significantly affected performance. These results suggest that species and propagule form directly influence the rate of vegetation establishment within the active zone of rivers and that plant physiology alongside hydrogeomorphology is critical to riparian vegetation dynamics. These results are explored in the context of the development of river islands, an endangered but ecologically important type of landform once common within natural, braided European rivers.
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Makungwa, Stephy David. „Enhancing productivity and estimation of carbon in CDM forestry projects : a Malawi case study“. Thesis, University of Edinburgh, 2016. http://hdl.handle.net/1842/20946.
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This thesis offers a method that informs on the most appropriate sites for successful tree establishment and provides protection to the planted trees in CDM forestry projects. It also offers a method that can accurately and precisely estimate woody biomass in CDM forestry projects established on an agricultural landscape. The thesis has established a set of evaluation criteria that are defined and generally agreed upon by a panel of local forestry experts in Malawi. These criteria express the degree of appropriateness of particular locations to support successful tree establishment and growth, and protect the planted trees from deforestation and forest degradation. They also influence farmers’ decision-making to allocate land for either tree planting or other competing land use options, e.g. crop cultivation. The thesis uses these evaluation criteria to functionally identify priority sites on the landscape of Central Malawi for the establishment of CDM forestry projects. The priority sites are identified using trade-off analysis tools of the GIS-based MCA protocols. Besides site identification, the thesis has established a magnitude of discrepancy that can result from the use of imported allometric models in estimating woody biomass in CDM forestry projects. Imported allometric models consistently under-estimate the woody biomass of the growing trees in the study area with a mean prediction error of as high as 50%. Local allometric models are therefore developed and they are found to be both accurate and precise in estimating woody biomass. These results imply that identification of priority sites, and accurate and precise estimation of woody biomass in CDM forestry project activities are likely and can be attained. In turn, successful establishment of CDM project activities lead to enhanced productivity that will attract expanded investments in CDM forestry projects. The thesis uses Malawi as a case study. The findings of this thesis can be scaled out to other countries whose socio-ecological characteristics are similar to Malawi. These are mostly tropical countries of the Sub-Saharan Africa. In so doing, the thesis contributes to improving productivity and estimation of carbon in CDM forestry project.
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Shaffer, James D. „FACTORS INFLUENCING THE ESTABLISHMENT AND SURVIVAL OF NATIVE HARDWOOD TREE SEEDLINGS OF THE KENTUCKY INNER BLUEGRASS BLUE ASH-OAK SAVANNA-WOODLAND“. UKnowledge, 2013. http://uknowledge.uky.edu/biology_etds/15.
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Historically, the Kentucky Inner Bluegrass blue ash-oak savanna-woodland was the primary ecosystem of the Inner Bluegrass Region (IBR) of Kentucky. After European settlement, the majority (>99%) of Bluegrass savanna was converted to agricultural and urban land uses. Currently remnant savanna tree species are failing to recruit. Therefore, a long-term restoration ecology project researching competition and disturbance on seedling establishment, survival, and growth has been established at Griffith Woods (the largest remaining savanna in Kentucky) in Harrison Co., KY. Fourteen native hardwood tree species (a total of 6,168 seedlings) have been experimentally planted. Light, soil, surrounding vegetation, and herbivory, factors thought to influence seedling survival, have been initially assessed. Results show that soils differed spatially in P, Ca, Mg, Zn, pH, N percent and soil organic matter percent. Light was significantly reduced by diffusive filtering through vegetation. Vegetation biomass was influenced by pH and Mg. Initial seedling survival was high, but significantly differed by species type, location, and soil pH, Mg, and Zn. This research demonstrates that under a similar range of conditions, native hardwood tree seedling establishment is possible. Therefore, the potential exists to restore Bluegrass savanna-woodland in order to return proper ecological functioning into a degraded landscape.
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Fujita, Tomohiro. „Encroachment of Tropical Montane Forest into Miombo Woodland in South-East Africa:Importance of Seed Dispersal and Facilitative Effects on Tree Establishment“. 京都大学 (Kyoto University), 2013. http://hdl.handle.net/2433/175200.
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Salazar, Ana. „Seed Dynamics and Seedling Establishment of Woody Species in the Tropical Savannas of Central Brazil (Cerrado)“. Scholarly Repository, 2010. http://scholarlyrepository.miami.edu/oa_dissertations/371.
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Studies of seed dynamics and seedling establishment at the community level in savanna ecosystems are scant, particularly in the tropical savannas of Central Brazil. The Brazilian savannas (cerrado) have the largest diversity of plant species among Neotropical savannas. Cerrado vegetation exhibits consistent changes in tree density and tree size along shallow topographic gradients. Vegetation types differ from closed savannas with high tree density, and a nearly continuous canopy cover in the uppermost portions, to open savannas with scattered short trees in the low portions of the topographic gradients. Whether or not dynamics of seeds and seedlings of woody species are consistent with variations in tree density and tree canopy cover across the cerrado landscape has not been determined, but could potentially influence such spatial patterns of tree density and canopy cover. The main objective of this study was to evaluate seed dynamics (i.e., seed rain, soil seed banks, and seed characteristics) and seedling establishment of woody species in three major cerrado vegetation types (closed, intermediate and open savannas) which differ in tree canopy cover and tree height. These vegetation types are located along topographic gradients of approximately 30 m in elevation and 1000 m in length. I conducted field work from June 2005 to August 2008 at the Instituto Brasileiro de Geografia e Estatística (IBGE) reserve, a field experimental station located 35 Km south of Brasilia, Brazil (15˚ 56' S, 47˚ 63' W, altitude 1100 m). I established permanent plots in each of the three vegetation types to assess seed rain, seed limitation, seed predation, and seed removal. I also quantified density and composition of the soil seed bank in each vegetation type and studied seed characteristics (i.e., kind of dormancy, moisture content, longevity) of 14 common cerrado woody species. In the field, I quantified establishment of woody seedlings in fire-protected savannas as well as in accidentally burned and frequently burned savannas. In the greenhouse I performed experiments to evaluate the effect of litter cover and light level on seedling emergence of 9 common cerrado woody species. Finally, I evaluated the effect of pulses of heat on seed germination of 5 common cerrado woody species under controlled conditions. The overall results of this study show that regardless of tree canopy cover, cerrado vegetation types are limited in seeds and seedlings of woody species, but these limitations are higher in open than in closed savannas. Most woody species do not form persistent soil seed banks along cerrado vegetation types because their seeds are short-lived, predated and quickly removed from the ground. In addition, dispersal season and dormancy appear to control timing of germination at the onset of the rainy season to ensure survival of seedlings in the field. In the absence of fire, establishment of woody seedlings is higher in closed than in open savannas because canopy cover mitigates the stressful environmental conditions of open savannas and thus facilitates establishment of woody seedlings. As a result, closed savannas are likely to maintain higher density of woody elements over time than open savannas. In burned savannas, however, species composition of woody and herbaceous seedlings is significantly affected because establishment of seedlings of woody and herbaceous species decreases but vegetative reproduction increases. This dissertation study indicates that interactions of early life-history stages of woody species with environmental and disturbance factors appear to play a more significant role in maintaining woody cover variations along cerrado topographic gradients than previously recognized.
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Germany, Markus Stefan [Verfasser], Alexandra [Akademischer Betreuer] Erfmeier und Helge [Gutachter] Bruelheide. „The role of tree species richness and identity for herb layer characteristics and next generation tree species establishment in a subtropical forest in China / Markus Stefan Germany ; Gutachter: Helge Bruelheide ; Betreuer: Alexandra Erfmeier“. Kiel : Universitätsbibliothek Kiel, 2021. http://d-nb.info/1228859078/34.
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Jones, Phillip Daniel. „Effects of five different intensities of stand establishment on wildlife habitat quality and tree growth in loblolly pine (Pinus taeda) plantations in southern Mississippi“. Diss., Mississippi State : Mississippi State University, 2008. http://library.msstate.edu/etd/show.asp?etd=etd-03192008-095948.
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Redwood, Mame S. „The Effect of Silviculture Management on the Spread of Three Invasive Species“. Ohio University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1337273012.
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Vinnemeier, Christof David [Verfasser], Jürgen [Akademischer Betreuer] May, Uwe [Akademischer Betreuer] Groß und Tim [Akademischer Betreuer] Friede. „Establishment of a clinical algorithm for the diagnosis of P. falciparum malaria in children from an endemic area using a Classification and Regression Tree (CART) model / Christof David Vinnemeier. Gutachter: Uwe Groß ; Tim Friede. Betreuer: Jürgen May“. Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2015. http://d-nb.info/1065882017/34.
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Sherman, Alexander R. „Growth and Establishment of Newly Planted Street Trees“. 2013. https://scholarworks.umass.edu/theses/1085.
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Developing quantified establishment period estimates for newly planted trees will help set realistic goals for plant performance in the urban landscape. Nine years of tree planting records obtained from the city of Boston, MA and the town of Brookline, MA were used to derive samples of trunk caliper for hedge maple (Acer campestre), London planetree (Platanus x acerifolia), and red oak (Quercus rubra). Several site characteristics were measured to identify effects on newly planted tree growth.
Breakpoint estimates of the piecewise regression models fell at 4 years and 6 years for London planetree and hedge maple respectively, showing establishment periods for urban trees are longer than the conventional 3 years. Pit area has a significant effect on caliper growth for London planetree and red oak, with larger growing spaces yielding larger trees. Observed soil bulk densities did not have a significant effect on caliper measurement for any of the species tested. Mean soil bulk density was 1.4 g/cm3, 1.45 g/cm3, and 1.49 g/cm3 for hedge maple, London planetree, and red oak respectively. Soil texture was significant for hedge maple only, with percent clay showing significant positive effects and percent sand as marginally significant. Pit type showed a significant effect on caliper measurement of London planetree with grass strips producing the largest caliper trees followed by open pits. Planting locations with tree grates produced the smallest caliper trees. Presence of perforated air vents produced significantly larger caliper trees than sites with an air vent present for red oak.
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LEE, PEI-FENG, und 李碧峰. „The Establishment of the Code for Landscape Trees Planting Engineering“. Thesis, 2012. http://ndltd.ncl.edu.tw/handle/81339693649591308816.
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碩士中原大學
建築研究所
100
The quality of landscape plant engineering in the public civil project, for the long time was not satisfied to the public. Also, it was generally criticized by all sorts of the parties from the industries, government units, and academics. During the construction for the civic engineering and landscape engineering, construction code is the standard to be conformed to ensure the construction quality. Therefore, the suitability and quality for the content of a “Landscape plant engineering construction code” is very important for ensuring plant engineering quality control standard. Due to there are various construction code versions from the central government or all levels of local authorities, there are lots of variants in the compiling formats and construction standard regulation … etc, and there are incompleteness. And the grand convention of Landscape Engineering Association of R.O.C. also came to the consensus that: currently, we need a set of suitable standard operating procedure (SOP). Therefore, study to establishing or updating the construction code related issues to improve the landscape engineering technique and quality comes to high priority. The study collected and compiled the current landscape plant engineering (including transplanting and planting) construction technology in Taiwan and mainland China specification, then analyzed, compared, to understand and to explore the specification content and practice related issues with document review methodology. And based on my personal practice experience for 30 years and opinions from representatives of Landscape Engineering Association, we gone through the “Expert Questionnaire” design and then conducted the questionnaire survey to collect the effective information, then analyzed the result with SPSS statistical software, and then explored the suitability for the current construction code and actual practice. With the construction code content comparison and analysis, we explore the format categorization, and further come to a draft specification chapter framework. During the study, we employed the focus group research method to the practice experts and in-depth interview to the academics experts. From these, we consolidated the related opinion and established the chapter framework. And then, we apply the landscape plant engineering practice application to analysis and verify the draft chapter framework. Lastly, based on this to establish a construction code for landscape arbor planting engineering suitable for Taiwan region as the reference for related civics service departments. This study indicates that: 1. Landscape industries generally consider that the suitability of the current landscape plant engineering construction code is not satisfactory; therefore, it is necessary to re-establish the code or to update the content. 2. After the confirmation from focus group and in-depth interview methodology, we are sure that the “ Chapter 7 and section 30’s SOP” content as “the process flows format” for the landscape arbor plant engineering construction code, can better meet the needs from the practice process flow and professional practices. 3. The content of the landscape arbor plant engineering construction code established by this study, after the landscape plant engineering practice application analysis comparison result verify: 30 items standard operation procedures (SOP) processes can better suitable for the actual landscape plant engineering application practice. 4. Based on the content of the current established specification code, we can further review and improve, such as setting up stay checking point, establish self check list, supplement the construction code illustration … etc, all these add-on can improve the actual application effectiveness of the specification code. 5. The topics for the construction technology of the landscape plant engineering are still required further studies both from the theory and practice facet, to further improve the construction technology of the landscape plant engineering.
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Chen, Yun-Fan, und 陳韻帆. „Studies on arbuscular mycorrhizal fungi application in assisting the establishment of trees“. Thesis, 2011. http://ndltd.ncl.edu.tw/handle/69535234251424505482.
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碩士國立中興大學
園藝學系所
99
From the literature review, we learn about the benefits of symbiotic relationship of arbuscular mycorrhizal fungi with plants. However, the application of mycorrhizal in the area of tree nurturing is still very limited. This study reviewed the effectiveness of arbuscular mycorrhizal fungi and their possibilities in enhancing the health of urban trees. Further investigation was also done to identify specific tree species which can benefit from the symbiotic relationship. Then, discussion was carried out on the commercial production and practical application of arbuscular mycorrhizal fungi in the conservation of urban trees nowadays. From the site survey, it was found urban trees were majorly in poor drainage and ventilation environment. Arbuscular mycorrhizal fungi was not exist in the anoxic environment. Therefore, the first and foremost step to do is to improve the ventilation and drainage conditions of urban trees, follow by application of arbuscular mycorrhizal fungi. In addition, production and commercialization of arbuscular mycorrhizal fungi in Taiwan, apart from the control for stable mass production methods, it is also important to distort concepts of user''s that need to be corrected for a wider application of arbuscular mycorrhizal fungi.
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Macyk, Terry M., und Vernon G. Belts. „Establishment of trees and shrubs on mined land in the subalpine region of Alberta“. 1995. http://hdl.handle.net/2429/10863.
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The Alberta Research Council has conducted a surface mine reclamation research program at the operations of Smoky River Coal Limited near Grande Cache, Alberta since 1972. The overall objective of this study is to develop and refine costeffective methods of establishing and maintaining a vegetative cover that is in harmony with adjacent undisturbed areas. A program to introduce trees and shrubs to the area was undertaken concurrently with the establishment of grasses and legumes. Due to the lack of seedlings available at the time for planting above an elevation of 1100 m, a cone collection program was undertaken to obtain seed for production of lodgepole pine (Pinus contorta var. latifolia), white spruce (Picea glauca), and engelmann spruce (Picea engelmanniil. Cuttings of willow (Salix spp.), balsam poplar (Populus balsamifera),
and root cuttings of aspen (Populus tremuloides) were rooted in the greenhouse prior to planting. Willow cuttings were also
collected and directly planted in the field.
Most of the trees and shrubs produced were planted in areas having an established grass, or grass and legume cover. Container grown conifer seedlings were superior to bare root stock in terms of survival and growth rate. Survival rate increased with increasing size of container. Mean annual growth measurements of lodgepole pine and engelmann spruce seedlings in the reclaimed areas and adjacent undisturbed forest indicated that the reconstructed soils will support tree growth that is equivalent to the growth achieved on the natural or undisturbed soils. The willow and alder provided excellent protection for the conifers when the conifers exceeded the height of the grass and legume cover.
Frost heaving of container seedlings and limited egress were the major causes of mortality for the conifers. Direct seeding
was initiated in the fall of 1983 using seed of pine, spruce, and alder. The results obtained showed that direct seeding is a
viable alternative to the use of container or bare root materials for specific locations in a mined area.
The research conducted to date indicates that trees and shrubs can become established in reclaimed areas in the subalpine. The methods that are utilized for any given location are dependent on the end land use desired, the time frame allowed, and specific site conditions.