Woody competition during mid-rotation limits available nutrients to crop species. Mid-rotation competition control was evaluated to determine if applications would result in significant increase in growth. Two studies were initiated using herbicides and prescribed burning on mid-rotation loblolly pine plantations. The first study contained afforested stands in Mississippi. Combination of imazapyr and burn was applied. The second study contained reforested sites in Mississippi. Treatments consisted of imazapyr and burn, imazapyr only, burn only, and a control. Five-year post-treatment measurements for the first study showed no significant treatment differences in height, diameter, basal area, or volume growth. Nine-year post-treatment measurements for the second study showed no significant differences in growth using the same measurements. Although previous research has documented significant growth responses to mid-rotation competition control, results from this study demonstrate that increased growth does not always result from mid-rotation competition control, suggesting initial site conditions may dictate degree of response.

by Chan Wai-yi. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references (leaves 142-154). / Abstract --- p.i / Acknowledgements --- p.iii / List of Tables --- p.iv / List of Figures --- p.vi / List of Plates --- p.vii / List of Appendices --- p.viii / Chapter CHAPTER 1 --- INTRODUCTION / Chapter 1.1 --- Urban environment and urban trees in Hong Kong --- p.1 / Chapter 1.2 --- Conceptual framework of the study --- p.3 / Chapter 1.3 --- Objectives of the study --- p.12 / Chapter 1.4 --- Scope and significance of the study --- p.12 / Chapter 1.5 --- Organization of the thesis --- p.14 / Chapter CHAPTER 2 --- STUDY AREA / Chapter 2.1 --- Location --- p.15 / Chapter 2.2 --- Climate --- p.19 / Chapter 2.3 --- Planter --- p.21 / Chapter 2.4 --- Soils --- p.22 / Chapter 2.5 --- Management --- p.23 / Chapter 2.5.1 --- Authority --- p.23 / Chapter 2.5.2 --- Management intensity --- p.26 / Chapter CHAPTER 3 --- INVENTORY OF PLANTER GREENERY / Chapter 3.1 --- Introduction --- p.30 / Chapter 3.2 --- Methodology --- p.33 / Chapter 3.2.1 --- Sampling --- p.33 / Chapter 3.3 --- Results --- p.36 / Chapter 3.3.1 --- Species composition --- p.36 / Chapter 3.3.2 --- Tree structure and size (physiognomy) --- p.40 / Chapter 3.3.3 --- Growth performance --- p.44 / Chapter 3.3.4 --- Tree growth problems --- p.45 / Chapter 3.3.5 --- Shrub and ground cover --- p.47 / Chapter 3.4 --- Discussion --- p.48 / Chapter 3.4.1 --- Inventory of planter greenery in the study areas --- p.48 / Chapter 3.4.2 --- Growth performance and problems --- p.57 / Chapter 3.5 --- Conclusion --- p.62 / Chapter CHAPTER 4 --- SELECTED PROPERTIES OF PLANTER SOILS / Chapter 4.1 --- Introduction --- p.65 / Chapter 4.2 --- Methodology --- p.67 / Chapter 4.2.1 --- Sampling --- p.67 / Chapter 4.2.2 --- Soil texture --- p.68 / Chapter 4.2.3 --- Soil reaction --- p.68 / Chapter 4.2.4 --- Organic carbon --- p.69 / Chapter 4.2.5 --- Total Kjeldahl nitrogen (TKN) --- p.69 / Chapter 4.2.6 --- Mineral nitrogen (ammonium and nitrate nitrogen) --- p.70 / Chapter 4.2.7 --- Total phosphorus --- p.70 / Chapter 4.2.8 --- Available phosphorus --- p.70 / Chapter 4.2.9 --- "Exchangeable K, Na，Ca and Mg" --- p.71 / Chapter 4.2.10 --- Carbon : nitrogen ratio --- p.71 / Chapter 4.3 --- Statistical analysis --- p.71 / Chapter 4.4 --- Results --- p.72 / Chapter 4.4.1 --- Soil texture --- p.72 / Chapter 4.4.2 --- Soil pH --- p.72 / Chapter 4.4.3 --- Organic matter --- p.73 / Chapter 4.4.4 --- Total Kjeldahl nitrogen --- p.74 / Chapter 4.4.5 --- Ammonium nitrogen and nitrate nitrogen --- p.75 / Chapter 4.4.6 --- Total phosphorus and available phosphorus --- p.76 / Chapter 4.4.7 --- Exchangeable cations --- p.78 / Chapter 4.5 --- Discussion --- p.80 / Chapter 4.5.1 --- Comparison with other studies --- p.80 / Chapter 4.5.2 --- "Are the planter soils optimal in pH, phosphorus and exchangeable cations?" --- p.84 / Chapter 4.5.3 --- "Deficiencies of SOM, TKN and mineral N" --- p.88 / Chapter 4.6 --- Conclusion --- p.91 / Chapter CHAPTER 5 --- NITROGEN AND PHOSPHORUS MINERALIZATION / Chapter 5.1 --- Introduction --- p.93 / Chapter 5.2 --- Methodology --- p.96 / Chapter 5.2.1 --- In situ incubation --- p.96 / Chapter 5.2.2 --- "Determination of N mineralization, leaching and uptake" --- p.98 / Chapter 5.2.3 --- "Determination of P mineralization, leaching and uptake" --- p.100 / Chapter 5.2.4 --- Statistical analysis --- p.101 / Chapter 5.3 --- Results --- p.102 / Chapter 5.3.1 --- Temporal changes of ammonification and nitrification --- p.102 / Chapter 5.3.2 --- Temporal changes of P mineralization --- p.103 / Chapter 5.3.3 --- "Net ammonification, NH4 leaching and uptake" --- p.104 / Chapter 5.3.4 --- "Net nitrification, N03 leaching and uptake" --- p.105 / Chapter 5.3.5 --- "Net N mineralization, leaching and uptake" --- p.106 / Chapter 5.3.6 --- "Net P mineralization, leaching and uptake" --- p.107 / Chapter 5.4 --- Discussion --- p.108 / Chapter 5.4.1 --- Comparison with other studies --- p.108 / Chapter 5.4.2 --- N mineralization in the planter soils --- p.112 / Chapter 5.4.3 --- P mineralization in the planter soils --- p.116 / Chapter 5.4.4 --- Leaching loss of mineral N and P in the planter soils --- p.118 / Chapter 5.4.5 --- Uptake of N and P in the planter soils --- p.121 / Chapter 5.5 --- Conclusion --- p.124 / Chapter CHAPTER 6 --- CONCLUSION / Chapter 6.1 --- Summary of findings --- p.127 / Chapter 6.2 --- Implications of the study --- p.131 / Chapter 6.2.1 --- Site-specific management programme --- p.131 / Chapter 6.2.2 --- Application of results --- p.134 / Chapter 6.3 --- Limitations of the study --- p.137 / Chapter 6.4 --- Suggestions for future study --- p.139 / REFERENCES --- p.142 / APPENDICES --- p.155

[Truncated abstract] Native vegetation (bushland) in urban areas remains in small, isolated patches embedded within a matrix of human-dominated land uses. Bushlands in urban areas have high biodiversity conservation and social values, and there has been a local-level movement towards protecting and managing urban bushlands in Australia. This thesis aims to test principles, theories and concepts relating to the ecology and management of bushland fragments in Australian cities ... A commonly used qualitative scale was compared with an ecologically based, quantitative technique developed in the research. The qualitative scale was found to be a reliable proxy for assessing vegetation condition, while also being more user-friendly for community groups and other bushland managers. The human-caused disturbances and weed cover in urban bushlands indicate a need for management intervention. Local government has an important role in local biodiversity management, yet there has been little research on this topic ... Positive partnerships developed where local governments have taken a ‘contract model’ approach to volunteer coordination, have a number of expectations of volunteer groups, and provide the groups with relatively high level of assistance. Also important is a local government that supports, respects, trusts and communicates with the community group, and recognises volunteers’ skills, knowledge and contributions. With increased resources allocated to local government bushland management and conservation, and coordination with community groups, the full potential of local bushland management would be realised.

Thesis (MSc)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Invasive alien plants (IAPs) are known for their detrimental impacts on biodiversity and ecosystem goods and services. A substantial body of research has contributed to our understanding of their impacts on ecology. In comparison the socio-economic aspects of IAPs, are not well understood. Additionally, valuation practises have usually excluded the positive and the non-monetary impacts (benefits and uses) that IAPs hold for local livelihoods. Holistic valuation has been regarded as imperative for decision-making and managerial frameworks. A study was conducted in Elim on the southern Cape coast of the Agulhas Plain, South Africa, which aimed to explore the various impacts of IAPs on the livelihoods of rural land-users. Individual qualitative interviews were conducted face to face with landholders (referred to as farmers) (N = 12) and individuals from the economically marginalized community (referred to as marginalized community) (N = 12). The grounded theory approach to data analysis was used and results of the coding method used were displayed by means of superscripts. Results indicate that farmers were aware of broader uses of IAPs although they themselves did not utilise them as extensively as members of the marginalized communities. Invasive alien and problem plants that held value for both land-users were not perceived as being „invasive‟. Invasive alien plants were believed to have detrimental impacts on biodiversity and ecosystems goods and services which support people‟s livelihoods. Alien clearing programmes such as Working for Water (WfW) and LandCare have done much to alleviate the socio-economic burden of unemployment in this marginalized community. Aside from the social development aims set out by WfW (i.e. employment of low-income communities, poverty alleviation and skills training), knock-on social development benefits (e.g. feelings of pride, responsibility and awareness as well as conflict management skills) were also realised by individuals from the marginalized community that were previously employed by the programme. Farmers regarded alien clearing and management as a process that demands excessive time, energy and financial resources. On single occasions it was found that farmers employed methods other than the conventional clearing and management strategies (e.g. livestock that feed on IAPs and giving refuse IAP biomass from clearing and felling to neighbouring poor communities). No clear consensus was reached about regarding alien clearing and management but more support is desired from government. Working for Water relies on private landholders for alien clearing as it is required by law. This study emphasizes that stronger relationships between government and private landholders as well as more substantial incentives to clear IAPs on private land are prerequisites if required outcomes are to be achieved. Educating society at large about the detrimental impacts of IAPs is fundamental. Additionally, informing landholders on effective alien clearing methods and policies and legislation pertaining to it are key activities for the South African government. Finally, clearing and management programmes need to consider the benefits that local land-users obtain from IAPs when prioritising areas for the management of alien vegetation. / AFRIKAANSE OPSOMMING: Uitheemse indringerplante (UIPe) is bekend vir die nadelige gevolge wat hulle vir biodiversiteit en ekosisteem goedere en dienste inhou. ʼn Aansienlike liggaam van navorsing het bygedra tot ons begrip van die impak daarvan op ekologie. In teendeel, die sosio-ekonomiese aspekte van UIPe word egter nie goed verstaan nie. Daarbenewens, evalueringspraktyke het gewoonlik die positiewe en nie-monetêre impakte (voordele en gebruike) wat UIPe vir plaaslike lewensbestaan hou, uitgesluit. Holistiese evaluering word as noodsaaklik beskou vir besluitneming en bestuursraamwerke. ʼn Studie was uitgevoer in Elim op die Suid-Kaapse kus van die Agulhas-vlakte, Suid-Afrika. Die doel was om die verskillende aspekte van UIP impakte op die lewensbestaan van landelike grondgebruikers aan te spreek. Individuele kwalitatiewe onderhoude is van aangesig tot aangesig gevoer met grondeienaars (na wie verwys word as boere) (N = 12) en individue van die ekonomies gemarginaliseerde gemeenskap (na wie verwys word as gemarginaliseerde gemeenskap) (N = 12). Die gegronde teorie metode tot data analise was gebruik en die resultate van die kodering metode is vertoon deur middel van boskrifte. Resultate dui daarop dat boere bewus was van ʼn wyer reeks van gebruike van UIPe alhoewel hulle dit nie so ekstensief benut het soos die lede van die gemarginaliseerde gemeenskappe nie. Uitheemse en probleem plante wat waarde gehou het vir beide landgebruikers,was nie soseer beskou as „indringers‟ nie. Daar was geglo dat UIPe nadelige impakte het op biodiversiteit en ekosisteme goedere en dienste wat mense se lewensbestaan ondersteun. Programme soos Werk vir Water (WvW) en LandCare wat fokus op die uitroeiing van UIPe, het baie gedoen om die sosio-ekonomiese laste as ʼn gevolg van werkloosheid in hierdie gemarginaliseerde gemeenskap te verlig. Benewens die sosiale ontwikkelings doelwitte uiteengesit deur WvW (o.a. indiensneming van lae-inkomste gemeenskappe, armoedeverligting en vaardigheidsopleiding), is daar ook domino-voordele (bv. gevoelens van trots, verantwoordelikheid en bewustheid sowel as konflik bestuursvaardighede) aangaande sosiale ontwikkeling ervaar deur individue van die gemarginaliseerde gemeenskap wat voorheen in diens van die program was. Boere beskou die uitroeiing en bestuur van UIPe as ʼn proses wat oormatige tyd, energie en finansiële hulpbronne vereis. Op enkele geleenthede was dit gevind dat boere gebruik maak van metodes anders as die konvensionele skoonmaak-en bestuurs strategieë (bv. vee wat voed op UIPe en biomassa wat na afloop van skoonmaak aan die naburige arm gemeenskappe gegee word). Geen duidelike konsensus is bereik met betrekking tot die uitroeiing en bestuur van UIP nie, maar meer ondersteuning van die regering word verlang. Werk vir Water maak staat op private grondeienaars vir die uitroeiing van UIPe. Hierdie studie beklemtoon dat sterker verhoudings tussen die regering en private grondeienaars sowel as meer aansienlike aansporings om UIPe op private grond skoon te maak ʼn voorvereiste is as verwagte uitkomste bereik wil word. Opvoeding van die breër gemeenskap oor die nadelige impakte van UIPe is fundamenteel. Om grondeienaars in te lig oor effektiewe UIP verwyderingsmetodes asook beleide en wetgewing met betrekking daartoe, is belangrikste aktiwiteite vir die Suid-Afrikaanse regering. Ten slotte, skoonmaak- en bestuursprogramme moet oorweging skenk aan die voordele wat plaaslike landgebruikers put uit UIPe wanneer daar geprioritiseer word vir gebiede vir die bestuur van indringerplante.

published_or_final_version / Geography and Geology / Doctoral / Doctor of Philosophy

The Kentucky Division of Water indicates that agriculture is responsible for 55% of the Commonwealth’s assessed streams not supporting their designated uses. Riparian buffers reduce nonpoint source pollution in agroecosystems by storing and cycling nutrients, stabilizing streambanks, increasing infiltration, and storing water. Specific information regarding riparian buffer management is needed for land managers to maximize buffer effectiveness at reducing agricultural contaminants impairing water quality. Baseline soil properties (texture, pH, C and nutrients) of the riparian buffer surrounding a tributary of Cane Run Creek in Fayette County, KY were characterized prior to imposing three mowing regimes (intense, moderate, and no mow treatments) and one native grass regime. Measurements were made along parallel transects located 2-m and 8-m distances from the stream. Root biomass, aggregate distribution, and saturated hydraulic conductivity were measured along the 2-m transect in two consecutive years following treatment establishment. The 2-m transect soils had the highest C, pH, Ca, Zn, and sand content. The 8-m transect had the highest P, K, Mg, and clay content. Semivariogram analysis of C content indicated slight to moderate spatial dependency along the 2m transect and moderate to strong spatial dependency along the 8m transect. Root biomass increased with decreased mowing frequency at the surface depth after one year; the native grass treatment had significantly less root biomass in both years compared to mowing treatments. There was no significant treatment effect on aggregate size distribution at the surface depth in either year. Mean weight diameter and large macroaggregates decreased from 2011 to 2012. Vegetation treatment had no statistically significant effect on water stable aggregates or saturated hydraulic conductivity. Experimental semivariograms provided evidence of spatial structure at multiple scales in root biomass, aggregates, and soil C. Spatial variability occurred over a shorter lag distance in 2012 than 2011, suggesting an effect of imposed treatments slowly developing over time. This study provides important insights on riparian buffer soil properties, soil sampling strategies to detect spatial variability in riparian buffers, and length of time needed to assess effects of vegetation management regimes on riparian root biomass, soil aggregates, and hydraulic conductivity.

n/a

Title from PDF of title page (University of Missouri--Columbia, viewed on Feb 17, 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. Thesis advisor: Dr. Kathleen M. Trauth. Includes bibliographical references.

Vegetation monitoring, recording the recovery or change in plant cover over time, for several Karoo shrubs was undertaken to evaluate the Savory Grazing System on a farm in the Succulent Karoo. This evaluation was quantified by establishing if the proposed 120- day rest period between grazing events was sufficiently long enough for complete recovery of the vegetation. Complete recovery was described as sufficient regrowth after a grazing event so that continual cover loss would not result over time. Optimum resting periods would ensure that cover loss, due to grazing, could be recovered so that plant size and reproductive potential was not detrimentally affected. The ellipse intercept method was used to sample piospheres (or zones of attenuating animal impact) around water points in two vegetation types. From these results, 320 line transects for vegetation monitoring were located between 140 and 180m from the water points. One and a half year old piospheres of one farm were compared to seventeen year old piospheres on another farm with similar vegetation composition. The piospheres on the younger farm were expanding at an approximate linear rate of 80m per year, however, this rate slows considerably, as was found on the farm with older piospheres. Stability or equilibrium appears to be reached at approximately 320m from the water point in the older system. The line transects were used to record the change in cover of palatable and unpalatable Karoo shrubs on a monthly basis over an 18 month period. In all instances it was concluded that the proposed 120-day rest period was not sufficiently long enough for complete recovery of the vegetation. The highly palatable species, especially Osteospermum sinuatum and Tetragonia spp., were the most heavily utilized and detrimentally affected. Larger individuals of the palatable shrubs O. sinuatum and Tetragonia spp. were more severely grazed than smaller individuals as a result of smaller individuals utilising spiny nurse plants under which to establish. If the present rest period is continued the result could be overgrazing and local extinction of these important fodder species. The responses of two highly palatable species, O. sinuatum and Tetragonia spp., were monitored closely in relation to rainfall and grazing events. Grazed and ungrazed (protected) individuals were monitored over one year to substantiate the results obtained from the line transects. The rest period was again found to be too short for full recovery and was also found to be reducing the reproductive output of O. sinuatum and Tetragonia spp.. The recruitment of O. sinuatum and Tetragonia spp. was also measured by comparing seedling establishment in grazed, ungrazed (vegetation protected from sheep grazing) and cleared vegetation. In an attempt to rehabilitate these rangelands, Pteronia pallens, a dominant unpalatable shrub, was cleared and the resultant seedling recruitment of O. sinuatum and Tetragonia spp. monitored and compared to grazed and ungrazed vegetation. Juvenile recruitment of these species was found to be significantly lower in the grazed than in the ungrazed vegetation. Recruitment of Tetragonia spp. was found to be significantly higher in the cleared strip compared to the grazed and ungrazed vegetation. The results obtained in this study suggest that the present grazing regime is having a detrimental effect on the vegetation and that revised management procedures are needed to ensure the conservation of these rangelands. The rest periods between grazing events need to be lengthened as well as a reduction in stock numbers. Certain camps need to be skipped on a seasonal basis during the flowering season in order to increase the reproductive output of highly palatable species. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1995.

Thesis (M.S.)--University of Nevada, Reno, 2005. / "August, 2005." Includes bibliographical references (leaves 110-117). Library also has microfilm. Ann Arbor, Mich. : ProQuest Information and Learning Company, [2005]. 1 microfilm reel ; 35 mm. Online version available on the World Wide Web.