Prescribed fire and herbicides are 2 silviculture tools used by forest managers to control hardwood competition in pine (Pinus spp.) forests. I tested effects of prescribed burning and herbicides on selected invertebrate communities, including carabid beetles, and compared 2 invertebrate sampling approaches in thinned, intensively managed pine stands in Kemper County, Mississippi. I used 6 replicate stands containing 4, 10-ha treatment plots each that were randomly assigned treatments of burn only, herbicide only, burn/herbicide, and control. I suction-sampled invertebrate communities and pitfall trapped carabid beetles to examine treatment responses. Direct effects of burning and overall vegetation response influenced communities most but responses were limited. Sampling inefficiencies may have obscured treatment effects and managers and researchers are advised to consider all available methods when integrating invertebrate research. Information on forest management effects is still lacking but future research incorporating invertebrate sampling will support a better understanding of management impacts on ecosystems.

An accurate fire model is a useful tool in predicting the behavior of a prescribed fire. Simulation of fire requires an extensive amount of data and can be accomplished best using GIS applications. This paper demonstrates integrative procedures of using of ArcGIS™, ERDAS Imagine™, GPS, and FARSITE© to predict prescribed fire behavior on the Kaibab-Paiute Reservation. ArcGIS was used to create a database incorporating all variables into a common spatial reference system and format for the FARSITE model. ArcGIS Spatial Analyst was then used to select optimal burn sites for simulation. Our predictions will be implemented in future interagency efforts towards vegetative restoration on the reservation.

Thesis (M.S.)--North Carolina State University, 2003. / Title from PDF title page (viewed on Mar. 26, 2005). Includes vita. Includes bibliographical references.

Thesis (MTech. degree in Nature Conservation)--Tshwane University of Technology, 2011. / The study was conducted on the Botsalano Game Reserve with the support of the North West Tourism and Parks Agency. No formal management plan is available for the game reserve and therefore the need for an ecological management plan and guidelines for the formulation of a vegetation monitoring plan constituted the basis of the study. The objectives of the study were: 1. To classify and map the plant communities of the Botsalano Game Reserve; 2. To provide quantitative data, collected during a formal vegetation classification, for use by the reserve management in terms of current vegetation condition; 3. To ascertain whether a classification of the vegetation on the BGR could be used for the objective placement of vegetation monitoring sites. Monitoring site placement will be based on representation of plant communities, reflecting community and topographical unit utilization and thus stocking rates based on management decisions.

No description available.

The long-term economic viability and ecological integrity of savanna rangelands is being undermined by increasingly dense woody thickets at the expense of palatable herbaceous cover. This process is known as shrub- or bush-encroachment. Bush encroachment is a subset of a broader ecological riddle underlying the coexistence of woody and herbaceous vegetation that has been the subject of many ecological models. The ecophysiological mechanisms and interactions between trees and grasses on which most assumptions of ecological models are premised have seldom been tested empirically. This document synthesises the results of greenhouse and field-based investigations of the underlying ecological mechanisms and ecophysiological interactions between encroaching Acacia mellifera trees and grasses in a semi-arid environment. In a greenhouse study, I determined the contribution of N2 fixation to the N-budget of Acacia mellifera under conditions of both varying N availability and competition from grass. Tree seedlings had longer shoots and greater total dry mass in the absence of grass. The leaf δ15N values were lower with grass than without grasses. Thus, trees were more reliant on N2 fixation in the presence of grasses. N2 fixation may enable the tree seedlings to survive competition with grass at critical and vulnerable developmental stages of germination and establishment. In a field removal experiment, I monitored the growth rates, water relations and mortalities of shrubs around which neighbouring woody plants were removed (target) and control shrubs over three years. Results showed target trees to have benefitted from removal of neighbours, which was manifested in significantly faster growth rates, less negative predawn water potential and a relatively small degree of canopy die-back. Nonetheless, neighbouring trees appeared to prevent the whole plant mortalities resulting from severe environmental stress. Growing in close proximity with neighbours could therefore yield positive and negative ecophysiological effects. In another greenhouse experiment, I tested the effects of the separation of moisture uptake with depth between tree seedlings and grasses on two common substrate types. I also examined the influence of repeated grass clipping on the persistence of soil moisture. Results indicated a three-tier rooting pattern with a top layer exclusively exploited by grasses, an intermediate layer occupied by both grass and tree roots and deeper layers exclusively tapped by trees. Tree seedling biomass was negatively affected by grass competition although the biomass of grass was enhanced in the presence of tree seedlings on sandy substrates only. The repeated clipping of grass benefitted tree seedlings on rocky substrate more than it did on sandy substrate. The effects of heavy grazing on soil moisture availability to woody shrubs and thus bush encroachment may be contingent on substrate type, being more acute on rocky terrains. Grass competition suppresses tree seedlings but the removal of grass by grazing weakens this suppressive effect, particularly on rocky substrates. The insufficiency of space and soil resources on rocky substrates may necessitate increased investment in root biomass by plants. It is not known why grasses have lower densities on rocky substrates than on sandy substrates, but the obstruction by rocks disadvantages grasses against tree seedlings, leaving grasses vulnerable to grazing pressure. This may allow the woody plants on rocky substrates to benefit more from grass removal than on sandy substrates. Root restriction by rock barriers and, perhaps, sparse soil volume further lead to small tree sizes on the rocky substrate. Small shrubs are less likely to compete intensively for resources and cause density-dependent mortality. Intraspecific competition may maintain shrub sizes within the threshold that can be supported by available resource pools. I conclude from my results that the two-layer hypothesis of niche separation between savanna vegetation is valid although there is an overlap in the grass and tree rooting depth/moisture uptake. An additional factor that affects the success of A. mellifera is the substrate.Trees are more dense on rocky substrates but grow larger on sand. I have further shown that A. mellifera trees fix nitrogen when competing with grasses but do not do so when grasses are absent. A mechanistic model of savanna dynamics will need to integrate water use patterns, substrate and nutrients to make effective predictions about encroachment patterns. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2010.

Made available in DSpace on 2015-03-26T13:30:53Z (GMT). No. of bitstreams: 1 texto completo.pdf: 858304 bytes, checksum: da35f09db97f5331375c2dc2fd32de89 (MD5) Previous issue date: 2014-02-14 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / In most Brazilian regions a landscape of patches of native vegetation is found in an array of productive systems. This has caused a decrease in pollinator diversity and consequently the production of various crops. This work was initially studied the stigmatic receptivity of chilli pepper, Capsicum frutescens and the importance of pollination in the production (Chapter 1). Subsequently, the main pollinators of chili, the importance of spontaneous vegetation in the abundance of floral visitors and production of chilli pepper (Chapter 2) was studied. The experiments lasting flower and stigmatic receptivity were conducted in the laboratory of Entomology EPAMIG with 30 buds. Have the experiment to evaluate the importance of pollination in the production was performed in Oratorios/MG , in which 896 flower buds were marked to compose the two treatments , and restricted free pollination . Finally experiments of importance of spontaneous vegetation attract pollinators and production of chilli pepper were conducted in the municipalities of Oratorios/MG in six plants composed of 100 experimental sites, three free spontaneous vegetation and three containing spontaneous vegetation in edge and the line between the cultivation of pepper and Piranga/MG which had four of eight experimental areas free of spontaneous vegetation and the other four had the presence of spontaneous vegetation at the edge of cultivation and leading. The stigmatic receptivity occurred on the day of anthesis of 9 to 12 hours. The main floral visitors were bees, Tetragonisca angustula being the only species considered common in the environment. The diversity of floral visitors was higher in areas with pepper and without spontaneous vegetation. However, the area with natural vegetation present in one of the edges of the crop had greater abundance of floral visitors, showing that spontaneous vegetation is important for attracting pollinators. The proceeds of fruits pollinated flowers had greater mass than fruits of restricted pollination. The areas surrounded with spontaneous vegetation had a higher production of pepper compared with areas without spontaneous vegetation. Therefore, the spontaneous vegetation is important for higher abundance of pollinators and increased production of pepper. / Na maioria das regiões brasileiras é encontrada uma paisagem de fragmentos de vegetação nativa em uma matriz de sistemas produtivos. Isso tem ocasionado uma diminuição na diversidade de polinizadores e consequentemente da produção de diversas culturas. Neste trabalho, no capítulo 1 foi estudada a duração das flores e receptividade estigmática de pimenta-malagueta Capsicum frutescens, e a importância da polinização na produção. No capítulo 2, foram estudados os principais visitantes florais de pimenta-malagueta, a importância da vegetação espontânea na abundância de visitantes florais e na produção de frutos. Os experimentos de duração da flor e de receptividade estigmática foram realizados no laboratório de Entomologia da EPAMIG avaliando-se 30 botões florais. Para avaliar a importância da polinização na produção foi realizado um experimento em Oratórios/MG. Foram marcados 896 botões florais para compor os tratamentos de polinização livre e restrita. Os experimentos de importância da vegetação espontânea na atração de polinizadores e produção de pimenta-malagueta foram realizados em Oratórios/MG em três áreas experimentais compostas de 100 plantas livres de vegetação espontânea e outras três áreas também com 100 plantas, porém com vegetação espontânea na borda e na entrelinha do cultivo de pimenta e em Piranga/MG em quatro áreas experimentais livres de vegetação espontânea e em quatro com vegetação espontânea na borda do cultivo e na entrelinha. A receptividade estigmática ocorreu no dia da antese de 9 às 12 h. Os principais visitantes florais foram abelhas, sendo Tetragonisca angustula a única espécie comum no ambiente. A diversidade de visitantes florais foi maior na área com pimenta sem vegetação espontânea. No entanto, a área com vegetação espontânea em uma das bordas do cultivo teve maior abundância de visitantes florais. Os frutos advindos de flores polinizadas tiveram maior massa que frutos de polinização restrita. Nas áreas rodeadas com vegetação espontânea observou-se produção superior de pimenta comparado com as áreas sem vegetação espontânea. Conclui-se que a vegetação espontânea é importante para obter maior abundância de polinizadores e maior produção de pimenta.

Forest understory vegetation in lowland woodlands is coming through systematical changes, which are documented from many regions. Abandonment of traditional coppicing management, nitrogen deposition and effect of high game densities in some regions are considered to be the main key drivers. Changes of seminatural woodland in protected area of Bohemian Karst were studied in this research. The abandonment of traditional management is probably the biggest environmental change in this area. Original data, semi-permanent plots with phytosociological relevés, were surveyed shortly after the last coppicing in the half of twentieth century. These plots were now re-visited. Partial task was to evaluate how important relocation accuracy is. Discovered changes have similar trends as in other lowland woodlands. After abandonment of coppicing, site conditions changed towards more shade and nutrient rich sites. Vegetation shifted to species assemblages of late succession dominated by shade-adapted and nutrient-demanding species. Slight decrease in gama-diversity, increase in alpha-diversity and decrease of beta-diversity indicated taxonomic homogenization was recorded. Re-visiting of semi-permanent plots was evaluated as appropriate tool for this type of research. Spatial heterogenity is partly affecting temporal change,...

Knowledge of the impacts of white-tailed deer (Odocoileus virginianus; hereafter deer) as dominant herbivores throughout the Southeastern United States of America is lacking. To address this, three paired experimental units of exclosures and controls were constructed in 2000 on three Wildlife Management Areas across Mississippi within the ecoregions of the Upper Coastal Plain, Lower Coastal Plain, and the Mississippi Alluvial Valley. Vegetation was sampled in the summers of 2000, 2005, and 2021 including vegetation structure, canopy coverage, basal area, and species composition. Additionally, in 2005 and 2021, biomass was sampled to determine potential impacts on nutritional carrying capacity. Among the three study sites, vegetation metrics followed successional trends and were not influenced by herbivory or lack thereof. Additionally, regional differences in nutritional carrying capacity seemed to be of greater importance than herbivory. This research illustrates the difference in effects of deer by region and forest type.

Thesis (MSc)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: West Coast Renosterveld is one of the most threatened vegetation types in South Africa. Less than 5% of the original extent of this vegetation type remains, of which 80% is on private land. In addition to fragmentation, much of the vegetation has been ploughed for crop production and then abandoned and invaded by alien plants. Restoration of transformed areas may improve the conservation status of this vegetation type. Indigenous species do not return to abandoned agricultural fields for decades even if these are adjacent to natural areas since their return is limited either by seed dispersal or seedling establishment. The aim of this study was to examine the recovery of indigenous vegetation on abandoned fields. Renosterveld, as we know it today, is an asteraceous shrubland, dominated mainly by renosterbos (Eytropappus rhinocerotis), but might have been a grassland or a grassland-shrubland mosaic. Historical records indicate that species of large game were common in the Western Cape when the early settlers arrived, but most of these have since disappeared. It is thus impossible to reconstruct exactly the ecological processes and functioning of Renosterveld. The first part of the study was designed to examine the effects of grass competition, grazing by indigenous large herbivores, and interaction of these two factors on the establishment, growth and survival of transplanted Renosterveld seedlings on an abandoned agricultural field. Experimental transplanting of indigenous shrubs into an old field showed that most of the plants investigated competed for resources with lawn grasses on the field, and competition affected the seedlings throughout the experiment. Mortality was higher, and growth was reduced for seedlings exposed to grass competition. With the exception of wild olive (Olea europaea spp.africana), herbivory alone had no significant impact on the target species. Herbivory was at a low intensity (20 ha/large animal unit); higher grazing pressures might have given different results. No interaction between competition and herbivory was found for the species investigated; competition and grazing therefore seem to influence the seedlings independently. The second part of this study was conducted to examine the effects of different management strategies, viz: brush cutting, burning and herbicide application on plant species recruitment and community composition and to ascertain their applicability by farmers for large scale restoration of Renosterveld. My comparison of the different strategies for controlling annual alien grasses indicated that these did not differ significantly in their effects on species richness. Burning reduced shrub cover and increased overall species richness and diversity. Burning also reduced grass biomass, and increased recruitment of indigenous seedlings. The use of herbicide resolved the problem of grass biomass invasion and increased shrub species richness. The herbicide application did not appear to have long-term negative effects on the soil quality. Brush cutting did not remove grass biomass on the old field. Experimental re-seeding with an indigenous grass and shrub species into treated plots resulted in low recruitment. My conclusion is that grass can reduce recruitment and growth of many indigenous shrub species. My recommendation for the restoration of old fields in West Coast Renosterveld is to apply herbicide to remove grass competition, and then, after the herbicide has degraded, to oversow the field with seeds of indigenous shrub and grass species of early successional stages to increase overall species diversity. / AFRIKAANSE OPSOMMING: Weskus Renosterveld is een van die mees bedreigde plantegroei soorte in Suid Afrika. Minder as 5% van die oorspronklike omvang van hierdie plantegroei tipe is oor, en dit hoofsaaklik (80%) op privaatlande. Saam met fragmentasie, is baie Renosterveld areas ook omgeploeg vir boerdery en dan net so gelos, met die gevolg dat uitheemse plante hierdie areas ingedring het. Restorasie of herstelling van sulke bewerkte lande kan dalk die bewaringsstatus van hierdie plantegroei tipe verbeter. Natuurlike vestiging van Renosterveld spesies op sulke ou bewerkte lande gebeur nie, selfs al is daar Renosterveld direk langs so ‘n ou veld. Die hervestiging van inheemse spesies is dus tot saadverspreiding or saailingbevestiging beperk. Die doel van hierdie studie is om die stadige terugkoms van inheemse plantegroei na verlate bewerkte velde te verduidelik. Renosterveld is ‘n struikveld waarin die renosterbos (Eytropappus rhinocerotis) domineer, maar kan ook ‘n grasveld of ‘n grasveld-struikland mengsel wees. Groot herbivore was algemeen in die Wes Kaap toe die eerste settelaars gearriveer het, maar intussen het omtrent al die groot wild spesies verdwyn. Dit is dus ontmoontlik om die ekologiese prosesse en funksionering van Renosterveld presies so te herstel. Die eerste deel van hierdie studie bestudeer die effek van graskompetisie, weiding deur inheemse groot herbivore, en die interaksie tussen hierdie twee faktore op die vestiging, groei en oorlewing van oorgeplante Renosterveld saailinge in ‘n verlate ou veld. Die eksperimentele oorplanting van inheemse struike in ‘n ou land het gewys dat die meeste van hierdie plante kompeteer vir hulpbronne met kweekgras wat op die ou veld groei. Kompetisie het die saailinge deur die hele eksperiment geaffekteer. ‘n Hoër mortaliteit en verminderede groei in saailinge wat aan gras kompetisie blootgestel was, is waargeneem. Met die uitsondering van Olea europaea spp. africana, het herbivorie alleen geen betekenisvolle impak op plant spesies gehad nie. Weidingsdruk was laag (20 ha/groot vee eenheid); ‘n groter weidingsdruk sou miskien ‘n ander uitkoms gehad het. Geen interaksie tussen kompetisie en herbivorie is waargeneem in die bestudeerde plantspesies nie. Dit wil dus voorkom of kompetisie en weiding die saailinge onafhanklik van mekaar beïnvloed. Die tweede deel van hierdie studie was onderneem om die effek van verskillende behandelings (kontrole, sny, brand en herbisied toediening) op plantspesie vestiging en samestelling te bestudeer asook om bestuurmetodes te toets was deur boere op groot skaal gebruik kan word om Renosterveld te herstel. In ‘n vergelyking van verskillende bestuur metodes (kontrole, besnoeiing, brand en herbisied) om eenjarige uitheemse gras te beheer, is gewys dat die behandlings nie betekenisvol van mekaar verskil in hulle effek op spesierykheid nie. Vuur het struikbedekking verminder en totale spesies rykheid en diversitiet verhoog. Die gebruik van ‘n herbisied het die probleem van grasindringing opgelos en het ook struikspesiesrykheid verhoog. Die herbisied het nie lang termyn negatiewe effekte op grond kwaliteit gehad nie. Sny het nie gras biomassa verlaag op die ou land nie. Eksperimentele plant van inheemse grasse en struike in die behandelde areas, het lae vestiging tot gevolg gehad. My algemene afleiding is dus dat gras die hervestinging en groei van baie inheemse struikspesies verminder. Ek stel voor dat herbisied gebruik moet word om gras kompetisie te verminder. Nadat herbisied residue in die grond afgebreek is, moet die ou land met inheemse struik en grasspesies, wat in vroeë suksessie stadiums is, beplant word om sodoende totale spesiediversiteit te verhoog en uiteindelik ou bewerkte lande in Weskus Renosterveld te herstel.