abstract: Baseline community composition data provides a snapshot in time that allows changes in composition to be monitored more effectively and can inform best practices. This study examines Arizona Upland plant community composition of the Sonoran Desert through three different lenses: floristic inventory, and fire and reseeding effects. A floristic inventory was conducted at Cave Creek Regional Park (CCRP), Maricopa County, AZ. One hundred fifty-four taxa were documented within Park boundaries, including 148 species and six infraspecific taxa in 43 families. Asteraceae, Boraginaceae, and Fabaceae accounted for 40% of documented species and annuals accounted for 56% of documented diversity. Fire effects were studied at three locations within McDowell Sonoran Preserve (MSP), Scottsdale, AZ. These fires occurred throughout the 1990s and recovered naturally. Fire and reseeding effects were studied at the site of a 2005 fire within CCRP that was reseeded immediately following the fire. Two questions underlie the study regarding fire and reseeding effects: 1) How did fire and reseeding affect the cover and diversity of the plant communities? 2) Is there a difference in distribution of cover between treatments for individual species or growth habits? To address these questions, I compared burned and adjacent unburned treatments at each site, with an additional reseeded treatment added at CCRP. MSP sites revealed overall diversity and cover was similar between treatments, but succulent cover was significantly reduced, and subshrub cover was significantly greater in the burn treatment. Seventeen species showed significant difference in distribution of cover between treatments. The CCRP reseeded site revealed 11 of 28 species used in the seed mix persist 12 years post-fire. The reseeded treatment showed greater overall diversity than burned and unburned treatments. Succulent and shrub cover were significantly reduced by fire while subshrub cover was significantly greater in the reseeded treatment. Sixteen species showed significant difference in distribution of cover between treatments. Fire appears to impact plant community composition across Arizona Upland sites. Choosing species to include in seed mixes for post-fire reseeding, based on knowledge of pre-fire species composition and individual species’ fire responses, may be a useful tool to promote post-fire plant community recovery. / Dissertation/Thesis / Masters Thesis Plant Biology and Conservation 2018

A study was initiated in 1981 to investigate the redevelopment of plant communities on a recontoured, surface-mined site in southwestern Wyoming. The landscape pattern of vegetation was compared with topographic position, the initial topsoil pattern, and cultural practices including shrub planting density, shrub planting pattern and topsoil treatments for the years 1982-1985. In addition, differences in vascular plant species diversity within these various factors and treatments were determined, along with the trend in intracommunity (alpha), intercommunity (beta) and landscape (gamma) diversity for the entire study area. The influence of site factors and tested cultural practices on the differentiation of the landscape vegetation pattern generally declined over time. There were no persistent differences in diversity among any cultural treatments or topographic positions, with the exception of plan ting pattern. The vegetation classified by cultural treatment, topographic position, or the initial plant comm uni ties identified in 1982 showed strong successional convergence by 1985. This is reflected in a decline in be ta and gamma diversity over the period 1984-1985. Alpha diversity remained stable over this same period, though species richness increased, indicating that a subset of species is becoming more dominant. The landscape vegetation pattern apparently converged to a rather uniform composition, increasingly dominated by perennial grasses, forbs and shrubs.

Throughout the past century, vegetation scientists have been studying plant communities to develop classification standards for global mapping purposes. In Turkey, although there are several vegetation classification schemes in use by botanists, foresters or geographers, none is widely accepted by all for vegetation mapping. In this study, a hierarchical, ecologically meaningful, physiognomic-floristic classification system was adapted and developed for terrestrial vegetation in Turkey. The system has eight hierarchical levels, with the alliance and the association as its lowest two floristic levels, and the classes are designed to be easily detected in the field or indirectly through remote sensing. To test of its utility, a supervised vegetation classification of the whole Mediterranean Region of Turkey was carried out using Landsat ETM images. The accuracy of the classification ranged between 55% and 69% depending on the level of hierarchy. A further test for its ecological utility was carried out by comparing identified vegetation classes with breeding bird communities derived from data gathered through field observations at 193 ecological communities at 83 sites. The proposed classification scheme has proven to be reasonably accurate when widely available satellite imagery is used and ecologically meaningful as shown by a high concordance with observed bird community patterns. It is suggested that this new system can be safely applied to other regions of Turkey for purposes of vegetation mapping, species habitat modeling, and nature conservation if proper image set and ancillary data is used.

This thesis is an investigation of the effects of long-term drainage on plant community composition, biomass and productivity in boreal continental peatlands. Because bogs are ombrotrophic, I hypothesized that bog plant community composition, biomass and productivity would be affected by drainage less than fens. I identified six Alberta peatlands (2 bogs, 4 fens) that were affected by long-term drainage through road construction or drainage ditches. I found that understory species composition in fens changed more in response to drainage than in bogs, and was related to the degree of canopy closure. Woody biomass increased in all poor fens sites with drainage, while understory biomass was not affected. I investigated the influence of drainage on primary productivity in two sites, and found that tree and moss productivity responded differently. These results have implications for peatland carbon cycling, as an increase in woody biomass will affect litter quality and future fire risk.

The Southern Ground Hornbill (SGH) (Bucorvus leadbeateri) has recently been listed globally by the IUCN Red list as Endangered or Critically Endangered. In South Africa, the declining population of the SGH has led it to be listed nationally as Vulnerable and falls under the “Protected Species” legislation. Research into the habitat preferences and identification of suitable reintroduction areas have been few since the initiation of reintroduction attempts, therefore resulting in mixed outcomes of previously-reintroduced SGH. The aim of this study was to identify and verify optimal reintroduction sites for the SGH, in the Musina area in the Limpopo Province. Five main objectives were determined, namely: to identify optimal reintroduction areas; to develop a habitat profile of the designated area; to determine the availability of prey items; to determine the availability of large trees needed for nesting and roosting; to evaluate pre-release sites by involving a number of stakeholders. Three study sites were selected on the farm Greyghost Safaris (Ludwigslust), each made up of a different plant community. Sampling was carried out a total of four times during the year: one sampling bout in each season. A niche-based modelling technique was used to describe the suitability of a particular habitat (“ecological space”) then used to project it onto another geographical space. Floristic and faunal surveys were conducted to determine the species composition of prey items and composition and frequency of the herbaceous and woody layer. High-resolution, natural-colour aerial imagery was used in order to determine the availability of trees for nesting and roosting. Pre-release site evaluations and stakeholder engagements were conducted by means of interviews with landowners on and around the study sites. The Limpopo River Valley and across to the KNP on the eastern border of the Limpopo Province, is suitable re-introduction sites for the SGH. This study site provided a good opportunity to explore what an optimal site for reintroduction should resemble. / Thesis (MSc (Zoology))--North-West University, Potchefstroom Campus, 2012.

The Southern Ground Hornbill (SGH) (Bucorvus leadbeateri) has recently been listed globally by the IUCN Red list as Endangered or Critically Endangered. In South Africa, the declining population of the SGH has led it to be listed nationally as Vulnerable and falls under the “Protected Species” legislation. Research into the habitat preferences and identification of suitable reintroduction areas have been few since the initiation of reintroduction attempts, therefore resulting in mixed outcomes of previously-reintroduced SGH. The aim of this study was to identify and verify optimal reintroduction sites for the SGH, in the Musina area in the Limpopo Province. Five main objectives were determined, namely: to identify optimal reintroduction areas; to develop a habitat profile of the designated area; to determine the availability of prey items; to determine the availability of large trees needed for nesting and roosting; to evaluate pre-release sites by involving a number of stakeholders. Three study sites were selected on the farm Greyghost Safaris (Ludwigslust), each made up of a different plant community. Sampling was carried out a total of four times during the year: one sampling bout in each season. A niche-based modelling technique was used to describe the suitability of a particular habitat (“ecological space”) then used to project it onto another geographical space. Floristic and faunal surveys were conducted to determine the species composition of prey items and composition and frequency of the herbaceous and woody layer. High-resolution, natural-colour aerial imagery was used in order to determine the availability of trees for nesting and roosting. Pre-release site evaluations and stakeholder engagements were conducted by means of interviews with landowners on and around the study sites. The Limpopo River Valley and across to the KNP on the eastern border of the Limpopo Province, is suitable re-introduction sites for the SGH. This study site provided a good opportunity to explore what an optimal site for reintroduction should resemble. / Thesis (MSc (Zoology))--North-West University, Potchefstroom Campus, 2012.

Thesis (M.S.)--Miami University, Dept. of Botany, 2006. / Title from first page of PDF document. Includes bibliographical references.

Os ecossistemas campestres co-evoluíram com distúrbios como a herbivoria e o fogo. Assim, estes fatores são importantes no surgimento e manutenção de características da comunidade, podendo modificar os processos de sucessão. Em áreas perturbadas, as sementes que persistem no solo participam da regeneração natural. Diante da alta taxa de conversão dos campos nativos no sul do Brasil em áreas de uso intensivo (lavoura ou plantios de espécies arbóreas), bem como do manejo pastoril com alta pressão animal, aumenta o interesse em estudos relacionados ao banco de sementes do solo (BSS), buscando compreender a sua função nas comunidades vegetais e na regeneração de áreas degradadas. O conhecimento já existente sobre BSS em biomas campestres do hemisfério sul ainda é incipiente. Grande parte dos trabalhos feitos em campos sul-americanos compararam o BSS entre áreas de vegetação pastejadas e áreas abandonadas, sendo poucos os que utilizaram diferentes intensidades de pastejo, apesar de efeitos claros de diferentes intensidades de pastejo sobre a composição e estrutura da vegetação. Em vista disto, foi avaliado, neste trabalho, o BSS em um experimento em campo submetido a diferentes intensidades de pastejo, em duas estações (primavera e outono), utilizando o método de emergência de plântulas. Também foi feito o levantamento da vegetação estabelecida para avaliar a similaridade com o BSS. Em total, foram encontradas 103 espécies no BSS e 162 na vegetação estabelecida. No BSS, a porcentagem de espécies de caráter ruderal foi alta. Diferenças significativas em termos de densidade e riqueza do BSS foram encontradas somente entre o tratamento com maior intensidade de pastejo e os demais. De forma geral, a semelhança entre o BSS e a vegetação estabelecida foi baixa. Assim, estes resultados indicam que o BSS tem um papel limitado na recuperação da vegetação campestre típica após distúrbios mais severos e que, aparentemente, a intensidade do manejo não tem um impacto muito grande para o BSS. Apesar disso, o BSS é importante pelo armazenamento das características naturais dos ambientes, agregando funções à regeneração da comunidade vegetal. / Grassland ecosystems co-evolved with disturbances such as fire and herbivory, and these factors are important for emergence and maintenance of community features areas. After disturbances, the seeds that persist in the soil contribute to regeneration processes. However, increasing conversion of natural grasslands into areas of intensive use (agriculture and exotic tree plantations), as well as overgrazing make the study of the regeneration of grassland vegetation after these severe disturbances an important research topic. Our knowledge on the role of the soil seed bank (SSB) in grassland biomes in the southern hemisphere still is incipient. The majority of studies realized in South American grassland compared the SSB between grazed and abandoned areas, and few consider different intensities of grazing, despite clear effects of different grazing intensities on vegetation composition and structure. In view of this, in this study, the SSB was evaluated in a grassland experiment under different intensities of grazing in two seasons (spring and autumn), using the seedling emergence method. In spring, a survey of the established vegetation was conducted to evaluate the similarity with the SSB. In total, we found 103 species in the SSB and 162 in established vegetation. The SSB was mostly composed of ruderal species. Grass species dominant in aboveground vegetation were largely absent in the SSB. Significant differences regarding SSB richness and density were only found between the treatment with higher intensity of grazing and the others, and overall composition did not differ among treatments. In general, the similarity between the SSB and established vegetation was low. Our results indicate that the SSB has a limited role in the recovery of natural grassland vegetation after more severe disturbances. Apparently, the intensity of management does not have a very large impact on the SSB or on the similarity between SSB and established vegetation. Nevertheless, the SSB is important for storage the natural characteristics of environments, adding functions to the regeneration of the plant community.

Os ecossistemas campestres co-evoluíram com distúrbios como a herbivoria e o fogo. Assim, estes fatores são importantes no surgimento e manutenção de características da comunidade, podendo modificar os processos de sucessão. Em áreas perturbadas, as sementes que persistem no solo participam da regeneração natural. Diante da alta taxa de conversão dos campos nativos no sul do Brasil em áreas de uso intensivo (lavoura ou plantios de espécies arbóreas), bem como do manejo pastoril com alta pressão animal, aumenta o interesse em estudos relacionados ao banco de sementes do solo (BSS), buscando compreender a sua função nas comunidades vegetais e na regeneração de áreas degradadas. O conhecimento já existente sobre BSS em biomas campestres do hemisfério sul ainda é incipiente. Grande parte dos trabalhos feitos em campos sul-americanos compararam o BSS entre áreas de vegetação pastejadas e áreas abandonadas, sendo poucos os que utilizaram diferentes intensidades de pastejo, apesar de efeitos claros de diferentes intensidades de pastejo sobre a composição e estrutura da vegetação. Em vista disto, foi avaliado, neste trabalho, o BSS em um experimento em campo submetido a diferentes intensidades de pastejo, em duas estações (primavera e outono), utilizando o método de emergência de plântulas. Também foi feito o levantamento da vegetação estabelecida para avaliar a similaridade com o BSS. Em total, foram encontradas 103 espécies no BSS e 162 na vegetação estabelecida. No BSS, a porcentagem de espécies de caráter ruderal foi alta. Diferenças significativas em termos de densidade e riqueza do BSS foram encontradas somente entre o tratamento com maior intensidade de pastejo e os demais. De forma geral, a semelhança entre o BSS e a vegetação estabelecida foi baixa. Assim, estes resultados indicam que o BSS tem um papel limitado na recuperação da vegetação campestre típica após distúrbios mais severos e que, aparentemente, a intensidade do manejo não tem um impacto muito grande para o BSS. Apesar disso, o BSS é importante pelo armazenamento das características naturais dos ambientes, agregando funções à regeneração da comunidade vegetal. / Grassland ecosystems co-evolved with disturbances such as fire and herbivory, and these factors are important for emergence and maintenance of community features areas. After disturbances, the seeds that persist in the soil contribute to regeneration processes. However, increasing conversion of natural grasslands into areas of intensive use (agriculture and exotic tree plantations), as well as overgrazing make the study of the regeneration of grassland vegetation after these severe disturbances an important research topic. Our knowledge on the role of the soil seed bank (SSB) in grassland biomes in the southern hemisphere still is incipient. The majority of studies realized in South American grassland compared the SSB between grazed and abandoned areas, and few consider different intensities of grazing, despite clear effects of different grazing intensities on vegetation composition and structure. In view of this, in this study, the SSB was evaluated in a grassland experiment under different intensities of grazing in two seasons (spring and autumn), using the seedling emergence method. In spring, a survey of the established vegetation was conducted to evaluate the similarity with the SSB. In total, we found 103 species in the SSB and 162 in established vegetation. The SSB was mostly composed of ruderal species. Grass species dominant in aboveground vegetation were largely absent in the SSB. Significant differences regarding SSB richness and density were only found between the treatment with higher intensity of grazing and the others, and overall composition did not differ among treatments. In general, the similarity between the SSB and established vegetation was low. Our results indicate that the SSB has a limited role in the recovery of natural grassland vegetation after more severe disturbances. Apparently, the intensity of management does not have a very large impact on the SSB or on the similarity between SSB and established vegetation. Nevertheless, the SSB is important for storage the natural characteristics of environments, adding functions to the regeneration of the plant community.

Os ecossistemas campestres co-evoluíram com distúrbios como a herbivoria e o fogo. Assim, estes fatores são importantes no surgimento e manutenção de características da comunidade, podendo modificar os processos de sucessão. Em áreas perturbadas, as sementes que persistem no solo participam da regeneração natural. Diante da alta taxa de conversão dos campos nativos no sul do Brasil em áreas de uso intensivo (lavoura ou plantios de espécies arbóreas), bem como do manejo pastoril com alta pressão animal, aumenta o interesse em estudos relacionados ao banco de sementes do solo (BSS), buscando compreender a sua função nas comunidades vegetais e na regeneração de áreas degradadas. O conhecimento já existente sobre BSS em biomas campestres do hemisfério sul ainda é incipiente. Grande parte dos trabalhos feitos em campos sul-americanos compararam o BSS entre áreas de vegetação pastejadas e áreas abandonadas, sendo poucos os que utilizaram diferentes intensidades de pastejo, apesar de efeitos claros de diferentes intensidades de pastejo sobre a composição e estrutura da vegetação. Em vista disto, foi avaliado, neste trabalho, o BSS em um experimento em campo submetido a diferentes intensidades de pastejo, em duas estações (primavera e outono), utilizando o método de emergência de plântulas. Também foi feito o levantamento da vegetação estabelecida para avaliar a similaridade com o BSS. Em total, foram encontradas 103 espécies no BSS e 162 na vegetação estabelecida. No BSS, a porcentagem de espécies de caráter ruderal foi alta. Diferenças significativas em termos de densidade e riqueza do BSS foram encontradas somente entre o tratamento com maior intensidade de pastejo e os demais. De forma geral, a semelhança entre o BSS e a vegetação estabelecida foi baixa. Assim, estes resultados indicam que o BSS tem um papel limitado na recuperação da vegetação campestre típica após distúrbios mais severos e que, aparentemente, a intensidade do manejo não tem um impacto muito grande para o BSS. Apesar disso, o BSS é importante pelo armazenamento das características naturais dos ambientes, agregando funções à regeneração da comunidade vegetal. / Grassland ecosystems co-evolved with disturbances such as fire and herbivory, and these factors are important for emergence and maintenance of community features areas. After disturbances, the seeds that persist in the soil contribute to regeneration processes. However, increasing conversion of natural grasslands into areas of intensive use (agriculture and exotic tree plantations), as well as overgrazing make the study of the regeneration of grassland vegetation after these severe disturbances an important research topic. Our knowledge on the role of the soil seed bank (SSB) in grassland biomes in the southern hemisphere still is incipient. The majority of studies realized in South American grassland compared the SSB between grazed and abandoned areas, and few consider different intensities of grazing, despite clear effects of different grazing intensities on vegetation composition and structure. In view of this, in this study, the SSB was evaluated in a grassland experiment under different intensities of grazing in two seasons (spring and autumn), using the seedling emergence method. In spring, a survey of the established vegetation was conducted to evaluate the similarity with the SSB. In total, we found 103 species in the SSB and 162 in established vegetation. The SSB was mostly composed of ruderal species. Grass species dominant in aboveground vegetation were largely absent in the SSB. Significant differences regarding SSB richness and density were only found between the treatment with higher intensity of grazing and the others, and overall composition did not differ among treatments. In general, the similarity between the SSB and established vegetation was low. Our results indicate that the SSB has a limited role in the recovery of natural grassland vegetation after more severe disturbances. Apparently, the intensity of management does not have a very large impact on the SSB or on the similarity between SSB and established vegetation. Nevertheless, the SSB is important for storage the natural characteristics of environments, adding functions to the regeneration of the plant community.