Temperate grasslands and the services they provide are threatened with severe degradation from human-driven land use changes. Among the worst affected services is pollinator support with grassland degradation contributing to the global decline in insect abundance due to habitat loss and a lack of floral resources. This has prompted conservation organizations to support pollinator conservation on working landscapes by increasing floral resources, but gaps remain in the consistent establishment of native forbs in intensively managed agricultural areas. We evaluated factors that influence native forb establishment during seed-based enrichment planting of tall fescue-dominated cattle pastures in two separate experiments: one testing a range of site preparation treatments with different seasons of sowing and comparing their effects on tall fescue suppression and seeded native plant establishment and the other investigating the effects of seed rate and pre-seeding cold stratification on native forb establishment on separate plots. For the site preparation experiment, we observed a mean target plant density of 0.12 target plants per m2 (SD = 0.247) The greatest target plant stem density (P < 0.0001) and species richness (P < 0.001) was in plots treated with a 2% glyphosate solution and sown with native seeds in early summer with the next five best treatments composed solely of fall sown replicates. For the seed and stratification experiment, we observed a mean target plant density of 88 target plants per m2 (SD = 73.9). Higher seeding resulted in greater target plant abundance in plots (P < 0.0001) with a seed rate of 56 kg/ha-1 resulting in almost three times as many target plants compared to 2.24 kg/ha-1. Pre-seeding stratification resulted in an increase in target plant abundance (P < 0.01). Target species richness was consistent between treatment levels. Results suggest that native forb establishment can be enhance by eliminating pasture grasses prior to seeding and the use of high seeding rates sown in the fall or using stratified seed. / Master of Science / Temperate grasslands and the services they provide are threatened with severe degradation from human-driven land use changes. Among the worst affected services is pollinator support with grassland degradation contributing to the global decline in insect abundance due to habitat loss and a lack of floral resources. To reverse this decline, conservation groups are encouraging the use of native plants throughout the landscape especially on farms and ranches to provide more resources for insect pollinators. One exciting opportunity exists in planting wildflowers into tall fescue-dominated cattle pastures that occupy millions of hectares of land in the Southeastern United States to provide food for pollinating insects. However little information exists on how to successfully establish wildflowers as much expertise is based on work done in the tallgrass prairie region of the Midwest. This study's goal was to investigate what control wildflower establishment by evaluating the success of an existing establishment experiment testing several site preparation techniques and different sowing seasons. A separate experiment was set up looking at the effect different seed rate and cold moist stratification had on establishment success of wildflowers. For the site preparation experiment, establishment was low for all treatments with a mean target plant density of 0.12 target plant per m2 (SD = 0.247). Summer sown 2% glyphosate had the highest wildflower richness and abundance at 0.35 target plants per m2 (SD = 0.247) and fall sown treatments were found to have higher sown wildflower abundance and richness than summer sown treatments. For the seed and stratification experiment, we observed a mean target plant density of 88 target plants per m2 (SD = 73.9). Target plant abundance did change between treatment levels with the highest and second highest seed levels yielding nearly three times and twice as many sown wildflowers as the lowest treatment respectively. Stratification resulted in an increase in sown wildflower abundance and sown wildflower richness did not differ significantly between treatment levels. Results suggest that native forb establishment can be enhance by eliminating pasture grasses prior to seeding and the use of high seeding rates sown in the fall using stratified seed.

No description available.

Invasive species are generally regarded as detrimental to native communities because they cause increased competition and community structure alterations. There is therefore a critical need to understand the ecological processes underlying the establishment and spread of invasive species. While most studies to date have focused on the role of competition in species invasions, trophic dynamics may also play a fundamental role in the establishment and spread of non-natives, especially in cases when a non-native species experiences differential predation pressure relative to a native competitor. Herein I explore the potential for differential granivory pressure by a native rodent (Heermann’s kangaroo rat, Dipodomys heermanni arenae) on native shrubs and an invasive plant (Veldt grass, Ehrharta calycina). Veldt grass, a perennial tufted grass native to South Africa and introduced to California in 1929, is highly invasive, and the shift of native coastal dune scrub to a grassland, dominated by Veldt grass, is considered one of the factors that led to the decline of the federally endangered Morro Bay kangaroo rat. However, kangaroo rats are largely graminivores (consume grass seed) and are known to consume invasive grasses and other plants. Differential seed preferences for native and Veldt seed were examined by placing feeding stations containing each seed type in habitats dominated by either native plants or Veldt grass. Each feeding station was monitored using motion-activated game cameras and the amount of each seed type collected by nineteen individually-marked, wild kangaroo rats was documented. These marked kangaroo rats were monitored both in native and Veldt grass habitats, allowing for the testing of habitat origin (Native vs. Veldt), sex (male or female) and seed type on the amount of seed taken. Nine of the kangaroo rats harvested Veldt grass seed. Though females collected more seed than males, there was no difference between the amounts (% of available seed) of Veldt grass and native seed collected. Habitat of origin (i.e., habitats with Veldt grass present or habitats without Veldt grass) had no effect on the amount of seed collected or the type of seed collected. During seed station trials, kangaroo rats were also recorded removing seed heads from naturally occurring Veldt grass stalks, providing clear documentation that Heermann’s kangaroo rats do collect Veldt grass seed. Accompanying laboratory seed preference trials were also conducted to confirm the consumption of Veldt grass seed. These controlled laboratory trials revealed that Heermann’s kangaroo rats will consume Veldt grass seed, although Veldt grass seed was consumed in smaller amounts (g) than millet and sunflower seed, which were presented simultaneously. These findings indicate that non-native Veldt grass may provide an additional or alternative source of seed for kangaroo rats, which could provide a partial explanation for why kangaroo rats are able to survive in monocultures of Veldt grass.

Non-native plants have invaded over 100 millions of acres of western arid land in the US and dramatically altered nutrient cycling rates. Changes in water cycling caused by invasive species are of particular interest because primary production in the Western US is typically limited by water availability and aquifer recharge reflects plant demand. Large-scale invasions can, therefore, be expected to cause large-scale changes in hydrological cycles, but until recently, there have been considerable limitations in the ability to measure the timing, location, and extent of water use. Here we injected a tracer, deuterated water (D2O), into five soil depths in two sampling periods (May and June) in two adjacent plant communities (native and non-native dominated). Plants were sampled at several distances from the tracer addition area to determine the horizontal and vertical extent of water use in native and non-native communities. The tracer injection was coupled with measurements of leaf level stomatal conductance, leaf area index, and volumetric soil water content to estimate plant transpiration. We found that both native and non-native plants transpired water from primarily the top 60 cm of the soil (>75%), with a particular emphasis (≥ 50%) on shallow soil water (<10 cm) while lateral roots did not exceed 50 cm for most species. Higher leaf area index resulted in significantly more water being transpired from the native community. Some sharp distinctions in timing and location of tracer uptake resulting from the differing phenologies of the dominant species in each community were observed and confirmed previous mechanisms thought to govern plant assemblages in these communities. In May, the non-native community dominated by annual grasses had higher tracer uptake at 10 cm than the native community but began using deep water (higher tracer uptake at 80 cm) as annual grasses senesced and tap-rooted fobs became dominant in June. The perennial native species, however, used the entire soil profile from the moment they became active until they senesced. Our approach shows promise for overcoming the lack of resolution associated with natural abundance isotopes and other enrichment approaches, and for providing detailed measurements of plant water-use space.

Parrotfeather [Myriophyllum aquaticum (Vellozo) Verdecourt] is a non-native aquatic plant from South America that was introduced into the United States in the 1890's. Research was conducted to elucidate seasonal life history, starch allocation patterns, and key environmental factors that may affect plant growth. Environmental factors identified in field studies were used to develop a conceptual model to display relationships between growth and environmental factors. The conceptual model served as a broad-based hypothesis to parameterize growth limiting factors as it related to M. aquaticum growth. Mesocosm experiments were then conducted to test relationships depicted in the model and define the growth requirements of this species. Emergent shoot biomass, submersed shoot biomass, and sediment root biomass were related to light transmittance. Submersed shoot biomass was also related to water temperature. Stolons accounted for 40-95% of total biomass. Starch allocation was also greatest in stolons (78.1 g m-2); where up to 16.3% of total starch was stored. Low points in biomass and starch occurred from October to March. Biomass was greater when plants were grown in 30% shade, whereas plant length was greatest when plants were grown in 50% shade, with reductions observed in full sunlight. Biomass increased by 53% when nitrogen and phosphorus were added to the water column at 1.80 and 0.01 mg L-1, respectively. Myriophyllum aquaticum yield response was positively related (r2 = 0.82) to increasing nitrogen content and a critical concentration of 1.80% nitrogen and 0.20% phosphorus was identified for M. aquaticum growth. Plants grown at 0 cm water depth had 96% greater biomass than plants grown at water depths of 137 cm. Total length was 25% greater when plants were grown at water levels from 0-77 cm. Winter drawdowns reduced biomass by 99% at 4 weeks when compared to pre drawdown biomass. Summer drawdown efficacy was more rapid where biomass was reduced by 98% at 2 weeks when compared to pre drawdown biomass. Subsurface herbicide applications were not more efficacious than herbicides applied to the foliage. The foliar application of 2,4-D was the only herbicide and application method that resulted in ¡Ý90% biomass reduction of M. aquaticum.

No description available.

No description available.

Many plants are not commercially produced due to a lack of accessible information on their horticultural requirements and landscape potential. Members of the Legume Family (Leguminosae) are often conspicuous components of the vegetation of arid and semi-arid subtropical regions. Many of these plants are suitable for landscaping use in areas suited to their cultivation. Coursetia glandulosa, Erythrina flabelliformis, Eysenhardtia orthocarpa, Haematoxylon brasiletto, Lysiloma watsonii, Pithecellobium mexicanum, and Sophora arizonica are woody legumes native to the Sonoran Desert region which offer a variety of form, texture, color and function. All of these plants grow readily from scarified seed. E. flabelliformis and E. orthocarpa are easy to propagate from stem cuttings. Some irrigation is necessary for establishment and reasonable growth in the landscape. Maintenance and pests are minimal. Freezing temperatures are the primary limiting factor to several of the plants. S. arizonica is slow growing and is prone to rot in the nursery.

Submitted by Cláudia Bueno (claudiamoura18@gmail.com) on 2015-11-03T20:18:59Z No. of bitstreams: 2 Dissertação - Daniel Cardoso Brandão - 2015.pdf: 2140787 bytes, checksum: 9a68dc762354ba92c5771f888e9f06d8 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2015-11-04T10:23:49Z (GMT) No. of bitstreams: 2 Dissertação - Daniel Cardoso Brandão - 2015.pdf: 2140787 bytes, checksum: 9a68dc762354ba92c5771f888e9f06d8 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-11-04T10:23:49Z (GMT). No. of bitstreams: 2 Dissertação - Daniel Cardoso Brandão - 2015.pdf: 2140787 bytes, checksum: 9a68dc762354ba92c5771f888e9f06d8 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2015-02-27 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / This study aimed to characterize morphologically, to study the phenology and identify the landscape potential of the species Mimosa setosissima Taub., native to the State Park region of Serra Pyrenees, located between the municipalities of Goiás Pirenópolis, Corumbá of Goiás and Cocalzinho of Goiás. To characterize the area were used data from the nearest meteorological station (in the city of Pirenópolis, GO): temperature, precipitation, humidity, sunshine, cloud cover, wind speed. For characterization of soils were collected at random subsamples in 0 cm layer to 20 cm deep. Were made photographic records of the plant and mounted voucher specimen for botanical identification and deposit in the Herbarium Conservation Unit of UFG. We studied ten plants, which had its registered location by GPS, they were assessed monthly for 13 months. Evaluations were made on the basis of previously established criteria, considered essential for the purposes of use proposed, according to the methodology proposed by Stumpf et al. (2007) with modifications. The species showed a high degree of capability and ornamental characteristics suitable for use in landscaping. / Este trabalho teve como objetivo caracterizar morfologicamente, estudar a fenologia e identificar o potencial paisagístico da espécie Mimosa setosissima Taub., nativa da região do Parque Estadual da Serra dos Pirineus, localizada entre os Municípios Goiânos de Pirenópolis, Corumbá de Goiás e Cocalzinho de Goiás. Para a caracterização da área foram utilizados dados da estação climatológica mais próxima (situada na cidade de Pirenópolis, GO): temperatura, precipitação, umidade, insolação, nebulosidade, velocidade dos ventos. Para caracterização dos solos foram coletadas aleatoriamente subamostras na camada de 0 cm à 20 cm de profundidade. Foram feitos registros fotográficos da planta e montada exsicata para identificação botânica e depósito no Herbário Unidade de Conservação da UFG. Foram estudadas dez plantas, que tiveram suas localizações registradas por GPS, avaliadas mensalmente por 13 meses. As avaliações foram feitas com base em características previamente estabelecidas, consideradas essenciais para as finalidades de uso propostas, segundo metodologia proposta por Stumpf et al. (2007), com modificações. A espécie demonstrou alto grau de potencialidade ornamental e características adequadas para utilização no paisagismo.

Made available in DSpace on 2016-08-12T19:15:37Z (GMT). No. of bitstreams: 1 RydleyKBL_DISSERT.pdf: 903646 bytes, checksum: c0d0a796d77f498e063d8b3a7801996c (MD5) Previous issue date: 2016-02-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / There are several native and exotic fruit species of economic importance with potential for exploration in semi-arid region. The Tacinga inamoena and Cereus jamacaru are native plants of the Northeast region, which are distributed throughout most of the semi-arid, with great potential among the cacti. The study aimed to characterize the physical, chemical and antioxidant potential of the pulp and peel of fruits of palm and native mandacaru. The experiment was completely randomized, with 4 repetitions. The fruits of Tacinga inamoena and Cereus jamacaru were obtained from populations of plants that are found spontaneous and dispersed in the Caatinga, located in the cities of Angicos and Mossoró-RN. The fruits were harvested directly from the plant and taken to the Laboratory of Physiology and Technology of Fruit Postharvest of the Universidade Federal Rural do Semi-Árido (UFERSA) in Mossoró-RN, at which time it we determined: fresh fruit mass, fruit yield, longitudinal and transverse diameter, firmness, titratable acidity, relation SS/AT, pH, soluble solids, total and reducing sugars, vitamin C, yellow flavonoids, total carotenoids, total anthocyanins, polyphenols total extractable, betalains and antioxidant activity. The pulp of the fruits of Tacinga inamoena have high levels of phosphorus, potassium, calcium, magnesium and titratable acidity; they are also sources of vitamin C. The fruit pulp of Cereus jamacaru has high levels of calcium and potassium, low levels of acidity and high content of sugars and soluble solids/acidity ratio. The peel of fruits of Cereus jamacaru has high levels of calcium, magnesium and phosphorus. The pulp of fruits of Tacinga inamoena and the pulp and peel of the fruit Cereus jamacaru have significant levels of phenolic compounds and betalains; however, it has a low content of anthocyanins, carotenoids, flavonoids and antioxidant activity by ABTS method. With Basis on quality variables evaluated in this study, we say the fruits of Tacinga inamoena and Cereus jamacaru have the potential for commercialization in natura and industrialization / Diversas são as espécies frutíferas nativas e exóticas de importância econômica com potencial para exploração na região semiárida. A Tacinga inamoena e o Cereus jamacaru são plantas nativas da região Nordeste, que se encontram distribuída em quase todo o semiárido, com grande potencialidade entre as cactáceas. Assim, este trabalho teve como objetivo caracterizar quanto aos aspectos físicos, químicos e potencial antioxidante da polpa e casca dos frutos da palma e do mandacaru. O experimento adotado foi o inteiramente casualizado, com 4 repetições. Os frutos da Tacinga inamoena e Cereus jamacaru foram provenientes de populações de plantas que se encontram de forma espontânea e dispersa na Caatinga, localizados nos municípios de Angicos e Mossoró-RN. Os frutos foram colhidos diretamente na planta e conduzidos ao Laboratório de Fisiologia e Tecnologia Pós-colheita de Frutos da Universidade Federal Rural do Semiárido (UFERSA), em Mossoró-RN, ocasião em que se determinou: massa fresca, rendimento, diâmetro longitudinal e transversal, firmeza, acidez titulável (AT), sólidos solúveis (SS), relação SS/AT, pH, açúcares totais e redutores, vitamina C, flavonóides amarelos, carotenóides, antocianinas, polifenóis, betalaínas e atividade antioxidante. A polpa dos frutos da Tacinga inamoena tem elevados teores de fósforo, potássio, cálcio, magnésio e acidez titulável; também são fontes de vitamina C. A polpa dos frutos do Cereus jamacaru tem elevados teores de cálcio e potássio, baixo teores de acidez e elevado conteúdo de açúcares e da relação sólidos solúveis/acidez. A casca dos frutos do Cereus jamacaru tem elevados teores de cálcio, magnésio e fósforo. A polpa dos frutos de Tacinga inamoena e a polpa e casca do fruto de Cereus jamacaru tem significativo teores de compostos fenólicos e betalaínas; entretanto, tem baixo conteúdo de antocianinas, carotenoides, flavonoides e atividade antioxidante pelo método ABTS. Com base nas variáveis de qualidade avaliada no presente estudo, os frutos da Tacinga inamoena e do Cereus jamacaru tem potencial para comercialização na forma in natura e para industrialização