Restoration and rehabilitation activities are presently considered to be a major priority in environmental management, whether the activity implies the restoration of neglected cultivated pastures or degraded rangelands due to overgrazing and climatic impacts, or the rehabilitation of the mining and industrial areas. However, the goals are not easily achieved, mainly due to the high input costs, including that of re-seeding activities. Reseeding success is influenced by the quality and effectiveness of the used seed regarding germination and establishment under natural field conditions. If techniques can be developed to enhance the effectiveness of germination and establishment percentage of the seed in restoration and rehabilitation sites, a better cover, density and biomass yield can be expected, which will improve the rehabilitation process. It is known that commercially available grass seed has a better germination percentage and establishment percentage in comparison with seed locally harvested, which may include many impurities such as sticks and stones. The availability of the locally harvested seed types, especially of certain ecotypes adapted to specific environments, can be poor. Advance Seed Company (Krugersdorp, South Africa) has taken commercially available grass seed to the next level by enhancing (coating) the seed with a multitude of different treatments to ensure better handling of the seed in reseeding applications. These treatments also have advantages such as a higher seed to soil contact, growth stimulants included in the treatment, higher seed purity and the protection of the seed against predation by ants and other insects and against harsh chemicals in the soil, which might have an influence on the germination percentage of the seed and the establishment of seedlings. The objective of this study was to investigate whether or not certain enhanced grass seed types of selected grass species will have a better germination and establishment percentage, fresh and dry above-(leaves) and below-ground (root) biomass yield (glasshouse trials) and dry above-ground biomass yields (natural fields trials) in comparison with non-enhanced types. The predation of enhanced and non-enhanced seeds by ants and other insects, as well as the development of the vascular tissue in the transitional region of the seedlings was also investigated. The grasses assessed included enhanced and non-enhanced seed types of Chloris gayana (Rhodes grass), Cynodon dactylon (Couch grass), Digitaria eriantha (Common finger grass) and Eragrostis curvula (Weeping love grass). In the case of E. curvula, four seed types, including the non-enhanced seed type were tested. These included non-enhanced seed, seed treated with "plain coat", enhancement with "organic insecticide on the base of the coaf' (Le. insecticide between the enhancement and the seed) and enhancement with "organic insecticide on the base of the coat and as an overspray" (Le. insecticide between the enhancement and the seed, as well as spraying the insecticide over the coated seed). The above mentioned species are commonly used in grass seed mixtures for rehabilitation and restoration purposes. Seeds were supplied by Advance Seed Company. The seed enhancement treatments as well as the non-enhanced seed types were tested under various conditions. The chemical composition of the enhancement treatment used in the coating process is only known by the seed technicians at Advance Seed Company. All the seed supplied by the seed merchant had a purity of >95%. With the application of dormancy breaking in the germination tests the non-enhanced seed types of Chloris gayana had the higher germination percentage of the seed type or the same species. Other differences included the germination percentage being significantly higher for the enhanced seed type of Cynodon dactylon than the non-enhanced seed type. Lower germination percentages were noted in the comparison of the E. curvula seed types, were the non-enhanced seed type had a higher germination percentage in comparison with the enhanced seed types. In the germination tests without dormancy breaking being applied, these results differ. With regard to the establishment percentages, similar statistical differences were noted in both the Coco Peat Moss medium and the Hygromix growth medium. In the above-and below-ground biomass production trials in the glass house the only significant difference were noted in the biomass production of D. eriantha plants. In the case of the dry above-and below-ground biomass yield the plants of the non-enhanced seed types of D. eriantha yielded a significantly higher biomass in comparison with the plants harvested from the enhanced seed type of the same species. With regard to the natural field trials a few significant differences were noted. The results indicated that the enhanced seed types of Chloris gayana and Cynodon dactylon, the non-enhanced seed type of D. eriantha as well as the non-enhanced and "organic insecticide on base and as overspray" enhancement of E cUNula can be used in re-seeding restoration and rehabilitation practices. Eragrostis cUNula enhanced with "plain coat" is not recommended to be used for re-seeding in disturbed areas. / Thesis (M.Sc. (Environmental Science and Management))--North-West University, Potchefstroom Campus, 2008.

Restoration and rehabilitation activities are presently considered to be a major priority in environmental management, whether the activity implies the restoration of neglected cultivated pastures or degraded rangelands due to overgrazing and climatic impacts, or the rehabilitation of the mining and industrial areas. However, the goals are not easily achieved, mainly due to the high input costs, including that of re-seeding activities. Reseeding success is influenced by the quality and effectiveness of the used seed regarding germination and establishment under natural field conditions. If techniques can be developed to enhance the effectiveness of germination and establishment percentage of the seed in restoration and rehabilitation sites, a better cover, density and biomass yield can be expected, which will improve the rehabilitation process. It is known that commercially available grass seed has a better germination percentage and establishment percentage in comparison with seed locally harvested, which may include many impurities such as sticks and stones. The availability of the locally harvested seed types, especially of certain ecotypes adapted to specific environments, can be poor. Advance Seed Company (Krugersdorp, South Africa) has taken commercially available grass seed to the next level by enhancing (coating) the seed with a multitude of different treatments to ensure better handling of the seed in reseeding applications. These treatments also have advantages such as a higher seed to soil contact, growth stimulants included in the treatment, higher seed purity and the protection of the seed against predation by ants and other insects and against harsh chemicals in the soil, which might have an influence on the germination percentage of the seed and the establishment of seedlings. The objective of this study was to investigate whether or not certain enhanced grass seed types of selected grass species will have a better germination and establishment percentage, fresh and dry above-(leaves) and below-ground (root) biomass yield (glasshouse trials) and dry above-ground biomass yields (natural fields trials) in comparison with non-enhanced types. The predation of enhanced and non-enhanced seeds by ants and other insects, as well as the development of the vascular tissue in the transitional region of the seedlings was also investigated. The grasses assessed included enhanced and non-enhanced seed types of Chloris gayana (Rhodes grass), Cynodon dactylon (Couch grass), Digitaria eriantha (Common finger grass) and Eragrostis curvula (Weeping love grass). In the case of E. curvula, four seed types, including the non-enhanced seed type were tested. These included non-enhanced seed, seed treated with "plain coat", enhancement with "organic insecticide on the base of the coaf' (Le. insecticide between the enhancement and the seed) and enhancement with "organic insecticide on the base of the coat and as an overspray" (Le. insecticide between the enhancement and the seed, as well as spraying the insecticide over the coated seed). The above mentioned species are commonly used in grass seed mixtures for rehabilitation and restoration purposes. Seeds were supplied by Advance Seed Company. The seed enhancement treatments as well as the non-enhanced seed types were tested under various conditions. The chemical composition of the enhancement treatment used in the coating process is only known by the seed technicians at Advance Seed Company. All the seed supplied by the seed merchant had a purity of >95%. With the application of dormancy breaking in the germination tests the non-enhanced seed types of Chloris gayana had the higher germination percentage of the seed type or the same species. Other differences included the germination percentage being significantly higher for the enhanced seed type of Cynodon dactylon than the non-enhanced seed type. Lower germination percentages were noted in the comparison of the E. curvula seed types, were the non-enhanced seed type had a higher germination percentage in comparison with the enhanced seed types. In the germination tests without dormancy breaking being applied, these results differ. With regard to the establishment percentages, similar statistical differences were noted in both the Coco Peat Moss medium and the Hygromix growth medium. In the above-and below-ground biomass production trials in the glass house the only significant difference were noted in the biomass production of D. eriantha plants. In the case of the dry above-and below-ground biomass yield the plants of the non-enhanced seed types of D. eriantha yielded a significantly higher biomass in comparison with the plants harvested from the enhanced seed type of the same species. With regard to the natural field trials a few significant differences were noted. The results indicated that the enhanced seed types of Chloris gayana and Cynodon dactylon, the non-enhanced seed type of D. eriantha as well as the non-enhanced and "organic insecticide on base and as overspray" enhancement of E cUNula can be used in re-seeding restoration and rehabilitation practices. Eragrostis cUNula enhanced with "plain coat" is not recommended to be used for re-seeding in disturbed areas. / Thesis (M.Sc. (Environmental Science and Management))--North-West University, Potchefstroom Campus, 2008.

Submitted by (edna.saturno@ufrpe.br) on 2016-06-15T16:10:24Z No. of bitstreams: 1 Clarissa Gomes Reis Lopes (1).pdf: 1021119 bytes, checksum: 8d291962a84690e30bd756708155fc47 (MD5) / Made available in DSpace on 2016-06-15T16:10:24Z (GMT). No. of bitstreams: 1 Clarissa Gomes Reis Lopes (1).pdf: 1021119 bytes, checksum: 8d291962a84690e30bd756708155fc47 (MD5) Previous issue date: 2011-06-16 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Tropical dry forests have been intensively disturbed, however knowledge of their regenerating processes is still restrict. The aim of this study is to evaluate if 16 years of regeneration in an area which the agriculture was descontinued are sufficient for the regeneration of structural and floristic features of an abondoned agricultural field and if the time of abandonment, the precipitation and the distance from a preserved fragment influence the regeneration of this area in Caruaru, PE, Brazil. All individuals with diameter ≥ 3 cm a level of soil were marked and had the height and diameter measured. Structure and floristic data were compared with secondary data of the forest fragment and of other regenerating areas of dry forest, and also to test the influence of the fragment upon the regeneration of the abandoned field. The population dynamics of aroeira, braúna and catingueira were evaluated in 105 plots (5 X 5 m) during two years. All individuals of these three species within the plots were counted and marked; the plots were monitored mensaly to record births and deaths. The field presented lower density, basal area and number of species than the forest fragment; however the number of families and the diversity were similar. Species composition and population density in altered areas of caatinga were more influenced by the precipitation than by the time of abandonment. The density, mean height and maximum diameter of individuals within the plots were not related to the distance from the forest, except for some species. The distance from the forest influenced the number of births and the density of aroeira and braúna, but it was not true for catingueira. The number of births and deaths and the population density varied between years. The total density of the area is one of the parameters of faster recuperation, whereas the basal area and the composition of species are slower ones. The results indicated that 16 years of abandonment were not sufficient for the regeneration of area. Role of preserved fragment on regeneration of antropized area influenced the species differently and this relation is stronger in M. urundeuva and S. brasiliensis. Annual variation in demography of tre species may be related to variations on rainfall. This study confirms the importance of forest fragments in the regeneration of altered areas, and suggests the importance of their preservation. / As florestas tropicais secas têm sido intensamente degradadas. Apesar disso, o conhecimento sobre o seu processo regenerativo em áreas abandonadas ainda é restrito. Objetivou-se avaliar se 16 anos de regeneração em uma área onde a agricultura foi descontinuada são suficientes para que volte a apresentar caracterísiticas estruturais e florísticas similares à encontrada na floresta madura e se o tempo de abandono, a precipitação e a distância de um fragmento preservado influenciam na regeneração em Caruaru, PE, Brasil. Todos os indivíduos com diâmetro maior ou igual a 3 cm a nível do solo foram marcados e medidos quanto a altura e diâmetro. Os dados estruturais e florísticos foram comparados com dados secundários tanto do fragmento florestal próximo quanto de outras áreas em regeneração. Os estudos floristicos e fitossociológicos em áreas antropizadas da caatinga publicados em periódicos que disponibilizaram os dados de composição e riqueza de espécies, densidade, área basal, precipitação anual e tempo de regeneração foram selecionados. As dinâmicas populacionais de Myracrodruon urundeuva Allemão, Schinopsis brasiliensis Engl. e Poincianella pyramidalis (Tul.) L.P.Queiroz foram avaliadas em 105 parcelas (5 X 5 m) durante dois anos. No interior das parcelas, todos os indivíduos destas três espécies foram contados e marcados e, mensalmente, as parcelas foram monitoradas para contagem dos nascimentos e mortes. O campo apresentou menor densidade, área basal e número de espécies que o fragmento preservado próximo, porém não diferiu significativamente em relação a número de famílias e diversidade. A composição de espécies e a densidade das populações nas áreas antropizadas da caatinga mostraram-se mais influenciada pela precipitação dos habitats do que pelo tempo de abandono. A densidade, a altura média e o diâmetro máximo dos indivíduos nas parcelas não tiveram a distância da mata, mas nas populações de algumas espécies houve relações significativas. A distância da mata influenciou o número de nascimentos e a densidade populacional de M. urundeuva e S. brasiliensis, mas não de P. pyramidalis. O número de nascimentos, mortes e densidade populacional variaram bastante entre os anos. A densidade total da área é um dos parâmetros de rápida recuperação, enquanto a área basal e a composição de espécies são mais lentos. Mesmo numa área pouco perturbada, 16 anos de abandono não foram suficientes para recuperação de uma área de agricultura em um ambiente semiárido. O papel do fragmento preservado na regeneração da área antropizada influenciou de forma diferenciada as espécies, sendo mais forte em M. urundeuva e S. brasiliensis. A variação anual na demografia das três espécies pode estar relacionada com variações nos totais de precipitação. Este estudo confirma a importância dos fragmentos florestais na regeneração de áreas antropizadas, sendo importante o desenvolvimento de políticas públicas voltadas para proteção destes fragmentos.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The nest refuse of leaf-cutting ants is the depleted material resulted from the degradation of vegetation harvested, after being partially consumed by workers, along with dead ants and remnants of own symbiotic fungus. It is an extremely rich material in many nutrients (N, P, K, Ca, Mg, S) and may act as an important component of the organic matter in tropical soils, influencing the development and diversity of plant species. In addition, as a renewable material, of relatively easy availability and sampling, it may be a compound with a high potential for organic farming. In this study, we evaluated the influence of nest refuse in two distinct situations: i) as a substrate for the production of vegetables and ii) the plant regeneration of newly deforested plots. To this purpose, the experiments were divided into two stages: first, the nest refuse was evaluated as a component in a substrate for production of lettuce seedlings (Lactuca sativa) and arugula (Eruca sativa) at different concentrations. The experimental design was completely randomized, consisting of six treatments and four replications. The treatments were the following mixtures: Control (Cont) considered the basic substrate containing bark of Pinus sp. + sand + vermiculite (3:3:1 v/v); commercial substrate (Tropstrato®- Trop); nest refuse of two species (Atta opaciceps and Acromyrmex balzani) + basic substrate, in two concentrations: 15% and 25% for each of the species tested (AT15, AT25, AC15 and AC25), respectively. All substrates were subjected to chemical analysis for determination of macro- and micronutrients. The influence of the substrate in the development of seedlings was evaluated by height, root length, stem diameter, dry weight and number of leaves at four periods: 15, 20, 25 and 30 days after sowing. For the second stage of the experiment, a portion of 10 m x 5 m was installed in a regeneration area. The plot was divided into 50 sub-plots of 1 m2, of these, 30 subplots were randomly selected for cataloguing herbaceous species present. After that, the original vegetation was completely removed in the whole plot area. Thereafter, it was installed at the center of each subplot a quadrant of 30 cm x 30 cm, 15 of them containing a mixture of a liter of sieved soil with 250 mL of nest refuse of Atta opaciceps (25% of nest refuse) and the remaining quadrants with 1 liter of bare soil (control). The quadrants remained in the field for 150 days to be reforested. Afterwards, richness, abundance, composition and dry biomass of the herbaceous species that colonized the plots were evaluated. Our results showed that the seedlings of vegetables in treatments containing nest refuse of leaf-cutting ants developed as well as those grown in the commercial product taking into account the evaluated attributes. Possibly, the highest average growth rates of seedlings from the AT25 and AC25 treatments are due to higher nutrient concentrations present in the material. The nest refuse also influenced the development of herbaceous species, since plots receiving nest refuse had higher biomass (vigor) in comparison with the control group. However, there was no influence of nest refuse in species diversity between treatments. Our results suggest that nest refuse produced by leaf-cutting ants may have applicability to either production of vegetables or to be disposed in areas that suffered some disturbance, pointing out another ecological service provided by ants. / O lixo de formigas cortadeiras é o material gerado da degradação do material vegetal após ser parcialmente consumido pelas operárias, juntamente com formigas mortas e resquícios do próprio fungo simbionte. É um material extremamente rico em diversos nutrientes e pode atuar como um importante insumo em solos tropicais, influenciando na diversidade e desenvolvimento de espécies vegetais. Além disso, por ser um material renovável, relativamente de fácil disponibilidade e coleta, pode ser um composto com alto potencial em cultivos orgânicos. Nesse estudo avaliamos a influência do lixo em duas situações distintas: i) como substrato para a produção de hortaliças e ii) na regeneração vegetal de parcelas recém desmatadas. Para alcance dos nossos objetivos, os experimentos foram divididos em duas etapas: na primeira, o lixo foi avaliado como componente na formulação de substratos para produção de mudas de alface (Lactuca sativa) e rúcula (Eruca sativa) em diferentes concentrações. O delineamento experimental utilizado foi inteiramente casualizado, formado por seis tratamentos e quatro repetições. Os tratamentos consistiram em: Cont (Pinus sp. + fibra de coco + vermiculita (3:3:1 v/v)); substrato comercial - (Trop); lixo de formigueiros + substrato Cont, oriundo de duas espécies (Atta opaciceps e Acromyrmex balzani) em duas concentrações de 15% e 25% para cada uma das espécies testadas (AT15, AT25, AC15 e AC25), respectivamente. Todos os substratos foram submetidos às análises químicas para determinação de macro e micronutrientes. A influência do substrato no desenvolvimento das mudas foi avaliada pela altura, comprimento da raiz, diâmetro do caule, massa seca e número de folhas, em quatro períodos: aos 15, 20, 25 e 30 dias após a semeadura. Para segunda etapa do experimento, uma parcela de 10 m x 5 m foi instalada em uma área em regeneração. A parcela foi subdividida em 50 subparcelas de 1 m2 destas, 30 subparcelas foram selecionadas aleatoriamente para levantamento das espécies herbáceas presentes. Após isso, a vegetação original foi totalmente removida em toda a área da parcela. Posteriormente, no centro de cada uma das 30 subparcelas foi demarcado um quadrante de 30 cm x 30 cm, sendo 15 contendo uma mistura de solo com Atta opaciceps (25% de lixo), totalizando um litro; e 15 com 1 litro de solo (controle). Os quadrantes permaneceram no local por 150 dias, para serem recolonizados pela vegetação. Após esse período avaliou-se a riqueza, abundância, composição e biomassa seca das espécies herbáceas que colonizaram as parcelas. Os nossos resultados mostraram que as mudas de hortaliças nos tratamentos contendo lixo de formigas cortadeiras se desenvolveram tão bem quanto as do tratamento comercial nos atributos avaliados. Possivelmente, as maiores médias de crescimento das mudas no tratamento AT25 e AC25 devem-se às maiores concentrações de nutrientes presentes no material. O lixo também influenciou o desenvolvimento das espécies herbáceas, as parcelas que receberam lixo apresentaram maior biomassa (vigor) em relação ao grupo controle. Porém, não foi observada influência do lixo na diversidade das espécies entre os tratamentos. Nossos resultados sugerem que o lixo produzido por formigas cortadeiras pode ter aplicabilidades tanto para a produção de hortaliças, quanto para ser inserido em áreas que sofreram alguma perturbação, ressalvando mais um serviço ecológico fornecido pelas saúvas.