The plant communities of the Long Mynd plateau are the culmination of over 3000 years of human intervention that largely deforested the uplands, and subsequently maintained the generally treeless heath and grassland communities now extant. The capacity of these communities to respond to directional change is well known, indeed the traditional mode of heathland management, burning, depends on the regenerative capacity of the target species, generally heather (Calluna vulgaris), for its success. However, changes in post WW2 stocking practice; the loss of ponies followed by an increase in the numbers of sheep and a change to them being overwintered on the hill, led to excessive grazing and damage to the heath. This coincided with the spread over the hill by bracken (Pteridium aquilinum) and other changes in the distribution and nature of the vegetation. A sequence of vegetation surveys made by various individuals and organisations over the past 75 years or so has been analysed in an attempt to delineate spatial and temporal changes in the vegetation. This demonstrated the need for a standardised survey methodology to allow consistent monitoring. The analysis showed that bracken had been infiltrating most of the communities from its origins outside the lower limits of the Common as well as from some of the valley sides. Within the last decade, this expansion has apparently been contained in line with the current management plan for control. A survey of 730 quadrats in some 30 stands was made to characterise the variation of the vegetation on the plateau, and to relate it to some of the associated environmental factors. Classification, unconstrained ordination and ordination constrained by the abiotic environmental variables, showed that, a) the strongest trend in the vegetation distinguished water-flushed communities, b) non-wetland communities differentiate between heathland and grassland, c) this trend can be only partly be attributed to the measured abiotic environmental variables, d) the amount of pure Pteridietum [U20] is limited, although much of the heathland and grassland has bracken within it. There are indications that invasion by bracken often correlates with a loss of dominance of Calluna in favour of Deschampsia flexuosa and Vaccinium myrtillus. Difficulties in associating these trends with measured abiotic variables suggests, other factors probably management processes, are critical in driving this trend. Distribution of ‘heathland’ bryophytes was found to be associated more with the structure of their ‘host’ vascular communities rather than with abiotic factors. Finally, this investigation considers the practical implications with regard to the future encouragement of heather and the control of bracken. Cutting rather than burning appears to be the ecologically most suitable method for heather regeneration and bracken control.

Estimating herbivore density is an important part of understanding their impact on vegetation.  Many studies have been carried out on the impact of reindeer and other herbivores on arctic and sub-arctic vegetation, but they are difficult to compare as they typically use different methods to estimate herbivore activities.  The aim of this study was to compare three methods that were based on the recent International Tundra Experiment herbivory protocol to measure the activities of three herbivore groups: reindeer, rodents and invertebrates. The robustness of the methods themselves was then evaluated.  Fieldwork was carried out at 12 sites in the Fennoscandian mountain area, with controls inside reindeer exclosures.  The results showed that the methods were the most robust when measuring reindeer activities.  The reindeer measurements were also well correlated with a reindeer-density estimate calculated from official reindeer population data.  This study recommends considering the use of photographs to increase the time-efficiency of pellet-counts.  The rodent activity estimates were good, but the patterns inside exclosures differed to the patterns outside exclosures.  The results for invertebrates were deemed to be less reliable as the measurements for one method were not recorded at an appropriate scale.  In conclusion, the findings of this study will help improve the comparability of future studies on the impact of reindeer herbivory and other herbivores, and gives suggestions for more accurate ways of measuring herbivore pressure in arctic and sub-arctic vegetation.

Submitted by Mario BC (mario@bc.ufrpe.br) on 2017-02-15T12:44:24Z No. of bitstreams: 1 Jorge Serrao Pinto Filho.pdf: 1255280 bytes, checksum: b96b8cb8323e3c90862fc8d89ce64c78 (MD5) / Made available in DSpace on 2017-02-15T12:44:24Z (GMT). No. of bitstreams: 1 Jorge Serrao Pinto Filho.pdf: 1255280 bytes, checksum: b96b8cb8323e3c90862fc8d89ce64c78 (MD5) Previous issue date: 2016-02-26 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The objective was to evaluate the carcass characteristics and components non-carcass of sheep kept on native pasture semiarid region subjected to different offer levels forage (2.0, 2.5, 3.0, 3.5 kg DM / kg BW). The pasture was made up of Caatinga, enriched with grass búffel (Cenchrus ciliares L. cv Biloela) and grass corrente (Urochloa mosambicensis (Hack.) Dandy.), with the predominance of mainly native species such as mororó (Bauhinia cheilantha (Bong.) Steud.) and the Feijão bravo (Capparis flexuosa L.). The grazing season was held at two years (2013 and 2014) with a duration of 39 and 84 days, respectively, being animals slaughtered above after these periods. It was made skinning and gutting and then it was obtained the absolute weights not carcass components, the empty body weight (EBW), hot carcass weights (HCW). After the carcass were placed in a cold chamber at 4 ° C for 24 hours. The still entire carcass were evaluated its morphometry. In the left half carcass It was made the cuts commercials shoulder, neck, hand saw, rib, loin and ham. Was used a completely randomized designing in split plot. Occurred quadratic effect (P<0,05) between herbage allowance levels of the consumption of dry matter (CDM), the consumption of organic matter (COM), the consumption of neutral detergent fiber (CNDF), the consumption of acid detergent insoluble protein (CADIP), digestibility of dry matter (DDM), the total weight gain, the average daily gain weight, body weight at slaughter (BWS), the the empty body weight (EBW), hot carcass weight (HCW), the cold carcass weight (CCW) and cut loin showing better values between the average level of 2.83 (kg DM / kg BW). The herbage allowance levels of (kg DM / kg BW) do not alter the characteristics of the weight of components not sheep carcasses kept on native pasture Semiarid. / Objetivou-se avaliar as características de carcaça e os componentes não-carcaça de ovinos mantidos em pasto nativo do Semiárido submetidos a diferentes níveis de oferta de forragem (2,0; 2,5; 3,0; 3,5 kg MS/ kg PC). O pasto era constituído de Caatinga, enriquecida com capim búffel (Cenchrus ciliares L. cv Biloela) e capim corrente (Urochloa mosambicensis (Hack.) Dandy.), com o predomínio principalmente das espécies nativas como o mororó (Bauhinia cheilantha (Bong.) Steud.) e o Feijão bravo (Capparis flexuosa L.). A estação de pastejo foi realizada em dois anos (2013 e 2014) com duração de 39 e 84 dias, respectivamente, sendo os animais abatidos logo após estes períodos. Foi feito a esfola e evisceração, em seguida foi obtido os pesos absolutos dos componentes não carcaça, o peso corporal vazio (PCVZ), pesos de carcaça quente (PCQ). Após as carcaça foram colocadas em um câmara fria a 4 ºC por 24 horas. As carcaça ainda inteiras foram avaliadas sua morfometria. Na meia carcaça esquerda foi feito os cortes comerciais paleta, pescoço, serrote, costela, lombo e pernil. Utilizou-se o desenho experimental interiamente casualizado em parcelas subdivididas. Ocorreu efeito quadrático (P<0,05) entre os níveis de oferta de forragem sobre o consumo de matéria seca (CMS), o consumo de matéria orgânica (CMO), o consumo de fibra em detergente neutro (CFDN), o consumo de proteína insolúvel em detergente ácido (CPIDA), a disgestibilidade da matéria seca (DMS), o ganho de peso total, o ganho de peso médio diário, o peso corporal ao abate (PCA), o peso corporal vazio (PCVZ), o peso de carcaça quente (PCQ), o peso de carcaça fria (PCF) e o corte lombo apresentando melhores valores entre o nível médio de 2,83 (kg de MS/ kg de PC). Os níveis de oferta de forragem (kg de MS/ kg de PC) não alteraram nas características dos componentes não carcaça de ovinos mantidos em pasto nativo do Semiárido.

No description available.

Open grassland productivity was measured within adjacent East Kootenay range units to evaluate forage availability and calculate elk (Cervus canadensis nelsoni) and cattle (Bos taurus) sustainable carrying capacity targets. This research extends rangeland monitoring with an analysis of site differentiation and comparative grazing pressure to 2008 population estimates. Significant productivity differences were found between grass and shrubs for range units (p=0.024 and p<0.0001) and different biogeoclimatic zones (p=0.042 and p<0.0001). Notable grazing pressure distinctions occurred: cattle exceeded the Rampart Mayook carrying capacity, elk exceeded the Pickering Hills carrying capacity, and both species had sustainable populations within the Power Plant range unit. These results provide clear direction for stock management and offer valuable rangeland insight. Furthermore, the study introduces cover-percentage productivity estimation (CPPE), a simple grassland productivity assessment method. Pearson correlation coefficients were significant and high between productivity results and cover estimates, indicating that CPPE will be a useful field tool.

The fact that large herbivores, such as Rangifer tarandus, play a part in shaping its environment through grazing and trampling of the ground is widely acknowledged today, as well as that these factors have the potential of affecting regional patterns and even global climate. This study investigated whether a considerable increase in grazing by R. tarandus for 25 years resulted in any measurable effects on the diversity of plant species in tundra vegetation. We evaluated if any differences in species composition could be found, based on differences in grazing pressure and productivity of the soil. The effect of difference in grazing pressure was studied through analysis of vegetation at 30 sites, each site comparing two different classes of grazing pressure separated by a fence, and pellets from R. tarandus were counted along transects. We did not find any evidence that the difference in grazing pressure affected the species composition on either side of the fence, depending on the site. The lack of difference in plant species composition may be explained by insufficient differences in abundance of R. tarandus, insufficient time passed since the change in grazing pressure, or varying grazing seasons at the sites on either side of the fence.

Periphyton biomass on artificial strips was observed monthly to see the impacts of nutrient differences on periphyton and periphyton-macroinvertebrates interaction. The experiment was conducted for four months in a mesocosm which were runned at six countries at the same time and with the same steps. Eight enclosures at two meters depth were used that four of them had high nutrient level and the other four had low nutrient level. Sediment, macrophyte, fish, plankton, benthic invertebrates and water were added at the same time and with the same way in all of the countries. Periphyton growth which formed on artificial 32 cm2 strips for June, July, August and September were brushed to filtered mesocosm water and dry mass, ash free dry mass, phosphorus content and chlorophyl-a concentrations were measured. Grazer pressure on the periphyton was observed with a laboratory experiment for July, August and September months. At the end of the mesocosm experiment macrophytes and fish were harvested. Macrophytes&rsquo / dry mass and fish&rsquo / abundance were measured. Moreover at the end of the experiment epiphyton was also measured. Three kajak cores were taken from sediment for macroinvertebrates at the end of the experiment and identified. All physical features of mesocosm enclosures and PVI data were recorded for every 2 weeks. Periphyton biomass was higher concentrations in HN enclosures than LN tanks. Only dry mass of periphyton biomass showed the opposite because of the marl deposition in LN tanks. This finding was also reinforced by epiphyton samples which was taken at the end of the experiment. LN enclosures had the more abundance of macroinvertebrate. The groups we found in sediment which had big grazer effect on periphyton such as gastropods and Chironomidae. Grazer experiment showed that grazer effect on periphyton increased in time. Although this raise, periphyton growth also increased in LN enclosures with nutrient increasing. This may be indicate that nutrient effect has a stronger effect than grazer pressure on periphyton. As it is explained before in the beginning of the experiment all of the conditions were the same except nutrient level. Thus, bottom-up effect changed the top-down control and at the end of the experiment we saw the more periphyton less macroinvertebrate and more fish in HN tanks while the opposite was seen in LN tanks.

Made available in DSpace on 2014-06-11T19:33:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-05-11Bitstream added on 2014-06-13T19:04:38Z : No. of bitstreams: 1 casagrande_dr_dr_jabo.pdf: 1193230 bytes, checksum: f4942366b12e0580d2389de8bbd1e175 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Objetivou-se com presente trabalho avaliar as características estruturais do dossel, o comportamento e o desempenho de novilhas de corte, suplementadas, em pastagem de capim-marandu submetidas à diferentes intensidade de pastejo, sob lotação contínua, assim como o efeito do histórico desses fatores sobre a fase de terminação. Para isso realizou-se quatro experimentos. No primeiro foram avaliadas três ofertas de forragem aliadas a dois tipos de suplementação, sal mineral e suplemento protéico energético. No segundo e terceiro experimentos os tratamentos foram três alturas do dossel aliados a três suplementos, sal mineral e dois suplementos protéicos energéticos. E no quarto foi estudado o efeito destes tratamentos sobre a terminação no confinamento ou no pasto. Observou que a altura do dossel influenciou todas as características estruturais do pasto. A suplementação não interferiu na estrutura do dossel, porém tendeu a reduzir o tempo de pastejo dos animais, principalmente nos períodos que antecederam o fornecimento do suplemento, contudo sem afetar o consumo de forragem. O uso de suplemento protéico energético aumentou o desempenho animal. Os fatores relacionado a fase de recria interferiram no período de terminação, porém não afetaram as características das carcaças. A terminação em confinamento aumentou a deposição de gordura nas carcaças e cortes cárneos. Concluiu-se que pastos de capim-marandu sob lotação contínua, sob pastejo por novilhas em recria, destinadas ao abate, podem ser manejados com alturas entre 15 a 35 cm, sendo a altura 25 cm a mais indicada. Suplementação protéica energética aumenta o desempenho animal e a produtividade do sistema / The objective of this study was to evaluate the structural characteristics of the canopy, grazing behavior, and performance of beef heifers supplemented at pasture of Marandu grass submitted to different grazing intensity under continuous stocking rate, and the effect of these historical factors on the finish of these, in different systems. Four experiments were conducted. The first evaluated three forage allowances combined with two types of supplementation, mineral and protein/energy supplement. In the second and third experiments the treatments were three canopy heights combined with three supplements: mineral and two protein/energy supplements. And in the fourth, studied the effect of these treatments on the finish system, feedlot or in pasture. It was observed that the height of the canopy affected all the structural characteristics of the pasture. Supplementation did not affect the structure of the pasture canopy, but tended to reduce the grazing time of the animals, especially in periods leading up to the supplement supply, however forage intake was not altered. Concentrate supplementation increased animal performance. At all the evaluated situations the animals’ weight gain was limited by energy intake. Factors related to the growing phase interfered in the finishing period, but did not affect the heifers’ carcass characteristics. The finishing in feedlot increased fat deposition in the carcasses and in the meat cuts. It was concluded that Marandu grass pasture under continuous stocking, grazing by growing beef heifers intended for slaughter, can be managed in heights between 15 and 35 cm height, and 25 cm appears to be most appropriate. Protein/energy supplementation increases animal performance and system productivity

Resumo: Objetivou-se com presente trabalho avaliar as características estruturais do dossel, o comportamento e o desempenho de novilhas de corte, suplementadas, em pastagem de capim-marandu submetidas à diferentes intensidade de pastejo, sob lotação contínua, assim como o efeito do histórico desses fatores sobre a fase de terminação. Para isso realizou-se quatro experimentos. No primeiro foram avaliadas três ofertas de forragem aliadas a dois tipos de suplementação, sal mineral e suplemento protéico energético. No segundo e terceiro experimentos os tratamentos foram três alturas do dossel aliados a três suplementos, sal mineral e dois suplementos protéicos energéticos. E no quarto foi estudado o efeito destes tratamentos sobre a terminação no confinamento ou no pasto. Observou que a altura do dossel influenciou todas as características estruturais do pasto. A suplementação não interferiu na estrutura do dossel, porém tendeu a reduzir o tempo de pastejo dos animais, principalmente nos períodos que antecederam o fornecimento do suplemento, contudo sem afetar o consumo de forragem. O uso de suplemento protéico energético aumentou o desempenho animal. Os fatores relacionado a fase de recria interferiram no período de terminação, porém não afetaram as características das carcaças. A terminação em confinamento aumentou a deposição de gordura nas carcaças e cortes cárneos. Concluiu-se que pastos de capim-marandu sob lotação contínua, sob pastejo por novilhas em recria, destinadas ao abate, podem ser manejados com alturas entre 15 a 35 cm, sendo a altura 25 cm a mais indicada. Suplementação protéica energética aumenta o desempenho animal e a produtividade do sistema / Abstract: The objective of this study was to evaluate the structural characteristics of the canopy, grazing behavior, and performance of beef heifers supplemented at pasture of Marandu grass submitted to different grazing intensity under continuous stocking rate, and the effect of these historical factors on the finish of these, in different systems. Four experiments were conducted. The first evaluated three forage allowances combined with two types of supplementation, mineral and protein/energy supplement. In the second and third experiments the treatments were three canopy heights combined with three supplements: mineral and two protein/energy supplements. And in the fourth, studied the effect of these treatments on the finish system, feedlot or in pasture. It was observed that the height of the canopy affected all the structural characteristics of the pasture. Supplementation did not affect the structure of the pasture canopy, but tended to reduce the grazing time of the animals, especially in periods leading up to the supplement supply, however forage intake was not altered. Concentrate supplementation increased animal performance. At all the evaluated situations the animals' weight gain was limited by energy intake. Factors related to the growing phase interfered in the finishing period, but did not affect the heifers' carcass characteristics. The finishing in feedlot increased fat deposition in the carcasses and in the meat cuts. It was concluded that Marandu grass pasture under continuous stocking, grazing by growing beef heifers intended for slaughter, can be managed in heights between 15 and 35 cm height, and 25 cm appears to be most appropriate. Protein/energy supplementation increases animal performance and system productivity / Orientador: Ricardo Andrade Reis / Coorientador: Telma Teresinha Berchielli / Banca: Sila Carneiro da Silva / Banca: Marco Antonio Alvares Balsalobre / Banca: Flavio Dutra de Resende / Banca: Alexandre Amstalden Moraes Sampaio / Doutor

Epiphytic lichens are under considerable grazing pressure due to invertebrate lichenivores, mostly gastropods. Preferences of tree-climbing gastropods affect vertical distribution of lichens, their habitat preferences and whole area of distribution. Higher grazing pressure is expected on sites with basic subsoil and sufficient sources of calcium, where the abundance of gastropods is higher. Most of researches about the topic of grazing pressure were therefore conducted on such sites, although this hypothesis has never been formally tested. Epiphytic communities are also affected by pH and other properties specific to its photophyte. Nevertheless, it is not known, if the same applies for grazing gastropods and how is the grazing pressure affected by tree species. I have addressed these questions in my thesis. I set an 80-days-long field transplantation experiment in the mixed forest of Moravský kras (South Moravia, Czech Republic). Glass fiber meshes with lichen thalli were placed on sixty trunks of three tree species (Carpinus betulus - hornbeam, Abies alba - fir, Fagus sylvatica - common beech) on both calcareous (limestone) and acidic (granodiorite) sites. Abundance and diversity of gastropods were measured. Determined grazing pressure was higher than pressure detected by other authors and was...