Made available in DSpace on 2017-07-10T17:40:58Z (GMT). No. of bitstreams: 1 Tese_2012_Valdemir_Aleixo.pdf: 1922736 bytes, checksum: a33bf96bdf4ef97638ed8d2af3ef4198 (MD5) Previous issue date: 2012-08-13 / This study evaluated the development of J. curcas in relation to floor area available to each plant under different cropping systems. The experiment was conducted in the period between october 2009 and may 2011, the Toledo, Paraná. The seedlings were grown in a greenhouse environment, in containers filled with commercial substrate (Plantmax®), for a period of 50 days before transplanting to the field. The experiment was established in systematic design, in factorial 3 x 4 x 5 with four replications. The treatments consisted of three provenances (DOU-Dourados, MS, JAN-Janaúba, MG; PET-Petrolina, PE), distributed in four cropping systems (WC-weed competition, GS-Growing Single, CAC-Consortium Agronomic Crops, PCH-Permanent Consortium with herb) and each with five areas useful (1.57, 4.71, 7.85, 11.00 and 14.50 m2 plant-1). Evaluations were made of the total plant height, diameter of the neck base, the canopy diameter, number of leaves, number of branches and the SPAD index at 540 days after transplant. The means were compared by Tukey test at 5% probability. For purposes of density, quantitative data were analyzed by polynomial regression at 5% probability. The Single cropping system was the most suitable for the vegetative growth of plants J. curcas. The three provenances tested were impacted by the available floor area per plant, the plant development. The transformation of the useful areas tested for a spacing means spacing rectangular 3.0 x 3.5 as appropriate. The SPAD index showed no differences as a function of floor area per plant / Este trabalho objetivou avaliar o desenvolvimento de J. curcas em relação à área útil disponível para cada planta, em diferentes sistemas de cultivo. O experimento foi conduzido no período compreendido entre outubro de 2009 e maio de 2011, no Distrito de Dois Irmãos, Município de Toledo, Paraná. As mudas foram produzidas em ambiente casa de vegetação, em tubetes preenchidos com substrato comercial (Plantmax®), por um período de 50 dias, antes do transplante a campo. O experimento foi implantado em delineamento sistemático, em esquema fatorial 3 x 4 x 5, com quatro repetições. Os tratamentos foram compostos por três procedências (DOU-Dourados, MS; JAN-Janaúba, MG; PET-Petrolina, PE), distribuídas em quatro sistemas de cultivo (TES-Matocompetição, SOL-Cultivo Solteiro, CCA-Consórcio de Culturas Agronômicas, CPH- Consórcio Permanente com Herbácea) e cada uma delas com cinco áreas úteis (1,57; 4,71; 7,85; 11,00 e 14,50 m2 planta-1). Foram realizadas avaliações da altura total da planta, do diâmetro da base do colo, do diâmetro da copa, do número de folhas, do número de ramos e do Índice SPAD, aos 540 dias após o transplante. As médias foram comparadas pelo teste Tukey a 5% de probabilidade. Para efeito de densidade, os dados quantitativos foram submetidos à análise de regressão polinomial ao nível de 5% de probabilidade. O sistema de cultivo Solteiro foi o mais adequado para o desenvolvimento vegetativo de plantas de J. curcas. As três procedências testadas sofreram influências da área útil disponível por planta, no desenvolvimento vegetal. A transformação das áreas úteis testadas para um espaçamento retangular indica o espaçamento 3,0 x 3,5 como o mais adequado. O índice SPAD não evidenciou diferenças em função da área útil por planta

The Ortolan Bunting (Emberiza hortulana) is a farmland bird species, whose population size has declined very sharply in recent decades, especia ll y in Western and Central European countries. The aim of our study in 2015 was to record where the last populations of this critically endangered species in the Czech Republic are located and also what habitat the species associated with. We examined nine areas (925 km2 in total). Two main areas of occurrence (surface mines in northern Bohemia and farmland landscape of Silesia) and two small isolated populations in central Bohemia were registered for this species. In contrast, observations in some traditional areas of its occurence (České středohoří in northern Bohemia, Hovorany-Čejkovice region in southe r n Moravia and Javoricko region in Silesia) were negative. Altogether, we counted 75-79 singing males. Our estimation of the size of the Czech population in 2015 is 75-100 singing males, which indicates further population decline compared to the last mapping in 2001-2003. Furthermore, habitat associat io ns were investigated at two spatial scales and we made habitat compar is o n between farmland and post-mining landscape. Our research highlights a high degree of flexibility in habitat selection of Ortolan Bunting and also positive association with high...

This study presents an investigation into the population dynamics and social structure of a small, closed elephant population. Specifically, it examined population growth rates for evidence of density-dependent regulation. It also quantified the association patterns of female elephants groups, and male elephants groups. Social structure was examined using Hamilton’s kinship theories of inclusive fitness, and age. Male-female patterns of association were also examined for inbreeding avoidance behaviours. The study population was located in Addo Elephant National Park, South Africa. Density-dependence was assessed using a long-term data set. Densities were considerably higher than estimated carrying capacities. Population growth rate was positively correlated with increasing density. No relationship between birth rate, the age of first calving or calf sex ratio and elephant density was detected but there was a positive relationship between birth rate and rainfall during conception year. Mortality rates, particularly for juveniles, were low, and mean inter-calf interval was 3.3 years. There is no evidence of density dependent regulation in this population. These findings indicate that density dependence should not be considered as an option in the control of elephant numbers in this Park, or where elephant resources are not seasonally limited. Examination of association patterns of the adult female component revealed that associations were not random at the population, family or individual scale. This is the second study on African elephants to confirm previous behavioural studies that predicted that preferred associates were close maternal relatives. This supports many studies showing that social species preferentially associate with their kin. The adult males in this population were found to have a well differentiated society with non-random associations. Generally, males were found to have weak associations with most other males and strong associations with only a few males. This association pattern was found to be persistent over the time frame of the study, as indicated by the time lag analysis. Males returned to their natal family, even when maternally related females were in oestrus. Oestrous females directed positive behaviours towards musth males. It appears that behavioural inbreeding avoidance mechanisms in this small, closed population are inhibited: musth status seems to override inbreeding avoidance. General principles from this case study were interpreted in terms of their applicability to other small, closed populations.

O perfilhamento é aspecto central da produtividade e perenidade de plantas forrageiras em pastagens, porém normalmente avaliado sob escalas reduzidas de experimentação (parcelas e piquetes). O objetivo deste experimento foi avaliar a densidade populacional de perfilhos e a dinâmica do perfilhamento em capim-marandu submetido a estratégias de pastejo rotativo e adubação nitrogenada em experimento de grande escala (pastejo) durante uma estação de crescimento das plantas forrageiras (outubro de 2009 a maio de 2010). Os tratamentos corresponderam a duas metas de altura pré-pastejo (25 e 35 cm) e duas doses de fertilizante nitrogenado (50 e 200 kg ha- 1 ano de N) (designados como 25/50, 25/200, 35/50 e 35/200) e foram alocados às unidades experimentais (EU) segundo um delineamento de blocos completos casualizados, com quatro repetições. Cada UE foi formada por 6 piquetes de 0,5 ha cada, os quais foram manejados como unidades auto-contidas. Foram utilizados animais da raça Nelore em número variável de conformidade com a necessidade de ajustes em taxa de lotação para manutenção das metas pré-pastejo. A meta de altura pós-pastejo foi única (15 cm), porém permitida variar acima do valor estipulado como forma de gerar flexibilidade e permitir a manutenção das metas de altura pré-pastejo. As variáveis analisadas foram: massa de forragem e relação folha/colmo, densidade populacional de perfilhos inicial (DPPi), intermediária (DPPm) e final (DPPf), taxas de aparecimento (TAP) e morte (TMP) e índice de estabilidade da população de perfilhos (IE). A DPPi foi semelhante para todos os tratamentos, porém as diferenças foram se acentuando ao longo da estação de crescimento, resultando em maior DPPf nos pastos manejados com a altura pré-pastejo 25 cm. De forma geral, pastos manejados a 35 cm apresentaram maior massa de forragem e menor relação folha/colmo em pré e póspastejo, caracterizando níveis distintos de competição por luz durante a rebrotação e de severidades de desfolhação, influenciando a dinâmica do perfilhamento. A mortalidade de perfilhos foi maior nos pastos manejados a 35 cm, com diferenças em aparecimento sendo registradas somente a partir de fevereiro de 2010, quando houve redução do aparecimento de perfilhos nos pastos manejados a 25 cm. Como consequência o balanço mensal entre aparecimento e morte nos pastos manejados a 35 cm foi menor, o que resultou em menor DDPf ao final do experimento. Pastos manejados a 25 cm apresentaram maior estabilidade da população de perfilhos, sugerindo melhores condições de crescimento e manutenção de plantas na área. O nitrogênio modificou apenas o timing de ocorrência dos efeitos dos tratamentos de pastejo sobre as plantas, conseqüência da modificação da velocidade de crescimento das mesmas. Os resultados demonstram a importância estratégica desse tipo de avaliação em experimentos de larga escala por permitem que inferências sejam feitas sobre a estabilidade da população de plantas além da produção de forragem e desempenho animal. A melhor estratégia de manejo foi aquela de altura pré-pastejo 25 cm, independente da dose de N utilizada, realçando a importância da colheita adequada e eficiente da forragem produzida antes do uso da adubação nitrogenada. / Tillering plays a central role in determining the productivity and the stability of forage grasses in pastures, but is normally evaluated under reduced scales of observation (plot and paddock scale experiments). The objective of this experiment was to evaluate tiller population density and tillering dynamics of marandu palisadegrass subjected to strategies of rotational stocking management and nitrogen fertilisation in a large scale grazing-type experiment during an entire plant growth season (October 2009 to May 2010). Treatments corresponded to combinations between two pre-grazing heights (25 and 35 cm) and two levels of nitrogen application (50 and 200 kg ha-1 year-1) (designated as 25/50, 25/200, 35/50 and 35/200), and were allocated to experimental units according to a complete randomised block design, with four replications. Each experimental unit was comprised of six 0.5 ha paddocks, and were managed as farmlets using Nellore steers in variable number in accordance with the need of adjustments in stocking rate to allow grazing to be executed according to management specifications for individual treatments. Target post-grazing height was 15 cm, but fluctuated above that as a means to contribute to maintain target pre-grazing heights. The following response-variables were studied: herbage mass and leaf/stem ratio; tiller population density at the beginning (TPDi), middle (TPDm) and end (TPDf) of the experimental period; and tiller population stability index (SI). TPDi was similar for all treatments, but differences became more pronounced during the experiment, resulting in larger TPDf on swards managed at 25 cm. In general, swards managed at 35 cm had larger herbage mass and smaller leaf/stem ratio at pre and post-grazing, characterising distinct levels of competition for light during regrowth and of severities of grazing, influencing tillering dynamics. Tiller death was larger on swards managed at 35 cm, with differences in tiller appearance being recorded only from February 2010 onwards, when there was a reduction in tiller appearance on swards managed at 25 cm. As a consequence, the monthly balance between tiller appearance and death on swards managed at 35 cm was smaller, resulting in lower TPDf. Swards managed at 25 cm showed larger stability of tiller population, suggesting better growth conditions and plant persistence. Nitrogen modified only the timing of occurrence of grazing treatment effects on plants, consequence of modifications caused in how fast plants grew. The results demonstrate the strategic importance of this type of study in large scale grazing experiments, since they allow inferences to be made regarding plant population stability in addition to those related to herbage production and animal performance. The most adequate grazing strategy corresponded to the pre-grazing height of 25 cm, regardless of the nitrogen application rate used, highlighting the importance of efficient harvest of the produced herbage before implementing the use of nitrogen fertilisation in the system.

O presente experimento foi conduzido no Departamento de Produção Animal da ESALQ/USP, em Piracicaba (SP), entre 15/12/98 e 04/07/99. Os tratamentos foram constituídos pelas combinações entre três cultivares de Cynodon spp. (Tifton-85, Florakirk e Coastcross) e quatro alturas de pasto (5, 10, 15 e 20 cm) mantidas por pastejo de ovinos em regime de lotação contínua e taxa de lotação variável. O delineamento experimental utilizado foi o de blocos completos casualizados em arranjo de parcelas subdivididas com quatro repetições. As parcelas corresponderam aos cultivares e as subparcelas (unidades experimentais) às alturas de pasto. Foram analisadas as seguintes variáveis: biomassa na área total, densidade populacional de perfilhos, massa por perfilho, massa de folha por perfilho e área foliar por perfilho. A partir dessas medições foram realizados cálculos de índice de área foliar do pasto (IAF), volume por perfilho, relação folha:haste por perfilho e relação área foliar:volume por perfilho (R). O mecanismo de compensação tamanho/densidade populacional de perfilhos operou em pastagens de Cynodon spp.. No entanto, as inclinações das retas foram consistentemente maiores que a proposição teórica de 3/2. Perfilhos individuais de Cynodon spp. apresentaram um padrão de crescimento isométrico e parecem agruparse em clones para assegurar estratégia competitiva e otimização de IAF. Pastos mantidos a 5 cm durante o outono apresentaram densidades populacionais reduzidas, indicando um padrão de tolerância ao pastejo dependente da época do ano. Tifton-85 e Coastcross apresentaram uma capacidade de aumento em biomassa que pode ir além da altura de 20 cm, enquanto que para o cultivar Florakirk essa capacidade situou-se em torno de 20 cm. O estádio reprodutivo das plantas interferiu de forma significativa nos processos de competição intra-específica e dinâmica populacional de perfilhos. / The experiment was conducted at the Department of Animal Production, ESALQ/USP, Piracicaba (SP), from 15/12/98 until 04/07/99. Treatments were combinations of three Cynodon spp. cultivars (Tifton-85, Florakirk and Coastcross) and four sward surface heights (SSH) (5, 10, 15 and 20 cm) maintained by sheep under continuous stocking and variable stocking rate. A complete randomised block design was used, with treatments arranged in split-plot and replicated four times. Grass cultivars were assigned to plots and SSH to sub-plots. Pastures responses evaluated were: total biomass above ground level, tiller population density, tiller weight, leaf mass and leaf area per tiller. From these measurements calculations of sward leaf area index (LAI), tiller volume, tiller leaf:stem ratio and tiller leaf area:volume ratio (R) were derived. A tiller size/population density mechanism operated in Cynodon spp. However, a slope steeper than the theoretical expectation of 3/2 was observed. Individual tillers presented an isometric pattern of growth and seemed to demonstrate a clonal integration among tillers in order to enhance competitive ability and optimise LAI. Swards maintained at 5 cm during autumn presented reduced tiller population densities, indicating a pattern of grazing tolerance dependent of time of the year. Tifton-85 and Coastcross pastures showed a capacity to increase total biomass that could go beyond 20 cm, while Florakirk stabilised around that SSH. Reproductive development of plants interfered with the processes related to intra-specific competition and tiller population dynamics.

A wide majority of orchid populations are decreasing due to habitat fragmentation and to changes in land management. Population size, density and habitat quality are factors that are expected to be positively related to the viability and future growth of a population. We evaluated if population size, density and soil organic matter were good predictors of growth, survival, flowering, recruitment, and growth rate in 18 populations of the long-lived orchid Gymnadenia conopsea. We followed the populations for four years. Recruitment in 2020 increased with population size, and survival in 2018 was higher in denser populations. However, flowering probability and number of flowers both decreased with population size in 2018. Soil organic matter did not significantly influence any vital rate. In total, the studied population factors could explain very little of the variation in demography. The matrix modelling showed that 14 of the 18 populations had a positive stochastic growth rate, even with an increased probability of summer drought (scenario with 50% of the years equal to the dry summer of 2018). In the populations with negative growth rate, the probability of quasi-extinction in the next 50 years varied from 90 to 100%. Declining populations were characterized by low survival following the dry year. In sum, population size, density and soil organic matter did not convincingly explain variation in growth rate of G. conopsea, suggesting that other environmental factors are responsible of governing variation in vitals rates and population dynamics.

The Important Bird Areas (IBAs) network of BirdLife International aims to identify sites that are essential for the long-term conservation of the world’s avifauna. A number of global change events have the potential to negatively affect, either directly or indirectly, most bird species, biodiversity in general and associated ecological processes in these areas identified as IBAs. To assist conservation decisions, I assessed a suite of ten landscape scale anthropogenic pressures to 115 Important Bird Areas (IBAs) in South Africa, both those currently placing pressures on IBAs and those that constitute likely future vulnerability to transformation. These threats are combined with irreplaceability, a frequently used measure of conservation importance, to identify the suite of IBAs which are high priority sites for conservation interventions: those with high irreplaceability and are highly vulnerable to anthropogenic threats. A total of 22 (19%) of the South African IBAs are highly irreplaceable and are highly vulnerable to at least some of the pressures assessed. Afforestation, current and potential future patterns of alien plant invasions affect the largest number of highly irreplaceable IBAs. Only 9% of the area of highly irreplaceable IBAs is formally protected. A total of 81 IBAs (71%) are less than 5% degraded or transformed. This result, together with seven highly irreplaceable IBAs found outside of formally protected areas with lower human densities than expected by chance provides an ideal opportunity for conservation interventions. However, all the pressures assessed vary geographically, with no discernible systematic pattern that might assist conservation managers to design effective regional interventions. Furthermore, I used the newly emerging technique of ensemble forecasting to assess the impact of climate change on endemic birds in relation to the IBAs network. I used 50 endemic species, eight bioclimatic envelope models, four climate change models and two methods of transformation to presence or absence, which essentially creates 2400 projections for the years 2070-2100. The consensual projection shows that climate change impacts are very likely to be severe. The majority of species (62%) lose climatically suitable space and 99% of grid cells show species turnover. Five species lose at least 85% of climatically suitable space. The current locations of the South African Important Bird Areas network is very likely ineffective to conserve endemic birds under climate change along a “business a usual” emissions scenario. Many IBAs show species loss (41%; 47 IBAs) and species turnover (77%; 95 IBAs). However, an irreplaceability analysis identified mountainous regions in South Africa as irreplaceable refugia for endemic species, and some of these regions are existing IBAs. These IBAs should receive renewed conservation attention, as they have the potential to substantially contribute to a flexible conservation network under realistic scenarios of climate change. Considering all the global change threats assessed in this study, the Amersfoort-Bethal-Carolina District and the Grassland Biosphere Reserve (IBA codes: SA018; SA020) are the key IBAs in South Africa for conservation prioritisation. / Dissertation (MSc)--University of Pretoria, 2008. / Zoology and Entomology / unrestricted

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Ecological inquiry is rooted fundamentally in understanding population abundance, both to develop theory and improve conservation outcomes. Despite this importance, estimating abundance is difficult due to the imperfect detection of individuals in a sample population. Further, accounting for space can provide more biologically realistic inference, shifting the focus from abundance to density and encouraging the exploration of spatial processes. To address these challenges, Spatial Capture-Recapture (“SCR”) has emerged as the most prominent method for estimating density reliably. The SCR model is conceptually straightforward: it combines a spatial model of detection with a point process model of the spatial distribution of individuals, using data collected on individuals within a spatially referenced sampling design. These data are often coarse in spatial and temporal resolution, though, motivating research into improving the quality of the data available for analysis. Here I explore two related approaches to improve inference from SCR: sampling design and data integration. Chapter 1 describes the context of this thesis in more detail. Chapter 2 presents a framework to improve sampling design for SCR through the development of an algorithmic optimization approach. Compared to pre-existing recommendations, these optimized designs perform just as well but with far more flexibility to account for available resources and challenging sampling scenarios. Chapter 3 presents one of the first methods of integrating an explicit movement model into the SCR model using telemetry data, which provides information at a much finer spatial scale. The integrated model shows significant improvements over the standard model to achieve a specific inferential objective, in this case: the estimation of landscape connectivity. In Chapter 4, I close by providing two broader conclusions about developing statistical methods for ecological inference. First, simulation-based evaluation is integral to this process, but the circularity of its use can, unfortunately, be understated. Second, and often underappreciated: statistical solutions should be as intuitive as possible to facilitate their adoption by a diverse pool of potential users. These novel approaches to sampling design and data integration represent essential steps in advancing SCR and offer intuitive opportunities to advance ecological learning about spatial processes.