Thesis--Auburn University, 2010. / Abstract. Includes bibliographic references.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2004. / Härtill 4 uppsatser.

Submitted by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2018-10-15T15:16:47Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação-Leandro.S.Fernandes.pdf: 1359976 bytes, checksum: 6a343537d69f7467ed412811332b1c45 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2018-10-15T15:16:59Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação-Leandro.S.Fernandes.pdf: 1359976 bytes, checksum: 6a343537d69f7467ed412811332b1c45 (MD5) / Made available in DSpace on 2018-10-15T15:16:59Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação-Leandro.S.Fernandes.pdf: 1359976 bytes, checksum: 6a343537d69f7467ed412811332b1c45 (MD5) Previous issue date: 2018-06-04 / FAPEAM - Fundação de Amparo à Pesquisa do Estado do Amazonas / Seed dispersal is an extremely important process in the population dynamics of plants. This process can be mediated by dispersing agents as in the case of primates. During feeding these animals can spit or swallow the seeds of the fruits. When swallowing the seeds, a process known as endozoochory, these animals can increase germination, or even move seeds away from the parent plant, this can favor plants by avoiding competition, predation and disease on seeds and seedlings. We performed experiments such as the free-living tamarim (Saguinus bicolor) primate in the laboratory, using 23 species of fruits that are part of its diet, to test the effect of the passage of seeds through the digestive tract and which factors influence the time of seed retention. Tamarins favor most defecated seeds, increasing germination (50%) and speed of emergence (38,88%). The retention time was not influenced by the characteristics of the seeds or the amount of fiber in the fruit pulp, and the first appearance of the seeds in the feces was correlated with the quantities of swallowed seeds. Thus, tamarim can be considered an effective dispersant potential because the seeds remain viable after being defecated and the time the seeds are retained possibly favors dispersion. Therefore, seed dispersion mediated by tamarins may be beneficial for the maintenance and recovery of environments where these animals transit. / A dispersão de sementes é um processo extremamente importante na dinâmica populacional das plantas. Esse processo pode ser intermediado por agentes dispersores como no caso dos primatas. Durante a alimentação esses animais podem cuspir ou engolir as sementes dos frutos. Ao engolirem as sementes, processo conhecido como endozoocoria, esses animais podem aumentar a germinação, ou até mesmo, deslocar as sementes para longe da planta progenitora, isso pode favorecer as plantas por evitar a competição, predação e doenças sobre as sementes e plântulas. Realizamos experimentos com o primata sauim-de-coleira (Saguinus bicolor) em laboratório, usando 23 espécies de frutos que fazem parte da sua dieta, para testar o efeito da passagem das sementes através do trato digestório e quais fatores influenciam o tempo de retenção das sementes. Os sauins favorecem a maioria das sementes defecadas, aumentado a germinação (50%) e a velocidade de emergência (38,88%). O tempo de retenção não foi influenciado pelas caraterísticas das sementes ou quantidade de fibras na polpa dos frutos, entretanto, o primeiro aparecimento das sementes nas fezes mostrou-se correlacionado com a quantidades de sementes engolidas. Dessa forma, o sauim pode ser considerado um potencial dispersor eficaz, porque as sementes permanecem viáveis após serem defecadas e o tempo que as sementes ficam retidas possivelmente favorece a dispersão. Portanto, a dispersão de sementes mediada pelos sauins pode ser benéfica para a manutenção e recuperação de ambientes onde estes animais transitam.

No description available.

A population of a critically endangered species Spiranthes spiralis was discovered in 1980 in the National Natural Monument Pastviště u Fínů near village Albrechtice, close to Sušice city. Since 1985 the number of flowering individuals in this population has been annually monitored. Since autumn 1998 all the specimen found there have been marked and biometrically measured. During these periods (12 or 26 years, respectively), large year-on-year fluctuations in the number of flowering plants and in the survival of the individual rosettes have been recorded. The main aim of my work was to assess the effect of weather conditions (temperature, precipitation, the number of days of snow) on the population dynamics and on the fitness of plants (leaf area, probability of flowering and probability of death). The year-round lower temperature and the wet end of autumn during the previous year (t-1) together with the wet spring of the following year (t) had a positive effect on the leaf area during the period of maximal rosette growth (end May in the year t). The probability of flowering was positively affected by the lower temperatures in May and June in the previous year (t-1) and in August just before flowering (year t). The probability of death (in the year t) was increased when the March precipitation (in t) and October temperatures (in t-1) were low. The average number of seeds in the capsule was 1528 ? 885 (s.d.). The number of flowers was positively correlated with the number of mature capsules. However, it did not affect the ratio of mature capsules. Capsules developed on average from 44% ? 24.6 % (s.d.) of the flowers. The average life time of individual plant cohorts was 4.7 years. The number of rosettes per each position was variable from 1 to 7 rosettes (73.2% positions had only 1 rosette). The annual life cycle of the underground organs is described at the end of the thesis.