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Title: Germination of Ocotea pulchella (Nees) Mez (Lauraceae) seeds in laboratory and natural restinga environment conditions
Author: Simoes, E.; Ferreira, L.; Joly, C. A.
Year: 2011
Is part of: Sustentabilidade em Debate, v. 2, p. 17 - 32


Citation: Simoes, E.; Ferreira, L.; Joly, C. A.; Germination of Ocotea pulchella (Nees) Mez (Lauraceae) seeds in laboratory and natural restinga environment conditions. Sustentabilidade em Debate, v.2, p. 17-32, 2011

Abstract: The germination response of Ocotea pulchella (Nees) Mez seeds to light, temperature, water level and pulp presence is introduced. The laboratory assays were carried out in germination chambers and thermal-gradient apparatus, whereas the field assays were performed in environments with distinct light, temperature and soil moisture conditions within a permanent parcel of Restinga forest of the Parque Estadual da Ilha do Cardoso, Cananeia, Sao Paulo. The seeds do not exhibit dormancy, they are non photoblastic, and a loss of viability in dry stored seeds can be related to a decrease in water content of the seed. The presence of the pulp and the flooded substratum influenced negatively the germination of O. pulchella seeds tested in the laboratory. Otherwise, light and temperature probably are not limiting factors of the germination of O. pulchella seeds in the natural environment of Restinga. The optimum temperature range for germination of Ocotea pulchella seeds was 20 to 32 degrees C, the minimum or base temperature estimated was 11 degrees C and the maximum ranged between 33 and 42 degrees C. The isotherms exhibited a sigmoidal pattern well described by the Weibull model in the sub-optimal temperature range. The germinability of O. pulchella seeds in the understorey, both in wet and dry soil, was higher than in gaps. Germination was not affected by fluctuations in soil moisture content in the understorey environment, whereas in gaps, germination was higher in wet soils. Thus, the germination of this species involves the interaction of two or more factors and it cannot be explained by a single factor.

Keywords: Ação social e Conservação da Biodiversidade; Atores e Negociação sobre os Commons; Institucionalização de normas e regras; Parque Estadual da Serra do Mar (SP);

Funding: The authors thank CNPq for the fellowship (LAP) and financial support (Process no: 473005/2003-4); the Programme "Diversidade, Dinamica e Conservacao em Florestas do Estado de Sao Paulo: 40 ha de Parcelas Permanentes" (Biota/Fapesp) for support; and Ednilson da Silva, Claudio Bernardes, Juninho, and Ary, for technical assistance.
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