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| Author(s): |
Rafael Costa Pinheiro
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Botucatu. 2015-05-14. |
| Institution: | Universidade Estadual Paulista (Unesp). Faculdade de Ciências Agronômicas. Botucatu |
| Defense date: | 2014-11-13 |
| Advisor: | Jean Paul Laclau; Iraê Amaral Guerrini |
| Abstract | |
Root behavior in deep soil layers is a subject poorly known for tree species. This topic can be important for breeding programs because a fast displacement of the root front is likely to explain different survival rates among clones in deep Ferralsols during exceptional drought periods. Although an inter-clonal variability in root development might account for different strategies to take up large amounts of water stored in deep soil layers after clearcutting, fine root distributions below a depth of 1 m have been poorly investigated for eucalypt clones. The objectives of our study were: a) to assess the inter-clonal variability among different Eucalyptus genetic materials in fine root densities down to the root front in 2 and 4-years-old clonal tests and in soils with different textures; b) to assess if the ratio between leaf area index (LAI) and root area index (RAI) was similar for different Eucalyptus genetic materials; and c) to assess if the relationship between mean stand height and maximum fine roots depth, as already found for a single E. grandis progeny, is similar for all genetic materials. Soils were sampled using a cylindrical auger at several distances from trees, down to a depth of 17 m for each genetic material. Fine roots (≤ 2 mm in diameter) and leaves were scanned and analysed by WinRhizo and ImageJ softwares, respectively. Fine root densities dropped from 0.2-0.4 g kg-1 in the upper soil layer to values < 0.1 g kg-1 below a depth of 25 cm, irrespective of the genetic material. Seedlings and clones exhibited a similar pattern of fine root development in very deep soil layers. However, mean fine root densities were higher for the seedlings and one clone (clone 14) than for the 2 other clones. Soil water content profiles showed that all the clones and seedlings had the capacity to withdraw water down to ... (AU) | |
| FAPESP's process: | 12/13380-3 - Variability in fine root distributions in very deep Ferralsols between four eucalyptus spp. genetic materials |
| Grantee: | Rafael Costa Pinheiro |
| Support Opportunities: | Scholarships in Brazil - Master |