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XXV IUFRO World Congress Forest Research and Cooperation for Sustainable Development 314

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XXV IUFRO World Congress Forest Research and Cooperation for Sustainable Development 314

environment of 10,000 pixels, wherein 50 breeding trials of the same genotypes (i.e. eucalyptus clones) are randomly allocated. We used 100 non-related genotypes expressing a low heritability quantitative trait that mimics yield. GIS-GE uses spatial interpolation to environmental data, referring either to FOLPDWLFDQGODQGVFDSHYDULDEOHVWRGH¿QH(QYLURQPHQWDO,QGH[HV(,E\WKHLUUHODWLRQVKLSWRWKHSKHQRW\SLFGDWDWRWDOLQJPLOOLRQRIHQYLURW\SLFPDUNHUV HQYLURW\SHVSL[HOV)RUWKLVHQYLURPHZHXVHGDGYDQFHGJHQHWLFPRGHOLQJWRHVWLPDWHWKH(,H൵HFWVDFURVVWKHZKROHVHWRISL[HOV:HVKRZ WKDW*,6*(SUHVHQWVDGYDQWDJHVLQEUHHGLQJLQFOXGLQJPDWFKLQJRIJHQRW\SHVWRWKHLUPRVWDSSURSULDWHVLWHVGH¿QLWLRQRIEUHHGLQJDUHDVRIKLJKHVWJHQHWLF correlation to genotypes; and indication of the locations that maximize the capture of lost phenotypic heritability in trials.

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(XFDO\SWXV plantations in Brazil are among the most productive forests of the world, reaching mean annual increments of about 50 m

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over short (6 - 7 yrs) rotations. We continuously monitored water vapor, CO

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). AET reached maximum values (1598 mm yr

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) about 2-3 years after planting (a.p) when LAI peaked and when deep rooting (about 15 m deep 2.5 yrs a.p) SURYLGHGDFFHVVWRWKHODUJHDPRXQWRIZDWHUVWRUHGLQGHHSVRLOOD\HUVGXULQJWKH¿UVWPRQWKVDIWHUFOHDUFXWWLQJDQGUHSODQWLQJ0RVWRIWKHDYDLODEOH energy (3852 MJ yr

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/LJKWXVHH൶FLHQF\DQGSURGXFWLYLW\RIJHQRW\SHVRIEucalyptus along a 6-year rotation in Brazil

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between 0.5 and 0.95). Subsequently, the variability of wood production explained by light was variable among genotypes (R

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RIRQDYHUDJH7KHH൵HFWRIJHQRW\SHRQVWHPZRRGSURGXFWLRQUHPDLQVKLJKDQGVLJQL¿FDQWDORQJ the rotation. These results and their implications for plantation management are discussed.

Unraveling drivers of growth dominance and its impact on stand growth of Eucalyptus plantations across Brazil

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Growth dominance (GD) occurs when trees grow disproportionally to their size compared to other trees. High growth dominance indicates that stand growth is concentrated in larger trees, leading to further increase in size heterogeneity in stand structure. Growth dominance increases have been associated with lower productivity in tree monocultures, especially in monoclonal stands such as the eucalypt plantations in Brazil. Understanding how GD develops for GL൵HUHQWHXFDO\SWJHQRW\SHVDQGWKHH൵HFWVRIVLWHDQGDJHDUHIXQGDPHQWDOWRXQGHUVWDQGWKHOLQNEHWZHHQVWDQGVWUXFWXUHDQGSURGXFWLYLW\:HXVHGGDWDIURP WKH7(&+6,3()FRRSHUDWLYHUHVHDUFKSURJUDPDFRQWLQHQWDOH[SHULPHQWDOSODWIRUPLQZKLFKGL൵HUHQWJHQRW\SHVZHUHSODQWHGLQVLWHVUDQJLQJIURPQRUWK

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throughout time, among genotypes. GD increased with age and tended to be lower with slowest development for the drier sites as well as for the throughfall

exclusion plots. After other factors were accounted for, increasing GD was associated with decreasing plot volume increment.

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