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1.
Sci Rep ; 10(1): 15303, 2020 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-32943731

RESUMO

Reproductive synchronicity within a seed orchard facilitates gene exchange and reduces self-fertilisation. Here we assessed key flowering traits, biomass and foliar 1,8-cineole concentrations of Eucalyptus loxophleba (subsp. lissophloia and gratiae) in an open-pollinated seed orchard. Monthly flowering observations were made on 1142 trees from 60 families and nine provenances across 2 years. The percentage of trees flowering in both years was similar at 87%. There were differences between provenances and families within provenances for flowering traits, biomass and 1,8-cineole and interactions between provenances and year for flowering traits. Heritability of start and end flowering, and 1,8-cineole were high to moderate ([Formula: see text] = 0.75-0.45) and duration of flowering, propensity to flower and biomass estimates were moderate to low ([Formula: see text] = 0.31-0.10). Genetic and phenotypic correlations between flowering traits were high (rg = 0.96-0.63 and rp = 0.93-0.34) except between duration and end of flowering. The correlations were weaker between flowering traits and biomass or 1,8-cineole. 'Dual flowering', when trees underwent two reproductive cycles in a year, was responsible for out-of-phase flowering and those with low biomass and 1,8-cineole concentration should be removed from the breeding programme to hasten selection for desirable traits.


Assuntos
Eucaliptol/metabolismo , Eucalyptus/genética , Eucalyptus/fisiologia , Flores/genética , Flores/fisiologia , Biomassa , Cruzamento/métodos , Eucalyptus/metabolismo , Flores/metabolismo , Fenótipo , Polinização/genética , Polinização/fisiologia , Reprodução/genética , Reprodução/fisiologia , Sementes/genética , Sementes/metabolismo , Sementes/fisiologia , Autofertilização/genética , Autofertilização/fisiologia
2.
Glob Chang Biol ; 22(6): 2106-24, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26683241

RESUMO

Accurate ground-based estimation of the carbon stored in terrestrial ecosystems is critical to quantifying the global carbon budget. Allometric models provide cost-effective methods for biomass prediction. But do such models vary with ecoregion or plant functional type? We compiled 15 054 measurements of individual tree or shrub biomass from across Australia to examine the generality of allometric models for above-ground biomass prediction. This provided a robust case study because Australia includes ecoregions ranging from arid shrublands to tropical rainforests, and has a rich history of biomass research, particularly in planted forests. Regardless of ecoregion, for five broad categories of plant functional type (shrubs; multistemmed trees; trees of the genus Eucalyptus and closely related genera; other trees of high wood density; and other trees of low wood density), relationships between biomass and stem diameter were generic. Simple power-law models explained 84-95% of the variation in biomass, with little improvement in model performance when other plant variables (height, bole wood density), or site characteristics (climate, age, management) were included. Predictions of stand-based biomass from allometric models of varying levels of generalization (species-specific, plant functional type) were validated using whole-plot harvest data from 17 contrasting stands (range: 9-356 Mg ha(-1) ). Losses in efficiency of prediction were <1% if generalized models were used in place of species-specific models. Furthermore, application of generalized multispecies models did not introduce significant bias in biomass prediction in 92% of the 53 species tested. Further, overall efficiency of stand-level biomass prediction was 99%, with a mean absolute prediction error of only 13%. Hence, for cost-effective prediction of biomass across a wide range of stands, we recommend use of generic allometric models based on plant functional types. Development of new species-specific models is only warranted when gains in accuracy of stand-based predictions are relatively high (e.g. high-value monocultures).


Assuntos
Biomassa , Ecossistema , Modelos Biológicos , Árvores/crescimento & desenvolvimento , Austrália , Carbono , Sequestro de Carbono , Eucalyptus/crescimento & desenvolvimento , Florestas , Caules de Planta/crescimento & desenvolvimento , Madeira/crescimento & desenvolvimento
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