Genetic control of coppice regrowth in Eucalyptus spp.

Abstract

Forest companies prefer a coppice system as a silvicultural strategy owing to its economic and sustainability advantages compared to developing new plantations for second rotations. However, studies aiming to determine the selection of superior genetic material for this management strategy are scarce. In this study, we evaluated five clonal tests of Eucalyptus spp. located in Itatinga and Angatuba, São Paulo State, Brazil, to determine the genetic correlations and control of productivity for regrowth management in two rotations. The volume (m3) and survival of the Eucalyptus spp. clonal tests were determined for the two rotations at 5.5 years of age. The experiments were carried out in a randomized block design with six replicates, five plants per plot, and unbalanced treatments. The heritability in the normal scale (\hat h_n^2) for the survival ranged from 0.056 to 0.11, the heritability in the broad sense (\hat h_g^2) ranged from 0.205 to 0.334, and the genotypic correlation was positive and high (0.71-0.86), and statistically significant to the genetic means for the two rotations. The ranking of the best clones in the second rotation was similar (76 %) to their ranking in the first selection. Thus, for the evaluated material, there was no need for the second measurement to obtain accurate selection when managing a coppice system.

Sapling and coppice biomass heritabilities and potential gains from Eucalyptus polybractea progeny trials

“…There is some debate as to whether selections should be done on first (sapling) or second (coppice) rotations for coppice crops. A study of five experiments of mixed eucalypt species in Brazil demonstrated that selection before the first rotation was appropriate (Amâncio et al 2020). This is contrasted with the results from a small E. polybractea trial that suggests that selection for biomass at first coppice rotation is better than when done at saplings or after the second coppice rotation (Goodger et al 2007).…”

“…Breeding decisions for E. polybractea on biomass performance have historically been based on assessment of sapling performance although the relationship between sapling and coppice biomass is unknown. Studies in other eucalypt species have revealed a wide range of genetic correlations between sapling and coppice biomass ranging from weak (Whittock et al 2003) to very strong (Amâncio et al 2020;Li et al 2012). This variation in genetic correlations may be underpinned by the genetic control of lignotuber development, which has been found to be responsible for the varying degrees of success of coppicing (Bortoloto et al 2020;Walters et al 2005;Whittock et al 2003).…”

A General Rule-Based Framework for Generating Alternatives for Forest Ecosystem Management Decision Support Systems

“…The two types of interventions are based on a regular coppice regime: a clear cut followed by a renewal planting (CCR) or a clear cut followed by sprouting from stumps (CCS). In this example, only one CCS is allowed, so after a coppice harvest, the next clear cut must be followed by a renewal (CCR) to plant new genetic material [75].…”

Evaluation of genetic parameters and clonal selection of Eucalyptus in the Cerrado region

“…Such survival rates are considered high, and they indicated that the experiments were properly conducted and there was a good adaptation of the clones, as observed in other clonal tests with Eucalyptus sp. (Silva et al 2017, Amâncio et al 2020).…”