Publicação
Arboriculture for timber: assessment of a mixed plantation with nitrogen fixing accessory species
| Resumo: | The mixed plantation of valuable species with nitrogen-fixing species can increase the productivity levels for the target species. So, in 1998, in the framework of the Project PRAXIS XXI – 3/3.2/Flor/2127/95, a mixture plantation trial with valuable broadleaved tree species: wild cherry (Prunus avium L.), red oak (Quercus rubra L.) and sweet chestnut (Castanea sativa Mill.) with the accessory species black locust, was established in a substitutive or replacement series design in Vimioso (Latitude 41º34'12''N; Longitude 6º30'7''W and altitude 700 m), before the publication of decree law 565/99. A completely random experimental de-sign of 30 permanent sample plots with 10 treatments and 3 replications was adopted and two types of mixtures were considered (alternating lines of the objective-species with black locust and objective-species alternating with black locust in the line). The aim of this study is to evaluate the benefits for the objective-species when mixed with a nitrogen fixing species. In the dormancy of 2016/2017 the trial was measured but we consider only the treatments with wild cherry and red oak as objective-species and the black locust as accessory species. The plantations were assessed according to the survival rate, height and diameter growth, considering the dendrometric variables: height, diameter, coefficient of stability, and relative yield and relative yield total. Logistic regression was used to model the survival of the objective species in the mixture. The Wald Z test used showed that wild cherry is associated to a high probability of survival (64-75%) both in the pure treatment and in those mixed with black locust. For the red oak, the test indicated a low probability of survival mainly because of the breakdown verified in the establishment phase (46-55% survival at 10 years old) worsen by the strong black frost in the spring of 2010. Currently the survival of red oak ranges from 35 to 54%. For each species, the growth was compared among the different treatments using the least significant difference test (LSD). The treatment line-by-line of the wild cherry with black locust showed positive response in all assessment criteria, mainly survival rate (75%), the relative yield and the relative yield total, and height growth. The other mixtures presented either negative or non-significant results. The facilitation/complementarity effect promoted by the accessory species is evident only in the wild cherry. |
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| Autores principais: | Mimouni, Othman |
| Assunto: | Forestry Robinia pseudoacacia Quercus rubra Prunus avium Survival rate Target and secondary species |
| Ano: | 2017 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Instituto Politécnico de Bragança |
| Idioma: | inglês |
| Origem: | Biblioteca Digital do IPB |
| Resumo: | The mixed plantation of valuable species with nitrogen-fixing species can increase the productivity levels for the target species. So, in 1998, in the framework of the Project PRAXIS XXI – 3/3.2/Flor/2127/95, a mixture plantation trial with valuable broadleaved tree species: wild cherry (Prunus avium L.), red oak (Quercus rubra L.) and sweet chestnut (Castanea sativa Mill.) with the accessory species black locust, was established in a substitutive or replacement series design in Vimioso (Latitude 41º34'12''N; Longitude 6º30'7''W and altitude 700 m), before the publication of decree law 565/99. A completely random experimental de-sign of 30 permanent sample plots with 10 treatments and 3 replications was adopted and two types of mixtures were considered (alternating lines of the objective-species with black locust and objective-species alternating with black locust in the line). The aim of this study is to evaluate the benefits for the objective-species when mixed with a nitrogen fixing species. In the dormancy of 2016/2017 the trial was measured but we consider only the treatments with wild cherry and red oak as objective-species and the black locust as accessory species. The plantations were assessed according to the survival rate, height and diameter growth, considering the dendrometric variables: height, diameter, coefficient of stability, and relative yield and relative yield total. Logistic regression was used to model the survival of the objective species in the mixture. The Wald Z test used showed that wild cherry is associated to a high probability of survival (64-75%) both in the pure treatment and in those mixed with black locust. For the red oak, the test indicated a low probability of survival mainly because of the breakdown verified in the establishment phase (46-55% survival at 10 years old) worsen by the strong black frost in the spring of 2010. Currently the survival of red oak ranges from 35 to 54%. For each species, the growth was compared among the different treatments using the least significant difference test (LSD). The treatment line-by-line of the wild cherry with black locust showed positive response in all assessment criteria, mainly survival rate (75%), the relative yield and the relative yield total, and height growth. The other mixtures presented either negative or non-significant results. The facilitation/complementarity effect promoted by the accessory species is evident only in the wild cherry. |
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