Contributo da Robinia pseudoacacia para a Valoriza？？o de Espécies Folhosas Produtoras de Madeira de Qualidade: Um Caso de Estudo

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, red oak and sweet chestnut with the accessory species black locust, was established in 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 design of 30 permanent sample plots with 10 treatments and 3 replications was adopted and two types of mixtures were considered (alternating lines of the target-species with black locust and target-species alternating with black locust in the line). the aim of this study is to evaluate the benefits for the target-species when mixed with a nitrogen fixing species. the maximum likelihood ratio test showed that the cherry was associated to a high probability of survival (77-80%). the remaining target-species indicated a low probability of survival mainly because of the breakdown verified in the establishment phase (46-55% survival). for each species, the growth was compared among the different treatments using the least significant difference test (lsd). the facilitation effect promoted by the accessory species is evident in the cherry. for both the red oak and the chestnut species a depressive effect of black locust on the target-species was observed in the intimate mixture situation, causing the facilitation effect not to be so obvious.