Procedimentos e metodologias que permitam avaliar a qualidade e a uniformidade das mudas são fundamentais para a homogeneização dos lotes em viveiros florestais e o sucesso dos plantios para reflorestamento. Foi conduzido um estudo com o objetivo de avaliar as correlações entre a alocação de biomassa e o índice de qualidade de Dickson (IQD) para mudas de seis espécies arbóreas nativas da Mata Atlântica, bem como selecionar indicadores de qualidade que mais influenciam o IQD e que possam ser utilizados de maneira prática e precisa para a avaliação da qualidade de mudas florestais nativas. Foram utilizadas mudas de seis espécies arbóreas tropicais: Calophyllum brasiliense, Eriotheca macrophylla, Inga laurina, Psidium cattleyanum, Roupala montana e Sloanea obtusifolia. Foram avaliados a massa seca de folhas (MSF), os caules (MSC) e as raízes (MSR), além da altura da parte aérea (H) e diâmetro do coleto (D). A partir dessas variáveis, foram calculadas as razões de massa de raízes (RMR), caules (RMC) e folhas (RMF), além da massa seca total (MST), a massa seca da parte aérea (MSPA), a razão de massa seca da parte aérea por massa seca de raízes (MSPA/MSR), a razão altura da parte aérea por diâmetro do coleto (H/D) e o IQD. Os resultados foram analisados mediante análises de correlação. Com base nas condições em que este estudo foi realizado é possível concluir que: (a) as diferenças entre os valores médios do IQD das espécies estudadas não foram explicadas pelo padrão de alocação de biomassa característico de cada espécie; (b) a MSR, a MST e o D são as melhores variáveis para predizer o comportamento do IQD das mudas das espécies florestais analisadas neste estudo; e (c) pelo fato de ser um método não destrutivo, o D pode ser considerado como o melhor indicador prático para estimar os valores de IQD de lotes de mudas de espécies florestais da Mata Atlântica.

Screening tree species in tropical rainforest according to their shade tolerance is important to efficiently manage the native trees of economic significance in secondary forest enrichment regimes. The objective of this study was to determine the whole-plant light compensation point (WPLCP) and compare the phenotypic plasticity in relation to growth and carbon allocation of Cariniana legalis and Gallesia integrifolia seedlings under low light availability. Seedlings were cultivated for 77 days under conditions of five photosynthetically active radiation (PAR) (0.02, 1.1, 2.3, 4.5 and 5.9 mol photons m ^-2 day ^-1) in three replicates. Growth and carbon allocation variables were determined. Growth rates of C. legalis were higher and lower than those of G. integrifolia under 1.1 and 5.9 mol photons m ^-2 day ^-1, respectively. The WPLCP differed significantly between the two species. In accordance with the criteria of the shade tolerance classification for these two tropical tree species, our results showed that C. legalis had lower WPLCP and phenotypic plasticity in terms of higher growth rates and greater shade tolerance than G. integrifolia. From a practical point of view, we demonstrated that the differential linkage between growth and changing PAR between the two species can become a useful tool for comparing and selecting tree species in forest enrichment projects.

Root deformation (RD) caused by errors in the pricking out process are irreversible and very difficult to detect in container-grown seedlings at the time of planting in the field. The objective of this study was to evaluate the effects of RD on leaf gas exchange, growth, biomass allocation and mineral nutrition of G. americana seedlings during the recovery phase after soil flooding. Four-months-old seedlings, with and without RD, were flooded for 42 days and their recovery was evaluated 28 days after soil drainage. There were no significant interactions between RD and soil flooding for all leaf gas exchange, growth and mineral nutrition after soil drainage, with the exception of leaf P concentrations. In plants with no RD, the P concentration in leaves of non-flooded plants was significantly higher than that of plants with RD. Soil flooding and RD did not influence leaf or root N concentrations or whole-plant N content. RD increased the K concentration in the roots, but not in the leaves. Changes in the nutrient concentrations in leaves and roots indicate that RD may affect physiological performance of seedlings after planting in the field.

We conducted a study to assess the morphometric attributes of Genipa americana fruit, and their relationship with variations in elevation and distances between sampling sites on the southern coast of Bahia, Brazil. Eight fruit were used per sampling site (ten sites; n = 80). Mantel’s test revealed that the spatial distance between sample sites, and elevation of all sampling sites were significantly correlated with the similarities found in fruit diameter (DF), fruit length (FL), and fresh fruit mass (FFM), but the spatial distance between sites, independently of the elevation, was only correlated with the number of seeds per fruit (NSF) and total fresh mass of seeds per fruit (FMSF). The morphometric attributes of fruits, and their associated relationships with elevation and distance between sampling sites are demonstrated.