Environmental factors affect the germination process, like the presence of seed coat and the quality of light; these informations are still scarce for many native species from Brazil, especially for Senna cana, which there are no adequate standards and methodologies to be used in germination tests. The aim of this research was to recommend adequate pre-germinative treatment(s) to overcome seed dormancy, and determine the degree of influence of different light regimes in seed germination of S. cana. Two experiments were carried out: T1-evaluation of different methods of dormancy overcoming (intact seeds (control), T2-imbibition of the intact seeds for 24 hours (in distilled water), T3-scarified seeds with sandpaper n° 100 in the hilum opposite region, T4-scarified seeds with sandpaper n° 100 in the region the hilo opposite region and imbibition in water (in distilled water) for 24 hours; T5-imbibition in water at 80°C); 2-Influence of light quality on seed germination and vigor (white light, red light, far red light and absence of light). The evaluated parameters were: first JEAI, 32(5): 1-9, 2019; Article no.JEAI.47671 2 germination count, percentage of germination, IVG (Germination speed index), MGT (Mean germination time). Treatments were compared by Tukey at 5% probability. The best method for overcoming seed dormancy was mechanical scarification with sandpaper nº 100. The germination of the seeds of S. cana can be classified as indifferent to the luminosity, despite germinative response be greater under white and red light. Original Research Article
The relation among basal area, light and functional characteristics variation is still an unexplored issue, especially in rainforests with different disturbance regimes. The following hypotheses were tested: 1) basal area of arboreal plants and light availability is a good predictor of the functional characteristics, once it is believed that in forest environments with a lower basal area and much light, functional characteristics values linked to the fast light resources utilization are found in leaves, stem and roots; 2) environments where there is greater light availability, the standard deviation values of the leaf characteristics will be greater. The functional characteristics values were not influenced by the geographic distance (spatial autocorrelation) neither by the species phylogeny. The prediction that in the areas with the lower basal area, values of characteristics associated with the rapid use of the light resource were confirmed for five characteristics: dry leaf matter (LMDC), stem (SDMC) and root (RDMC), the density of wood stem (WDC) and root (WDR). Significant investment was not found in structural carbon (greater dry matter values of leaf and wood) in environments with the greater basal area. It is considered that in urban fragments the disturbances are frequent, it is possible to suppose that plants with lower values of LDMC, DWC, DWR, SDMC, and RDMC have also "established" in the two areas with a greater basal area. It is concluded that in fragments in urban rainforest studied, perturbations may change the succession path due to population dynamics, especially in the area with more abundant light availability and lesser basal area (A4<AB). the study suggests that this greater light input in the A4<AB environment, due to the greater perturbations, would lead plants with the strategy of using a slow resource, favoring those with fast use of the resource, and as a result, there would be less variability of the leaf characteristics in A4<AB. The basal area and light intensity are not good predictors of variations of functional characteristics in the urban fragments studied.
The aim of this study was to quantify extracts from the bark and green fruits of A. colubrina and M. tenuiflora, compared to A. mearnsii bark using the formaldehyde method. Ten M. tenuiflora and ten A. colubrina trees were selected to collect the studied material and five A. mearnsii individuals. Moisture content, total solids, Stiasny index and condensed tannin content were analyzed. The results were compared by Tukey test at 5% probability. In relation to the Stiasny index, the species A. mearnsii and M. tenuiflora did not differ statistically, with averages of 68.3 and 62.6%, respectively. The content of condensed tannins found in A. colubrina fruits, did not differ statistically from the content of the bark of the same species, corroborates with data referenced in the literature in research with this species that is traditionally exploited in the Northeast Region of Brazil by the Original Research Article
This work aimed to evaluate the effect of different priming treatments in the longevity of H. serratifolius seeds. Seeds were osmo-conditioned in PEG -1.0 MPa at 10, 15 and 20°C or hydro-primed at 5, 10 and 15°C. Final germination, speed and uniformity of germination were assessed. Priming did not affect the final percentage nor uniformity of germination; however, the germination speed was increased after hydropriming at 15°C and osmo-conditioning at 15°C compared to the control. Primed and not primed seeds were placed into an incubator (25°C, dark, 100% RH) until they reached 15% moisture content. Then, seeds were incubated in a container at 40°C for 0 to 144 hours, so, samples were taken in each period for determination of viability. The results suggest that priming increases longevity of H. serratifolius seeds.
Secondary forests play an important role in tropical landscapes and have important ecological functions such as the ability to accumulate biomass. Although the literature points to the convergence between primary and secondary forests, however there are few studies in Atlantic Rainforest in a chronosequence to show it. This study aimed to characterize the changes of floristic composition in a chronosequence (5, 16, 24, 30 years of regeneration and mature forest) in the Atlantic Rainforest. In each forest 30 plots of 10 × 10 m were installed for canopy sampling, and within these 100 m2 were installed plots of 5 × 5 m for sampling the woody sub-forest at the lower left corner. The growth habits analyzed were arboreal (diameter at breast height, DBH ≥ 5 cm), shrubs (DBH < 5 cm and stem diameter at ground level > 1 cm), herbs, epiphytes and climbing plants. The results suggest that from 16 young forests tended to converge with the mature forest in terms of the proportion of growth forms.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.