9 research outputs found

    Leaf Morphology Of Saplings And Adult Individuals Of Caesalpinia Echinata Lam. In A Semidecidual Forest Of Southern Bahia, Brazil [morfologia Foliar De Indivíduos Jovens E Adultos De Caesalpinia Echinata Lam. Numa Floresta Semidecídua Do Sul Da Bahia]

    No full text
    Caesalpinia echinata Lam. (Caesalpiniaceae) is a tree species that naturally regenerates in the forest understory and reaches the upper canopy through small gaps. We conducted a study with the objective of comparing some aspects of leaf morphology of adult individuals, in which the leaves were exposed to full sunlight, and saplings, grown in the forest understory. The study was conducted in a semidecidual forest in Jussari, southern Bahia, Brazil. Initially, eight adult and eight sapling individuals were selected and marked. In September/October, 2004 and April, 2005 eight leaves for each adult and three leaves for each sapling individual were collected and analyzed. In general, the area of leaves, rachis and leaflets, the length of rachis, the width of leaves, the number of pinnes and the dried mass of leaves were significantly higher in young individuals. Notwithstanding, the specific mass of leaves and leaflets were significantly higher in the adults. For both, adults and saplings, strong relationships were observed between the leaf dried mass and leaf area. Based on the results, we conclude that the leaves of C. echinata present characteristics that allow the maximization of light absorption in environments in which light radiation is a limiting factor, at the same time allocating carbon to the support tissues. The results obtained in the present study were in accordance with the successional status of this tree species and its strategies to occupy small canopy gaps of the semidecidual forest environments.335885893Aguiar, F.F.A., Germinação de sementes e formação de mudas de Caesalpinia echinata Lam. (Pau-brasil): Efeito de sombreamento (2005) Revista Árvore, 29 (6), pp. 871-875Amorim, A.M., The vascular plants of a forest fragment in southern Bahia (2005) Brazil. Sida, 21, pp. 1726-1752Aphalo, P.J., Ballaré, C.L., On the importance of information acquiring systems in plant-plant interactions (1995) Functional Ecology, 9 (1), pp. 5-14Aranda, I., Anatomical basis of the change in leaf mass per area and nitrogen investiment with relative irradiance within the canopy of eight temperate tree species (2004) Acta Oecologica, 25 (3), pp. 187-195Björkman, O., Responses to different quantum flux densities (1981) Physiological Plant Ecology I. Encyclopedia of Plant Physiology, 12, pp. 57-107. , In: LANGE, O.L.OSMOND, C. B. & ZIEGLER, H., (Eds.), Heidelberg: SpringerBoeger, M.R.T., Wisniewski, C., Comparação da morfologia foliar de espécies arbóreas de três estádios sucessionais distintos de floresta ombrófila densa (Floresta Atlântica) no sul do Brasil (2003) Revista Brasileira De Botânica, 26 (1), pp. 61-72Carvalho, P.E.R., (1994) Espécies Florestais Brasileiras, , Brasília, Embrapa-SPICorrêa, A.M.S., Morfologia polínica de Caesalpinia echinata Lam (2003) Revista Brasileira De Botânica, 26 (3), pp. 355-359Duz, S.R., Crescimento inicial de três espécies arbóreas da Floresta Atlântica em resposta à variação na quantidade de luz (2004) Revista Brasileira De Botânica, 27 (3), pp. 587-596Evans, J.R., Poorter, H., Photosynthetic acclimation of plants to growth irradiance: The relative importance of specific leaf area and nitrogen partitioning in maximizing carbon gain (2001) Plant, Cell and Environment, 24 (8), pp. 755-767Gebler, A., Ecophysiology of selected tree species in different plant communities at the periphery of the Atlantic Forest of SE - Brazil III. Three legume trees in a semi-deciduous dry forest (2005) Trees, 19 (5), pp. 523-530Ishida, A., Yazaki, K., Hoe, A.L., Ontogenetic transition of leaf physiology and anatomy from seedlings to mature trees of a rain forest pioneer tree, Macaranga gigantea (2005) Tree Physiology, 25 (5), pp. 513-522Kitajima, K., Relative importance of photosynthetic traits and allocation patterns as correlates of seedling shade tolerance of 13 tropical tree species. Oecologia (1994) Numero, 98, pp. 419-428Lambers, H., Chapin III, S.T., Pons, T.J., (1998) Plant Physiological Ecology, , New York: Springer-VerlagLee, D.W., Effects of irradiance and spectral quality on seedling development of two southeast Asian Hopea species (1997) Oecologia, 110 (1), pp. 1-9Lima Jr., E.C., Aspectos fisioanatômicos de plantas jovens de Cupania vernalis Camb. submetidas a diferentes níveis de sombreamento (2006) Revista Árvore, 30 (1), pp. 33-46Lüttge, U., (1997) Physiological Ecology of Tropical Plants, , Berlin: SpringerMelo, S.C.O., Microsatellite markers for Caesalpinia echinata Lam. (Brazilwood), a tree that named a country (2007) Conservation Genetics, 8 (6), pp. 1269-1271Montgomery, R.A., Chazdon, R.L., Light gradient partitioning by tropical tree seedlings in the absence of canopy gaps (2002) Oecologia, 131 (1), pp. 165-174Poorter, L., Leaf optical properties in Venezuelan cloud forest trees (2000) Tree Physiology, 20 (8), pp. 519-526Rezende, C.M., Constituintes químicos voláteis das flores e folhas do pau-brasil (Caesalpinia echinata Lam.) (2004) Química Nova, 27 (3), pp. 414-416Rijkers, T., Pons, T.L., Bongers, F., The effect of tree height and light availability on photosynthetic leaf traits of four neotropical species differing in shade tolerance (2000) Functional Ecology, 14 (1), pp. 77-86Santiago, L.S., Coordinated changes in photosynthesis, water relations and nutritional traits of canopy trees along a precipitation gradient in lowland tropical forest (2004) Oecologia, 139 (4), pp. 495-502Thomas, S.C., Winner, W.E., Photosynthetic differences between saplings and adult trees: An integration of field results by meta-analysis (2002) Tree Physiology, 22 (2-3), pp. 117-127Wang, G.G., Qian, H., Klinka, K., Growth of Thuja plicata seedlings along a light gradient (1994) Canadian Journal of Botany, 72 (12), pp. 1749-175

    Characterization of eucalyptus clones subject to wind damage

    No full text
    <div><p>Abstract: The objective of this work was to test a new methodology to assess the resistance of trees to wind damage and determine the characteristics that increase clone resistance to winds. Tree resistance to breakage, basic density, ultrastructure, anatomy, mechanical properties, and wood growth stress have been evaluated in seven Eucalyptus grandis × Eucalyptus urophylla clones, collected from a region with a high incidence of wind damage. The Pearson correlation coefficient between the tree resistance to breakage and the ratio between the area damaged by the winds and the total planted area was -0.839, showing the efficiency of the methodology adopted and that high breaking strength results in a smaller area affected by wind damage. Trees with a high basic density, cell wall fraction, modulus of elasticity of the middle lamella and fibers, fiber hardness, modulus of rupture, growth stress and low microfibril angle and height and width of the rays showed greater resistance to wind damage. Therefore, the selection of clones with these features may reduce the incidence of damage by winds in Eucalyptus plantations.</p></div

    Critical care usage after major gastrointestinal and liver surgery: a prospective, multicentre observational study

    No full text
    Background Patient selection for critical care admission must balance patient safety with optimal resource allocation. This study aimed to determine the relationship between critical care admission, and postoperative mortality after abdominal surgery. Methods This prespecified secondary analysis of a multicentre, prospective, observational study included consecutive patients enrolled in the DISCOVER study from UK and Republic of Ireland undergoing major gastrointestinal and liver surgery between October and December 2014. The primary outcome was 30-day mortality. Multivariate logistic regression was used to explore associations between critical care admission (planned and unplanned) and mortality, and inter-centre variation in critical care admission after emergency laparotomy. Results Of 4529 patients included, 37.8% (n=1713) underwent planned critical care admissions from theatre. Some 3.1% (n=86/2816) admitted to ward-level care subsequently underwent unplanned critical care admission. Overall 30-day mortality was 2.9% (n=133/4519), and the risk-adjusted association between 30-day mortality and critical care admission was higher in unplanned [odds ratio (OR): 8.65, 95% confidence interval (CI): 3.51–19.97) than planned admissions (OR: 2.32, 95% CI: 1.43–3.85). Some 26.7% of patients (n=1210/4529) underwent emergency laparotomies. After adjustment, 49.3% (95% CI: 46.8–51.9%, P<0.001) were predicted to have planned critical care admissions, with 7% (n=10/145) of centres outside the 95% CI. Conclusions After risk adjustment, no 30-day survival benefit was identified for either planned or unplanned postoperative admissions to critical care within this cohort. This likely represents appropriate admission of the highest-risk patients. Planned admissions in selected, intermediate-risk patients may present a strategy to mitigate the risk of unplanned admission. Substantial inter-centre variation exists in planned critical care admissions after emergency laparotomies

    Body mass index and complications following major gastrointestinal surgery: A prospective, international cohort study and meta-analysis

    No full text
    Aim Previous studies reported conflicting evidence on the effects of obesity on outcomes after gastrointestinal surgery. The aims of this study were to explore the relationship of obesity with major postoperative complications in an international cohort and to present a metaanalysis of all available prospective data. Methods This prospective, multicentre study included adults undergoing both elective and emergency gastrointestinal resection, reversal of stoma or formation of stoma. The primary end-point was 30-day major complications (Clavien–Dindo Grades III–V). A systematic search was undertaken for studies assessing the relationship between obesity and major complications after gastrointestinal surgery. Individual patient meta-analysis was used to analyse pooled results. Results This study included 2519 patients across 127 centres, of whom 560 (22.2%) were obese. Unadjusted major complication rates were lower in obese vs normal weight patients (13.0% vs 16.2%, respectively), but this did not reach statistical significance (P = 0.863) on multivariate analysis for patients having surgery for either malignant or benign conditions. Individual patient meta-analysis demonstrated that obese patients undergoing surgery formalignancy were at increased risk of major complications (OR 2.10, 95% CI 1.49–2.96, P < 0.001), whereas obese patients undergoing surgery for benign indications were at decreased risk (OR 0.59, 95% CI 0.46–0.75, P < 0.001) compared to normal weight patients. Conclusions In our international data, obesity was not found to be associated with major complications following gastrointestinal surgery. Meta-analysis of available prospective data made a novel finding of obesity being associated with different outcomes depending on whether patients were undergoing surgery for benign or malignant disease

    Critical care usage after major gastrointestinal and liver surgery: a prospective, multicentre observational study

    No full text
    corecore