Monroe P.H.M.,State University of Southwest Bahia |
Gama-Rodrigues E.F.,State University of Norte Fluminense |
Gama-Rodrigues A.C.,State University of Norte Fluminense |
Marques J.R.B.,CEPEC CEPLAC
Agriculture, Ecosystems and Environment | Year: 2016
Cacao agroforestry systems (AFS) are characterized by accumulating large amounts of soil organic carbon (SOC). However, information on the influence of shade trees on SOC stock up to 100 cm depth is scarce in the literature. The objectives of this study were to quantify the SOC storage under different cacao AFS, natural forest and pasture to a depth of 100 cm; and to evaluate the origin of SOC using the 13C isotopic ratio as an indicator of relative contribution of trees (C3 plants) and grass (C4 plants), after 4 years of pasture conversion into cacao and rubber AFS. SOC was determined by dry combustion in six layers (0-10, 10-20, 20-40, 40-60, 60-80 and 80-100 cm). The natural abundance of 13C technique was used only on cacao and rubber lines in contrast to the SOC accumulated by pasture before conversion into AFS. The SOC stock in a depth between 0-100 cm was significantly high in the pasture and in both younger cacao and rubber AFS (4 years old). Systems that were more than 20 years old 'cabruca', cacao and Erythrina and cacao and rubber system (20 years) had lower SOC stocks and did not differ significantly from the natural forest. In the surface layers of soil there were significant differences in the SOC stock. However, below 20 cm all the systems were similar to each other. The SOC stock in the first 20 cm accounted between 31 and 44% of total SOC stored in the 100 cm in the seven systems, followed by 19-23% at a depth of 20-40 cm, 15-18% at a depth of 40-60 cm and 11-14% in the last two depths. After four years of establishment cacao and rubber AFS were the most efficient systems in the accumulation of SOC in the first 20 cm of soil and consequently up to 100 cm deep. Cacao was more efficient than rubber tree to accumulate C3-derived C. While the rubber increased by almost 70% of C3, cacao increased 131%. After the 40 cm of depth the SOC is still from the original natural forest. © 2016 Elsevier B.V.
Alves F.Q.,CEPEC CEPLAC |
Argolo A.J.S.,State University of Santa Cruz |
Carvalho G.C.,Federal University of Bahia
Phyllomedusa | Year: 2014
The Neotropical genus Lachesis Daudin, 1803 includes snakes restricted to the humid forests of Central and South America. The species L. muta is the most widely dispersed, occurring throughout the Amazon rainforest, and with an isolated population in the Atlantic Forest, from the north of the state of Ceará to the south of the state of Rio de Janeiro, Brazil. We present information about the reproductive biology of L. muta from a large series of samples gathered in southern Bahia. Mature males L. muta are larger than females. Degree of sexual size dimorphism (SSD) is 0.16. Vitellogenic follicles and eggs are not distributed equally throughout the year. Clutch size was 3-14 oviductal eggs and was positively correlated with female SVL. Testes volume and ductus deferens diameter in mature individuals did not vary significantly throughout the year. The reproductive pattern of L. muta differs from that of the phylogenetically related genera because L muta is oviparous, and has a discontinuous cycle and reproductive synchrony between the sexes. © 2014 Departamento de Ciências Biológicas - ESALQ - USP
Silva D.V.,University Estadual Of Santa Cruz |
Araujo I.S.,Federal University of Rio Grande do Norte |
Branco S.M.J.,University Estadual Of Santa Cruz |
Aguilar-Vildoso C.I.,University Estadual Of Santa Cruz |
And 7 more authors.
Plant Pathology | Year: 2014
This study evaluates resistance to witches' broom disease in flower cushions of Theobroma cacao under field conditions. The aim was to determine optimal inoculation methods to evaluate the disease incidence using flower cushions in the field. A segregating mapping population of 580 trees (cultivar TSH 1188 × CCN 51) was analysed under two field conditions: high and low inoculum levels (in different years), corresponding respectively to trees with or without dried witches' brooms hanging on the trees and producing basidiocarps. The number of newly formed cushion brooms in each tree was counted by the conventional method, and also the healthy and infected flower cushions in three 30 cm-long regions along the trunk and the two main branches. The field inoculation methods discriminated between genotypes, with a 26% increase in disease incidence by Moniliophthora perniciosa at high inoculum. Two different segregation patterns were also observed: 27:27:9:1 under low, and 27:9:9:9:3:3:3:1 under high inoculum potential. It was also determined that at least 20 flower cushions were needed to accurately determine the percentage of infection. These methodologies allowed identification of the extreme phenotypes in this mapping population, and can therefore facilitate the detection of sources of resistance to witches' broom disease. © 2014 British Society for Plant Pathology.