RESUMO
For decades there have been controversies related to the changes generated by oil palm plantations in the physicochemical properties of the soil, soil biota, and ecological interactions. Therefore, the present investigation evaluated root diameter and biomass at three ages of oil palm cultivation. Besides, we evaluated the effect of the ages on the physicochemical parameters of the soil in comparison with pasture plots. To know the diameter, fresh, and dry biomass of roots, soil sampling was carried out around the oil palm (3-, 5-, and 15-years-old) at distances of 1, 2, and 3 m from the trunk plant. Also, to know the changes in the properties of the soil, the sampling was carried out randomly in the same plots and the pasture plot (control). The results showed that both the diameter and the fresh and dry root biomass increased in 15-year-old plantations compared with 3- and 5-year-old. In addition, correlation analysis and principal component analysis indicated that the parameters evaluated are associated with the adult age of the oil palm. Also, the results of soil physicochemical showed that low soil fertility was associated with an increase in the age of the palm.
RESUMO
The Convention on Biological Diversity (CBD) aims at the conservation of all three levels of biodiversity, that is, ecosystems, species and genes. Genetic diversity represents evolutionary potential and is important for ecosystem functioning. Unfortunately, genetic diversity in natural populations is hardly considered in conservation strategies because it is difficult to measure and has been hypothesised to co-vary with species richness. This means that species richness is taken as a surrogate of genetic diversity in conservation planning, though their relationship has not been properly evaluated. We tested whether the genetic and species levels of biodiversity co-vary, using a large-scale and multi-species approach. We chose the high-mountain flora of the Alps and the Carpathians as study systems and demonstrate that species richness and genetic diversity are not correlated. Species richness thus cannot act as a surrogate for genetic diversity. Our results have important consequences for implementing the CBD when designing conservation strategies.
Assuntos
Biodiversidade , Variação Genética , Plantas/genética , Ecossistema , GeografiaRESUMO
La transmisión oral de la enfermedad de Chagas habitual en el ciclo selvático es una forma rará en el ser humano. En este último, se debe a la contaminación de las heces con Trypanosoma cruzi (Tcruzi) en los alimentos o a la manipulación infectada de los mismos. Más raramente a la ingesta de carne de reservorios infectados. En esta comunicación, se ponen en el tapete, los trabajos experimentales y naturales del investigador Díaz-Ungría quien demostró el importante papel que juega la mosca doméstica en la contaminación de los alimentos con las heces infectadas de los vectores. Igualmente, se destaca la importancia del perro como reservorio doméstico, todos los cuales podrían ser factores determinantes en la causa de los brotes agudos presentados en los dos últimos años en nuestro país. Se exponen las características de la miocarditis aguda chagásica como la expresión más constante de la forma aguda de la enfermedad por transmisión oral. Se destacan las medidas de prevención efectuadas por las autoridades sanitarias en estas circunstancias
Oral transmission of Chagas disease is common in the forest'cycle and is a rare form in humans. In the human is due to contamination of the stool with T.cruzi in food or infected by their manipulation. More rarely due to reservoirs infected T.cruzi meat intake. In this communication we described the natural and experimental works of the Díaz-Ungría researcher who demonstrated the important role played bi the house fly in the contamination of food with vectors infected faeces. It also highlights the importance of the dog as domestic reservoir, all of which could be determining factors in the cause of acute outbreaks in the past two years in our country. The features of acute Chagasic'myocarditis are exposed as the constant expression of the acute form of the disease by oral transmission. The prevention measures carried out by the health authorities in these circunstances are high lighted
