BOLETIM DA FACULDADE DE CIÊNCIAS AGRÁRIAS DO PARÁ, n. 22, 1994

Abstract

1) The data presented in this paper result from an extensive phenological study carried out by the first author in the Jari river basin, in which 1508 trees of 14 plant families were surveyed through 36 consecutive monthly observations. The quantitative phenology of individual tree species in primary forest situation constilute important Information for the autecology of tropical forest species. Due to the vast amount of information which resulted from the study, the results will be published in selected families, the present one, being on species of trees of the families Caryocaraceae, Connaraceae and Humiriaceae, in which the species phenology of the trees will be interpreted according with lhe theories of the evolutionary biology of pollination and dispersal.

2) This paper identifies factors explaming reforestation expansion in Brazil and evaluates the socioeconomic impacts of lhe Brazihan forestation and reforeslation program on land property and wealth distribution. It also assesses the program's social benefits. Single equation is stimated using the Nerlovian Partial Adjustment Model. The results suggest that log prices and governmental fiscal incentives are the main sources of reforestation growth in Brazil. Regarding socioeconomic impacts. the Brazilian reforestation program has created few jobs. However, it did have a major impact on the concentration of land property and wealth. The reforestation program benefited society as a whole, but only consumers appropriate the benefits. Producer loss was compensated by fiscal incentives.

3) In the Amazon region studies ofthe rainfall erosivity are of great importance considering that the majority existents soils are of low fertility and submited to the high rainfall indexes. The present study was performed wilh the objectives of identify the rainfall erosivity, in a ten year period (1980-1989), for Belém area, as well as local rainfall characteristics, such as rainfall coeficient and maximum intensities. The used methodology, for EI30 calculaíion, was the Wischmeier, Smilh. modifted by Foster et al, and the rainfall coefficient (Rc), the proposed byFournier., modifted by Lombardi Neto. Regressions were effected among the El30 index, and the rainfall coefficient and precipitation. The result presented mean anua lerosivity index (El30) equal to 22.452 MJ.mm.h. -1 h. -1 year, wilh the december-may period responsable by 72% of the animal erosivity and 86% for rainfall coefficient. The maximum intensity of the rainfall erosive precipited in the 30 minutes period, ranged between 25 mm.h.-1 and 75 mm.h-1, wilh 61,5% of the total precipitation. Erosivity index varied from year to year, with 12.89 9MJ.mm.ha.-1h.-1 year in 1983 and 34.672 MJ.mm.ha.-1 h.-1 year in 1989. The best regression equations found were: El30 = 7,75 * P - 137.13 (r = 0,99**) and EI30 = 41,74 * Rc + 753,11 (r = 0.99 **), respectively for precipitation (P) and rainfall coefficient (Rc).

4) The inflation in Brazil is analysed in lhe short and long term. The model of expectational Phillips curve combined with lhe co-integration and causality theory is used. The results suggest that supply shocks and level of expected prices are the main responsable for variations in industrial costs and it is transmited to the prices through flexible mark-up. However, the agricultural prices have little influence on the evolution of whole sale prices. Finaliy it is indicated that the practice of price freezing doesn 't cause the inflationary process because the increase of average industry wage above of productivity gain is the main force behind price increase.

5) The new conditions imposed to riverine communities as a result of the increased pressures over the region's natural resources have brought deleterious socio-environmental consequences leading to two major types of interrelated problems. The first one concerns the degradation of life quality, as reflected by socio-economical indicators such as the increasing of conflicts, a reduction of the food supplies, the dearticulation of traditional economical activities and the urban-rural exodus. The second problem concerns the degradation of the environment, as can be seen through indicators such as the reduction of certain economical activities which were once more vigorous, such as fishing, hunting, agriculture, gathering of extractive products, commerce and manufacturing. Adding to the aggravation of these are the isolation which such communities have been subjected to, the insipient or even lacking presence of the State and the increased demand for natural resources. In the two communities studied it was noted a significam reduction or even the disappearance of certain activities, such as the extraction of lhe balala gum, brazil nut and rubber. The dose dependency on natural resources and the geographical and social isolation to which these communities have been subjected to have influenced directly the incrcase of three major types of conflicts: conflicts of fishing activities, conflicts for the use of natural resources and conflicts for land.