BOLETIM DA FACULDADE DE CIÊNCIAS AGRÁRIAS DO PARÁ, n. 25, jan/jun. 1996

Abstract

1) This paper presents an analysis of tree species dynamic comprising plants 5,0cm DBH and above, in a terra-firme equatorial forest, near Manaus (Brazil), under five thinning intensities by canopy tree girdling. Species behavior was evaluated on basal area annual increment (mVha/year) basis by DBH classes into function and ecophysiological groups stated previously. The floristic composition was enriched owing non listed species elimination. However, this is reversible in a period that depends on ecophysiological group of non listed species. Results showed that shade tolerant species are the main liable for non listed species behavior in l0cm and 20cm DBH classes. In 30cm, 40cm, 50cm and 60cm diameter classes there were overestimation of basal area annual increment owing to compounds accumulation on girdling belt. In general, each ecophysiological group, in each diameter class, has an optimal growing band in relation to ligh. For listed species, from T00 to T03, a straight relation between thinning intensity and basal area increment became conspicuous in l0cm, 40cm and 50cm DBH classes. Nevertheless, this relation was inverse in 20cm and 30cm DBH classes. There was not growth preponderance in terms of mean for individuais in no DBH class. However, in terms of total basal area, there was preponderance of individuais of 30cm class. The basal area annual increment of shade tolerant and intermediary listed species increased as a function of thinning intensities. Nevertheless, the listed species function group behavior was weighed by shade tolerant and intermediary species mainly by shade tolerant.

2) Comparative study between the interpretation of drainage quantitatives index applied to soils was determined by aerial photography in the 1:70.000 scale and the TM LANDSAT images in the 1:100.000 scale. The parameters analysed through of circular samples with 10km2 were drainage density, rivers frequency and textural ratio and among was established a factor of loss information in relations at scales utilized. Concluded that the use of TM images presented loss of details in relation at aerial photography, showing least effícient that this, presenting however similarity between the soils associations.

3) The studies of the hidrografic basin, however the importance that they present, don't have been used as earn in the river potential contribution valuation in the regional development. It was chosen the specific study of the Capim/Guamá river Basin area for Staté of Pará for the significance they present, speciaiiy, for the Guajarina region. Its Geology is caracterized for the sedimentary lands' presence of the barricaté's formation, where in the strongly dissected relief, the short platéaus appear frequently. The weather is constantly hot without importam changes during the year. Dominated for the yellow "latos" soil and for the podizolic red-yellow, soils need an adequaté management for them utilization, having as short cycle culture as long cycle. For the basin^ analysis it was realized studies that saught the bigger hidrographic magnitude system caracterization between Capim and Guamá rivers. It was checked that the system is droven for Capim river, with approachly 967 km in extension and with a width of 1.500 m in its discharge that, joint with the Acará river, it formes the Guajará Bay. It has a retangular form a little submited to inundations and presents a density with a lower drain. It can a good superficial flowage and in the fluvial hierarquic the Capim river basin configure itself as being of the 7a order. For the existent natural recources valuation, for the environment preservation or conservation of the environment there is a necessity of an action planing in a governmental level for a best adequation of the area problems.

4) This paper presents the results ofcanopy opening by tree girdling over an equatorial forest near Manaus (Brazil), at rNPA's Tropical Silvicultural Experimental Station. The tree girdling technique is very promising since 370 girdling trees (81.9%) died and the remainder living trees (18.1%) were distribuited among 34 species, of which Chimarrhis sp. (canela de velho), Geissospermus sericeum (Sagot) Benth. (acariquara-branca). Duckeodendron cestroides Kuhlm. (pupunharana) and Swartzia reticulata Duke (arabá-roxo) are possessed of buttressed or fluted stems which could not receive adequate girdling. This tree girdling technique is simple, demand non qualified manpower, a megligible equipament cost (only axes), and no chemical products cost. The high mortality of tree girdling over the treatments indicates that the canopy opening by no comercial tree girdlinh was succefull. However, tree girdling resulted in mechanical damages over remainder trees, mainly in the heavy treatments (T03 and T04).

5) Considering the clinicai signs and pathologic lesions suggesting C. A . E., in a dairy caprine raising in Castanhal town, state of Pará, 60 blood serum samples were examined by agar gel immunodiffusion test, utilizing antigen derivated from infected cell culture by virus with a surface envelope glycoprotein (gp 135) and a core protein (p 27). The positive reaction was shown in sera of 24 (40%) animal carriers of precipitant antibodies against C. A. E. V., it was observed the most frequency of positive serum in Parda Suiça breed 6 (60%), while the Saanen breed shown 18 (36,7%). The results show the infection in caprines by the virus of caprine arthritis encephalitis in the state of Pará - Brasil.