I. A. Alvarez

Produção e distribuição de biomassa de espécies arbóreas no semi-árido brasileiro

The objective of the study was to quantify the production and biomass distribution of some potential arboreal species of multiple uses, under dry land conditions, in the Brazilian Semi-arid. The study was developed in the Experimental Station of Caatinga, of Embrapa Semi-Arido, Petrolina-PE, Brazil. Plant height and diameter at breast height (DBH) of 16 central trees of each plot, from three replicates, were measured. The following species were studied: Leucaena diversifolia, Caesalpinia velutina, Caesalpinia coriaria, Mimosa tenuiflora and Ateleia herbert-smithii. Biomass was estimated based on the medium height tree in each plot, evaluating each component separately: leaf, bark, branch, root and log, except for A. herbert-smithii that produced more leaf than bark. Total biomass production was superior for C. velutina (51.6 kg ha-1), followed by L. diversifolia (36.6 kg ha-1), A. herbert-smithii (26.4 kg ha-1), Caesalpinia coriaria (23.0 kg ha-1) and Mimosa tenuiflora (21.6 kg ha-1 However, leaf dry matter, the main potential component of forage species, was higher for C. velutina y A. herbert-smithii (2.8 kg ha-1) and C. coriaria (2.2 kg ha-1), L. diversifolia (2.0 kg ha-1) and M. tenuiflora (1.3 kg ha-1) representing, respectively, 7.2, 10.7, 9.5, 5.3 and 6.3% of total biomass. C. velutina stands out as the most productive, as well as wood (log = 30.8 t ha-1) as forage (leaves = 3.7 t ha-1), while M. tenuiflora showed the lowest forage potential.

CLIMATE-TREE GROWTH RELATIONSHIPS OF Mimosa tenuiflora IN SEASONALLY DRY TROPICAL FOREST, BRAZIL

Mimosa tenuiflora is a native pioneer tree from the Caatinga used commercially as firewood due to its high calorific value. It is deciduous, its trunk does not reach large diameters and it has good regrowth capacity. This study intended to determine the annual increment in diameter of M. tenuiflora and its correlation with rainfall, as basis for fuel wood management. Disks from the stem base of M. tenuiflora trees were collected in 2008 in Sertânia and Serra Talhada, Pernambuco State, from regrowth of trees coppiced in 2003 and in Limoeiro do Norte, Ceara State, from a plantation established in 2002. The trees have well-defined annual growth rings, highly correlated with annual precipitation and are well-suited for dendrochronological investigations. Forest managers must consider the influence of previous drier years in the wood production when predicting fuel wood harvesting. The high growth correlation with the previous years rainfall in regions where the rains start after photoperiodic stimulation indicate the necessity of understanding the growth dynamics of the species under dry forest conditions through additional ecophysiology studies.

Comparação entre videografia e fotografia aérea para diagnóstico da vegetação em ambiente urbano de Piracicaba, SP

In urban planning, a good diagnosis of the presence of vegetation serves as a basis to draw up a plan of action to implant green spaces and manage the existing tree cover. This study obtained the plant cover by Urban Areas Index (PCUAI) and by Greenery per Inhabitant Index (GII). Videography was compared to aerial photography of the same area in the city of Piracicaba, Sao Paulo State, Brazil, by means of the General Exactness and Kappa Index obtained by SIG programs. The values obtained were: PCUAI = 18.41% (aerial photography) and 16.48% (videography); GII = 116.93m2/inhab (aerial photography) and 65.21 m2/inhab (videography). The PCUAI and GII showed that the studied area had a reasonable percentage of greenery. Videography was shown to be viable as an alternative means of obtaining plant cover data, especially sidewalk trees cover.