Navegando por Assunto "Serrapilheira"

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Acesso aberto (Open Access)
Effect of seasonal flooding cycle on litterfall production in alluvial rainforest on the middle Xingu River (Amazon basin, Brazil)
(Universidade Federal do Pará, 2015-08) CAMARGO-ZORRO, Mauricio; GIARRIZZO, Tommaso; JESUS, Allan Jamesson Silva de
The assumption for this study was that litterfall in floodplain environments of the middle Xingu river follows a pattern of seasonal variation. According to this view, litterfall production (total and fractions) was estimated in four alluvial rainforest sites on the middle Xingu River over an annual cycle, and examined the effect of seasonal flooding cycle. The sites included two marginal flooded forests of insular lakes (Ilha Grande and Pimentel) and two flooded forests on the banks of the Xingu itself (Boa Esperança and Arroz Cru). Total litterfall correlated with rainfall and river levels, but whereas the leaf and fruit fractions followed this general pattern, the flower fraction presented an inverse pattern, peaking in the dry season. The litterfall patterns recorded in the present study were consistent with those recorded at other Amazonian sites, and in some other tropical ecosystems.
Acesso aberto (Open Access)
Estimativa da produção anual de serapilheira dos bosques de mangue no Furo Grande, Bragança-Pará
(2007-10) FERNANDES, Marcus Emanuel Barroncas; NASCIMENTO, Antonia Aparecida Monteiro do; CARVALHO, Muzenilha Lira
It is well known that environmental conditions of a determined place can influence the productivity of mangroves. So, the present study estimated the total and components litter production in Furo Grande, Bragança-PA. This study comprised four annual cycles (July/2000 to August/2004) at three sites. Seven traps were placed at each site along a 140 m transect, with 20 m intervals. Each trap had a useful area of 1 m2, with 1 mm2 mesh, suspended above the spring tide level. Accumulated material in the traps was collected on a monthly basis, sorted manually into leaves, flowers, fruits, stipules, twigs, and miscellaneous and then oven-dried to constant weight at 70ºC. The mean production of four years was 9.85 t.ha-1.year-1 at site 1, 6.41 t.ha-1. year -1 at site 2, and 5.99 t.ha-1. year -1 at site 3, with significant difference between sites 1 and 3 (H=7.53; df=2; p<0.05). Overall, the results showed that leaf was the most productive component, and together with flower, had peak in the dry season, which seems to favor energy saving to invest in reproduction, whereas fruit peak in the wet season, providing propagule dispersion and hence the renewal and maintenance of these forests.
Acesso aberto (Open Access)
Estoque e ciclagem de carbono de sistemas agroflorestais em Tomé-Açu, Amazônia Oriental
(Universidade Federal do Pará, 2010) BRANCHER, Tobias; VASCONCELOS, Steel Silva; http://lattes.cnpq.br/0719395243841543
Agroforestry systems (SAFs) constitute an important agricultural practice of land use directed at food production and environmental services. The objective of this study was to evaluate carbon stock and cycling of 4 agroforestry systems (SAF) with different age and species composition, and a secondary vegetation (“capoeira”), in Tomé-Acu, northeast of Pará State, Eastern Amazon. Carbon stocks in soil, litter and aboveground biomass were measured. Carbon flux associated with litterfall and aboveground biomass increment was measured over a year between 2008 and 2009. The SAFs were divided into four categories, called SAF 1, SAF 2, SAF 3 and SAF 4, being (SAF 1: cacau, açaí, bananeira e seringueira, 14 years old, SAF 2: cacau, açaí, bananeira, seringueira, taperebá, paricá e macacaúba, 14 years old, SAF 3: cupuaçu, açaí, teca e mogno, 9 years old, SAF 4:cupuaçu, açaí e paricá, 9 anos years old). In each system we set four plots, where soil and plant samples were collected, including diameter at breast height (DAP) and height (h), which were used to estimate the aboveground biomass. Within plots were installed collectors to measure the deposition of litterfall and sampled soil and litter used to estimate carbon stocks. There was no significant difference between SAFs in relation to soil carbon stock. The SAF 3 was significantly lower than the other SAF in relation to aboveground carbon and SAF 4 had the highest annual litterfall deposition among all treatments. The SAF did not differ in relation to soil and litter carbon stocks. Net primary production reached 2.54, 6.11, 9.54 and 16.27 Mg C ha-1 yr-1 in SAF 1, 2, 3 and 4, respectively. The age of the SAFs had no significant effect on the amount of carbon accumulated during one year.
Acesso aberto (Open Access)
Influência da dinâmica atmosférica na produção de serapilheira em um manguezal da costa amazônica.
(Universidade Federal do Pará, 2019-02-19) SOUZA, Hyago Elias Nascimento; VITORINO, Maria Isabel; http://lattes.cnpq.br/2313369423727020
This work aimed to investigate the influence of atmospheric dynamics on litterfall production in the Cuiarana mangrove, Salinópolis, Amazon Coast. The seasonal rainfall variation was analyzed along with the precipitating systems on the Amazon coast and its influence on the variability of litterfall production. It was also characterized the temporal variation of the direction and speed of the wind and its influence on the spatiotemporal production of litterfall. In a mangrove forest, 3 sample plots were delineated with 3 mangrove species Rizophora mangle, Avicennia germinans and Laguncularia racemosa. In each plot, 4 traps 1 m2 were randomly installed. Meteorological data were obtained from the Micrometeorological Tower of the UFRA located in the study area. The main statistical methodologies used were two-way and one-way ANOVA, linear regression analysis (p <0.05) and Principal Components Analysis (PCA). The results show that the temporal variation of precipitation is modulated by different meteorological systems, where the months of March, April and May appear as the region's rainiest quarter. The annual distribution of wind direction showed predominance in the eastern (E), frequency of winds with higher velocity were recorded in the second semester. In the litterfall production there was a significant difference between the values of monthly production and between the fractions. The annual total litter production was 9.4 ± 0.06 Mg ha-1 year-1, where 67% was composed by the leaf fraction. Leaves had negative trends with precipitation, but woody and reproductive material had positive trends. The ACP shows in 4 components negative correlation with reproductive material and positive correlation with wood associated with the temporal variation of winds and rainfall.