Produção de serapilheira e incremento diamétrico em uma Floresta de Terra Firme na Amazônia Central
The above ground production in tropical forest has the litter and trunk increment of trees the main components of net primary production. The growth in the trunk is the way to capture carbon from the atmosphere and allocate in woody tissues. The litter fall is like as loss of carbon in the system...
| Autor principal: | Ourique, Lucas Kosvoski de |
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| Grau: | Dissertação |
| Idioma: | por |
| Publicado em: |
Instituto Nacional de Pesquisas da Amazônia - INPA
2020
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| Assuntos: | |
| Acesso em linha: |
https://repositorio.inpa.gov.br/handle/1/5126 http://lattes.cnpq.br/1555143325830180 |
| Resumo: |
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The above ground production in tropical forest has the litter and trunk increment of
trees the main components of net primary production. The growth in the trunk is the
way to capture carbon from the atmosphere and allocate in woody tissues. The litter
fall is like as loss of carbon in the system, but is essential for the recycling of
nutrients, which keeps the Amazon forest with high biomass in poor soils. The
different types of soils and rainfall seasonality in central Amazon require adaptive
differences of vegetation, and thus, the growth and yield of trees variable depending
on their position. Therefore, the study objects to quantify litter fall production and the
trunk increment of trees in two topographic classes (plateau and “baixio”), with
different soils and their relations with precipitation and soil moisture in an old growth
forest in central Amazon. This study was carried out in the ZF-2 Experimental
Station of the National Institute for Research in the Amazon (INPA), some 90 km
North of Manaus, Brazil. Litter production and diameter increment in two transects
with (20x2500m) were monitored. The collection was performed with 120 litter traps
(60 plateau, 60 “baixio”) with dimensions of 0.5 x 0.5 meters, with an area of 0.25
m2 were systematically arranged in two equidistant lines at 40 meters. The material
was collected in the period 15-30 days, dried 65°C until constant weight, and
separated into leaves, twigs (diameter < 2cm) and miscellaneous for weight. The
collection of diametric increment was performed in 250 trees with “dendrometer”
bands, with 125 in each topographic class (plateau and valley), randomly distributed
among individual trees of different diameters. The data accumulated rainfall and soil
water potential were collected with the aid of automatic equipment installed in the
study area. Litter production and diameter increment were analyzed with a factorial
analysis of variance with repeated measures. Pearson correlations with Bonferroni
probability were performed to verify the tightness of the relationships analyzed in
the study. Sampling was conducted between September 2012 and October 2013.
Litter production on the plateau was 7.1 ± 0.2 Mg. ha- 1.yr - 1 (CI=95%) and was
significantly higher than in the valley 6.3 ± 0.1 Mg. ha- 1.yr - 1 (n = 120 p = 0.008).
Litter production for the period was variable during the year, with peak production in
the dry season (June to October), with a correlation with rainfall (r = -0.77, p =
0.0029 ). Litter production had leaf production with approximately 70% of the total,
with most of the production. The increase in mean diameter was 1.43 ± 0.18
millimeters.yr-1 did not differ between the topographies. However, the increments
were slightly higher on the plateau. Rates increase followed trends in rainfall, where
diameter growth was higher in the rainy season than in the dry season (r=0.56, p =
0.005). Trees with a diameter greater than 30 cm showed higher increments. The
increment and litter fall showed no correlation with soil water potential. The
correlation between litter production and the increment was (r=-0.60, p=0.06) where
as the highest values for litter fall with to the smallest increment values. These
results suggest that trees in the study site invest in growth propitious moments,
especially with the presence of abundant water. When there is less water available,
the plant decreases the cambial activity and is intended to maintain the minimum
investment in your physiology, senile dispersing equipment and preparing to new
phenology event. |