Estoque de combustível fino e decomposição de folhas em florestas de igapó do rio Negro
In years of low rainfall, fires have occurred in Amazonian black-water floodplain forests, including the Middle Rio Negro. The fires are documented from satellite images. Forest fires require ignition sources, fuel and dry weather. To understand the susceptibility of these forests to fire we investi...
| Autor principal: | Santos, Aline Ramos dos |
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| Grau: | Dissertação |
| Idioma: | por |
| Publicado em: |
Instituto Nacional de Pesquisas da Amazônia - INPA
2020
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| Acesso em linha: |
https://repositorio.inpa.gov.br/handle/1/11987 http://lattes.cnpq.br/5185774705372094 |
| Resumo: |
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In years of low rainfall, fires have occurred in Amazonian black-water floodplain forests, including the Middle Rio Negro. The fires are documented from satellite images. Forest fires require ignition sources, fuel and dry weather. To understand the susceptibility of these forests to fire we investigated the stock of fine fuel on the ground at 29 sites in black-water floodplain forest and 28 sites in upland forest of the Middle Rio Negro. We examined the relationships of fine fuel load (diameter ≤ 2.5 cm) with surface soil texture and flood level. Black-water floodplain forest had a greater stock of litter + fine roots compared to upland forest (P <0.0001). The fine litter stock was 11.65 ± 3.5 Mg ha-1 (mean ± standard deviation) in floodplain forest and 1.2 ± 7.24 Mg ha-1 in upland forest. The stock of fine roots above the mineral soil was 13.73 ± 10.6 Mg ha-1 in floodplain forest and 1.84 ± 3.5 Mg ha-1 in upland forests. There was no relationship between the fuel load and soil texture in either forest type. We also studied leaf decomposition rates in different habitats as it influences the difference in standing stock of leaf litter. Nylon screen bags with 1 mm mesh and 10 mm openings containing air-dried leaves of Clitoria fairchildiana (Fabaceae) were exposed to three treatments over 81 days in the dry season in the Central Amazon: (1) non-flooded upland forest floor, (2) shallow submergence and (3) deep submergence in a calm back-water of the Rio Negro. At the end of the experiment the non-submerged leaves had lost ~50% of initial mass, but only ~30% was decomposed the other treatments. Faster decomposition of leaves in the upland forest was partially due to soil fauna, especially termites. |