Incêndios rasteiros em florestas alagáveis e de terra firme na Amazônia central
A fire in November 2009 about 100 km south of Manaus penetrated seasonally flooded forest of low fertility (igapó) and neighboring upland forest, providing a natural experiment for comparing fire damage between these two widespread Amazonian forest types. In ten plots of 250 m x 20 m, basal area...
| Autor principal: | Resende, Angélica Faria de |
|---|---|
| Grau: | Dissertação |
| Idioma: | por |
| Publicado em: |
Instituto Nacional de Pesquisas da Amazônia - INPA
2020
|
| Assuntos: | |
| Acesso em linha: |
https://repositorio.inpa.gov.br/handle/1/5125 http://lattes.cnpq.br/9650063863562261 |
| Resumo: |
|---|
|
A fire in November 2009 about 100 km south of Manaus penetrated seasonally flooded
forest of low fertility (igapó) and neighboring upland forest, providing a natural experiment for
comparing fire damage between these two widespread Amazonian forest types. In ten plots of
250 m x 20 m, basal area (> 10 cm DBH) and stem density were measured in each forest type, 3-
4 years after the fire. Ten unburned plots per forest type were used as proxies for pre-burn forest
structure. As indicators of fine fuel flammability, five sensors were installed 50 cm above the
litter layer in each of the unburned forest types in the 2013 dry season, providing a comparison of
mid-day extremes of relative humidity and temperature. Both forest types had significantly lower
stem density after burning, when compared to unburned forest of the same type. The average
stem loss of 59% in the flooded forests was significantly greater (p=0.001 ANOVA) than the
18% of stem loss in terra firme forest. Average basal area loss was 49% in the flooded forest, also
higher (p=0.034, Mann-Whitney U test) than in terra firme forest (23 %). Mid-day extremes of
relative humidity were lower (p=0.009) and extremes of temperature were higher (p=0.008,
Mann-Whitney U test) in the understory of seasonally flooded forest. The study allowed us to
conclude that the infertile floodplain forests are more flammable. This difference in microclimate
-- together with higher fuel loads and greater susceptibility of fine roots to fire damage in a
superficial the root mat shown in a previous study – leads to greater damage when floodplain
forests (igapó) are penetrated by ground fires. |