Mortalidade de cacaueiros (Theobroma cacao L.) em várzeas após cheia extrema no baixo Rio Madeira
The cocoa has been cultivated for centuries in Amazonia floodplains. This was the product most exported of this region and nowadays it has been an important non-timber forest product for riverine populations of white water rivers. In 2014, the rivers water level in lower Madeira river reached the...
| Autor principal: | Simão, Marcos Vinícius Ribeiro de Castro |
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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/1/5127 http://lattes.cnpq.br/0371932049521169 |
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oai:repositorio:1-5127 Mortalidade de cacaueiros (Theobroma cacao L.) em várzeas após cheia extrema no baixo Rio Madeira Simão, Marcos Vinícius Ribeiro de Castro Mesquita, Rita Cacau Várzea Produtos florestal não madereiro The cocoa has been cultivated for centuries in Amazonia floodplains. This was the product most exported of this region and nowadays it has been an important non-timber forest product for riverine populations of white water rivers. In 2014, the rivers water level in lower Madeira river reached the highest level ever recorded, resulting in the mortality of many cocoa trees on the floodplains. Despite some reports of cocoa tree mortality after extreme floods, these are events rarely studied in the amazon region. Then, the goals of this paper were: understand the floods dynamic in the lower Madeira river; to estimate the cocoa tree mortality rate after an extreme flood; and to identify the influence of environmental and dendrometric variables over this mortality rate. It was found a growth trend of the higher water levels reached over the last three decades, highlighting the flood of 2014, which exceeded 3.71 meters the mean of the maximum levels of this historical series. It was observed that since the beginning of the 21st century it has happened an increase in the cocoa plantations in the region, since the majority (85%) of the cocoa plantations were set down over the last 15 years. This fact potentialized the mortality caused by the extreme flood, considering that small cocoa trees experience higher mortality rates after floods. The extreme flood occurred in 2014 caused the mortality of 100% of young cocoa tress and 46% of adult cocoa trees. Taking into account only adult cocoa trees, those bigger in diameter experienced lower mortality because they were more resistant to the action of the flow and the injuries caused in the trunk. The increase in canopy cover contributed to lower mortality probably by reducing the impact of logs brought by the flow and reducing the stress caused by excess radiation in cocoa trees, which is a shade tolerant species. Mortality was not influenced by the depth of the sediment layer deposited during the flood; this result can be attributed to the species capacity to emit adventitious root from the trunk. The variation in the flooding duration, between 70 and 105 days, also did not influence mortality. It is possible that this result is due to the extreme magnitude of this flood, which did not allow to sample cocoa plantations that went through less than 70 days of flood. The pruning and the distance of the cocoa plantation at the riverbank also did not influence the mortality. Thus, in view of the trend of increasing flood peaks in the lower Madeira river and of intensification of new cocoa plantations in the region, the results of this work are important steps for understanding these mortality events and for adaptation of the cultivation of cocoa tree in the floodplains. O cacau é cultivado há séculos nas várzeas da Amazônia. Esse já foi o produto mais exportado da região e atualmente é um importante produto florestal não madeireiro para famílias ribeirinhas que residem em várzeas de rios de água branca. Em 2014, o nível de água no baixo Rio Madeira atingiu sua maior cota já registrada, o que resultou em grande mortalidade de cacaueiros nas várzeas. Apesar de haver relatos esparsos de mortalidade de cacaueiros após uma cheia extrema, esses são eventos pouco estudados na região Amazônica. Assim, os objetivos desse trabalho foram: compreender a dinâmica das cheias no baixo rio Madeira; estimar a taxa de mortalidade dos cacaueiros após uma cheia extrema; e identificar a influência de variáveis ambientais e dendrométricas sobre essa taxa de mortalidade. Constatou-se uma tendência de crescimento das cotas máximas atingidas pelo rio nas últimas três décadas, destacandose a cheia de 2014, a qual superou em 3,71 metros a média das máximas dessa série histórica. Observou-se que a partir do início do século XXI houve aumento do cultivo de cacau na região, já que a maioria (85%) dos cacauais foram implantados nos últimos 15 anos. Isso potencializou a mortalidade causada pela cheia extrema, haja vista que cacaueiros de menor porte sofrem maior mortalidade após alagamento. A cheia extrema ocorrida em 2014 causou a mortalidade de 100% dos cacaueiros jovens e 46% dos cacaueiros adultos. Considerando apenas os cacaueiros adultos, aqueles com maior diâmetro sofreram menor mortalidade por serem mais resistentes à ação da correnteza e a injúrias causadas no tronco. O aumento da cobertura do dossel contribui para redução da mortalidade provavelmente por diminuir o impacto de troncos trazidos pela correnteza e por reduzir o estresse causado pelo excesso de radiação no cacaueiro, que é uma espécie umbrófila. A mortalidade não foi influenciada pela profundidade da camada de sedimentos depositada durante a cheia, resultado esse atribuído à capacidade da espécie em emitir raízes adventícias a partir do tronco. A variação da duração do alagamento, entre 70 e 105 dias, também não influenciou a mortalidade. É possível que isso seja devido à extrema magnitude dessa cheia, o que impossibilitou amostrar cacauais que sofreram alagamento por menos de 70 dias. A realização de poda de copa e a distância do cacaual à margem do rio também não influenciaram a mortalidade. Assim, diante do cenário de tendência de aumento dos picos de cheia no baixo rio Madeira e da intensificação do plantio de cacau na região, esses resultados constituem passos importantes para a compreensão dos eventos de mortalidade e para adaptação do cultivo de cacau nas várzeas. 2020-01-10T16:46:31Z 2020-01-10T16:46:31Z 2017-02-16 Dissertação https://repositorio.inpa.gov.br/handle/1/5127 http://lattes.cnpq.br/0371932049521169 por Attribution-NonCommercial-NoDerivs 3.0 Brazil http://creativecommons.org/licenses/by-nc-nd/3.0/br/ application/pdf Instituto Nacional de Pesquisas da Amazônia - INPA Ciências de Florestas Tropicais - CFT |
| institution |
Instituto Nacional de Pesquisas da Amazônia - Repositório Institucional |
| collection |
INPA-RI |
| language |
por |
| topic |
Cacau Várzea Produtos florestal não madereiro |
| spellingShingle |
Cacau Várzea Produtos florestal não madereiro Simão, Marcos Vinícius Ribeiro de Castro Mortalidade de cacaueiros (Theobroma cacao L.) em várzeas após cheia extrema no baixo Rio Madeira |
| topic_facet |
Cacau Várzea Produtos florestal não madereiro |
| description |
The cocoa has been cultivated for centuries in Amazonia floodplains. This was the
product most exported of this region and nowadays it has been an important non-timber
forest product for riverine populations of white water rivers. In 2014, the rivers water
level in lower Madeira river reached the highest level ever recorded, resulting in the
mortality of many cocoa trees on the floodplains. Despite some reports of cocoa tree
mortality after extreme floods, these are events rarely studied in the amazon region.
Then, the goals of this paper were: understand the floods dynamic in the lower Madeira
river; to estimate the cocoa tree mortality rate after an extreme flood; and to identify the
influence of environmental and dendrometric variables over this mortality rate. It was
found a growth trend of the higher water levels reached over the last three decades,
highlighting the flood of 2014, which exceeded 3.71 meters the mean of the maximum
levels of this historical series. It was observed that since the beginning of the 21st
century it has happened an increase in the cocoa plantations in the region, since the
majority (85%) of the cocoa plantations were set down over the last 15 years. This fact
potentialized the mortality caused by the extreme flood, considering that small cocoa
trees experience higher mortality rates after floods. The extreme flood occurred in 2014
caused the mortality of 100% of young cocoa tress and 46% of adult cocoa trees. Taking
into account only adult cocoa trees, those bigger in diameter experienced lower
mortality because they were more resistant to the action of the flow and the injuries
caused in the trunk. The increase in canopy cover contributed to lower mortality
probably by reducing the impact of logs brought by the flow and reducing the stress
caused by excess radiation in cocoa trees, which is a shade tolerant species. Mortality
was not influenced by the depth of the sediment layer deposited during the flood; this
result can be attributed to the species capacity to emit adventitious root from the trunk.
The variation in the flooding duration, between 70 and 105 days, also did not influence
mortality. It is possible that this result is due to the extreme magnitude of this flood,
which did not allow to sample cocoa plantations that went through less than 70 days of
flood. The pruning and the distance of the cocoa plantation at the riverbank also did not
influence the mortality. Thus, in view of the trend of increasing flood peaks in the lower
Madeira river and of intensification of new cocoa plantations in the region, the results of
this work are important steps for understanding these mortality events and for
adaptation of the cultivation of cocoa tree in the floodplains. |
| author_additional |
Mesquita, Rita |
| author_additionalStr |
Mesquita, Rita |
| format |
Dissertação |
| author |
Simão, Marcos Vinícius Ribeiro de Castro |
| title |
Mortalidade de cacaueiros (Theobroma cacao L.) em várzeas após cheia extrema no baixo Rio Madeira |
| title_short |
Mortalidade de cacaueiros (Theobroma cacao L.) em várzeas após cheia extrema no baixo Rio Madeira |
| title_full |
Mortalidade de cacaueiros (Theobroma cacao L.) em várzeas após cheia extrema no baixo Rio Madeira |
| title_fullStr |
Mortalidade de cacaueiros (Theobroma cacao L.) em várzeas após cheia extrema no baixo Rio Madeira |
| title_full_unstemmed |
Mortalidade de cacaueiros (Theobroma cacao L.) em várzeas após cheia extrema no baixo Rio Madeira |
| title_sort |
mortalidade de cacaueiros (theobroma cacao l.) em várzeas após cheia extrema no baixo rio madeira |
| publisher |
Instituto Nacional de Pesquisas da Amazônia - INPA |
| publishDate |
2020 |
| url |
https://repositorio.inpa.gov.br/handle/1/5127 http://lattes.cnpq.br/0371932049521169 |
| _version_ |
1787144668332425216 |
| score |
11.755432 |