49 research outputs found
Crescimento e incremento de espécies arbóreas dominantes na Amazônia Central
Forest management in the Amazon needs to supply the timber market
by keeping the forest live. Studies of tree growth and increment are essential
to determine the cutting cycle of the forest. In order to encourage forest
management of the hyperdominant species in Central Amazon, this thesis
focused on three general objectives: i. Comparison of methods to determine
growth rates; Ii. Describe the temporal variation of the increment; Iii.
Determine the periodic annual increment (PAI) of the matamatá amarelo in
Amazonas state.
The comparison of methods used the PAI determined with isotopic
methods (δ18Owc and 14C) compared to that of permanent plots of 23 years
with annual measurements with dendrometric tapes and 14 years of monthly
measurements with dendrometric bands. For selected species of matamatá
amarelo and ucuuba puna the 18O isotopic rings presented strong evidence (p
= 0.0001) to reject the hypothesis of similarity in the estimation of the growth
rates when compared to those of permanent plots; Ii. The PAI determined by
14C when compared to the estimate in permanent plots does not present
evidence to reject the similarity between the methods. In this case, the
increment of trees estimated by 14C dating have high similarity when compare
the growth rates estimated in 23 years of monitoring the permanent plots
Bionte (p = 0.997) and 14 years of monthly monitoring with dendrometric
bands (p = 0.83).
The temporal variation of the current annual increment (CAI) was
described based on the standard deviation of the increment over time and
with the detection and analysis of the frequency of years with null increment
or negative in two types of permanent plots. The variation of CAI over time
proves the occurrence of years of null increment in the trees in the Central
Amazon. 60% of the trees monitored between 10 and 14 years with
dendrometric bands presented at least one year of null increment. On
average, 20% of the monitored time of these trees was zero increment. There
was a strong positive correlation (r = 0.87 and p = 0.002) between % of trees
with null increment and the number of days without rain in the respective year.
Periods of two or more years of consecutive null increment can occur in
Amazonian trees, which are not justified only by the intensity of the dry period.
The gaps between the dating methods by 14C and δ18O can be explained by
periods of missing rings that prevent recognizing the passage of time in tools
that require continuous growth in the trunk.
The PAI research of the matamatá amarelo morphospecies in Central
Amazon contemplated two specific objectives: i. Determine the PAI using 14C
dating in 6 locations in the Amazon; Ii. To investigate which environmental
and morphometric factors are related to the yellow matamatá PAI. The mean
PAI of the matamatá amarelo in Amazonas was 2.04 ± 0.53 mm / year. There
is strong evidence of variation of the growth rates of this species in the
different sites (p = 0.0005). The sites with low levels of nutrients soils such as
Maués and São Gabriel da Cachoeira presented the smallest growth rates.
The trees was grow in soils from the Andes origens in the place with greater
seasonality of the dry periods presented a higher growth rates (Manicoré).
The variation of the increment according to the environmental variations in
Amazonas indicates that the matamatá amarelo is an elastic species. Elastic
species are interesting to forest management because they are potentially
manageable when responding to silvicultural interventions, such as opening of
clearings. The high variation of the increment in the different sites indicates
that is necessary determine a cut cycle for each site.O manejo florestal na Amazônia precisa abastecer o mercado
madeireiro mantendo a floresta em pé. Estudos de crescimento e incremento
das árvores são essenciais para determinar o ciclo de corte na floresta. Com
o intuito de incentivar o manejo florestal da espécie hiperdominante na
Amazônia Central a presente tese focou em três objetivos gerais: i.
comparação de métodos para determinar incremento; ii. descrever a variação
temporal do incremento; iii. determinar o incremento periódico anual (IPA) do
matamatá amarelo no Amazonas.
A comparação de métodos utilizou o IPA determinado com métodos
isotópicos (δ18Owc e 14C) comparados com o de parcelas permanentes de 23
anos medições anuais com fitas dendrométricas e 14 anos de medições
mensais com bandas dendrométricas. Para selecionadas espécies de
matamatá amarelo e ucuuba puna os anéis isotópicos de 18O apresentaram
forte evidência (p=0.0001) para rejeitar a hipótese de similitude na estimativa
do incremento quando comparado com as de parcelas permanentes; ii. o IPA
determinado por 14C ao comparar com o estimado em parcelas permanentes
não apresenta evidências para rejeitar a semelha entre os métodos, ou seja,
a datação de 14C estima o incremento das árvores com elevada semelhança
ao estimado em 23 anos de monitoramento em parcelas testemunha do
Bionte (p=0.997) e 14 anos de monitoramento mensal com bandas
dendrométricas (p= 0.83).
A variação temporal do incremento corrente anual (ICA) foi descrita
com base no desvio padrão do incremento ao longo do tempo e com a
detecção e análise da frequencia de anos com incremento nulo ou negativos
em dois tipos de parcelas permanentes. A variação do ICA ao longo do
tempo comprova a ocorrência de anos de incremento nulo nas árvores na
Amazônia Central. 60% das árvores monitoradas entre 10 e 14 anos com
bandas dendrométricas apresentaram ao menos um ano de incremento nulo.
Em média 20% do tempo monitorado dessas árvores foi de incremento nulo.
Há uma forte correlação positiva (r= 0,87 e p= 0,002) entre % de árvores com
incremento nulo e o número de dias sem chuva no respectivo ano. PerÃodos
de dois anos ou mais de incremento nulo consecutivos podem ocorrer em
árvores amazônicas, que não são justificados apenas pela intensidade do
perÃodo seco. As lacunas entre os métodos de datação por 14C e δ18O podem
ser explicadas por perÃodos de anéis ausentes que impedem reconhecer a
passagem do tempo em ferramentas que necessitam um crescimento
contÃnuo no tronco.
A investigação do IPA da morfoespécie matamatá amarelo na
Amazônia Central contemplou dois objetivos especÃficos: i. determinar o IPA
utilizando datação por 14C em 6 localidades do Amazonas; ii. investigar quais
fatores ambientais e morfométricos estão relacionados com o IPA do
matamatá amarelo. O IPA médio do matamatá amarelo no Amazonas foi de
2,04±0.53 mm/ano. Há fortes evidências de variação do incremento desta
espécie nos diferentes sÃtios (p=0,0005). As localidades com solos com
baixos teores de nutrientes como Maués e São Gabriel da Cachoeira
apresentaram os menores valores de incrementos. As árvores sitiadas em
solos oriundos dos Andes no local com maior sazonalidade do perÃodos seco
apresentaram um maior taxa incremento (municÃpio de Manicoré). A variação
do incremento de acordo com as variações ambientais no Amazonas
apontam que o matamatá amarelo é uma espécie elástica. Espécies elásticas
se detacam no manejo florestal por serem potencialmente manejáveis ao
responder a intervenções silviculturais, como abertura de clareiras. A elevada
variação do incremento nos diferentes sÃtios aponta a necessidade de
determinar um ciclo de corte para cada sÃtio
Discriminação de espécies florestais com a utilizaçao da razão isotópica 13 C e 15 N e espectroscopia no infra-vermelho próximo (FT-NIRs))
The combined use of high technology instruments and appropriate techniques
for discriminating tree species isnecessary to improve the biodiversity inventory
system in tropical countries. This study was carried out to verify the
performance of C and N isotopes ratios, the total leaf concentration values of C
and N (%) and near-infrared spectroscopy readings as indicators to discriminate
eight species of Eschweilera and two of Corythophora of the Brazilian Amazon.
It was observed that the isotopes analysis and the leaf N and C
concentrationswere not reliable enough to discriminate the studied species.
However, the near infrared spectroscopy (FT-NIRS) presented an outstanding
performance; therefore, it seems to be a promising tool to improve tree species
discrimination system. Utilizing thirty-six spectral readings to represent an
individual, we obtained 99.4% of correct species discrimination. When only one
spectral reading from any part of the leaf was used, the correct discrimination
reached 97.1 %.In the near future, a portable FT-NIRS, for instance, could be
used in forest inventory data collection. The only requirement is the memory
feeding, which should be done using the most reliable and consistent botanical
identification of the most abundant Amazonian tree species. This process
should be refined over time with the feedback from new inventories. By any
means, the use of FT-NIRS has demonstrated that it is much more reliable than
the rule of thumb highly practiced for tree identification during forest inventory
carried out in the Brazilian Amazon.Combinar alta tecnologia e técnicas apropriadas para discriminar espécies
florestais é necessário para aprimorar o sistema de inventário da
biodiversidade em paÃses tropicais. Este estudo foi realizado para verificar o
desempenho da razão isotópica 13C e 1 5 N, os valores de concentração totais
de N e C (%) e a espectroscopia no infravermelho próximo (NIRs) nas folhas
como indicadores para discriminar 8 espécies de Eschweilera e duas de
Corythophorada Amazônia. Pôde-se observar que as análises isotópicas e a
concentração de N e C foliar não são suficientes para distinguir espécies do
mesmo gênero. A espectroscopia no infravermelho próximo (FT-NIRS), no
entanto, apresentou excelente desempenho, destacando-se como uma
ferramenta promissora para aprimorar o sistema de discriminação de espécies.
Ao utilizar a média de 36 leituras espectrais para representar um indivÃduo,
obteve-se 99,4% de discriminação das espécies. Com apenas uma leitura
espectral por indivÃduo, foi encontrado uma taxa de discriminação de 97,1%.
Num futuro próximo, um FT-NIRS portátil, por exemplo, poderá ser utilizado na
floresta para coletar os dados de inventários. A única exigência é a alimentação
da memória, que deve ser realizada com a identificação mais confiável e
consistente dos botânicos, com as mais abundantes espécies arbóreas
amazônicas. Este processo deve ser aperfeiçoado ao longo do tempo em
novos inventários. De qualquer modo, o uso do NIRS demonstrou ser mais
confiável do que a prática duvidosa de identificação utilizada em muitos
inventários na Amazônia Brasileira
Demonstration of a strict molecular oxygen requirement of yellow latex oxidation in the central Amazon canopy tree muiratinga (Maquira sclerophylla (Ducke) C.C. Berg)
Plant-derived latex is widely used in rubber production and plays important roles in ecological processes in the tropics. Although it is known that latex oxidation from the commercially important tree Hevea brasiliensis, results in latex browning, little is known about latex oxidation in highly diverse tropical ecosystems. Here we show that upon physical trunk damage, yellow latex released from the canopy tree Muiratinga (Maquira sclerophylla (Ducke) C.C. Berg) is rapidly and extensively oxidized to a black resin in the presence of air within 15-30 min. In a nitrogen atmosphere, latex oxidation was inhibited, but was immediately activated upon exposure to air. The results suggest the occurrence of O2-dependent oxidative enzymes including polyphenol oxidase (PPO) within the latex of Muiratinga and supports previous findings of a key role of oxidation during latex coagulation. © 2018 Secretaria Regional do Rio de Janeiro da Sociedade Brasileira de Quimica.All right reserved
Tree climbing techniques and volume equations for Eschweilera (Matá-Matá), a hyperdominant genus in the Amazon Forest
The Eschweilera genus has great ecological and economic importance due to its wide abundance in the Amazon basin. One potential use for the Eschweilera genus is in forest management, where just a few trees are removed per hectare. In order to improve the forest management in the Amazon, this study assessed two critical issues: volume equations fitted for a single genus and the development of a non-destructive method using climbing techniques. The equipment used to measure the sample trees included: climbing rope, ascenders, descenders, and carabiners. To carry out the objectives of this study, 64 trees with diameter at breast height (DBH) = 10 cm were selected and measured in ZF-2 Tropical Forestry Station near the city of Manaus, Brazil. Four single input models with DBH and four dual input models with DBH and merchantable height (H) were tested. The Husch model (V = a × DBHb) presented the best performance (R2 = 0.97). This model does not require the merchantable height, which is an important advantage, because of the difficulty in measuring this variable in tropical forests. When the merchantable height data are collected using accurate methods, the Schumacher and Hall model (V = a × DBHb × Hc) is the most appropriated. Tree climbing techniques with the use of ropes, as a non-destructive method, is a good alternative to measure the merchantable height, the diameter along the stem, and also estimate the tree volume (m3) of the Eschweilera genus in the Amazon basin. © 2017 by the authors
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Volatile monoterpene ‘fingerprints’ of resinous Protium tree species in the Amazon rainforest
Volatile terpenoid resins represent a diverse group of plant defense chemicals involved in defense against herbivory, abiotic stress, and communication. However, their composition in tropical forests remains poorly characterized. As a part of tree identification, the ‘smell’ of damaged trunks is widely used, but is highly subjective. Here, we analyzed trunk volatile monoterpene emissions from 15 species of the genus Protium in the central Amazon. By normalizing the abundances of 28 monoterpenes, 9 monoterpene ‘fingerprint’ patterns emerged, characterized by a distinct dominant monoterpene. While 4 of the ‘fingerprint’ patterns were composed of multiple species, 5 were composed of a single species. Moreover, among individuals of the same species, 6 species had a single ‘fingerprint’ pattern, while 9 species had two or more ‘fingerprint’ patterns among individuals. A comparison of ‘fingerprints’ between 2015 and 2017 from 15 individuals generally showed excellent agreement, demonstrating a strong dependence on species identity, but not time of collection. The results are consistent with a previous study that found multiple divergent copies of monoterpene synthase enzymes in Protium. We conclude that the monoterpene ‘fingerprint’ database has important implications for constraining Protium species identification and phylogenetic relationships and enhancing understanding of physiological and ecological functions of resins and their potential commercial applications. © 2019 The Author
Highly reactive light-dependent monoterpenes in the Amazon
Despite orders of magnitude difference in atmospheric reactivity and great diversity in biological functioning, little is known about monoterpene speciation in tropical forests. Here we report vertically resolved ambient air mixing ratios for 12 monoterpenes in a central Amazon rainforest including observations of the highly reactive cis-β-ocimene (160 ppt), trans-β-ocimene (79 ppt), and terpinolene (32 ppt) which accounted for an estimated 21% of total monoterpene composition yet 55% of the upper canopy monoterpene ozonolysis rate. All 12 monoterpenes showed a mixing ratio peak in the upper canopy, with three demonstrating subcanopy peaks in 7 of 11 profiles. Leaf level emissions of highly reactive monoterpenes accounted for up to 1.9% of photosynthesis confirming light-dependent emissions across several Amazon tree genera. These results suggest that highly reactive monoterpenes play important antioxidant roles during photosynthesis in plants and serve as near-canopy sources of secondary organic aerosol precursors through atmospheric photooxidation via ozonolysis. © 2015. The Authors