947 research outputs found
CHEMICAL ATTRIBUTES AND ORGANIC MATTER IN FOREST COMPLEX SEASONALLY FLOODED IN RESTINGA OF MARAMBAIA, RIO DE JANEIRO STATE
Esse trabalho teve como objetivo avaliar as propriedades qu\uedmicas
e caracterizar a mat\ue9ria org\ue2nica de solos sob duas
forma\ue7\uf5es florestais periodicamente inundadas, na ilha da
Marambaia, RJ. Essas forma\ue7\uf5es apresentam diferen\ue7as
quanto ao grau de satura\ue7\ue3o h\ueddrica do solo, causada
pela influ\ueancia do len\ue7ol fre\ue1tico, sendo que na
forma\ue7\ue3o 1 (F1) o len\ue7ol apresenta-se mais pr\uf3ximo
\ue0 superf\uedcie em compara\ue7\ue3o \ue0
forma\ue7\ue3o 2 (F2). Amostras foram coletadas nas camadas
0,00-0,05, 0,05-0,10 e 0,10-0,20 m. As propriedades ed\ue1ficas
avaliadas foram: pH, H++Al+3; Ca+2, Mg+2, Na+, K+, P, N, carbono
org\ue2nico total (COT) e satura\ue7\ue3o por bases (V%); carbono
da fra\ue7\ue3o humina (C-HUM), carbono da fra\ue7\ue3o
\ue1cido h\ufamico (C-FAH) e carbono da fra\ue7\ue3o \ue1cido
f\ufalvico (C-FAF). Valores estatisticamente superiores de pH foram
observados para F1. Em F2 verificaram-se maiores valores de Mg+2, P, N
e V%. Foi verificada correla\ue7\ue3o entre os teores de Mg+2, N,
\ue1cido h\ufamico e \ue1cido f\ufalvico em F1 com o
len\ue7ol fre\ue1tico, e do len\ue7ol em F2 com os elementos Na+
e K+. A fra\ue7\ue3o C-HUM foi a mais representativa do carbono
org\ue2nico total, seguida por C-FAH e C-FAF. Os teores de COT foram
maiores na forma\ue7\ue3o F1. A rela\ue7\ue3o C/N foi menor em
F2, com valores variando entre 9 e 12, e em F1 foram verificados
maiores valores dessa rela\ue7\ue3o, variando de 9 a 15. Dentre as
vias de forma\ue7\ue3o dos solos de constitui\ue7\ue3o
org\ue2nicas, em ambas as \ue1reas a principal via de
acumula\ue7\ue3o da mat\ue9ria org\ue2nica \ue9 a de
heran\ue7a.This study aimed to evaluate and characterize the chemical properties
of soil organic matter under two periodically flooded forest formations
on the island of Marambaia, Rio de Janeiro. These formations differ on
the degree of soil water saturation, caused by the influence of water
table, and in the (F1) formation presents the water table nearer the
surface compared to the (F2) formation. Samples were collected in
layers from 0.00 to 0.05, 0.05-0.10 and 0.10-0.20 m. The soil
properties evaluated were: pH, H+ + Al+3, Ca+2, Mg+2,Na+, K+, P, N,
total organic carbon (TOC) and base saturation (V%), humin carbon
fraction (C-HUM), carbon of humic acid fraction (HAF-C) and fulvic acid
fraction carbon (FAF-C). Statistically higher pH values were observed
for F1. In F2 there are higher values of Mg+2, P, N and V% value.
Correlation was found between the concentrations of Mg+2, N, humic acid
and fulvic acid with water table in F1, and water table in F2 with Na+
and K+. Fraction C-HUM was more representative of the total organic
carbon, followed by C-HAF and C-FAF. The TOC levels were higher in F1.
The C / N ratio was lower in F2, with values ranging between 9 and 12,
and F1 were found higher values of this relationship, ranging from 9 to
15. Among the pathways of formation of organic soils in both areas it
appears that the major route for organic matter accumulation is the
inheritance route
Litter deposition and decomposition in three forest fragments periodically floodable in the island of Marambaia, RJ
O presente estudo foi realizado em tr\ueas forma\ue7\uf5es
florestais de restinga que se encontram periodicamente inundadas, na
Restinga da Marambaia, RJ. Para a quantifica\ue7\ue3o da
produ\ue7\ue3o de serapilheira foram utilizados dez coletores
c\uf4nicos por forma\ue7\ue3o, durante outubro de 2005 a setembro
de 2006. A avalia\ue7\ue3o da decomposi\ue7\ue3o se deu por
meio de sacolas de decomposi\ue7\ue3o (litter bags), sendo
distribu\ueddas 15 sacolas por forma\ue7\ue3o. A
produ\ue7\ue3o anual de serapilheira estimada para cada uma das
forma\ue7\uf5es florestais, variou de 11,3, 10,8 e 11,1 Mg
ha-1ano-1, para F1, F2 e F3 respectivamente, com maiores valores de
deposi\ue7\ue3o na esta\ue7\ue3o chuvosa. A fra\ue7\ue3o
folhas foi a mais representativa em todas as forma\ue7\uf5es. O
nitrog\ueanio foi o nutriente devolvido em maior quantidade a esses
solos, 130,8 kg ha-1 ano-1 em F3. A decomposi\ue7\ue3o se
apresentou como uma curva do tipo exponencial, sendo a constante de
decomposi\ue7\ue3o (k) e o tempos de meia vida foi de 0,0032 g g-1e
217 dias em F2, 0,0031 g g-1e 227 dias em F3 e 0,0028 g g-1; 247 dias
em F1The litter production and decomposition of three sandy coastal plain
forest formations periodically floodable in the Island of Marambaia,
Mangaratiba, RJ, were studied from October 2005 to September 2006. For
the litter deposition evaluation, 10 litter traps were installed and in
each forest formation to quantify the litter decomposition 15 litter
bags were allocated in each area. The annual litter production was
11.3, 10.8 and 11.1 Mg ha-1year-1, to F1, F2 and F3, respectively, the
highest deposition was verified in the rainy season. To nutrients
devolution, the highest value was observed to N, 130.8 kg ha-1 year-1
in F3. The fraction leaves were of higher contribution in relation to
the others in all areas. The litter decomposition, evaluated by
constant of decomposition (k) and half time life was 0.0032 g g-1and
217 days (F2), 0.0031 g g-1and 227 days (F3) and 0.0028 g g-1 and 247
days (F1)
Funding research using climate change mitigation: The case of the Carbone boréal research infrastructure
Since 1988, the Intergovernmental Panel on Climate Change (IPCC) has gathered research and produced reports to inform decision makers on climate change. Among crosscutting topics, ecosystem management and nature-based solutions (NBS) have received growing attention as they are readily available and relatively inexpensive. NBS are part of the Agriculture, Forestry and Other Land Uses economical sector [1]. While carbon prices can reach up to USD100 t-1 CO2-eq, greenhouse gas (GHG) land-based mitigation can be achieved for less in agriculture (e.g. soil carbon management, agroforestry, soil biochar addition), forestry (e.g. afforestation, reforestation, decreased deforestation) and using other ecosystems (e.g. peatland and wetland restoration) [1]. NBS have the potential to reduce GHG emissions by 8–14 Gt CO2-eq yr-1 between 2020–2050 [1], which represents 32–82% of the emission gap by 2030 to limit global warming between 1.5–2°C by 2100 compared with the preindustrial era [2]. In addition to CO2 removal from the atmosphere, NBS also render valuable ecosystem services such as biodiversity conservation, water and nutrient cycling regulation and soil preservation [3–6]. Several positive impacts on human well-being and sustainable development goals can also be achieved through NBS [1]
Aporte e decomposição de serapilheira em Floresta Periodicamente Inundável na Restinga da Marambaia, RJ
http://dx.doi.org/10.5902/198050985079Restinga (sandbank) areas are fragile environments, which have been subjected to anthropogenic pressures since the country colonization. So that mitigate actions can be taken, it must be developed studies to better understand the ecological processes in these environments. Thus, this study aims to quantify litter and nutrients devolution and litter decomposition in a periodically flooded forest in ‘Restinga da Marambaia’, Rio de Janeiro. In the study area 10 conic collectors and 30 litter bags were installed. The annual litter devolution was 7.64 Mg.ha-1, and September was the highest contribution month. Nitrogen was the element returned to the soil to a higher amount (71.9 kg ha-1 yr-1), followed by potassium (41.1 kg ha-1 yr-1). Litter decomposition rate 0.0015 g g-1 day-1 and the half-life were 462 days. Potassium was the element that showed the highest losses in comparison to the others. Cellulose appeared as a major participant in the structure of leaf litter, followed by lignin, the latter being associated with the leathery texture of the leaves in this formation.http://dx.doi.org/10.5902/198050985079As áreas de restingas são ambientes frágeis, que desde a colonização do país, vêm sendo submetidas a pressões antrópicas. Para que medidas mitigatórias possam ser tomadas, é necessário que sejam desenvolvidos estudos para uma melhor compreensão dos processos ecológicos nestes ambientes. Desta forma, este estudo teve como objetivo quantificar o aporte de serapilheira e nutrientes e sua decomposição numa floresta periodicamente inundada na restinga da Marambaia, RJ. Na área foram instalados dez coletores cônicos e 30 litter bags. O aporte anual de serapilheira foi de 7,64 Mg.ha-1, sendo setembro o mês de maior aporte. O nitrogênio foi o elemento devolvido ao solo em maior quantidade (71,9 kg ha-1 ano-1), seguido pelo potássio (41,1 kg ha-1 ano-1). A velocidade de decomposição da serapilheira foi de 0,0015 g g-1 dia-1 e o tempo de meia vida de 462 dias. O K foi o elemento que apresentou as maiores perdas em comparação ao demais. A celulose apresentou-se como maior participante na estrutura da serapilheira foliar, seguida pela lignina, sendo essa última associada à textura coriácea das folhas nesta formação
LITTER DEVOLUTION AND DECOMPOSITION IN A PERIODICALLY FLOODED FOREST IN RESTINGA DA MARAMBAIA, RIO DE JANEIRO
As \ue1reas de restingas s\ue3o ambientes fr\ue1geis, que desde a
coloniza\ue7\ue3o do pa\ueds, v\ueam sendo submetidas a
press\uf5es antr\uf3picas. Para que medidas mitigat\uf3rias
possam ser tomadas, \ue9 necess\ue1rio que sejam desenvolvidos
estudos para uma melhor compreens\ue3o dos processos ecol\uf3gicos
nestes ambientes. Desta forma, este estudo teve como objetivo
quantificar o aporte de serapilheira e nutrientes e sua
decomposi\ue7\ue3o numa floresta periodicamente inundada na
restinga da Marambaia, RJ. Na \ue1rea foram instalados dez coletores
c\uf4nicos e 30 litter bags. O aporte anual de serapilheira foi de
7,64 Mg.ha-1, sendo setembro o m\ueas de maior aporte. O
nitrog\ueanio foi o elemento devolvido ao solo em maior quantidade
(71,9 kg ha-1 ano-1), seguido pelo pot\ue1ssio (41,1 kg ha-1 ano-1).
A velocidade de decomposi\ue7\ue3o da serapilheira foi de 0,0015 g
g-1 dia-1 e o tempo de meia vida de 462 dias. O K foi o elemento que
apresentou as maiores perdas em compara\ue7\ue3o ao demais. A
celulose apresentou-se como maior participante na estrutura da
serapilheira foliar, seguida pela lignina, sendo essa \ufaltima
associada \ue0 textura cori\ue1cea das folhas nesta
forma\ue7\ue3o.Restinga (sandbank) areas are fragile environments, which have been
subjected to anthropogenic pressures since the country colonization. So
that mitigate actions can be taken, it must be developed studies to
better understand the ecological processes in these environments. Thus,
this study aims to quantify litter and nutrients devolution and litter
decomposition in a periodically flooded forest in \u2018Restinga da
Marambaia', Rio de Janeiro. In the study area 10 conic collectors and
30 litter bags were installed. The annual litter devolution was 7.64
Mg.ha-1, and September was the highest contribution month. Nitrogen was
the element returned to the soil to a higher amount (71.9 kg ha-1
yr-1), followed by potassium (41.1 kg ha-1 yr-1). Litter decomposition
rate 0.0015 g g-1 day-1 and the halflife were 462 days. Potassium was
the element that showed the highest losses in comparison to the others.
Cellulose appeared as a major participant in the structure of leaf
litter, followed by lignin, the latter being associated with the
leathery texture of the leaves in this formation
Litter contribution and decomposition and root biomass production in forests at different successional stages in Pinheiral, RJ
Este estudo objetivou avaliar a deposi\ue7\ue3o e
decomposi\ue7\ue3o da serapilheira e a produ\ue7\ue3o de
biomassa radicular de tr\ueas fragmentos florestais em diferentes
est\ue1gios sucessionais (avan\ue7ado, m\ue9dio e inicial)
localizados no munic\uedpio de Pinheiral, RJ. Para
intercepta\ue7\ue3o da serapilheira instalaram-se em cada
fragmento, dez coletores c\uf4nicos. Avaliou-se a biomassa radicular
em dois per\uedodos (chuvoso e seco), amostrando-se pelo m\ue9todo
do mon\uf3lito, em 0-10, 10-20 e 20-30 cm e dez repeti\ue7\uf5es
por profundidade. N\ue3o ocorreram diferen\ue7as na
deposi\ue7\ue3o de serapilheira entre as \ue1reas, mas apenas uma
tend\ueancia de aumento com a evolu\ue7\ue3o sucessional.
N\ue3o foram verificadas varia\ue7\uf5es temporais de
serapilheira entre as \ue1reas mais jovens, inicial e m\ue9dio no
decorrer do ano, com tend\ueancia de aumento nos meses de julho e
agosto. Em est\ue1gio avan\ue7ado, o aporte da serapilheira
p\uf4de ser agrupado em dois per\uedodos: \u201cfevereiro a
julho\u201d, menores valores e \u201cagosto a janeiro\u201d, maiores
valores. A deposi\ue7\ue3o das fra\ue7\uf5es folhas e material
reprodutivo diminu\uedram, enquanto ramos e outros aumentaram com o
avan\ue7ar sucessional. A decomposi\ue7\ue3o da serapilheira
mostrou em est\ue1gio sucessional m\ue9dio a menor constante k
(0,0038 g.g-1.dia-1) e maior tempo de meia vida (182 dias), seguida por
inicial (0,044 g.g-1.dia-1 e 154 dias) e avan\ue7ado (0,0064
g.g-1.dia-1 e 108 dias). A biomassa radicular nas diferentes \ue1reas
e profundidades, no per\uedodo seco e chuvoso, apresentou maiores
valores em est\ue1gio avan\ue7ado, intermedi\ue1rios em
m\ue9dio e menores em inicial. As diferen\ue7as sazonais da
biomassa radicular ocorreram sobretudo em est\ue1gio m\ue9dio, com
maiores valores na coleta de junho.The aim of this study was to evaluate litter input and decomposition
and root biomass of three forest fragments at different successional
stages (advanced, medium and initial) in Pinheiral Municipality, in the
state of RJ, Brazil. To evaluate litter input, 10 conic collectors were
installed in each fragment. The root biomass was quantified by monolith
method in two periods (wet and dry) at depths of 0-10, 10-20 and 20-30
cm, and 10 samples were collected in each area. To evaluate the
decomposition rate in each area, 12 litter bags were distributed. No
significant differences were observed for litter input between the
areas, but there was a tendency to increase litter input with
successional evolution. No significant differences were observed for
seasonal litter input between areas during the year, but there was a
small increase in the months of July and August. At the advanced stage,
litter input could be grouped into two periods: February to July, with
lower values; and August to January, with higher values. The leaf
fractions and reproductive material input were reduced, while branch
and other fractions increased with succession. For litter
decomposition, the intermediate stage showed the lowest decomposition
constant (k) (0.0038 g g -1day-1) and the highest half life time (182
days) , followed by the initial (0044 g g -1day-1 and 154 days) and
advanced (0.0064 g g -1day-1 and 108 days) stages. The root biomass in
different areas and depths for both two periods studied showed higher
values in the advanced stage, followed by the intermediate stage and
the lowest values were found in the initial stage. The seasonal root
biomass difference occurred mainly in the intermediate stage, with
higher values in June
Perception of the population of the city of Passos on the factors that determine the appearance of cancer: myths and truths
Introdução: As neoplasias malignas são responsáveis por inúmeras mortes em todo o mundo, por isso são encaradas pela população com muito temor e curiosidade. Sendo assim muitas pessoas recorrem aos meios de comunicação mais convenientes, que nem sempre abordam corretamente as doenças, para se informar sobre prevenção do câncer, ou então se baseiam na cultura popular passada por gerações sem nenhum embasamento científico. Objetivo: Analisar a percepção da população sobre os fatores de risco para o câncer e classificá-las de acordo com o nível de evidência encontrado nas pesquisas científicas. Metodologia: Foram selecionados 146 participantes, de maneira aleatória, que responderam a um questionário enviado por e-mail o qual indagava o que o pesquisado considera que seja um fator de risco para se desenvolver cânceres. Esses dados foram tabelados e uma pesquisa bibliográfica foi realizada para reconhecer os fatores de risco mencionados pela população como evidentes ou não evidentes cientificamente. Resultados: O estresse e causas psicológicas foram mencionados por 43,84% das pessoas pesquisadas e pelo estudo bibliográfico foi classificado como evidência parcialmente positiva. O cigarro foi mencionado por 39,04% dos participantes e foi classificado como evidência positiva, a herança genética foi indicada por 38,36% e classificada como evidência positiva, sexo sem proteção foi mencionado por apenas uma pessoa e foi classificado como evidência positiva. Conclusão: Com os dados obtidos observamos que, a maioria das respostas possuem relação com evidências científicas publicadas e comprovadas, no entanto, mais estudos e divulgações acerca de formas preventivas devem ser realizados.Introduction: Malignant neoplasms are responsible for a great and increasing number of deaths worldwide, what justify the fear and curiosity which population face these diseases. To learn about cancer prevention, many people search for information in the most convenient means of communication, which do not always show the clinical evidences of the diseases correctly. Moreover, much of the knowledge, are based on popular beliefs inherited from generations without any scientific basis. Objective: Analyze the population’s perception of the risk factors associated with cancer and classify them according to the level of evidence found in scientific literature. Methodology: 146 participants were randomly selected and answered a questionnaire sent by email asking what the respondent considers to be a risk factor for developing cancers. These data were tabulated and a bibliographic search was carried out to recognize the risk factors mentioned by the population as scientifically evident or not evident. Results: Stress and psychological causes were mentioned by 43.84% of the people surveyed and classified as partially positive evidence by the bibliographic study. The cigarette smoking was mentioned by 39.04% of the participants and it was classified as positive evidence, the genetic inheritance was indicated by 38.36% and classified as positive evidence, unprotected sex was mentioned by only one person and was classified as positive evidence. Conclusion: The data obtained showed that the majority of the responses were related to published and proven scientific evidence, however, further studies and more impacting prevention plans hould be carried out
Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an
Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis
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