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Influence of Hydrological Variables on Macrophytes in a Black Water River Ecosystem
Full text linkThis study assessed the influence of hydrological variables on
macrophytes in a Black Water River ecosystem of Enyong River in Itu and
Ibiono Local Government Areas of Akwa Ibom and Cross Rivers States,
Nigeria. Four vegetation plots were chosen and in each of the plots,
four belt transect were laid. In each transect, macrophyte were
systematically sampled in four 10 m
7 10 m quadrat at regular
intervals. Macrophytes were identified to species level and their
frequency and density determined. Water samples were obtained in each
quadrat where the macrophytes were sampled and analyzed for their
physicochemical properties using standardized methods. Altogether, 10
macrophyte species were encountered. Vossia cuspidata had the highest
density (100.00\ub18.00 st/ha) and frequency values (100 %).
Sacciolepis africana had the least density of 7.10\ub10.45 st/ha
while Ludwigia octovalvis , Persicaria senegalensis , and Sacciolepis
africana had the least frequency of 25 %, respectively. The pH of the
water was strongly acidic (5.54\ub10.03), electrical conductivity was
low (20.00\ub15.77 \u3bcs/cm), temperature (29.00\ub11.10
\ubaC), Dissolved Oxygen (DO) (9.20\ub10.12 mg/l) and turbidity
(7.10\ub10.06 NTU) values were high while Biological Oxygen Demand
(BOD) (2.00\ub10.29 mg/l) Total Dissolved Solids (TDS)
(10.00\ub10.29 mg/l) and Total Suspended Solids (TSS) were low
(5.00\ub11.15 mg/l). Water Nutrients followed this decreasing order;
chloride (3.55\ub10.02 mg/l) > nitrate (2.45\ub10.03 mg/l) >
sulphate (2.02\ub10.06 mg/l) > phosphate (0.08\ub10.01 mg/l) and
sulphide (0.03\ub10.02 mg/l). Heavy metals also followed this
descending order; Pb (0.50\ub10.03 mg/l) > Zn (0.07\ub10.02
mg/l) > Cu (0.03\ub10.02 mg/l). Canonical Correspondence Analysis
delineated 11 hydrological variables (temperature, pH, sulphate,
turbidity, phosphate, BOD, nitrate, DO, TDS, sulphide and TSS) which
exerted great influence on macrophyte distribution. V. cuspidata had
affinity to pH and temperature, Sacciolepis africana had affinity to
turbidity and BOD, Ludwigia octovalvis and Nymphaea lotus had
affinity to sulphate and chloride, respectively, while Ipomoea aquatica
and Alternanthera sessils had affinity to phosphate. On the other
hand, Persicaria senegalensis, Salvinia molesta , Azolla pinnata and
Ceratophyllum demersum had affinities to sulphide, DO, TSS and TDS,
respectively. Since hydrological variables regulate macrophyte
diversity and distribution, this study calls for consistent, monitoring
and management of this ecosystem against future environmental changes
Evaluation of Petrophysical Parameters of Reservoir Sand Wells in Uzot-Field, Onshore Niger Delta Basin, Nigeria
Full text linkEvaluation of the petrophysical parameters in Uzot-field was carried
out using Well log data. The target for this study was the D3100
reservoir sand of wells Uz 004, Uz 005, U008 and Uz 011 with depth
range of 5540ft to 5800ft across the four wells. Resistivity logs were
used to identify hydrocarbon or water-bearing zones and hence indicate
permeable zones while the various sand bodies were then identified
using the gamma ray logs. The results showed the delineated reservoir
units having porosity ranging from 21.40% to 33.80% indicating a
suitable reservoir quality; permeability values from 1314md to 18089md
attributed to the well sorted nature of the sands and hydrocarbon
saturation range from 12.00% to 85.79% implying high hydrocarbon
production. These results suggest a reservoir system whose performance
is considered satisfactory for hydrocarbon production
Unresolved Water Conflicts by Water Sector Institutions in Ewaso Ng\u2019iro North River Sub-Basin, Kenya
No full textWater conflicts have huge impacts on livelihoods and without proper
redress, have capacity to stall economic development of a community.
This paper therefore explicates the impacts of unresolved water related
conflicts in Ewaso Ng\u2019iro North River sub-basin in Kenya and
their persistence despite past major institutional and policy reforms
in the water sector. Repetitive unresolved water conflicts curtail the
prosperity of the communities on river basins. Study objective was to
assess continued unresolved conflicts albeit the numerous and robust
water reforms. Mixed methods research design was adopted to capture
both primary and secondary data. Game Theory supported the study
explicating how water users both upstream and downstream are players
whose payoffs if not transparent cause conflicts. Sampling formula was
utilized to derive a sample size of 384 respondents and employed simple
random sampling. Primary data were collected through structured
questionnaires, Key Informant interviews, Focused Group Discussions and
Transect walks. Results show that water users aware of regulations in
place governing water on river basins however had weak compliance. The
legal and policy reforms need to be up scaled to enhance capacity to
resolve conflicts by WRUAs and WRA. Compliance to regulations governing
water to be enforced by mandated institutions to curb the
repetitiveness of unresolved water conflicts
Effect of Seasonal Changes of the Electric Field Pattern in Ibadan Nigeria on Some Meteorological Parameters
Full text linkThe objective of this work is to investigate the variation of the
electric field in the atmosphere to specific meteorological parameters
such as (temperature, heat and relative humidity) in Ibadan using data
collected from the Nigeria Meteorological (NiMet) Office in Lagos. The
data obtained were used to analyze the patterns of electric field in
every season in this location for a period of one year ranged from
September to October
Management of ecological filters for increasing the native vegetation cover in a mine treated with sewage sludge in the Cerrado Biome
No full textThe dominance of invasive species and the compaction of mine surfaces
are ecological filters that usually restrict the establishment and
growth of native plant species. The understanding of ecological filter
mechanisms aiming to overcome their effects on the ecological
succession is crucial for the ecological restoration of ecosystems. In
order to evaluate the effects of reducing the intensity of the surface
compaction and the grass dominance on the plant recruitment, we set up
24 experimental plots at six repetitions in a mine dominated by
Urochloa brizantha . Treatments consisted in control (T1), herbicide
application on U. brizantha (T2), mechanized plowing to ameliorate
surface compaction (T3), and the combination of T2 and T3 (T4). Results
showed that the chemical attenuation of U. brizantha dominance and
surface decompaction allowed the recruitment of 29 plant species, 66%
of which are invasive species, exotic to the Cerrado biome. However,
the treatments T2, T3, and T4 resulted in the formation of richer and
more diverse plant communities in comparison to the plots used as
control (T1). U. brizantha cover redeveloped after both surface
unpacking and herbicide application, but the plant species that
recruited on U. brizantha cover in the meantime improved the ecological
condition in experimental plots.Domin\ue2ncia de esp\ue9cies ex\uf3ticas invasoras e
compacta\ue7\ue3o de substratos minerados s\ue3o filtros
ecol\uf3gicos que geralmente restringem o estabelecimento e o
crescimento de esp\ue9cies nativas de plantas em jazidas mineradas. O
entendimento dos mecanismos de atua\ue7\ue3o e a
elimina\ue7\ue3o desses filtros s\ue3o de grande import\ue2ncia
para a restaura\ue7\ue3o ecol\uf3gica de ecossistemas. Visando
melhorar a condi\ue7\ue3o ecol\uf3gica de uma jazida tratada com
lodo de esgoto dominada por Urochloa brizantha (Braquiar\ue3o) e
com a superf\uedcie compactada, dois tratamentos foram aplicados em
parcelas experimentais para se analisarem os efeitos da
atenua\ue7\ue3o desses filtros sobre o recrutamento de plantas: uso
de herbicida para redu\ue7\ue3o da domin\ue2ncia de U. brizantha
e escarifica\ue7\ue3o mecanizada da superf\uedcie compactada,
aplicados individualmente e combinados. A atenua\ue7\ue3o da
domin\ue2ncia de U. brizanthae a descompacta\ue7\ue3o da
superf\uedcie minerada fomentaram o recrutamento de 29 esp\ue9cies
de plantas, 66% das quais descritas como esp\ue9cies ex\uf3ticas e
invasoras do Cerrado. Os tratamentos aplicados individualmente ou
combinados resultaram na forma\ue7\ue3o de biocenoses mais ricas em
esp\ue9cies e mais biodiversas em compara\ue7\ue3o \ue0s
parcelas usadas como controle. A cobertura de U. brizantha se recuperou
at\ue9 o final do per\uedodo chuvoso nas parcelas que receberam os
dois tratamentos, mas o recrutamento de esp\ue9cies que permaneceram
sobre a cobertura de U. brizantha melhorou a condi\ue7\ue3o
ecol\uf3gica nas parcelas experimentais
Arboreous composition and diversity in the urbanized blocks of Palmas, Tocantins state
No full textO processo de urbaniza\ue7\ue3o \ue9 o principal elemento
transformador dos ambientes urbanos. Com a implanta\ue7\ue3o das
estruturas que comp\uf5e o ambiente urbano (ruas, avenidas,
pr\ue9dios, etc.) a arboriza\ue7\ue3o aut\uf3ctone \ue9
indiscriminadamente suprimida em praticamente todas as cidades
brasileiras, promovendo a perda de biodiversidade e altera\ue7\ue3o
na qualidade de vida das pessoas que nestas habitam. O objetivo deste
trabalho foi quantificar a arboriza\ue7\ue3o e avaliar sua
composi\ue7\ue3o e diversidade arb\uf3rea nas quadras urbanizadas
da cidade de Palmas/TO. O invent\ue1rio da vegeta\ue7\ue3o
ocorreu nas \ue1reas verdes e em 50% das ruas de 33 quadras
residenciais urbanizadas de Palmas, sendo coletados dados de todos os
indiv\uedduos arb\uf3reos em cada um desses locais. Foram
amostrados 16.294 indiv\uedduos arb\uf3reos de 200 esp\ue9cies e
47 fam\uedlias bot\ue2nicas nas quadras residenciais urbanizadas de
Palmas. As esp\ue9cies nativas do Cerrado foram as mais frequentes,
com 51,28% dos indiv\uedduos amostrados. A diversidade de
esp\ue9cies foi elevada (H\u2019=4,046) e significativamente maior
(t=12,364, p<0,001) nas \ue1reas verdes (H\u2019=3,892) em
rela\ue7\ue3o \ue0s ruas (H\u2019=3,572). Comparado a outros
centros urbanos, Palmas se destaca em termos de diversidade de
esp\ue9cies nativas do Cerrado, estando esse fator diretamente
relacionado \ue0 presen\ue7a de \ue1reas verdes n\ue3o
edificantes em cada quadra residencial, devendo esses espa\ue7os ser
conservados e incrementados com um maior n\ufamero de esp\ue9cies
nativas, proporcionando a manuten\ue7\ue3o da biodiversidade e
melhoria da qualidade de vida e bem estar dos moradores de cada local.The process of urbanization is the main transformational element of
urban environments. Along with the implementation of structures that
make up the urban environment (streets, avenues, buildings, etc.),
natural stands of trees are indiscriminately removed in practically all
Brazilian cities, promoting the loss of biodiversity and degrading the
quality of life of the people living in these cities. The objective of
this work was to evaluate the changes in vegetation and species
diversity during the urbanization process of the city of Palmas, TO
state. The vegetation inventory occurred in green areas and in 50% of
the streets of 33 urban residential blocks, with data collected from
all individual trees in each of these sites. A total of 16,294 trees
were sampled in the urbanized residential blocks of Palmas, which came
from 200 species and 47 botanical families. In general, the native
species of the Cerrado biome were the most frequent ones, comprising
51.28% of the individuals. The species diversity was high (H'= 4.046)
and it was statistically higher (t = 12.364, p <0.001) in green
spaces (H' = 3.892) than in the streets (H'= 3.572). Compared to other
urban centers, Palmas stands out in terms of the diversity of native
tree species of Cerrado, with its diversity directly relating to the
presence of empty green space in each residential block. These open
spaces should be conserved and increased to promote a greater number of
species that will maintain the biodiversity and improve the quality of
life and well-being of the city inhabitants
Occurrence of Lecanodiaspis dendrobii (Hemiptera: Lecanodiaspididae) and the associated parasitoid Cephaleta sp. (Hymenoptera: Pteromalidae) in african mahogany in Brazil
No full textA expans\ue3o do cultivo de mogno africano no Brasil, assim como
outras esp\ue9cies ex\uf3ticas, remete ao surgimento de pragas e
doen\ue7as at\ue9 ent\ue3o n\ue3o relatadas na literatura.
Nesse sentido, amostras suspeitas de conter uma nova esp\ue9cie de
cochonilha atacando a casca, ramos e hastes de plantas de mogno
africano e parasitadas por um microhimen\uf3ptero, foram coletadas em
um plantio de dez hectares, com cinco anos de idade em uma fazenda no
munic\uedpio de Cant\ue1, Roraima, Brasil. O material amostrado
continha cochonilhas lecanodiaspid\ueddeos, em todas as fases de
desenvolvimento, ovos, ninfas e adultos, machos e f\ueameas, as quais
foram identificadas como Lecanodiaspis dendrobii Douglas, 1892
(Hemiptera: Lecanodiaspididae). O parasitoide associado foi
identificado como Cephaleta sp. (Hymenoptera: Pteromalidae)
apresentando grande potencial no controle biol\uf3gico de
Lecanodiaspis dendrobii. Este \ue9 o primeiro registro de ataque da
cochonilha Lecanodiaspis dendrobii (Hemiptera: Lecanodiaspididae) e do
parasitoide associado Cephaleta sp. (Hymenoptera: Pteromalidae) em
mogno africano no Brasil.The expansion of African mahogany cultivation in Brazil, as well as
other exotic species, refers to the appearance of pests and diseases
previously unreported in the literature. In this sense, samples
suspected of containing a new species of cochineal species attacking
the bark, branches and stems of African mahogany plants and parasitized
by a microhimenopter, were collected in a ten hectare plantation with
five years of age on a farm in the municipality of Cant\ue1, Roraima
state, Brazil. The sampled material contained lecanodiaspididae in all
stages of development, eggs, nymphs and adults, both male and female,
which were identified as Lecanodiaspis dendrobii Douglas, 1892
(Hemiptera: Lecanodiaspididae). The associated parasitoid was
identified as Cephaleta sp. (Hymenoptera: Pteromalidae) presenting
great potential in the biological control of Lecanodiaspis dendrobii.
This is the first attack record of Lecanodiaspis dendrobii (Hemiptera:
Lecanodiaspididae) and the associated parasitoid Cephaleta sp.
(Hymenoptera: Pteromalidae) in African mahogany in Brazil
Delineation of Near-Surface Structural Features Suitable for Groundwater Accommodation Using 1-D and 2-D Resistivity Methods in Igarra, Akoko-Edo, Southwestern Nigeria
Full text linkElectrical resistivity methods using dipole-dipole and Schlumberger
configurations of Vertical Electrical Sounding (VES) were carried out
to evaluate the near-surface structural and lithological features
suitable for groundwater development in parts of Igarra, Southwestern
Nigeria. Two profiles with lengths of greater than 350m were carried
out. A total of fifteen sounding locations along the profile lines were
occupied. Dipole-dipole data were interpreted using DiprofWin software
while interpretation of the VES data followed two stages of qualitative
and quantitative data interpretation using Resist software.
Dipole-dipole interpretation results indicate the occurrence of local
fractures while VES interpretation results reveal the typical basement
rock profile ranging from topsoil, lateritic sand, weathered front,
fractured to fresh basement. The significant variations in terms of
persistence and thicknesses of these basement vertical rock profiles
were revealed by the geoelectrical correlation panels, which indicate
typical basement inhomogeneities over short distances. The local
structural domains, the weathered front (where thick) and the fractured
basement are demonstrably potential sources of groundwater, at least
for domestic and small scale enterprises in this part of Igarra
Equilibrium, Kinetic and Thermodynamic Studies of Biosorption of Methylene Blue on Goethite Modified Baobab Fruit Pod ( Adansonia Digitata L.)
Full text linkMethylene Blue (MB) was adsorbed from aqueous solution using Baobab
(Adansonia digitata L.) fruit pod and its goethite modified form.
Adsorbents were characterized using Fourier Transform-Infra Red (FT-IR)
spectroscopy and Scanning Electron Microscopy (SEM). Batch experiments
were conducted at room temperature (26.8 \ub0C) and the adsorption
data were fitted using Langmuir, Freundlich, Temkin and
Dubinin-Radushkevich isotherms. Also, kinetic data was fitted using
Pseudo-first order, pseudo-second order, Elovich and intra-particle
diffusion models. Goethite modified baobab (GMB) appeared to have a
coarse microporous surface with smoother surface and larger pore
volumes compared to unmodified baobab (UB). The \u2013C=O band was
observed at 1631 and 1636 cm-1 for UB and GMB. The \u2013OH band was
observed at 3447.00 cm-1 and 3442 cm-1 for UB and GMB respectively.
Langmuir model was suitable for describing the adsorption data of UB
with R2 of 0.9293 while Temkin model was best for fitting adsorption
data of MB on GMB with R2 of 0.9691. However, maximum adsorption
capacity was obtained with Freundlich adsorption isotherm (15.4253 and
43.1301 mg/g for UB and GMB respectively). The maximum biosorption were
8.98 mg/g and 9.86 mg/g for UB and GMB respectively at pH 10.
Pseudo-second-order kinetic model best fitted the kinetic data with R2
values of 0.9968 and 0.9993 for UB and GMB, \uf044Ho values were
83.123 KJ/mol and 361.094 KJ/mol for UB and GMB, while \uf044So
values were 3.084 J/mol/K and 1.765 J/mol/K for UB and GMB
respectively. GMB adsorbed more of MB than UB and the process was
endothermic
Establishment and Early Regeneration of Stem Cuttings from Chicken Weed ( Portulaca quadrifida L.) as Influenced by Soil Types
Full text linkDifferences in the ability of soil are a requirement for early
regeneration of a plant. It was a pot experiment carried out at Sokoto
in the Sudano Sahelian agro-ecological Zone of Nigeria. The objective
was to investigate the regenerative ability of stem cuttings of Chicken
weed on different soil type as a strategy for the weed control. The
experimental set up was 3
7 7 factorial arrangement in a
Completely Randomized Design. The treatments consisted of seven stem
cuttings types namely (NLA-D - node leaf attached at distal stem
location, NLR-D - node leaf removed from distal stem location, NLA-P-
node leaf attached at proximal stem location, NLR-P- node leaf removed
from proximal stem location, IN-D - internodes at distal stem location,
IN-P- internodes from proximal stem location and SRA- stem roots
attached) and three soil textural class (Sandy, Silty clay and Loamy
sand). Result revealed that Silty clay recorded highest number of
survived plants. Plant height, number of leaves, nodes, internodes and
internodes length were greatly favoured by sandy soil. Loamy sand
supported the earliness to leaf emergence and flowering. NLA-D
supported the early regeneration of the plant in all stem cuttings
tested, but earliness to leaf emergence and flowering was better with
NLA-P. This finding gave information that Chicken weed regenerate
profusely and control measures should be administers to save target
crop from yield losses