Environment and Forestry

The forest ecosystem of BAGBASENDE village in TSHOPO province, DRC was a target to bring a comparative study of insects between the two seasons in two forest types (intact and disturbed), with four traps that we used to capture insects In the case of the light traps, fermented bait aerial traps, pot barbers and invertebrate traps, the species richness in the wet season was higher than in the dry season; the Shannon index gave a high value in the wet season and the Wilcoxon statistical test gave a significant difference between the two seasons.

Heavy metals concentration was studied in tilapia fishes (Oreochromis niloticus) from New Calabar river (Station 1), Elechi creek (Station 2), Woji creek (Station 3) in Port Harcourt, Nigeria using Atomic spectrophotometer. From the results obtained, Zinc showed concentration of 8.38mg/kg, 7.31mg/kg and 9.32mg/kg in the three stations respectively which do not exceed the WHO regulatory limit of 30.0mg/kg. Nickel concentration in the tilapia fish in Station I (0.55mg/kg), exceeded the regulatory limit of 0.5mg/kg, while fishes from Station II and III had 0.43mg/kg and 0.37mg/kg respectively. Cadmium and Chromium were not detected in the fish from three different Stations. Iron was highest with concentration of 54.17mg/kg, 50.10mg/kg, and 35.30mg/kg in the different stations respectively and were lower than WHO regulatory limit of 100.0 mg/kg .Lead showed the lowest concentration of heavy metals in the different stations and were also lower than the WHO regulatory limit of 5.0mg/kg. There was high concentration of (Iron) Fe in the fish species from the three stations while high concentration of Nickel was also observed from species from Station I. Following the high concentrations of metals in these stations, it’s imperative therefore that adequate measures should be put in place to reduce activities related to heavy metal contamination to avoid futuristic adverse effects. Finally, Oreochromis niloticus may perhaps be a good indicator to monitor heavy metal contamination in the waterbody.

The bioecological study of Harithalodes derogata in northern Kerala is scanty. The larval instars of Harithalodes derogata feeds on many crops in northern Kerala, especially in okra. It also causes severe damage in Hibiscus sp. The study was conducted in the monsoon and post monsoon seasons of 2019 to 2020. Leaf roll was up to 80- 85 % in okra and 35-40 % in hibiscus and the defoliation was observed 70-75 % in okra and 30-35 % in hibiscus under heavy infestation. The field population of larvae was highest in August and December, while it was lowest in June and July.

The study was carried out to evaluate the effect of anthropogenic activities on physiochemical properties of soils in Ezinihitte Mbaise L.G.A. Imo State. 36 soil samples were collected randomly at the depth of 0-5cm, 5-15cm, and 15-30cm. The samples were collected from four different locations, farmland, market area, play ground and forest. The samples were prepared and analyzed for physiochemical properties such as sand, silt, clay pH, conductivity, organic carbon, moisture content, available phosphate, calcium, magnesium, sodium, aluminum, nickel, cadmium, chromium and copper, using standard methods. The result of the analysis revealed that the soil pH was basic, ranging from 6.45-8.98; electrical conductivity ranged from 0.120-0.155µs/cm. The textual class was sandy-clay-loam, implying that the soil contain sand in a higher proportion. Moisture content, organic carbon, organic matter, available phosphate, calcium, magnesium, potassium, sodium, aluminum ranged from 6.56-16.70%, 0.32-1.52%, 0.55-2.61%, 5.53-58.52mg/kg, 0.4-6.7mg/kg, 1.0-8.5mg/kg, 424-624mg/kg, 224-392mg/kg, 0.001-2.8mg/kg respectively. Heavy metal concentration in the soil was Ni (0.099-0.416mg/kg), Cd (0.016-0.173mg/kg), Cr (0.004-0.216mg/kg), Cu (0.000-0.013mg/kg). From these results, it was found that there was a marked variation in parameters of various soil samples in different sampling points. These variations were as a result of different anthropogenic activities in the locations. The study recommends that efforts should be made to improve soil quality and its fertility status through continuous application of manure and compost, soil amendments, cropping pattern most especially in farmland.

The impacts of organic wastes contamination on microbial population and physicochemical properties of Woji creek in Port Harcourt Rivers State were studied for two years. Surface water samples were collected monthly for a duration of two year at five sampling points using standard methods. The samples were subjected to microbiological analysis based on total heterotrophic bacteria count and those of hydrocarbon utilizing bacteria, hydrocarbon utilizing fungi, total coliform and total fungi. Physicochemical properties evaluated include: temperature, pH, turbidity, total dissolved solid, total suspended solid, dissolved oxygen, BOD, COD, total organic carbon. Results of microbiological analysis showed no significant difference between seasons. THBC values ranged from 1.98x105 to 2.59x108cfu/ml, while TFC values was higher in the wet season (1.55x104 ± 5.46x103cfu/ml) than in the dry season (5.63x103 ± 2.55x103cfu/ml). Temperature range was found to be significantly higher in the dry season (27.92±0.210C) than in the wet season (25.81±0.210C). The findings of this study indicate that organic wastes are the major factors responsible for deterioration of the Woji creek.

Present study focused on pathological and genetic characterization of predominant post harvest fungal pathogens causing stem end rot, anthracnose and side rots of mango. Aggressiveness of these fungal isolates was tested through artificial inoculations under controlled conditions and all isolates were proved pathogenic with varying degree of aggressiveness in reference to control on both Sindhri and White Chounsa variety with exception of Colletotrichum gloeosporioides which showed no disease symptoms and characterized as non-aggressive isolates. All pathological results were proved highly significant at P<0.05 through ANOVA. DNA of fungal pathogens was successfully extracted and amplification was done through ITS1 and ITS4 primers and the amplified amplicons were productively digested with restriction enzymes (MboI, AluI, EcoRI, HaeIII, TaqI). Good genetic variability was obtained among the isolates of Lasiodiplodia theobromae, Aspergillus niger and Aspergillus flavus but Colletotrichum gloeosporioides did not show genetic variability.

Microorganisms play a significant role in bioremediation of heavy metal contaminated soil and wastewater. In this study heavy metal resistant fungi were isolated from the waste water treated soil samples of Hudiara drain, Lahore. The optimum pH and temperature conditions for heavy metal removal were determined for highly tolerant isolates of Aspergillus species along with the initial metal concentration and contact time. Biosorption capacity of Aspergillus flavus and Aspergillus niger was checked against Cu (II) and Pb (II) respectively. The optimal pH was 8-9 for A. flavus and 4-5.4 for A. niger, whereas the optimal temperature was 26°C and 37°C respectively. Moreover, the biosorption capacity of A. flavus was 20.75-93.65 mg/g for Cu (II) with initial concentration 200-1400 ppm. On the other hand the biosorption capacity of A. niger for Pb (II) ranged from 3.25-172.25 mg/g with the same range of initial metal concentration. It was also found that equilibrium was maintained after maximum adsorption. The adsorption data was then fitted to Langmuir model with a coefficient of determination greater than 0.90. The knowledge of the present study would be helpful for further research with reference to bioremediation of polluted soils.

The review aimed at identifying the gaps left out in the studies on how landuse influences ecosystem health of adjacent rivers in East and Southern Africa. These gaps left have affected both interpretation of results and rendered the studies incomplete. The gaps of interest here were three including; sampling procedure, relationship between river size and land use size as well as limited full ecosystem health components consideration. In our discussion, we have highlighted what the researchers should have done to seal the gaps and complete the ecosystem health assessment. The works reviewed in this paper include 22 peer reviewed papers in various journals, 3 technical ecological reports and 6 academic theses. The time frame of the works reviewed range between 2001 – 2019. It was concluded that a standard protocol be set for all researchers about the elements that must constitute a complete ecological health study such that if an element is left out, the study is not recognized as a complete ecological study. Sampling procedure should follow the before, in and after a stressor or landuse.

In the present study, a simple and convenient synthesis of CaAl2O4 nanoparticle was reported. The static renewal bioassay was conducted to determine the lethal toxicity of CaAl2O4 nanoparticle and sublethal exposure reveals the effect of nanoparticle on the haematology and biochemical parameters of the test species Cyprinus carpio. The acute toxicity (96hrs LC50) of CaAl2O4 NPs was observed between 25- 225ppm. As a novel attempt, our study showed the impact of CaAl2O4 nanoparticles in acute toxicity and biochemical parameters of freshwater fish Cyprinus carpio.

P- and S-wave attenuations are studied using vertical and horizontal vibrator sources and zero offset VSP data from the Ross Lake heavy oilfield, Saskatchewan. We find that the S-wave shows a larger amplitude loss and phase change than the P-wave over the same depths. This suggests that we will need to pay attention to attenuation in matching the phase of PP and PS images. A new approach to spectral ratio method has been developed to calculate a robust continuous interval Q factor from zero-offset VSP data. We also establish an estimate quality indicator (QQI) curve to highlight where we can obtain a reasonable Q factor. Poor Q estimates may arise from casing-bond problems, multiple casing areas, or source inconsistencies. Our VSP-derived Qp curve shows an inverse linear relationship with the VSP-derived Vp/Vs curve. Finally, the bulk value of Qp, Vp/Vs and Vp are estimated for three main geological formations in this oilfield.