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.

A study was conducted on the structure and diversity of lianas in a chronosequence of Congolese tropical forests in the Yoko Forest Reserve (Tshopo Province, DR Congo). The main objective was to study the dynamics of lianas after the abandonment of agriculture at our site. A chronosequence approach was used to carry out this study. Four forests were considered on the basis of their age: 5-year old forest, 12-year old forest, 20-year old forest and 60-year old forest. The mixed primary forest of unknown age was also retained for comparison. Inventories of lianas with a diameter at breast height (dbh) ? 1 cm on supports were carried out in three 40 m × 40 m plots (totalling 0.48 ha) set up in each of these five forests. The functional traits of the lianas were observed in the field and supplemented by the basic literature. The following results were obtained: - the number of species varied from the 5-year-old forest (i.e. 28 species/0.48ha) to a peak in the 60-year-old forest (i.e. 35 species/0.48ha). As for floristic diversity, the 12-year-old forest had the highest Fisher index value (? = 10.66) and the 20-year-old forest for the Shannon (H = 2.92) and Simpson (D = 0.923) indices. The most abundant families are Dilleniaceae (in the 5-year-old forest), Euphorbiaceae (in the 12-year-old forest and in the 60-year-old forest), Fabaceae (in the 20-year-old forest) and Dichapetalaceae (for the primary mixed forest). And the families with the highest importance value indices are Passifloraceae (5-year forest), Euphorbiaceae (12-year and 60-year forests) and Fabaceae (20-year forest and primary mixed forest). - The density of lianas was positively related to the age of the forest up to around 60 years, after which an older forest was associated with a decrease in the density of liana stems. Furthermore, the density and basal area of the lianas peaked at the age of 60, before beginning to decline. - Most lianas were voluble (49.88%), zoochorous (63.73%) and hemi-heliophilous (47.51%). This pattern emerged in all 5 chronosequence forests in this study. The relative dominance of functional traits changed with forest age, and functional diversity was higher than predicted by the null model framework of species richness (SES MPD > 0) in the 20-year-old forest and the mixed primary forest. 

A study was carried out on the colonisation of trees by lianas in tropical forests in the Yoko forest reserve (Tshopo, DR Congo). Observations focused on the main parameters (structure and diversity) of the lianas in order to determine the relationship patterns that exist between the host tree and the liana at our site. Inventories of stems with a diameter at breast height (dbh) ? 10 cm for trees and (dbh) ? 1 cm for woody lianas hosted on supports were carried out in fifteen 40 m × 40 m plots (totalling 2.4 hectares) set up in the tropical forests of the Yoko forest reserve. Creeper attachment mechanisms were observed in the field and supplemented by basic literature, and the number of creepers climbing each tree trunk was counted. The following results were obtained: - Overall, 57 liana species were inventoried, and 41 genera and 23 families were recorded. The liana species best represented in terms of IVI value are : Manniophyton fulvum (40.02%), Millettia duchesnei (21.04%), Strychnos camptoneura (17.57%), Dichapetalum mundense (14.97%), Landolphia parvifolia (13.91%) and Dalhousiea africana (12.37%). The most abundant families were Euphorbiaceae (20.6%), Dichapetalaceae (13.31%), Fabaceae (11.86%), Connaraceae (11.06%), Aponaceae (10.26%) and Rubiaceae (8.25%). A total of 1,247 individuals of lianas were inventoried in all fifteen plots, giving an average density of 519 stems/ha. They represent a basal area of 3.79 m2/ha. Most of the lianas are voluble and climb their supports (49.88%), followed by sarmentose lianas (21.84%). A total of 1,177 trees were surveyed, 381 of which (32.3%) had lianas on their trunks. - The proportion of infested trees differed according to diameter category, with medium and large trees having more lianas on their trunks and a higher total basal area of lianas than small trees. Trees with thorny, rough bark are more likely to support vines. - Trees with thorny bark are positively associated with lianas with tendrils, and trees with rough bark are positively associated with lianas with hooks. Trees 40 cm and taller were positively associated with lianas with hook and sarment modes of attachment. 

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.