Nutrient contents and rate of litter decomposition were investigated in Leucaena leucocephala plantation in the University of Agriculture, Abeokuta, Ogun State, Nigeria. Litter bag technique was used to study the pattern and rate of litter decomposition and nutrient release of Leucaena leucocephala. Fifty grams of oven-dried leaf litter of the species was weighed into 0.2 mm mesh litter bag, 35 cm × 25 cm in size, these bags were closed at all ends. Eighteen litter bags were used for the studies. The litter bags were numbered and placed on the field (above ground) on 26th April 2005. Three bags were retrieved randomly from the field at 20-day intervals for 120 days. The nutrient concentration in L. leucocephala followed the trend N > P > Mg > Ca > K > Na for leaf litter and seed components. Nutrient concentration in twigs and pods ranked N > Mg > P > Ca > K > Na. Among all the litter components, leaf litter contributed more nutrients, especially nitrogen, than other litter components. High potassium concentration during the dry season was due to lack of rainfall to leach out the element. Lower magnesium content in leaf litter was due to chlorophyll decay. High N-flux reflected the quantity and quality of nitrogen in the soil. Mass loss was significantly correlated with calcium (P < 0.05). At 120 days, 80% of the litter had decomposed; this implies that decomposition rate was at 0.6% per day. A net immobilization of all the nutrient elements at 20 days was due to lack of rainfall to leach out the nutrients. High rate of decomposition at the early stage was due to less moisture content in the soil and high temperature. Litter decomposed more during the wet season than the dry season.

No abstract

Climate change adaptation plan has been marred with assertion that genders are not treated equally both in designing and implementation which have been eventually the cog in the wheel of progress of many developmental programmes in forest-based communities such as REDD+ (Reducing Emissions from Deforestation and Forest Degradation). This assertion has however not been “perceptionally” proven aside from the general vulnerability-gender relationships. This study used both quantitative and qualitative methods of data collection. Primary data was collected with the aid of questionnaire from 200 respondents (male and female category) randomly selected within six purposive UN-REDD+ piloted villages according to Cochran formula in South-South, Nigeria. Sixteen perceptional statements were developed with Likert scale rating along categorical variables such as participation, decision making, recognition and inclusion, forest resources management as well as village institution composition to assess and explain different factors militating against procedural component of climate justice (participation, decision making and level of engagement) at an individual level. The result of the research showed that the participation and decision making rate of women/female in the REDD+ in South-south Nigeria is weak, mostly only at the level of Tokenism, where over 97% were not aware of such project in the community, but the remaining 3% were privy to the information via their husbands where either their views or opinions have influenced policy. The female participation level about REDD + projects is low. This is due to cultural and socio-political societies that still retain traditional gender roles which only locate and position women/female for domestic affairs thus undermining their position and responsibilities in public places as attested to by Focus Group Discussion(FGD). Besides, discrimination by male leaders and their lack of self-esteem, and low levels of education weaken them from playing a role in their village community even in the implementation of the REDD+ project. This underscores the importance of proactive gender mainstreaming with all encompassing inclusiveness intervention rather than “ male versus female” or “men versus women” in order to address gender bias both in designing and implementation of adaptation action plan such as REDD+. This study has extended the “individual perceptional statements” of climate justice to create the most flexible approach in analysing the level of engagement of disaggregated “gender level” in REDD+ piloted site in South-south, Nigeria.

Forest carbon is identified in three major pools that is, above and below ground living vegetation, dead organic matter and soil organic carbon whose quantities have been identified for few forest types. The study investigated the carbon stock in above and below ground biomass in three age series of Pinus (1991, 1992 and 1996) and Nauclea (1974, 1975 and 1976) plantations at area J4, Ogun state Nigeria. Five plots of 20m x 20m dimension were randomly laid making a total of 30 plots. Diameter at breast height and height were measured using diameter tape and Spiegel Relaskop respectively. Soil samples were collected in each plantation at 0–15cm and 15–30cm depth with the aid of soil auger and laboratory analysis carried out. Data were analyzed using the General Linear Model of SAS software. Analysis of Variance (ANOVA) and Duncan Multiple Range Test was used to separate means and correlation analysis was carried out. Above ground was estimated using Brown et al. (1989) equation {Y= 34.4703- 8.0671 (DBH) + 0.6589(DBH2)} and below ground biomass was also estimated as 20% of above ground biomass. Result showed that Organic carbon stored up in the soil was highest (3.05±0.52g/kg) in Nauclea plantation (1975). Pinus plantation (1996) had a higher total carbon stock (1166.35ton/ha) than Nauclea plantation (1976) with (380.41ton/ha). Pinus plantation (1996) had the highest above ground biomass, below ground biomass and carbon dioxide concentration (728966.19, 160372.56 and 4198845.28/ha) lowest (227644.66, 50081.83 and 1311233.26/ha), Pinus plantation (1992) respectively. Variation in the above ground carbon stock among these plantations could be result of tree stand density, hence, higher number of trees in a plantation will eventually result to high above ground carbon stock of that plantation.

Urban forests are an essential component of urban areas as they provide many environmental and social services that contribute to the quality of life in cities. Urban forests in most cities of Nigeria are gradually becoming bitty as a result of urbanization activities, thereby posing adverse effects. In this study, we assessed the changes in the urban forests cover under the influence of different human settlement (HS) extents across the urban area of Ibadan city using remotely sensed data. The pattern of change(s) in the urban forests cover over 20 years were examined by analysing and manipulating Landsat and Sentinel-2 datasets using Google Earth Engine, ArcGIS 10.1, and Erdas 2014 software. The extents of human settlement (for the year 2000, 2005, 2010, 2015, and 2020) were extracted (from Landsat datasets), analysed, and mapped to evaluate the status of the urban forests cover under different human settlement extents. The result reveals a substantial land cover changes within the urban area of Ibadan.  The urban forest cover decreased from 24.14% to 7.99%. Also, there is a significant decrease in the urban forests cover as a result of a substantial increase in human settlement extent (102,806 to 122,572 pixels). The study provides an opportunity to map the status of urban forest cover and extents of HS in a developing city using remotely sensed data and applications of GIS tools.