Assessing the impact of climate change on the built environment in Kaduna Metropolis and environs

The Kaduna's tropical climate for the last twenty years with its uniform characteristics of high temperature, humidity and precipitation witnessed an unprecedented widespread weather variability resulting to an extended dry spell and rising temperature. The study was conducted in Kaduna metropolis and environs using integrated dynamic model technique with the aim to ascertain the impact of climate change on the environment. Data were compiled from various land use map and historical climate and weather data (rainfall, ambient air temperature, heat weave, wind speed, direction, cloud cover and relative humidity) from the Country Planning department and Nigeria Meteorological Department respectively. The finding indicated that higher temperatures intensified urban heat island, especially during dry season (February to April). Decades rainfall revealed an upward trend of 408mm while temperature shows to increase by 0.1996oC. The average evaporation was found to be 163 cm yr−1 (±9%) and likewise relative humidity was found to increase by 66.5%. The rain fall regime in the metropolis is highly variable and its seasonality change is another good indicator of climate change which revealed some fluctuation in rainfall seasonality in the metropolis resulting to flooding. Also, the monthly evaporations and relative humidity have seasonal variability indicating an important relationship between evaporation, relative humidity and seasonal changes in the environment. Conclusively, there is no doubt that the human populations, infrastructure and ecology of cities are at risk from the impacts of climate change as flooding is more frequent and intense rainfalls leading to stream and riverine flooding and overwhelming of urban drainage systems. However, tools are becoming available for addressing some of the worst effects. For example, appropriate building design and climate sensitive planning, avoidance of high-risk areas through more stringent development control, incorporation of climate change allowances in engineering standards applied to flood defences

Forests carbon input and changes in soil properties of the tropical rain forest, Malaysia

The tropical forest ecosystem plays a critical role in the forest carbon input and it is important to understand the rate of occurrences by quantifying the forest biomass and its effect on soil properties in relation to microclimate condition and environmental factors. The study was conducted in the tropical forest ecosystem of Malaysia with the aim to estimate the forest carbon input and its effects on changes in soil properties The Malaysia lowland tropical forest was found to be a carbon sink with an accumulation rate of total above ground biomass (TAGB), below ground biomass (BGB) and total forest carbon (SOCs) of 2788.64 to 3009.97, 100.88 to 134.94 and 2996.13 to 3088.98 mg ha-1 respectively and varied between February and September and October and January. The soil properties; total organic carbon (TOC), soil organic carbon (SOC) and soil carbon stock (SOCstock) varied in relation to forest biomass at a ranges of 1.1 to 3.0, 1.1 to 5.89 and 58.01 to 70.46 mg ha-1, respectively. The forest biomass gradually increases over time and also influences the concentration and increase in soil properties influences environmental factors responsible for physiological activity. The multiple linear regression and Pearson correlation indicated a strong positive correlation (R2=0.98, p<0.01) between forest biomass, soil properties and environmental factors. The tropical lowland forest of Malaysia indicated increase in the forest biomass over time and significantly influenced the concentration of soil properties

Influence of Nimbia forest biomass on soil properties in Southern Kaduna

Changes in Forest biomass frequently influence the physicochemical composition of soil. In the Nimbia Forest Reserve, Southern Kaduna, certain physical and chemical soil parameters were investigated across changes in the forest biomass sequence. The objective was to ascertain how changes in forest biomass will impact on soil properties. In order to represent changes in forest biomass stages. Soil samples (0–20 cm depth) were taken from three different forest plots: (Plot A, Plot B, and Plot C). Between 2021 and 2022, soil samples were examined for the following soil properties: soil organic matter (SOM), soil microbial biomass carbon (SMBC), pH, NH4 +-N, available potassium (K), available phosphorus (P), and microelements (available copper (Cu), available zinc (Zn), available iron (Fe), and available boron (B)). The findings demonstrated that the changes in forest biomass had higher amounts of SOM, SMBC, Cu, Zn, Fe, and B. (Plot B). In contrast, P and pH were higher in the Plot A but lower in the Plot B. While SOM, Zn, Cu, Fe, and B increased with increasing forest biomass, pH, NH4 +-N, P, and K decreased. In the three different forest plots, the soil pH was less than 4.5, which showed that Nimbia's surface soil was acidic, a consistent tendency

A comparison of soil CO2 efflux rate in young rubber plantation, oil palm plantation, recovering and primary forest ecosystems of Malaysia

Tropical deforestation and land conversion has been an environmental challenge over time and this is likely to have wide-reaching consequences for soil CO2 efflux. Such soil-carbon dynamic disturbances are critical in light of climate change, as tropical forests store almost 30% of global forest carbon. Soil CO2 efflux and environmental factors were determined in four different forest ecosystems of primary Dipterocarp forest, a 50-year-old recovering Dipterocarp forest, and a 5-year-old rubber and oil palm plantation using an automated soil CO2 chamber technique (Li-Cor 8100) with an in-built infrared gas analyzer. The forest sections are located within 1,800 m of each other while the plantation is 1,500 m away in the tropical lowland forest of Pasoh, Peninsular Malaysia. The aim was to determine the influence of environmental factors influencing soil CO2 efflux in relation to different forest ages and stand densities as a result of forest disturbance. Multiple regression analysis has been conducted on the relationship between soil CO2 and environmental factors. Soil CO2 efflux rate was found to range from 1.47-13.22 μmolCO2 m-2·s-1 (5.37 μmolCO2 m-2·s-1), 1.18-10 μmolCO2 m-2·s-1 (5.107 μmolCO2 m-2·s-1), 0.88-12.07 μmolCO2 m-2·s-1 (3.260 μmolCO2 m-2·s-1), and 2.33-7.89 μmolCO2 m-2·s-1 (4.678 μmolCO2 m-2·s-1) in the 50-year-old recovering forest, primary forest, oil palm plantation, and rubber plantation, respectively. Likewise, the highest forest biomass occurred in the primary forest and was followed by the 50-year-old recovering forest, rubber and oil palm plantation. Although the mean soil CO2 efflux rate did not differ significantly, differences were evident in the environmental factors such as soil temperature and moisture occurring at a range of 23 to 32°C and 15 to 35.56%, respectively, to influence soil CO2 efflux. The highest CO2 efflux rate was recorded in the 50-year-old recovering forest and followed by the primary forest, and rubber and oil palm plantation. The finding revealed a significant and strong correlation between soil CO2 efflux and soil temperature, moisture, and forest carbon input. Furthermore, the spatial variation in soil CO2 efflux was attributed to total above-ground biomass, below ground biomass, and forest carbon stock. We can conclude that the spatial variation in Soil CO2 efflux across the four different forest ecosystems is as a result of forest disturbance and land conversion triggering changes in environmental factors as well as forest carbon, thereby increasing microbial activity to emit soil CO2

Factors responsible for spatial and temporal variation of soil CO2 efflux in a 50 year recovering tropical forest, Peninsular Malaysia

Environmental abiotic and biotic factors are important in controlling soil CO2 efflux in forest ecosystems of different ages, as they play an important role in soil respiration. In understanding the spatial and temporal variation of soil CO2 efflux after several years of forest logging, there is a need to quantify the changing soil properties, environmental factors, and the total above and below ground biomass. This study was conducted in a 50-year old recovering tropical lowland forest in Peninsular Malaysia, measuring soil CO2 efflux using the continuous open flow chambers technique connected to a multi gas-handling unit and infrared gas analyser. The aim of this study was to determine the spatial and temporal variation of soil CO2 efflux in relation to changes in soil properties, environmental factors and forest carbon in a recovering forest. The efflux rates of about 389.20, 634.78, 564.81, 537.92 and 428.72 mg m−2 h−1, respectively, varied across the days and months, increasing from February and attaining the maximum in March and then gradually decreasing from April to June. The soil properties revealed a considerable amount of soil organic carbon, total organic carbon, and soil organic carbon stock, while the total above ground biomass, below ground biomass, soil pH, nitrogen to carbon ratio were found to provide nutrients for microbial activities in soil and to emit soil CO2. The multiple linear regression model indicated that the soil temperature and moisture explained the spatial and temporal variation in soil CO2 efflux; likewise, the changes in the soil properties and forest carbon significantly increased the soil CO2 efflux indicating a strong positive correlation (R 2 = 0.93)

Soil carbon dioxide efflux and atmospheric impact in a 10 years Dipterocarpus recovering lowland tropical forest, Peninsular Malaysia

Recovering logged-over forest ecosystem increases CO2 efflux into the atmospheric carbon pool in response of environmental factors to change in soil temperature and moisture. These CO2 outbursts can have a marked influence on the ecosystem carbon balance and thereby affect the atmospheric carbon pool. The study was conducted in a 10 years logged-over forest of Sungai Menyala forest, Port Dickson, Negeri Sembilan, Malaysia. The measurements of soil CO2 effluxes were conducted using a continuous open flow chambers technique connected to a multi gas-handling unit and infrared CO2/H2O gas analyser. The aim of this study is to determine the percentage of CO2 contributed into the atmosphere from a recovering 10 year logged-over lowland forest. One-way analysis of variance (ANOVA) was used to test the significance correlation between soil CO2 efflux and environmental variables. Post-hoc comparisons were made using Tukey test (p < 0.05), and multiple linear regressions were used to determine the impact of environmental factors on soil CO2 efflux. Soil CO2 efflux range from 345.6 to 600.4 mg/m−2/h−1 with the highest efflux in the afternoon attributed to increase in soil temperature and moisture. Higher soil temperature and moisture recorded signify the influential factor. Furthermore, the predictor environmental variables; Soil Organic Carbon (SOC), Total Organic Carbon (TOC), Soil Moisture Content (SMC), Bulk Density, Below Ground Carbon Stock, Total Aboveground Carbon Biomass (TAGB), soil pH, Nitrogen to Carbon ratio account for the spatial and temporal variation in soil CO2 efflux. These factors attributed to increase in CO2 efflux into the atmosphere

Rainfall trend detection in Northern Nigeria over the period of 1970-2012

This study examined the trends in variability and spatial distribution of annual rainfall over northern Nigeria during the period 1970-2012 with a view to understand the pattern of rainfall trend (significance and magnitude), by applying various statistical tools on the data obtained from 11 weather stations. The non-parametric Mann– Kendall test was used to determine the statistical significance of trends while the magnitude of trends was derived from the Sen slope estimator of the linear trends using Kendall robust line fitting. Map of rainfall trends was generated by applying a geo-statistical interpolation technique to visualize the detected tendencies. The findings revealed that a significant positive increase of 2.16mm in rainfall was recorded in the entire northern Nigeria within the period of 1970 to 2012. It further indicated that majority of the stations revealed an upward trend, with Bauchi, Borno, Kebbi and Sokoto stations showing significant positive trends of 8.13mm, 4.30mm, 4.76mm and 4.42mm respectively. It is concluded that there is high variability in rainfall in the northern Nigeria which signifies a clear evidence of climate change in the region

Influence of monsoon regime and microclimate on soil respiration in the tropical forests

The consequence of precipitation and how environmental factors influence soil respiration remain poorly understood in the tropical forest ecosystems under a monsoon climate in Malaysia. This study was conducted in a recovering tropical lowland Dipterocarpus forest in Peninsular Malaysia, and its monthly variations were examined in association with changing precipitation. Soil respiration was measured using a continuous open flow chamber system connected to a multi gas-handling unit and an infrared gas analyser. The aim of this study was to determine the effects of the monsoon period and microclimate of the tropical region on soil respiration. The average monthly soil respiration rates were 152.79 to 528.67, 120.97 to 500.73, 106.77 to 472.89, 122.89 to 453.89 and 120.33 to 434.89 mg m⁻² h⁻¹ in the respective months from September to January. The emission rate varied across the days and months, with the highest value recorded between September and October, and then gradually decreasing from November to January. Soil temperature explained more than 90% of the soil respiration rate whereas precipitation had a major effect during the monsoon regime. Soil organic carbon (SOC), total organic carbon (TOC), soil organic carbon stock (SOCstock), forest biomass, carbon to nitrogen ratio (C/N) and soil pH were found to vary in considerable amounts, provide nutrients and the environment favourable for microorganism activities, leading to emission of soil CO₂. The low values of soil respiration rate between November and January were due not only on the amount of soil moisture and water potential but also on the intensity and frequency of precipitation. Therefore, these results indicate that the monsoon regime can significantly alter the emission of soil CO₂ and influence the microclimatic conditions and other environmental factors

Forest logging and it impact on soil carbon dioxide effluxin the tropical forest, Peninsular Malaysia

Forest harvesting is expected to have an impact on soil CO2 efflux as it influence soil properties and changes in microclimatic conditions which can have implications on the regional carbon balance. Soil CO2 efflux was measured using a continuous open flow chambers technique connected to a multi-gas-handling unit and infrared CO2/H2O gas analyser. Soil temperature, soil moisture, water potential, Total Organic Carbon (TOC), Soil Organic Carbon (SOC), Soil Organic Carbon stock (SOCstock), Bulk density and pH were examinedto ascertain their contribution onsoil CO2 efflux and effect ofenvironmental factors in a canopy gap created through the logging of groups of trees in the Sungai Menyala forest, Peninsular Malaysia

Comparison of soil CO2 efflux in tropical forests of different ages, Peninsular Malaysia

The forest age, environmental abiotic and biotic factors are important in controlling soil CO2 efflux in forest ecosystems, as they play an important role in soil respiration. The aim of this study was to determine the environmental factors associated with each forest age and their impact on the soil CO2 efflux rate. This study was conducted in 10-, 30-, 50- and 70-year-old recovering tropical lowland forests in Peninsular Malaysia, measuring soil CO2 efflux using the continuous open flow chamber technique connected to a multi gas-handling unit and infrared gas analyser. The forest biomass and soil properties were quantified using the Kjeldahl method and Walkley-black wet oxidation technique. The results show that soil CO2 efflux was higher in the 10-year-old forest than the older forests and lowest in the 70-year-old forest. Soil CO2 efflux ranged from 92.09 to 634.78, and 106.77 to 536.00 mg m-2 h-1 between February and June, and September and December for all forests. The higher soil CO2 efflux in the 10-year-old forest was significantly positively correlated with high soil temperature (R=0.96) compared to the spatial and temporal variation in the 30-, 50-and 70-year-old forests. The entire spatial and temporal variation in soil CO2 efflux can be largely accounted for by the soil properties, forest carbon input and environmental factors. In conclusion, soil CO2 efflux, soil properties, microclimate condition and forest biomass varies significantly with forest age. Soil CO2 efflux decreases with forest age, and increases the carbon use efficiency. The environmental factors, dominated by soil temperature, affect soil CO2 efflux substantially