Climate change and other biotic factors are causing desertification and degradation of the range resources at an alarming rate especially in the arid and semiarid regions worldwide. The mountain region of Sheikh Badin National Park (SBNP) –famous for its floristic composition and biodiversity, is facing serious consequences of climate and anthropogenic effects in Pakistan. The influential role of extreme climate changes needs to be explored to mitigate growing risk of degradation of natural vegetation and biological resource in this mountain region. In the present study, relationship of NDVI (Normalized Difference Vegetation Index) was investigated with seasonal LST (Land Surface Temperature), and TRMM (Tropical Rainfall Measurement Mission rainfall) rainfall of 2000-2018 period in the SBNP, Khyber Pakhtunkhwa province of Pakistan for sustaining ecosystem health. The findings of the study revealed increasing trends in NDVI during winter, spring, summer and autumn with corresponding increase in rainfall in the study area. The correlation coefficient R value between NDVI and LST was found -0.37 for winter, -0.72 for spring, -0.002 for summer and -012 for autumn (significant at p<0.05). The correlation between NDVI and rainfall revealed R values 0.41, 0.79, 0.64 and 0.7 for winter, spring, summer and autumn seasons (significant at p<0.05), respectively. The rainfall appears to be a major determinant of vegetation health and consequent ecosystem sustainability in the study area. However, the seasonal changes in climate and their implications necessitate adoption of integrated management of ecosystem to conserve biological resource on sustainable basis in this region in future.
Tree-ring growth is closely related to climate and the environmental changes during the growth period; thus, it can record precise information on climate variations. This study aimed to understand radial growth changes and develop tree-ring chronologies of Citrus reticulata, validated by tree-ring chronologies of Pinus roxburghii within the same micro-site. Tree-ring data were obtained from the sample cores collected from the two different altitudinal sites (1,150 to 1,250 masl) 400 to 500 m apart and compared to the climate data from Drujeygang meteorological station. Using dendroclimatological methods, summary statistics were obtained through cross-dating and standardization, and tree-ring chronology was written. Ring-width chronologies spanning 36 to 41 years were developed for C. reticulata and 57 to 174 years for P. roxburghii. One-way ANOVA test analysis showed spatial patterns of variability within the altitudinal range of 1,150 to 1,250 masl. Correlation analysis indicated that the growth of C. reticulata was highest at the mean annual temperature range of 19.0 to 19.4°C and mean precipitation range of 86.51 to 147.45 mm. C. reticulata showed a positive relationship with mean annual temperature and precipitation, and in contrast, P. roxburghii showed a negative relationship. However, the growth variability of both C. reticulata and P. roxburghii in both regions depicted the remarkable variability due to fluctuating climatic factors. This study evaluated the relationship between tree-ring growth and climate factors and is expected to contribute to the understanding of changes in productivity, which will be affected by climate change in the future.
Assessment of heavy metals (HMs) concentrations and remediation potential of indigenous plants in urban environments are necessary for safeguarding and restoring soil quality. This study evaluated the status of total HMs and remediation potential of the predominant plant species growing at contaminated sites in both Benin City and Abudu. The species were sampled along with soil around auto-mechanic workshops and from two respective uncontaminated sites and analyzed for total concentrations of eight metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) with an Atomic Absorption Spectroscopy. The geo-accumulation index revealed that both sites were extremely polluted with four HMs in the order of Fe > Zn > Mn > Cu. Benin was severely polluted with Pb, Cd and Cr and moderately to highly polluted with Ni, while Abudu was moderately to severely polluted with Pb and Cd, moderately polluted with Cr and slightly polluted with Ni. Eleucine indica identified at Abudu and Perperomia pellucida in Benin City were both found to contain toxic levels of four HMs (Fe, Zn, Cd and Cr), only E. indica at Abudu was found to exceed the limit of Cu, Pb and Ni set for plants while the level of Mn in both species were far from the permissible limit set by WHO. No plant was proven to be a hyperaccumulator but such potential towards Zn, Pb and Cd was observed for E. indica while the same phenomenon could be ascribed to P. pellucida for Cu and Zn if assisted with soil amendment. Heavy metal pollution levels of the sites demand clean up and predominant indigenous plant species can be used to manage them.
Heavy metal contamination in industrial effluents poses significant environmental and health risks, necessitating the development of effective, low-cost adsorbents. This study explored the potential of Millet Husk and Millet Straw, agricultural waste materials, for the removal of Lead (Pb), Arsenic (As), and Mercury (Hg) from industrial effluents. Millet Husk and Millet Straw activated carbon (MHS) was prepared through sodium hydroxide (NaOH) activation and characterized using Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), X-Ray Diffraction (XRD), and Energy Dispersive X-ray Spectroscopy (EDX). Batch adsorption experiments were conducted to assess the performance of MHS in removing heavy metals from effluent samples, with removal efficiency analyzed using Atomic Absorption Spectrometry (AAS). Characterization results revealed that MHS exhibited enhanced surface morphology, high porosity, and functional groups that facilitated heavy metal adsorption. The optimal removal efficiencies were 58.67% for Pb, 69.83% for As, and 100% for Hg. Factors such as adsorbent dosage, contact time, and pH significantly influenced adsorption rates, with maximum adsorption observed at a dosage of 0.1 g. The study concluded that MHS is a promising adsorbent for heavy metal removal from wastewater, with its adsorption capacity dependent on initial metal concentrations and pH levels. Further research is recommended to explore the scalability of MHS in real-world applications, investigate modifications to enhance its adsorption capabilities, and study its regeneration and reuse potential for long-term viability as an eco-friendly adsorbent.
This study investigates the contribution of livestock production to CO2 emissions in SAARC countries from 1990 to 2020 through an empirical analysis using panel data. The study included variables such as CO2 emissions and stocks, namely cattle, chickens, and goats. Data for the Maldives were excluded due to unavailability, and swine population data were also omitted for the same reason. Unit root tests revealed that the series were non-stationary at levels but became stationary after first differencing. The ARDL bounds test with a lag length of 3 (AIC = -7.951, SC = -7.060, HQ = -7.590) identified significant long-run relationships. Specifically, cattle (coefficient = 2.948, p-value = 0.000) and chickens (coefficient = 2.369, p-value = 0.000) were positively associated with CO2 emissions, while goats showed a negative association (coefficient = −5.594, p-value = 0.000). It was proven that there was a long-term equilibrium by cointegration tests like the Kao Residual cointegration test (ADF t-Statistic = -1.646, p-value = 0.049) and the Johansen Fisher panel cointegration test (Trace test and Max-Eigen test: p-value < 1%). Cross-sectional analysis revealed variability, with Afghanistan's cointegration coefficient at -0.325 (p-value = 0.000) and Bhutan's at 0.034 (p-value = 0.000). The results showed notable variability across countries, suggesting the need for tailored mitigation strategies. The study highlights the significant role of livestock in greenhouse gas emissions and calls for improved management and regional collaboration to mitigate environmental impacts in SAARC countries.
