Assessment of Mangrove Sediment Quality Parameters from Different Seasons, Zones and Sediment Depths

Heavy metal concentrations have risen throughout Malaysia's coastline because of industrial wastewater discharge, affecting mangrove ecology significantly. Lead (Pb), Zinc (Zn), Chromium (Cr), and Nickel (Ni) were used to establish the Mangrove Sediment Quality Index (MSQi), which assesses and monitors the quality of mangrove sediment. This study was conducted at Matang Mangrove Forest Reserve (MFFR) in Perak, Malaysia to examine changes in MSQi features across seasons, mangrove zones, and sediment depths at three separate MMFR locations. Sediment samples were taken using auger in two different seasons (dry and wet seasons). After the silt was removed using aqua regia techniques, heavy metals were examined using an Atomic Absorption Spectrophotometer. According to MSQi criteria in various seasons at three different locations, the highest concentration of heavy metals (HMs) was detected in the dry season in the least disturbed region at three different locations. During dry seasons, only Cr and Ni levels are higher in moderately and highly disturbed areas. Pb and Zn levels in moderately and highly disturbed areas are higher than in least disturbed areas during the rainy season. MSQi parameters in different mangrove zones at three locations showed that most HMs content is highest in the landward zone and it can be concluded that HMs sources are anthropogenic. Furthermore, MSQi measurements at three locations revealed that heavy metals content is highest at 015 cm and lowest at other depths

Development of mangrove sediment quality index in Matang Mangrove Forest Reserve, Malaysia: a synergetic approach

Sediment is an important part of heavy metal cycling in the coastal ecosystem, acting as a potential sink and source of inorganic and organic contaminants as environmental conditions change. The productivity of mangroves is utterly dependent on sediment enrichment. Moreover, mangrove sediment can trap pollutants discharged by households, industries, and agriculture activities. In this regard, it is essential to assess sediment quality in the presence–absence of heavy metals that are toxic to most living organisms. Thus, the question of how sediment quality is used as an index in the mangrove domain has arisen. Due to the many complex characteristics such as seasonal zones, tidal patterns, flora and fauna, and water, no specific method is used in Malaysia for assessing and monitoring mangrove sediment quality. Thus, the current study intended to develop a mangrove sediment quality index (MSQi) in the Matang mangrove forest in Perak, Malaysia. An area was selected based on the distinct level of mangrove disturbances. At 1.5 m depth, sediments were sampled in five segments (0–15, 15–30, 30–50, 50–100, and 100–150 cm). All the sediment physicochemical properties were then analysed. Fourteen variables were chosen and included in MSQi. This index categorises mangrove sediment levels as I = Very Bad, II = Bad, III = Moderate, IV = Good, and V = Excellent. MSQi will be used as a guideline in monitoring mangrove sediment pollution. In conclusion, the data analysis showed that the Sepetang River (SR) was highly disturbed, followed by the Tinggi River (TR) (moderately disturbed), and the Tiram Laut River (TLR) (least disturbed)

Assessment of stable isotopes and elemental composition at three different ages of Mangrove Forest in Matang, Malaysia

Matang Mangrove Forest Reserve (MMFR) is considered as one of the most productive and best-managed mangrove forest in the world. However, in the last few decades, there have been concern on the issues of productivity in MMFR and few field-based studies based on timber volume, density and biomass have been performed to assess its productivity. This study also attempts to assess the productivity using stable isotopes (δ15N and δ13C) and selected elemental composition. This study was the first to use stable isotopes and elemental composition to determine the productivity in mangrove forest of Malaysia and the factors which effect on productivity. In order to do that, four main objectives were outlined, namely; (1) to investigate the productivity of different aged-stands (compartment) with nutrients productivity model using stable isotopes with salt stress and nutrient abundancy, (2) to identify elemental concentrations and stable isotope ratios in inter- and intra-mangrove species stands along the inundation gradient of the mangrove forest, (3) to compare elemental concentration between similar and different aged stands, (4) to study the heavy metal concentration in the sediment using contamination indices (pollution load index, geoaccumulation index and contamination element or part and hazard assessment code) For objective 1: 90 samples of leaves from R. apiculata trees collected from six compartments (Compt. 18, 31, 71, 74, 42 and 55) and run for analysis. The selection of these compartments was based on age and management as discussed earlier. Sixteen variables; stable isotopes (δ13C, δ15N), macronutrients (C, N, P), cations (Ca, Mg, Na, K) and trace elements (Cd, Cu, Fe, Mn, Pb, Zn) were analyzed and fitted into established productivity equation. To validate the model, productivity using biomass estimation also were performed in study plot of 10m x 10m within five managed sites namely, Compt. 18, 31, 71, 74 and 67. Results show that in the 15 year-aged stands, Compt. 18 showed higher productivity than in Compt. 31; for the 25 year-aged stands, Compt. 74 has higher productivity than Compt. 71; but mean biomass of two 25-year compartments was higher than the mean biomass of the two 15-year compartments. It can be concluded from the models that even with similar aged-stand, there is a variation in terms of productivity. Interestingly, the trend for biomass estimation produced similar results that can be validated by productivity models in which similar aged stand showed different value of productivity. To investigate variation in productivity between same age and different age compartments following studies were conducted. Different species of mangroves i.e., Avicennia alba, Rhizophora. apiculata, Bruguiera parviflora and Sonneratia ovata in different compartments (Compt. 39, 40, 30 and 18) were analysed to achieve objective (2): trace elements (Mn, Fe, Cu, Zn), cations (Na, K, Ca, Mg) and stable isotope (δ13C and δ15N) ratios were found to follow different patterns along the inundation gradient in the leaves of the sampled plant species. Elemental concentrations of Na, K, Fe, Cu, Zn and Mn along with stable isotopic ratio were found differed significantly within similar and different mangrove species. For achieve objective (3): nutrients concentrations were examined in leaves, root and sediment of Rhizophora apiculata stand in six compartments with different aged (Compt. 18 and 31=15-year-old stand; Compt. 71 and 74 = 25-year-old stand; Compt. 42 and 55= virgin jungle reserve) were collected and analysed. Results show that nutrient concentrations between all stands on average were similar and can be arranged collectively as Ca>Na>Fe>K>Mn>Mg>Zn>Cu>Pb>Cd and C%>N%>S%>P%. Concentrations of Cu, Cd, Pb, Mn and Zn were found at high range that indicating heavy metal pollution most probably due to human activities. The ratio of δ15N showed positive values and could be translated as there was no deficiency of N element. Ratio of δ13C on the other hand, showed more negative values indicating that there is less salinity stress in all studied areas, the fourth (4) objective: sediment samples were collected at the depth of 7cm and analyzed for assessing heavy metal contamination in six compartments (Compt. 18, 31, 42, 71, 74 and 55). High concentrations for Cu, Ni and Cd were observed in Compt. 42 while Compt. 18 and 74 had higher Zn and Pb concentrations, respectively. Assessment shows that all six compartments are categorized from low to moderate polluted areas. Geo-accumulation index (I-geo), pollution load index (PLI) and contamination factor (CF) classified the compartments in low contaminated area. Our findings also suggested R. apiculata as a suitable candidate for bioremediation of heavy metal-contaminated sediments and for restoration of degraded ecosystem with high levels of heavy metal contamination. In conclusion there is no prominent increase in biomass with age. This suggests that Rhizophora apiculata is not showing high productivity

Elemental Composition of Above and Belowground Mangrove Tissue and Sediment in Managed and Unmanaged Compartments of the Matang Mangrove Forest Reserve

Mangrove productivity depends on the storage of nutrients and elements. Elemental concentrations were examined in leaves, roots, and sediments for three age stands (15, 25 years, and VJR) of Rhizophora apiculata in the Matang Mangrove Forest Reserve (MMFR). Six compartments with two compartments each for each age group were used to analyze sixteen elements. Four types of elemental patterns were examined with decreasing order during analysis: (1) Cd (S) (S) (S) (S) (S) (L) (L) (S) (R) (R) and P%(S) (S) (L) (R) collectively for all samples. Evidence that elements do not store primarily in above-ground biomass can be found in the observation that elements are stored more in sediment and roots. The outcome of the present study shows that the rate of increase of elements in trees (leaves and roots) was less as compared to sediments, where the elemental concentration increased considerably with time. Elemental concentration comparison within three age classes showed that C, N, and S were significantly different in all three types of samples. The δ15N ratios showed positive values in all six compartments which supported the concept that the δ15N ratio could not be observed in N concentration in this study. The δ13C values showed more negative values in all six compartments which represented less salinity and a freshwater intake. The S, P, and heavy metals concentrations were high. The concentrations of Cd, P, N, C, and S in the sediment influenced variations in four compartments in accordance with the three mangrove age groups. The results of this study can be utilized to create management plans for MMFR and conduct risk assessments of the elements’ concentration in sediment

Lithofacies Architecturing and Hydrocarbon Reservoir Potential of Lumshiwal Formation: Surghar Range, Trans-Indus Ranges, North Pakistan

Western environs of the Indo-Pak Plate are comprised of thick Mesozoic sedimentary sequence and extensively extended toward Trans-Indus Salt ranges of North Pakistan. This sequence consists of detrital clastic sediments in the lower level and shallow to deep marine sediments in the upper level. In the Trans-Indus Salt ranges the Lumshiwal Formation represents the transitional level of the lower Cretaceous sequence. In Surghar Range the lower part of formation is composed of cyclic alteration of clayey, silty, very fine grained greenish gray, glauconitic sandstone to rusty brownish gray sandstone. The middle part of formation is comprised of thick bedded to massive, cliff forming, sugary texture, whitish to light yellowish gray occasionally rusty brownish gray medium to coarse grained, moderate to well cemented sandstone. The upper part is comprised of feldspathic, ferruginous, weathering yellowish brown, rusty brown to light gray with locally calcareous sandstone beds. The sandstone is reddish to brownish gray, coarse to granules texture, moderately cemented thick bedded to massive. Total thickness of the formation is 220m at Baroch Nala section 230m in Karandi section at a dip of 60°. Along trend lithological variations and diversified primary sedimentary structures which classifies fifteen different sub-lithofacie in Lumshiwal. Middle and upper parts of the formation show massive to thick, current bedded deposits. Lithofacies analysis revealed that the Lumshiwal Formation was deposited in shallow marine for the lower cyclic part to transitionally prodeltaic to deltaic for the middle to upper part respectively. High silica contents in the upper part compare to the middle and lower part of the formation. On the basis of high silica and low alumina with other low fractions of rock fragments, the sandstone is categorized into quartzarenite, sub-litharenite and sub-arkose. Cross beds in the middle and upper parts of formation indicate west to east directed Paleo-current system prevailed during deposition of Lumshiwal Formation. Diagenetic and tectonically induced fractures make the formation exceedingly porous and permeable as suitable reservoir horizon for the accumulation of hydrocarbon in the Trans-Indus ranges. The same formation has already been proven as potential reservoir horizon for hydrocarbon in the Kohat Plateau of northwest Pakistan. Secondly, the formation is dominantly comprised of silica/quartz sandstone (quartzarenite) which can be used as silica sand, one of the essential raw materials for glass industries. The formation is also comprised of local coal seams which can be mined for production of coal in the region

Monitoring mangrove forest degradation and regeneration: landsat time series analysis of moisture and vegetation indices at Rabigh Lagoon, Red Sea

Rabigh Lagoon, located on the eastern coast of the Red Sea, is an ecologically rich zone in Saudi Arabia, providing habitat to Avicennia marina mangrove trees. The environmental quality of the lagoon has been decaying since the 1990s mainly from sedimentation, road construction, and camel grazing. However, because of remedial measures, the mangrove communities have shown some degree of restoration. This study aims to monitor mangrove health of Rabigh Lagoon during the time it was under stress from road construction and after the road was demolished. For this purpose, time series of EVI (Enhanced Vegetation Index), MSAVI (Modified, Soil-Adjusted Vegetation Index), NDVI (Normalized Difference Vegetation Index), and NDMI (Normalized Difference Moisture Index) have been used as a proxy to plant biomass and indicator of forest disturbance and recovery. Long-term trend patterns, through linear, least square regression, were estimated using 30 m annual Landsat surface-reflectance-derived indices from 1986 to 2019. The outcome of this study showed (1) a positive trend over most of the study region during the evaluation period; (2) most trend slopes were gradual and weakly positive, implying subtle changes as opposed to abrupt changes; (3) all four indices divided the times series into three phases: degraded mangroves, slow recovery, and regenerated mangroves; (4) MSAVI performed best in capturing various trend patterns related to the greenness of vegetation; and (5) NDMI better identified forest disturbance and recovery in terms of water stress. Validating observed patterns using only the regression slope proved to be a challenge. Therefore, water quality parameters such as salinity, pH/dissolved oxygen should also be investigated to explain the calculated trends

Assessment of above-ground biomass in Pakistan forest ecosystem’s carbon pool: A review

Climate change is acknowledged as a global threat to the environment and human well-being. Forest ecosystems are a significant factor in this regard as they act both as a sink and a source of carbon. Forest carbon evaluation has received more attention after the Paris Agreement. Pakistan has 5.1% forest cover of its total land area, which comprises nine forest types. This study covers the studies conducted on above-ground biomass and carbon stock in various forest types of Pakistan. Most of the studies on biomass and carbon stock estimation have been conducted during 2015–2020. The non-destructive method is mostly followed for carbon stock estimation, followed by remote sensing. The destructive method is used only for developing allometric equations and biomass expansion factors. The information available on the carbon stock and biomass of Pakistan forest types is fragmented and sporadic. Coniferous forests are more important in carbon sequestration and can play a vital role in mitigating climate change. Pakistan is a signatory of the Kyoto Protocol and still lacks regional and national level studies on biomass and carbon stock, which are necessary for reporting under the Kyoto Protocol. This study will help researchers and decision-makers to develop policies regarding Reducing Emissions from Deforestation and forest Degradation (REDD+), conservation, sustainable forest management and enhancement of forest carbon stock