Environment and Natural Resources Journal

Interactive Governance for the Sustainability of Marine and Coastal Resources in Thailand

Suvaluck Satumantpan — 2022-08-25

Coastal zones are biodiverse, with complex and dynamic interconnectivity between terrestrial and marine areas, and with multiple interactions between ecological and social systems. Despite on-going efforts to conserve and protect these ecosystems, destructive extraction and unsustainable resource utilization are persistent, posing challenges for governance. Issues and concerns in coastal zones are cross-sectoral and cross-boundary, often with overlapping jurisdictions. They are considered ‘wicked’ governance problems, requiring nuanced approaches to address, rather than technical quick fixes. Interactive governance is one such approach that examines relationships within and between the ecological and social systems, as well as with the governing system. Theoretically, the governability of coastal zones depends on the inherent quality of these systems and their interactions, and improving governability needs to take place in all three orders of governance. At the ‘first order’, a better understanding of the diversity, complexity and dynamics of coastal zones, and related scale issues is required. Improving governability at the ‘second order’ involves evaluating and adjusting the existing legal and institutional frameworks to improve the performance and the correspondence with the systems they aim to govern. Finally, discussion about coastal governance needs to be elevated to ‘meta-order’ where principles are set and values derived so that hard choices can be made, for instance, between conservation and utilization of coastal resources. Guided by the interactive governance framework, the paper presents an overview of coastal governance in Thailand, summarizing key features of the natural, social and governing systems associated with coastal zones, and discussing what can be done to improve coastal governability.

Soil Contamination by Phthalate Esters in Cultivated and Non-Cultivated Soils in North African Arid Regions: A Tunisian Case Study

Abdelhakim Bouajila — 2022-08-15

Over the last decades, several studies showed that phthalic acid esters (PAEs) were ubiquitous environmental contaminants and became a major threat to human health. This study provided the first case study about the concentration and the potential sources of soil’s PAEs, both in Tunisia and North Africa. Soil samples were collected from four cultivated (CS) and two adjacent native soils (NS) at 0-10 cm and 10-30 cm layers in southeastern Tunisia. The PAEs concentrations were analyzed using a gas chromatography-mass spectrometry (GC-MS) system. Results showed that the total concentration of PAEs ranged from 2.40 to 11.05%. Higher values were detected in NS in the 0-10 cm layer contrary to CS which showed higher PAEs concentration in 10-30 cm depth. The di-n-butyl phthalate (DBP) and di-(2-ethylhexyl) phthalate (DEHP) were the most abundant PAEs. In the 0-10 cm layer, PAEs concentration was highly related to the age of the plastic film in CS. We observed a positive association between PAEs concentration and conductivity (EC) values. The PAEs concentrations were affected by the presence of soil organic matter (SOM) in CS. This decrease of PAEs in CS compared to the NS may be related to the microbial decomposition activity stimulated by the presence of fresh organic residues and fertilizers. These results showed that CS and adjacent NS in the studied regions were contaminated by PAEs which is probably a result of agricultural activities. More investigations on PAEs concentrations in various soil managements are needed to confirm these results.

Spatial and Temporal Habitat Use by the Main Prey Species of Tigers in Two Protected Areas of Thailand’s Southern Western Forest Complex

Sasi Suksavate — 2022-08-01

Tigers (Panthera tigris) have disappeared from over 90% of their historical range, and extant populations face habitat loss, direct poaching, and prey depletion in otherwise suitable habitats. In Thailand, tiger numbers continue to decline due to prey depletion, yet a few strongholds remain. Recently, tigers have been detected in the Southern Western Forest Complex (sWEFCOM), following intensification of conservation efforts. However, there is still a lack of primary data on the status of tigers and their prey in the sWEFCOM. To fill this knowledge gap, we conducted camera trapping surveys between 2019 and 2020 in Khuean Srinagarindra National Park (KSR) and Salakphra Wildlife Sanctuary (SLP). Located near a tiger source population in Thungyai Naresuan and Huai Kha Khaeng, these areas are potential areas for tiger recovery. In particular, our study assessed the status of prey, a prerequisite to the persistence and recovery of tigers. Based on relative abundance indices, time overlap and occupancy models, we analysed the effect of anthropogenic and ecological factors on the spatial and temporal habitat use of the main prey species. We highlight that anthropogenic factor impacted species-specific habitat relationships. Mainly, shifts in ungulate temporal and spatial habitat use was linked to human activities. These relationships, however, differed between the two protected areas. As tiger recovery depends on prey recovery, we suggest that increased conservation law enforcement and greater engagement with villages within and adjacent to protected areas are essential to minimising unsustainable resource use practices that currently affect prey.

Bacterial Community of Klong Tub Mangrove Forest in Chonburi Province, Thailand

Papon Ganjanasiripong — 2022-08-24

Mangrove forests are located in the transition zone of terrestrial and river/marine ecosystems, making these forests a unique environment harbouring diverse microbes. This study investigated the bacterial community of Klong Tub Mangrove Forest in Chonburi Province, Thailand. The distinct feature of this forest is its nearby location to a narrowleaf cattail wetland. Assessment of the abiotic parameters of the sediments from site#1 nearby the narrowleaf cattail wetland and site#2 in the mangrove forest revealed differences in pH and salinity values between these two sites. Biochemical identification of bacterial isolates (n=233) indicated that these species belonged to 16 families and 29 genera as follows: Moraxellaceae (17.60%) > Vibrionaceae (16.31%) > Paenibacillaceae (15.88%) > Staphylococcaceae and Bacillaceae (9.87% each) > Aeromonadaceae and Pseudomonadaceae (8.58% each) > Enterobacteriaceae (4.29%) > Lactobacillaceae (2.58%) > Moraxellaceae (2.15%) > Comamonadaceae (1.72%) > Alcaligenaceae (0.86%) > Morganellaceae, Burkholderiaceae, Pasteurellaceae and Streptococcaceae (0.43% each). Among the genera, 12 were commonly isolated from both sites. Bacterial strains from 7 and 10 genera were detected only in site#1 and site#2, respectively. Analysis of the partial 16s rRNA gene sequence of four filamentous gram-positive isolates showed their high sequence similarity to three genera, including three novel species, Streptomyces sp. NA03103, Micromonospora fluminis sp. nov. and Bacillus velezensis sp. nov. In conclusion, the Klong Tub Mangrove Forest possesses high microbial diversity, and the bacterial taxon in the sediments differ between the narrowleaf cattail wetland and mangrove forest. Several bacterial isolates from the forest show a high biotechnological potential.

Evaluating Ecological Risk Associated with Heavy Metals in Agricultural Soil in Dong Thap Province, Vietnam

Nguyen Thanh Giao — 2022-08-16

Heavy metal pollution in soil has received more attention in recent years because of an increase in human activities and its potential effects on ecology and human health. This study assessed the occurrence of heavy metals (As, Pb, Cu, Zn, and Cd) in different cultivated land and their ecological risk in Dong Thap Province, Vietnam. Seventeen samples collected in paddy, vegetable, perennials, and ornamental soils were measured for heavy metal concentrations and soil structure. The data were analyzed using Pearson correlation, principal component analysis (PCA), cluster analysis (CA), Nemerow pollution index (PI_N), geoaccumulation index (I_geo), pollution load index (PLI), and potential ecological risk index (RI). The results revealed that the soil structure was clay loam and silt clay loam. Heavy metal concentrations were within the national limits with the order of Zn>Cu>Pb>As>Cd. Pearson correlation and PCA indicated that heavy metals were strongly correlated, and agriculture and soil formation were responsible for their presence in soil. The sampling sites were divided into four groups using CA, in which paddy and crop soils had the highest content of heavy metals. Based on PI_N values (0.82-2.92), the heavy metal pollution ranged from warning to moderate level. As had the highest accumulation potential in the soil, with the I_geo values ranging from 0.12-2.05. The risk of heavy metal pollution in agricultural soil to ecology was low to moderate. Despite that, it is recommended to annually monitor the occurrence of heavy metals in agricultural soils to have proper solutions to protect public health.

Exploration of Potential Indigenous Non-phytopathogenic Fungi for Bio-organic Fertilizer Recycling from Organic Waste

Abul Hossain Molla — 2022-08-18

Using potential microbes in biodegradable solid waste management is an emerging science. Microbes play a significant role in recycling of organic solid wastes. Therefore, the present project was carried out to isolate indigenous potential non-phytopathogenic fungi from local relevant decomposed substrates for the purpose of organic waste recycling as bio-organic fertilizer (BOF). A total of thirteen fungal strains were isolated. Seven of them were identified as Trichoderma spp., and the rest were Penicillium spp. Germination of mung bean (Vigna radiata), mustard (Brassica campestris), and wheat (Triticum aestivum) seeds were assessed by application of 13 fungal isolate suspensions. Significant increase of germination percent was achieved in mung bean (98.35%), mustard (96.65%), and wheat (93.35%) by fungal treatments RW-T02, PL-P01, and CD-T01/MSW-T05, respectively, compared to the controls. But radicle and plumule lengths were not promoted by fungal treatments in the majority of cases. Significantly, the longest radicle and plumule lengths of mung bean and mustard were found in control treatments. Conversely, in wheat the longest radicle and plumule length were achieved in treatments MSW-T05 and RW-T03, respectively. Based on superior performances of percent germination and radicle/plumule length, six fungal isolates were selected for compatibility performance in mixed cultures. In the compatibility tests, two fungal combinations (ABF and BCE) presented superior mutual intermingle appearances. Perhaps these combinations may play significant roles in biodegradation of organic wastes.

Biochar Derived from Sesbania sesban Plant as a Potential Low-Cost Adsorbent for Removal of Methylene Blue

Nguyen Trung Hiep — 2022-09-14

In this study, biochar made from the Sesbania sesban plant, under slow pyrolysis at 300°C was used to adsorb methylene blue (MB) in aqueous solution. The biochar properties were clarified by diverse analytical methods such as FTIR, SEM, and BET. The results indicated that the surface of biochar was relatively smooth, had porous texture, and stacked evenly. In addition, the biochar had a large specific surface area of 561.8 m²/g and the pH_pzc value was 6.9. The effect of adsorbent dosage, initial pH, contact time, and concentration of dye solution on biochar were investigated. The optimum conditions for MB adsorption were found at the MB concentration of 50 mg/L, initial pH of 11, biochar mass of 0.6 mg, and contact time of 30 min. Under these optimal conditions, MB dye removal efficiency was above 90%. Adsorption isotherm data were fitted with the Langmuir isotherm model (R²=0.897) suggesting the adsorption was monolayer, and its maximum adsorption capacity was about 6.6 mg/g. The adsorption kinetic models showed that the linear pseudo-second-order by R²=0.999 was well fitted. The results indicated the enormous potential of Sesbania sesban plant to produce biochar as a low-cost and rather high-effective adsorbent for dye removal from wastewater as well as water quality improvement.

Methane and Nitrous Oxide Emissions from Lowland Rice as Affected by Farmers’ Adopted Fertilizer Applications under Two Crop Establishment Methods in Myanmar

Myo Thet Tin — 2022-09-06

Identifying the optimal rice establishment option combined with specific fertilizer application can lower the global warming potential (GWP) and greenhouse gases intensity (GHGI) of rice production. In this study, methane (CH₄) and nitric oxide (N₂O) emissions and rice yields under different fertilizer application methods and two different planting methods, transplanted rice (TPR) and wet bed direct seeded rice (WDSR), was measured. Field experiments using a split plot design and closed chamber-GC method for gas flux measurements were conducted. CH₄ and N₂O emissions ranged from 1.83-4.68 mg/m²/h and 0.073-0.135 mg/m²/h, respectively. Minimum CH₄ and N₂O emissions were observed at 48-69 days after seedling (DAS) (tiller stage), while maximum emissions were generally found at 90 DAS or early primordial initiation (EPI) stage. It was found that TPR produced more CH₄ and N₂O than WDSR across fertilizers methods almost each growth stage throughout the growing period. Regarding GHGs emission factors, CH₄ emissions were negatively correlated with soil pH (-0.35*, N=18). At higher soil pH, lower CH₄ emissions were found in early growth stages. The N₂O emissions did not correlate with soil pH (-0.04 ns, N=18). The highest average CH₄ emission was reached in 90 days after seedling and EPI when the soil temperature was maximal at 34.8ºC. The correlation coefficient (r) between CH₄ emission and soil temperature was 0.48*, N=18, indicating a positive correlation.

Selectivity of Malachite Green on Cationic Dye Mixtures Toward Adsorption on Magnetite Humic Acid

Nur Ahmad — 2022-09-07

Magnetite humic acid (MHA) was successfully synthesized by the coprecipitation method followed by hydrothermal process, as evidenced by the XRD, FTIR, VSM, and SEM analysis characterization results. XRD diffraction shows diffraction peaks at 2=21.53º, 35.95º, and 57.93º. The FTIR spectra have a typical absorption at 3,410, 1,589, 1,396, 1,026, 910, 794, and 540 cm^-1. Magnetite humic acid was paramagnetic with magnetization (Ms) 17.04 emu/g. Humic acid and magnetite humic acid have an irregular structure; the morphology of magnetite humic acid is smoother than humic acid. Malachite green was more selective than methylene blue and rhodamine B on magnetite humic acid. The adsorption of malachite green on humic acid and magnetite humic acid was carried out at pH_pzc 8.06 and 6.08. The adsorption capacity (Q_max) of humic acid (77.519 mg/g) and magnetite humic acid (169.492 mg/g) were found with pseudo-second-order kinetic and Langmuir isotherm models. After five regeneration cycles, the adsorption percentages of malachite green with humic acid and magnetite humic acid ranged from 94.67-61.37% and 62.03-21.11%, respectively. Magnetite humic acid has high stability and reusability. The good regeneration of MHA was supported by the XRD diffractogram. Magnetic properties in the material simplify the adsorption process and minimize the potential for damage to the surface of the material.

Population Structure and Spatial Distribution of Tree Species in Lower Montane Forest, Doi Suthep-Pui National Park, Northern Thailand

Dokrak Marod — 2022-09-13

Plant diversity is important for sustainable development, particularly in watershed areas. This study explored tree population and diversity in a lower montane forest (LMF). A 16-ha permanent plot was established in LMF at Huai Kogma sub-watershed, northern Thailand. All trees with a diameter at breast height ≥ 2 cm were tagged, measured, identified, and their coordinates were mapped. The results showed that 220 species in 139 genera from 63 plant families were found. The dominant families based on species numbers and tree density were Fagaceae, Lauraceae, and Theaceae. The most dominant species were Castanopsis acuminatissima, Schima wallichii, Castanopsis armata, and Styrax benzoides. Diameter classes for climax species frequently followed negative exponential distributions, indicating their populations could be maintained into the future. By contrast, pioneer species, such as Macaranga indica, Morus macroura, and Rhus javanica, had discontinuous distribution, and were mostly found in gap areas, indicating successful regeneration may require high light intensity. Spatial distribution patterns based on Morisita’s index showed that most of the selected species had clumped patterns, particularly those in the Fagaceae family, which were predominantly distributed along the mountain ridge. Tree distribution patterns can affect ecological dynamics, thus reinforcing patterns dependent on local interactions such as the abundance of and distance to available resources. Our finding can aid evaluations of forest sustainability, and support the biodiversity conservation plans. In particular, the selection of suitable species for LMF restoration programs where mixed plantings of pioneer and climax species are planned.