Changes in Salinity, Mangrove Community Ecology, and Organic Blue Carbon Stock in Response to Cyclones at Indian Sundarbans.

Climate change-induced frequent cyclones are pumping saline seawater into the Sundarbans. Fani, Amphan, Bulbul, and Yaas were the major cyclones that hit the region during 2019-2021. This study represents the changes in the soil parameters, mangrove biodiversity and zonation due to the cyclone surges in the Indian Sundarbans between 2017 and 2021. Increasing tidal water salinity (parts per thousand) trends in both pre-monsoon (21 to 33) and post-monsoon (14 to 19) seasons have been observed between 2017 and 2021. A 46% reduction in the soil organic blue carbon pool is observed due to a 31% increase in soil salinity. Soil organic blue carbon has been calculated by both wet digestion and the elemental analyzer method, which are linearly correlated with each other. A reduction in the available nitrogen (30%) and available phosphorous (33%) in the mangrove soil has also been observed. Salinity-sensitive mangroves, such as Xylocarpus granatum, Xylocarpus moluccensis, Rhizophora mucronata, Bruguiera gymnorrhiza, and Bruguiera cylindrica, have seen local extinction in the sampled population. An increasing trend in relative density of salinity resilient, Avicennia marina, Suaeda maritima, Aegiceras corniculatum and a decreasing trend of true mangrove (Ceriops decandra) has been observed, in response to salinity rise in surface water as well as soil. As is evident from Hierarchical Cluster Analysis (HCA) and the Abundance/Frequency ratio (A/F), the mangrove zonation observed in response to tidal gradient has also changed, becoming more homogeneous with a dominance of A. marina. These findings indicate that cyclone, climate change-induced sea level rise can adversely impact Sustainable Development Goal 13 (climate action), by decreasing organic soil blue carbon sink and Sustainable Development Goal 14 (life below water), by local extinction of salinity sensitive mangroves.

Exploring Indigenous and Local Knowledge and Practices (ILKPs) in Traditional Jhum Cultivation for Localizing Sustainable Development Goals (SDGs): A Case Study from Zunheboto District of Nagaland, India.

Globally, shifting cultivation is known to be an important driver of tropical deforestation. However, in this paper, we argue that it can be sustainably managed if the environmental boundary conditions, laid by the traditional customs and practices, are fully respected. We narrate an empirical study from the Zunheboto district of Nagaland, India, where we deployed a mixed research method to explore the Indigenous and Local Knowledge and Practices (ILKPs) associated with shifting cultivation (aka Jhum), particularly concerning farm-level practices, forest and biodiversity conservation, and disaster risk reduction measures. The research method included analysis of primary data obtained through Focus Group discussions (FGDs), key informant interviews (n = 21), and a questionnaire survey (n = 153) with Jhum farmers from two different age groups, i.e., below 50 years (middle-aged farmers) and above 50 years (older farmers). From the qualitative inquiry, we identified 15 ILKPs, which were then validated from survey responses. We used the Mann-Whitney U test to examine differences in agreement between two groups of framers. Based on this analysis, we conclude that upholding of the ILKPs holds strong potential for the local implementation of several Sustainable Development Goals (SDGs), particularly, SDG-1(No poverty), SDG-2 (Zero hunger), and SDG-15 (Life on land). However, eight of the identified ILKPs showed a statistically significant difference between older and middle-aged farmers, underlining a declining trend. Finally, we suggest suitable policy measures to mainstream ILKPs to balance the trade-offs in food production and biodiversity conservation, and to ensure the future sustainability of Jhum cultivation in the region and beyond.

Rethinking forest monitoring for more meaningful global forest landscape change assessments.

Forest ecosystems play an indispensable role in addressing various pressing sustainability and social-ecological challenges such as climate change, biodiversity loss, and ecosystem services deterioration, hence the monitoring of the world's forests is crucial. As part of the global forest assessment workflow, a forest is generally classified and mapped based on land use and/or using a tree canopy cover threshold. In this paper, we examine the limitations of this approach and argue that the use of a land use-based forest definition and tree canopy cover thresholds can overlook forest degradation and enhancement, disguise the actual status of forest landscapes, and misinform management planning. These limitations can delay the development and implementation of forest restoration and conservation measures. To help overcome these issues, we propose some enhancements to the global forest assessment workflow, including the sharing of spatial data and inclusion of tree canopy cover estimates in assessment reports. Such enhancements are needed to achieve more meaningful forest monitoring and reporting in the context of global environmental initiatives, such as those related to climate change mitigation and adaptation, forest restoration, biodiversity conservation, and ecosystem services monitoring.

Bushmeat, wet markets, and the risks of pandemics: Exploring the nexus through systematic review of scientific disclosures.

The novel coronavirus (SARS-CoV-2) is the third coronavirus this century to threaten human health, killing more than two million people globally. Like previous coronaviruses, SARS-CoV-2 is suspected to have wildlife origins and was possibly transmitted to humans via wet markets selling bushmeat (aka harvested wild meat). Thus, an interdisciplinary framework is vital to address the nexus between bushmeat, wet markets, and disease. We reviewed the contemporary scientific literature to: (1) assess disease surveillance efforts within the bushmeat trade and wet markets globally by compiling zoonotic health risks based on primarily serological examinations; and (2) gauge perceptions of health risks associated with bushmeat and wet markets. Of the 58 species of bushmeat investigated across 15 countries in the 52 articles that we analyzed,one or more pathogens (totaling 60 genera of pathogens) were reported in 48 species, while no zoonotic pathogens were reported in 10 species based on serology. Burden of disease data was nearly absent from the articles resulting from our Scopus search, and therefore was not included in our analyses. We also found that perceived health risks associated with bushmeat was low, though we could not perform statistical analyses due to the lack of quantitative perception-based studies. After screening the literature, our results showed that the global distribution of reported bushmeat studies were biased towards Africa, revealing data deficiencies across Asia and South America despite the prevalence of the bushmeat trade across the Global South. Studies targeting implications of the bushmeat trade on human health can help address these data deficiencies across Asia and South America. We further illustrate the need to address the nexus between bushmeat, wet markets, and disease to help prevent future outbreaks of zoonotic diseases under the previously proposed "One Health Framework", which integrates human, animal, and environmental health. By tackling these three pillars, we discuss the current policy gaps and recommend suitable measures to prevent future disease outbreaks.

Hydrological Simulation for Predicting the Future Water Quality of Adyar River, Chennai, India.

Just a few decades ago, Adyar River in India's city of Chennai was an important source of water for various uses. Due to local and global changes (e.g., population growth and climate change), its ecosystem and overall water quality, including its aesthetic value, has deteriorated, and the water has become unsuitable for commercial uses. Adverse impacts of excessive population and changing climate are expected to continue in the future. Thus, this study focused on predicting the future water quality of the Adyar river under "business as usual" (BAU) and "suitable with measures" scenarios. The water evaluation and planning (WEAP) simulation tool was used for this study. Water quality simulation along a 19 km stretch of the Adyar River, from downstream of the Chembarambakkam to Adyar (Bay of Bengal) was carried out. In this analysis, clear indication of further deterioration of Adyar water quality by 2030 under the BAU scenario was evidenced. This would be rendering the river unsuitable for many aquatic species. Due to both climate change (i.e., increased temperature and precipitation) and population growth, the WEAP model results indicated that by 2030, biochemical oxygen demand (BOD) and Escherichiacoli concentrations will increase by 26.7% and 8.3%, respectively. On the other hand, under the scenario with measures being taken, which assumes that "all wastewater generated locally will be collected and treated in WWTP with a capacity of 886 million liter per day (MLD)," the river water quality is expected to significantly improve by 2030. Specifically, the model results showed largely reduced concentrations of BOD and E.coli, respectively, to the tune of 74.2% and 98.4% compared to the BAU scenario. However, even under the scenario with measures being taken, water quality remains a concern, especially in the downstream area, when compared with class B (fishable surface water quality desirable by the national government). These results indicate that the current management policies and near future water resources management plan (i.e., the scenario including mitigating measures) are not adequate to check pollution levels to within the desirable limits. Thus, there is a need for transdisciplinary research into how the water quality can be further improved (e.g., through ecosystem restoration or river rehabilitation).

The future of Southeast Asia's forests.

While Southeast Asia's forests play important roles in biodiversity conservation and global carbon (C) balance, the region is also a deforestation hotspot. Here, we consider the five shared socioeconomic pathways (SSPs) to portray a range of plausible futures for the region's forests, employing a state-of-the-art land change modelling procedure and remotely sensed data. We find that by 2050 under the worst-case scenario, SSP 3 (regional rivalry/a rocky road), the region's forests would shrink by 5.2 million ha. The region's aboveground forest carbon stock (AFCS) would decrease by 790 Tg C, 21% of which would be due to old-growth forest loss. Conversely, under the best-case scenario, SSP 1 (sustainability/taking the green road), the region is projected to gain 19.6 million ha of forests and 1651 Tg C of AFCS. The choice of the pathway is thus critical for the future of the region's forests and their ecosystem functions and services.

The syntheses and photophysical properties of PNP-based Au(i) complexes with strong intramolecular AuAu interactions.

Herein we report the syntheses, X-ray structures and photophysical studies of the dinuclear dimeric gold(i) complexes [ClAu(C6H5N)(PPh2)2]2 (1), [Au(C6H5N)(PPh2)2]2[SbF6]2 (2) and [Au(2,6-Me2C6H3N)(PPh2)2]2[SbF6]2 (4). We have used ligands with different substituents to see the effect of the substituents on the photophysical properties. All these complexes feature strong intramolecular AuAu interactions (2.7987-3.0056 Å) and were found to exhibit excellent luminescence properties with high quantum yields as well as different colors of emission.

Catalyst free boron carbon bond cleavage and facile formation of five-membered PNBCC heterocycles.

The [3 + 2] cycloaddition reaction of phosphanyl aminoborane [N(2,6-iPr2C6H3)(PPh2)(BCy2)] (1) with activated alkynes led to boron and phosphorus containing five-membered heterocycles [(2,6-iPr2C6H3)NPPh2(CO2R)C-C(Cy)(CO2R)(BCy)] [R = Me (2), Et (3) and H (4)] with facile cleavage of the B-C bond and concomitant formation of a P-C bond with an ylidic character. DFT calculations indicate that 1 can be considered as a non-conjugated 1,3-dipole having two reaction centers viz., a nucleophilic P-center and an electrophilic B-center. The reaction of 1 with the alkynes proceeds through a stepwise dipolar addition mechanism, followed by the migration of the cyclohexyl group from the B-atom to the adjacent C-atom.

Strikingly diverse reactivity of structurally identical silylene and stannylene.

The reactivity of structurally identical silylene and stannylene [PhC(NtBu)2EN(SiMe3)2] (E = Si (1) and Sn (2)) towards coinage metals has been explored. While 1 has the propensity to form an adduct with coinage metals (4 and 5), 2 undergoes a ligand exchange reaction with copper halides and silver triflate leading to PhC(NtBu)2SnX (X = Br (6), Cl (7), and OSO2CF3 (8)) with concomitant formation of [M{N(SiMe3)2}] (M = Cu, Ag). However, with AgSbF6 both 1 and 2 led to ion pairs, 9+·SbF6-and 10+·SbF6- displaying weaker Ag·F interactions in the latter.

Organic and Inorganic Pollutant Concentrations Suggest Anthropogenic Contamination of Soils Along the Manali-Leh Highway, Northwestern Himalaya, India.

Most studies on roadside soil pollution have been performed in areas where petrol is the main fuel. Very little work has been conducted in regions where diesel predominates. We collected soil samples from four sites that span a precipitation gradient along the Manali-Leh Highway in northwestern Himalaya, India. This road traverses rough terrain and most of the vehicles that travel along it are diesel-driven. At each site, we collected samples at incremental distances from the highway (0, 2, 5, 10, 20, and 150 m), and at each distance we collected samples from three depths (3, 9, and 15 cm). We assessed the concentrations of 10 heavy metals (Al, Fe, Cr, Cu, Pb, Ni, Co, Zn, V, and Ba), total sulphur, and total organic carbon (TOC) at each distance, and we measured the concentration of 16 polycyclic aromatic hydrocarbons (PAHs) at 2 m from the highway. Overall, we found that metal concentrations are low and there is no relationship between concentrations and distance from the highway, or depth within the soil profile. Sulphur concentrations, on the other hand, are high in roadside soils and there is a negative relationship between concentration and distance from the highway. PAH concentrations are low, but the proportion of different ringed species suggests that their source is anthropogenic. Correlations between TOC and the various pollutants further suggest that diesel vehicles and potentially biomass combustion are starting to affect the roadside environment in remote northwestern India. We suggest that pollutant concentrations be regularly monitored.