Effects of perceptions of forest change and intergroup competition on community-based conservation behaviors.

Approximately one quarter of the earth's population directly harvests natural resources to meet their daily needs. These individuals are disproportionately required to alter their behaviors in response to increasing climatic variability and global biodiversity loss. Much of the ever-ambitious global conservation agenda relies on the voluntary uptake of conservation behaviors in such populations. Thus, it is critical to understand how such individuals perceive environmental change and use conservation practices as a tool to protect their well-being. We developed a participatory mapping activity to elicit spatially explicit perceptions of forest change and its drivers across 43 mangrove-dependent communities in Pemba, Tanzania. We administered this activity along with a questionnaire regarding conservation preferences and behaviors to 423 individuals across those 43 communities. We analyzed these data with a set of Bayesian hierarchical statistical models. Perceived cover loss in 50% of a community's mangrove area drove individuals to decrease proposed limits on fuelwood bundles from 2.74 (forest perceived as intact) to 2.37 if participants believed resultant gains in mangrove cover would not be stolen by outsiders. Conversely, individuals who believed their community mangrove forests were at high risk of theft loosened their proposed harvest limits from 1.26 to 2.75 bundles of fuelwood in response to the same perceived forest decline. High rates of intergroup competition and mangrove loss were thus driving a self-reinforcing increase in unsustainable harvesting preferences in community forests in this system. This finding demonstrates a mechanism by which increasing environmental decline may cause communities to forgo conservation practices, rather than adopt them, as is often assumed in much community-based conservation planning. However, we also found that when effective boundaries were present, individuals were willing to limit their own harvests to stem such perceived decline.

Efectos de las percepciones del cambio forestal y la competencia intergrupal en los comportamientos de conservación comunitarios Resumen Aproximadamente una cuarta parte de la población mundial aprovecha directamente los recursos naturales para satisfacer sus necesidades diarias. Estos individuos se ven desproporcionadamente obligados a alterar sus comportamientos en respuesta a la creciente variabilidad climática y la pérdida de biodiversidad global. Gran parte de la ambiciosa agenda de conservación global se basa en la adopción voluntaria de comportamientos de conservación en dichas poblaciones. Por lo tanto, es fundamental comprender cómo esas personas perciben el cambio ambiental y utilizan las prácticas de conservación como herramienta para proteger su bienestar. Desarrollamos una actividad de mapeo participativo para generar percepciones espacialmente explícitas del cambio forestal y sus causantes en 43 comunidades dependientes de manglares en Pemba, Tanzania. Administramos esta actividad junto con un cuestionario sobre preferencias y comportamientos de conservación a 423 personas en esas 43 comunidades. Analizamos estos datos mediante un conjunto de modelos estadísticos jerárquicos bayesianos. La pérdida de cobertura percibida en el 50% del área de manglares de una comunidad llevó a los individuos a reducir los límites propuestos para los paquetes de leña de 2.74 (bosque percibido como intacto) a 2.37 si los participantes creían que las ganancias resultantes en la cobertura de manglares no serían robadas por personas ajenas a la comunidad. Por el contrario, las personas que creían que los bosques de manglares de su comunidad corrían un alto riesgo de robo flexibilizaron los límites de cosecha propuestos de 1.26 a 2.75 haces de leña en respuesta a la misma disminución percibida del bosque. Por lo tanto, las altas tasas de competencia entre grupos y pérdida de manglares estaban impulsando un aumento, que se auto reforzaba, en las preferencias de aprovechamiento insostenibles en los bosques comunitarios de este sistema. Este hallazgo muestra un mecanismo por el cual el creciente deterioro ambiental puede hacer que las comunidades renuncien a las prácticas de conservación, en lugar de adoptarlas, como a menudo se supone en gran parte de la planificación de la conservación basada en la comunidad. Sin embargo, también encontramos que cuando existían límites efectivos, los individuos estaban dispuestos a restringir sus propias cosechas para frenar esa disminución percibida.

Multifarious plant growth-promoting traits of mangrove yeasts: growth enhancement in mangrove seedlings (Rhizophora mucronata) for conservation.

Plant Growth-Promoting Yeasts (PGPY) have garnered significant attention in recent years; however, research on PGPY from mangroves remains a largely unexplored frontier. This study, therefore, focused on exploring the multifaceted plant growth-promoting (PGP) capabilities of yeasts isolated from mangroves of Puthuvype and Kumbalam. The present work found that manglicolous yeasts exhibited diverse hydrolytic properties, with the predominance of lipolytic activity, in addition to other traits such as phosphate solubilization, and production of indole acetic acid, siderophore, ammonia, catalase, nitrate, and hydrogen cyanide. After screening for 15 PGP traits, three strains P 9, PV 23, and KV 35 were selected as the most potent ones. These strains also exhibited antagonistic activity against fungal phytopathogens and demonstrated resilience to abiotic stresses, making them not only promising biocontrol agents but also suited for field application. The potent strains P 9, PV 23, and KV 35 were molecularly identified as Candida tropicalis, Debaryomyces hansenii, and Aureobasidium melanogenum, respectively. The potential of these strains in enhancing the growth performance of mangrove seedlings of Rhizophora mucronata, was demonstrated using the pot-experiment. The results suggested that the consortium of three potent strains (P 9, PV 23, and KV 35) was more effective in increasing the number of shoot branches (89.2%), plant weight (87.5%), root length (83.3%), shoot height (57.9%) and total leaf area (35.1%) than the control seedlings. The findings of this study underscore the significant potential of manglicolous yeasts in contributing to mangrove conservation and restoration efforts, offering a comprehensive understanding of their diverse plant growth-promoting mechanisms and highlighting their valuable role in sustainable ecosystem management.

Novel insights into the synergetic degradation of pyrene by microbial communities from mangroves in China.

Pyrene is a high molecular weight polycyclic aromatic hydrocarbon (HMW-PAHs). It is a ubiquitous, persistent, and carcinogenic environmental contaminant that has raised concern worldwide. This research explored synergistic bacterial communities for efficient pyrene degradation in seven typical Southern China mangroves. The bacterial communities of seven typical mangroves were enriched by pyrene, and enriched bacterial communities showed an excellent pyrene degradation capacity of > 95% (except for HK mangrove and ZJ mangrove). Devosia, Hyphomicrobium, Flavobacterium, Marinobacter, Algoriphahus, and Youhaiella all have significant positive correlations with pyrene (R>0, p < 0.05) by 16SrRNA gene sequencing and metagenomics analysis, indicated that these genera play a vital role in pyrene metabolism. Meanwhile, the functional genes were involved in pyrene degradation that was enriched in the bacterial communities, including the genes of nagAa, ndoR, pcaG, etc. Furthermore, the analyses of functional genes and binning genomes demonstrated that some bacterial communities as a unique teamwork to cooperatively participate in pyrene degradation. Interestingly, the genes related to biogeochemical cycles were enriched, such as narG , soxA, and cyxJ, suggested that bacterial communities were also helpful in maintaining the stability of the ecological environment. In addition, some novel species with pyrene-degradation potential were identified in the pyrene-degrading bacterial communities, which can enrich the resource pool of pyrene-degrading strains. Overall, this study will help develop further research strategies for pollutant removal.

Mangrove mapping and monitoring using remote sensing techniques towards climate change resilience.

Mangroves are amongst the richest ecosystems in the world providing valuable goods and services to millions of people while enhancing the resilience of coastal communities against climate change induced hazards, especially island nations. However, these mangroves are severely affected by many anthropogenic activities. Therefore, understanding the spatial variability of mangroves in island nations is highly essential in the events of ongoing climatic change. Thus, this study assessed the use of remote sensing techniques and GIS to map and monitor mangrove cover change at selected sites, namely Le Morne and Ferney, on the tropical island of Mauritius. Freely available 2013 SPOT-5 and 2023 Sentinel 2A images were retrieved and processed using ArcGIS Pro tools and SNAP; mangroves were mapped based on Google Earth Pro historical imagery and ground truthing at the respective sites. Following the application of selected vegetation indices, GLCM and PCA analysis, mosaicked images were classified using the Random Trees algorithm. Kappa values of all the classified images were in the 90 s; Le Morne showed a significant increase in mangrove cover over the decadal scale with main class change from mudflat to mangroves. This study demonstrates how geo-spatial tools are crucial for monitoring mangroves as they provide spatially explicit and time sensitive information. Decision makers, researchers, and relevant stakeholders can utilize this data to bolster tailored mitigation and adaptation strategies at specific sites, thereby enhancing resilience to climate change.

Sounding out maerl sediment thickness: an integrated data approach.

Maerl beds are listed as a priority marine feature in Scotland. They are noted for creating suitable benthic habitat for diverse communities of fauna and flora and in supporting a wide array of ecosystem services. Within the context of climate change, they are also recognised as a potential blue carbon habitat through sequestration of carbon in living biomass and underlying sediment. There are, however, significant data gaps on the potential of maerl carbon sequestration which impede inclusion in blue carbon policy frameworks. Key data gaps include sediment thickness, from which carbon content is extrapolated. There are additional logistical and financial barriers associated with quantification methods that aim to address these data gaps. This study investigates the use of sub-bottom profiling (SBP) to lessen financial and logistical constraints of maerl bed sediment thickness estimation and regional blue carbon quantification. SBP data were cross validated with cores, other SBP data on blue carbon sediments, and analysed with expert input. Combining SBP data with estimates of habitat health (as % cover) from drop-down video (DDV) data, and regional abiotic data, this study also elucidates links between abiotic and biotic factors in determining maerl habitat health and maerl sediment thickness through pathway analysis in structural equation modelling (SEM). SBP data were proved to be sufficiently robust for identification of maerl sediments when corroborated with core data. SBP and DDV data of maerl bed habitats in Orkney exhibited some positive correlations of sediment thickness with maerl % cover. The average maerl bed sediment thickness was 1.08 m across all ranges of habitat health. SEM analysis revealed maerl bed habitat health was strongly determined by abiotic factors. Maerl habitat health had a separate positive effect on maerl bed sediment thickness.

Flushing emissions of methane and carbon dioxide from mangrove soils during tidal cycles.

Mangroves are transition areas connecting land, freshwater, and the ocean, where a great amount of organic carbon accumulates in the soil, forming a considerable carbon sink. However, the soil might also be a source of greenhouse gas (GHG) emissions. This study hypothesized that measuring GHG emissions solely during low tides can represent diurnal GHG emissions in mangroves. Methane (CH4) and carbon dioxide (CO2) emissions were quantified during tidal cycles using an ultraportable gas analyzer in Kandelia obovata (without pneumatophores) and Avicennia marina (with pneumatophores) mangroves in summer and fall. The results showed that the CH4 fluxes varied greatly during tidal cycles, from -1.25 to 96.24 µmol CH4 m-2 h-1 for K. obovata and from 2.86 to 2662.00 µmol CH4 m-2 h-1 for A. marina. The CO2 fluxes ranged from -4.23 to 20.65 mmol CO2 m-2 h-1 for K. obovata and from 0.09 to 24.69 mmol CO2 m-2 h-1 for A. marina. The diurnal variation in GHG levels in mangroves is predominantly driven by tidal cycles. The peak emissions of CH4 and CO2 were noted at the beginning of the flooding tide, rather than during daytime or nighttime. While the patterns of the CO2 fluxes during tidal cycles were similar between K. obovata and A. marina mangroves, their CH4 flux patterns during the tidal cycles differed. Possibly due to different transport mechanisms, CO2 emissions are primarily influenced by surface soils, whereas CH4 is predominantly emitted from deeper soils, thus being influenced by root structures. To reduce the uncertainty in measuring GHG emissions in mangrove soils during a tidal cycle, it is advisable to increase the number of GHG flux measurements during the period spanning 30 min before and after the beginning of the flooding and ebbing tides.

Phosphate buffering in mangrove sediment pore water under eutrophication and deforestation influences.

Phosphorus (P) behavior was evaluated in mangrove wetlands impacted by urban sewage, including a deforested site. Sediment cores were analyzed for grain size, organic carbon, total nitrogen, stable isotopes (δ13C and δ15N), P contents, and pore water PO43- concentrations and net consumption/production rates. Under stronger eutrophication influence, significantly higher P (1390 vs. <1000 µg/g), δ15N (8.9 vs. <6.7 ‰) and algal material contents (with lower C/N ratio and heavier δ13C) occurred. Depth-integrated PO43- consumption rates in eutrophicated sites were up to two orders of magnitude higher (at the deforested site) than in a moderately preserved mangrove. The whole core of the moderately preserved site presented no saturation of PO43- buffering capacity, while more eutrophicated sites developed buffering zones saturated at ∼18-26 cm depth. Contrasting to nearby subtidal environments, eutrophication did not cause larger pore water PO43- concentration, evidencing the role of PO43- buffering on P filtering by mangrove wetlands.

Ecological ramifications of marine debris in mangrove ecosystems: Estimation of substrate coverage and physical effects of marine debris on mangrove ecosystem in Negombo Lagoon, Sri Lanka.

The adverse environmental impacts on mangrove ecosystems due to anthropogenic marine debris contamination have attracted public attention not only in Sri Lanka but worldwide. Therefore, quantification of marine debris in sensitive ecosystems like mangroves is critical to assess the impacts on ecosystem vitality and services. We conducted this study to assess the abundance and density of marine debris in Negombo lagoon, Western Province, Sri Lanka. We selected two sites (n = 2) using the purposive sampling technique. Marine debris cover and concentration were calculated to explore the extent of pollution from marine debris. The findings revealed that 9.83 ± 1.05 % of the substrate of the mangrove ecosystem is covered by debris. Nine types of marine debris were recorded, and a higher abundance belonged to single-use plastic items. A significantly higher debris cover was found in Kadolkele (18.80 ± 1.74 %, n = 120) than in Molekadolwetiya (0.85 ± 0.03 %, n = 120) (One-way ANOVA, p < 0.05). The study indicated that the mangroves in lagoon are highly polluted with marine debris and act as "litter catchers." Correlation coefficient analysis was used to find the impact of debris cover on physical damage to roots, seedlings, and undergrowth vegetation. Correlation analysis revealed that physical damage to seedlings and branches/barks have a positive correlation with debris cover. To conserve these valuable coastal habitats in Negombo lagoon, it is recommended to take remedial measures to reduce arriving debris loads and to remove the debris present in mangroves.

Nitrogen enrichment changed the biogeochemical role of sesarmid crabs by shifting their diets in tropical mangrove ecosystems.

Sesarmid crabs modulate nutrient dynamics of tropical mangroves through their leaf-eating habit. How N enrichment may alter this regulatory role, and the implications for mangrove nutrient dynamics, remain unclear. Using a mesocosm experiment, we tested how N enrichment could change the microphytobenthos (MPB) communities, thus modifying the crabs' diet and their role in nutrient dynamics. The factorial experiment combined with field investigation revealed a significant increase in the relative abundance of cyanobacteria. Stable isotope analysis suggested that the main carbon source of crabs shifted from leaf litter to cyanobacteria in mesocosms under both high (20×) and low (2×) N enrichment treatments. The significantly lower total cellulase activity of crabs in the mesocosms might explain the decreased carbon assimilation from leaf litter. The changes in the MPB and the microbiome with N enrichment in the presence of crabs may drive significantly higher carbon processing rate in tropical mangroves.

Replacing Spartina alterniflora with northward-afforested mangroves has the potential to acquire extra blue carbon.

Climate change provides an opportunity for the northward expansion of mangroves, and thus, the afforestation of mangroves at higher latitude areas presents an achievable way for coastal restoration, especially where invasive species S. alterniflora needs to be clipped. However, it is unclear whether replacing S. alterniflora with northward-afforested mangroves would benefit carbon sequestration. In the study, we examined the key CO2 and CH4 exchange processes in a young (3 yr) northward-afforested wetland dominated by K. obovata. We also collected soil cores from various ages (3, 15, 30, and 60 years) to analyze the carbon storage characteristics of mangrove stands using a space-for-time substitution approach. Our findings revealed that the young northward mangroves exhibited obvious seasonal variations in net ecosystem CO2 exchange (NEE) and functioned as a moderate carbon sink, with an average annual NEE of -107.9 g C m-2 yr-1. Additionally, the CH4 emissions from the northward mangroves were lower in comparison to natural mangroves, with the primary source being the soil. Furthermore, when comparing the vertical distribution of soil carbon, it became evident that both S. alterniflora and mangroves contributed to organic carbon accumulation in the upper soil layers. Our study also identified a clear correlation that the biomass and carbon stocks of mangroves increased logarithmically with age (R2 = 0.69, p < 0.001). Notably, both vegetation and soil carbon stocks (especially in the deeper layers) of the 15 yr northward mangroves, were markedly higher than those of S. alterniflora. This suggests that replacing S. alterniflora with northward-afforested mangroves is an effective long-term strategy for future coasts to enhance blue carbon sequestration.

Spatio-temporal variation of water salinity in mangroves revealed by continuous monitoring and its relationship to floristic diversity.

Salinity is among the most critical factors limiting the growth and species distribution of coastal plants. Water salinity in estuarine ecosystems varies temporally and spatially, but the variation patterns across different time scales and salinity fluctuation have rarely been quantified. The effects of salinity on floristic diversity in mangroves are not fully understood due to the temporal and spatial heterogeneity of salinity. In this study, we monitored water salinity at an interval of 10-min over one year in three mangrove catchment areas representing the outer part, middle part, and inner part respectively of Dongzhai Bay, Hainan, China. The number of mangrove community types and dominant mangrove species of the three catchment areas were also investigated. We found that the diurnal variation and dry-season intra-month variation in water salinity were driven by tidal cycles. The seasonal variation in water salinity was mainly driven by rainfall with higher salinity occurring in the dry season and lower salinity occurring in the wet season. Spatially, water salinity was highest at the outer part, intermediate at the middle part, and lowest at the inner part of the bay. The intra-month and annual fluctuations of water salinity were highest at the middle part and lowest at the outer part of the bay. The number of mangrove community types and dominant species were lowest at the outer part, intermediate at the middle part, and highest at the inner part of the bay. These results suggest that the temporal variation of water salinity in mangroves is driven by different factors at different time scales and therefore it is necessary to measure water salinity at different time scales to get a complete picture of the saline environment that mangroves experience. Spatially, lower salinity levels benefit mangrove species richness within a bay landscape, however, further research is needed to distinguish the effects of salinity fluctuation and salinity level in affecting mangrove species richness.

Microplastics in Scylla Serrata: A baseline study from southwest India.

Scylla serrata plays a crucial role in India's seafood exports yet there exists limited understanding on the occurrence of microplastics (MPs) in these crabs. In this baseline study, we examined the presence of microplastics in the digestive tracts of S. serrata collected from the Kota mangroves, southwestern coast of India. Our analysis revealed the presence of 264 MPs in all the samples with an average (± standard deviation) of 29.33 (±11.53) MPs/Individual. The most dominant categories were fibres (98.86 %) and fragments (1.14 %). Primarily 0.1-0.3 mm (50.90 %) and 0.3-1 mm (37.65 %) size range dominated. The predominant polymers were polypropylene (33.71 %), high-density polyethylene (31.44 %), and polyethylene terephthalate (17.80 %). Scanning electron microscopy revealed extensive weathering on the surface of the microplastics. Risk assessments indicated severe risks to S. serrata due to microplastic ingestion emphasizing the need to protect delicate ecosystems like mangroves and the biota within.

Differences in organic carbon accumulation in mangrove soils due to foraging by herbivorous crabs.

Crabs in mangroves could enhance the transfer of organic carbon (OC) from leaf litter to soils, whose variation with the difference in crab size is, however, not well known. A 32-day laboratory feeding experiment was conducted to explore the effects of different sizes of the crabs Parasesarma plicatum foraging on leaf litter of Kandelia obovata on OC accumulation in mangrove soils. Mean rates of soil OC accumulation due to leaf foraging by large, medium, and small crabs were 21.11, 16.11, and 0.77 mg C ind-1 d-1, corresponding to the rates of OC removal from leaf litter of 62.60%, 51.37%, and 2.19%, respectively. Large and medium crabs ingested larger amounts of leaf litter, and soil OC accumulation rates resulting from leaf foraging by large and medium crabs were approximately 8 times higher than those by leaf litter decomposition and triple those by non-leaf foraging. Small crabs ingested the smallest amount of leaf litter, which was almost used for their growth and metabolism. These results underline the key ecological roles of leaf foraging by crabs, especially those with large and medium sizes, in OC accumulation in mangrove soils, which is conducive to estimating carbon sequestration in mangrove soils.

Impacts of Climate Change on Marine Foundation Species.

Marine foundation species are the biotic basis for many of the world's coastal ecosystems, providing structural habitat, food, and protection for myriad plants and animals as well as many ecosystem services. However, climate change poses a significant threat to foundation species and the ecosystems they support. We review the impacts of climate change on common marine foundation species, including corals, kelps, seagrasses, salt marsh plants, mangroves, and bivalves. It is evident that marine foundation species have already been severely impacted by several climate change drivers, often through interactive effects with other human stressors, such as pollution, overfishing, and coastal development. Despite considerable variation in geographical, environmental, and ecological contexts, direct and indirect effects of gradual warming and subsequent heatwaves have emerged as the most pervasive drivers of observed impact and potent threat across all marine foundation species, but effects from sea level rise, ocean acidification, and increased storminess are expected to increase. Documented impacts include changes in the genetic structures, physiology, abundance, and distribution of the foundation species themselves and changes to their interactions with other species, with flow-on effects to associated communities, biodiversity, and ecosystem functioning. We discuss strategies to support marine foundation species into the Anthropocene, in order to increase their resilience and ensure the persistence of the ecosystem services they provide.

China's conservation and restoration of coastal wetlands offset much of the reclamation-induced blue carbon losses.

China's coastal wetlands have experienced large losses and gains with rapid coastal reclamation and restoration since the end of the 20th century. However, owing to the difficulties in mapping soil organic carbon (SOC) in blue carbon stocks of coastal wetlands on a national scale, little is known about the spatial pattern of SOC stock in China's coastal wetlands and the loss and gain of SOC stock following coastal reclamation, conservation, and restoration over the past decades. Here, we developed a SOC stock map in China's coastal wetlands at 30 m spatial resolution, analyzed the spatial variability and driving factors of SOC stocks, and finally estimated SOC losses and gains due to coastal reclamation and wetland management from 1990 to 2020. We found that the total SOC stocks in China's coastal wetlands were 77.8 Tg C by 2020 with 3.6 Tg C in mangroves, 8.8 Tg C in salt marshes, and 65.4 Tg C in mudflats. Temperature, rainfall, and seawater salinity exerted the highest relative contributions to SOC spatial variability. The spatial trend of SOC density gradually decreased from south to north except for Liaoning province, with the lowest density in Shandong province. About 24.9% (19.4 Tg C) of SOC stocks in China's coastal wetlands were lost due to high-intensity reclamation, but SOC stock gained from conservation and restoration offset the reclamation-induced losses by 58.2% (11.3 Tg C) over the past three decades. These findings demonstrated the great potential of conservation and restoration of coastal wetlands in reversing the loss trend of blue carbon and contributing to the mitigation of climate change toward carbon neutrality. Our study provides significant spatial insights into the stocks, sequestration, and recovery capacity of blue carbon following rapid urbanization and management actions, which benefit the progress of global blue carbon management.

Novel insights into aerobic 17ß-estradiol degradation by enriched microbial communities from mangrove sediments.

Various persistent organic pollutants (POPs) including estrogens are often enriched in mangrove regions. This research investigated the estrogens pollution levels in six mangroves located in the Southern China. The estrogen levels were found to be in the range of 5.3-24.9 ng/g dry weight, suggesting that these mangroves had been seriously contaminated. The bacterial communities under estrogen stress were further enriched by supplementing 17ß-estradiol (E2) as the sole carbon source. The enriched bacterial communities showed an excellent E2 degradation capacity > 95 %. These communities were able to transform E2 into estrone (E1), 4-hydroxy-estrone, and keto-estrone, etc. 16 S rDNA sequencing and metagenomics analysis revealed that bacterial taxa Oleiagrimonas, Pseudomonas, Terrimonas, and Nitratireductor etc. were the main contributors to estrogen degradation. Moreover, the genes involved in E2 degradation were enriched in the microbial communities, including the genes encoding 17ß-hydroxysteroid dehydrogenase, estrone 4-hydroxylase, etc. Finally, the analyses of functional genes and binning genomes demonstrated that E2 was degraded by bacterial communities via dehydrogenation into E1 by 17ß-hydroxysteroid dehydrogenase. E1 was then catabolically converted to 3aα-H-4α(3'-propanoate)- 7aß-methylhexahydro-1,5-indanedione via 4,5-seco pathway. Alternatively, E1 could also be hydroxylated to keto-estrone, followed by B-ring cleavage. This study provides novel insights into the biodegradation of E2 by the bacterial communities in estrogen-contaminated mangroves.

The carbon stock potential of the restored mangrove ecosystem of Pasarbanggi, Rembang, Central Java.

Mangrove ecosystems can absorb significant amounts of carbon and help mitigate climate change. However, their existence continues to be endangered by natural and human forces. Therefore, mangrove restoration is regarded as a crucial component of the global climate change agenda. This study aims to estimate the potential total carbon stock of restored mangrove ecosystems in Pasarbanggi, Rembang, Central Java. The above-below-ground (root) carbon stock was calculated using several published allometric equations. The loss-on-ignition method analyzed leaf litter and sediment carbon stocks. This study estimates the Pasarbanggi mangrove ecosystem's total carbon stock potential at 0.02 × 106 MgC, which is equivalent to the potential CO2 emission of 0.08 × 106 MgCO2e, with up to 65% stored in sediments. This study highlights the critical role of restored mangrove ecosystems on the climate change mitigation agenda by reducing the concentration of atmospheric CO2.

Pseudodonghicola flavimaris sp. nov. and Sedimentitalea xiamensis sp. nov., two novel species belonging to the family Roseobacteraceae.

Two Gram-stain-negative, chemoheterotrophic, aerobic bacteria, designated IC7T and JM2-8T, were isolated from seawater of the Yellow Sea of China and rhizosphere soil of mangroves in Xiamen, Fujian, respectively. Phylogenetic analyses based on 16S rRNA gene and genome sequences showed that these two novel strains belonged to the family Roseobacteraceae. Strain IC7T formed a coherent lineage within the genus Pseudodonghicola, showing 98.05 % 16S rRNA gene sequence similarity to Pseudodonghicola xiamenensis Y-2T. Strain JM2-8T was most closely related to members of the genus Sedimentitalea, showing 96.51 and 96.73 % 16S rRNA gene sequence similarities to Sedimentitalea nanhaiensis NH52FT and Sedimentitalea todarodis KHS03T, respectively. The two novel strains contained Q-10 as the major quinone, and phosphatidylethanolamine, aminophospholipid, phosphatidylglycerol and phosphatidylcholine as the principal polar lipids. The main fatty acid of strain IC7T was C19 : 0 cyclo ω8c, while the fatty acid profile JM2-8T was dominated by summed feature 8 containing C18 : 1 ω7c and/or C18 : 1 ω6c. The average nucleotide identity and digital DNA-DNA hybridization values between these two novel isolates and their closely related species were below the cut-off values of 95-96 and 70 %, respectively. The combined genotypic and phenotypic data show that strain IC7T represents a novel species of the genus Pseudodonghicola, for which the name Pseudodonghicola flavimaris sp. nov. is proposed, with the type strain IC7T (=MCCC 1A02763T=KCTC 82844T), and strain JM2-8T represents a novel species of the genus Sedimentitalea, for which the name Sedimentitalea xiamensis sp. nov. is proposed, with the type strain JM2-8T (=MCCC 1A17756T=KCTC 82846T).

Avicennia germinans leaf traits in degraded, restored, and natural mangrove ecosystems of Guyana.

Mangrove leaves have unique features that enable them to cope with shifting environmental conditions while preserving their general functionality and efficiency. We examined the morphological characteristics and chlorophyll content (spectroscopically) of 600 mature Avicennia germinans leaves selected from 30 trees located in one degraded, one restored, and one natural mangrove ecosystem along Guyana's coastline. Systematic sampling was carried out using the closest individual sampling method in the wet and dry seasons. We hypothesized that both habitat type and seasonality influence the leaf traits and chlorophyll content of A. germinans. Our findings showed that A. germinans leaves are mesophyllous, and traits such as leaf perimeter, area, length, width, dry mass, wet mass, turgid mass, leaf-specific area, and relative water content showed fluctuations in ecosystems (one-way ANOVA, p < .05) as well as seasonally (paired t-test, p < .05). Substantial, positive correlations (p < .05, R > .75) were also established for over 10 leaf parameters in both seasons while PCA and multiple regression analyses further confirmed the strong relationships between leaf morphological features and their respective locations. Changes in chlorophyll concentration were most noticeable in the degraded ecosystem while variations in leaf traits were more pronounced in the restored mangrove area. This may be due to the various disturbances found in each ecosystem coupled with fluctuations in the seasons. Our results demonstrate that mangroves, to some extent, alter their plant structures to cope with environmental stressors present in the various ecosystems they thrive in to maintain their survival.

An Updated Review of Fossil Pollen Evidence for the Study of the Origin, Evolution and Diversification of Caribbean Mangroves.

Recently, the evolutionary history of the Caribbean mangroves has been reconsidered using partial palynological databases organized by the time intervals of interest, namely Late Cretaceous to Eocene for the origin, the Eocene-Oligocene transition for major turnover and Neogene to Quaternary for diversification. These discussions have been published in a set of sequential papers, but the raw information remains unknown. This paper reviews all the information available and provides the first comprehensive and updated compilation of the abovementioned partial databases. This compilation is called CARMA-F (CARibbean MAngroves-Fossil) and includes nearly 90 localities from the present and past Caribbean coasts, ranging from the Late Cretaceous to the Pliocene. Details on the Quaternary localities (CARMA-Q) will be published later. CARMA-F lists and illustrates the fossil pollen from past mangrove taxa and their extant representatives, and includes a map of the studied localities and a conventional spreadsheet with the raw data. The compilation is the most complete available for the study of the origin, evolution and diversification of Caribbean mangroves, and is open to modifications for adapting it to the particular interests of each researcher.