Natural Mangrove Research Articles

Unveiling hidden interactions: Microorganisms, enzymes, and mangroves at different stages of succession in the Shankou Mangrove Nature Reserve, China

Understanding the interactions between microorganisms, soil extracellular enzymes, and mangroves is crucial for conserving and restoring mangrove ecosystems. However, the unique environments associated with mangroves have resulted in a lack of pertinent data regarding the interactions between these components. Root, stem, leaf, and soil samples were collected at three distinct stages of mangrove succession. Stoichiometry was employed to analyze the carbon, nitrogen, and phosphorus contents of these samples and to quantify extracellular enzyme activities, microbial biomass, and various physicochemical factors in the soil. The results showed that the trends of C, N, and P in the mangrove plants were consistent. Microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), and microbial biomass phosphorus (MBP) were the highest in the Kandelia obovate community. Catalase (CAT) and β-D-G showed the highest content in K. obovate and Bruguiera gymnorrhiza, whereas cellulase showed the opposite trend. Urease was least abundant in the K. obovate community, whereas neutral protease (NPR) and acid phosphatase (ACP) were most abundant. The overall soil environment in mangroves exhibited a state of N limitation, with varying degrees of limitation observed across different succession stages. The demand for P became more intense in the later stages of succession, particularly in the K. obovate and B. gymnorrhiza communities. In conjunction with correlation analysis, it indicated that the input of mangrove plant litter had a significant regulatory influence on the C, N, and P contents in the soil. There was a significant positive correlation between MBC, MBN, and MBP, indicating synergistic effects of C, N, and P on soil microorganisms. Therefore, evaluating the nutrient ratios and sufficiency of mangroves allowed us to comprehensively understand the present environmental conditions. This study aims to develop sustainable management strategies for the conservation and restoration of mangroves.

Assessing the Contributions of Nypa fruticans wumb in Climate Change Mitigation by Accounting for the Above Ground Carbon Stock within the Douala-Edea National Park, Littoral Region, Cameroon

Aim: Nypa fruticans Wurmb is a palm species found in mangrove ecosystems with moderate salt load which circumscribes well to the actual areas of its occurrence in the gradient from seawater habitats to inland sites. This study aimed at carrying out a baseline assessment of above ground carbon stock in stands of Nypa fruticans wurmb.
 Methods: Representative samples of seedlings, juveniles, adults and mature stands were harvested through a destructive sampling technique. These samples were air dried and further oven dried in the laboratory at 105°C until a constant mass was attained. The biomass was then converted to per carbon stock using the published carbon concentration of 0.5 for above-ground biomass.
 Results: Nypa fruticans wurmb has an average estimated carbon per mature frond of 0.77 kg, followed by the adult fronts with average estimated carbon per frond of 0.24 kg, the juvenile records an average carbon per juvenile frond of 0.11 kg and the seedlings with average estimated carbon per seedling frond of 0.02 kg.
 Conclusion: Nypa fruticans wurmb have a relatively small amount of biomass and carbon stock as compared to other woody mangrove species. 
 Recommendations: It is recommended that, carbon in the roots of this palm should be evaluated to complete the required information on this subject. The spread of this palm should be checked due to its negative impact on native mangroves and the indirect adverse effects it poses to climate change mitigation.

Ecological and archaeological consequences of ongoing, largely human-mediated colonisation of endemic soft, shelly habitats by mangroves in a northern New Zealand embayment

ABSTRACT Areal extent of native mangroves, Avicennia marina, has doubled in Bay of Islands since 1951. This expansion is widely attributed to deforestation and poor land-use practices beginning in the late 1800s to early 1900s, and led to greatly transformed intertidal and supratidal habitats. One example has been the ecological isolation and crowding (sometimes, colonisation) by mangroves of shelly beaches, together with their associated ‘chenier-like’ spits – themselves now among the rarest of New Zealand’s inshore marine habitats, with only six still relatively intact ecologically out of at least 44 in the Bay of Islands. These shores were also where pre Contact Māori often gathered to harvest intertidal cockles Austrovenus stutchburyi and to fish, archaeological signatures typically becoming obscured once mangroves colonised upper shores. Although recent seaward intrusion by mangroves into the cockle habitat of the Parekura Bay study site appears to have been proportionately small, there may be potential for more as elevated levels of sedimentation persist. With wholesale mangrove removals demonstrably ineffective in re-establishing original communities, the ongoing ecological and archaeological disruption of endemic soft, shelly contexts through largely human-mediated mangrove colonisation might be curbed in certain situations through strategic, proactive removal of new mangrove recruits, particularly on expanding edges.

Stochastic processes drive the diversity and composition of methanogenic community in a natural mangrove ecosystem

Methanogens are considered to be crucial components of mangrove ecosystems with ecological significance. However, understanding the assembly processes of methanogenic communities in mangrove ecosystems is relatively insufficient. In the current study, a natural mangrove in a protection zone was employed to investigate the diversity and assembly processes of methanogenic community by using amplicon high-throughput sequencing, a null model as well as a neutral community model. The results showed that methanogenic community in mangrove sediments were highly diverse, with the predominance of methylotrophic Methanolobus, and hydrogenotrophic Methanogenium, Methanospirillum. The diversity, composition, and gene abundance varied obviously across the mangrove sampling sites, whereas the measured environmental variables exhibited a negligible effect. Null model showed that the values of beta nearest-taxon index were mostly between −2 and 2, indicating that stochastic processes contributed more than deterministic processes driving the methanogenic community assembly in mangrove sediments. Neutral community model revealed a high estimated migration rate of methanogenic community, further substantiating the significance of stochastic processes. Among the keystone species identified in network analysis, methanogens affiliated to hydrogenotrophic Methanospirillum may have a crucial role in maintaining the structure and function of methanogenic community. Notably, these keystone species were almost unaffected by measured environmental factors, indicating that the methanogenic community in mangrove sediments is more likely to be affected by stochastic processes. This study deepens the understanding of the diversity and assembly of methanogenic community in mangrove sediments, and provides clues to maintain mangrove ecosystem functioning.

Community structure and regeneration capacity of mangrove forest

Mangrove forests play a vital role in the environment. They provide a number of ecosystem services for supporting marine biodiversity, humans, and other living organisms inhabiting the area. This study aimed to determine the community structure and regeneration capacity of mangrove forests in Lebak, Sultan Kudarat, Philippines. Community structure was determined through relative density, relative frequency, relative dominance, and importance value. Using the center point circular plot method, 13 plots with 40 m diameter were established in two sampling sites: natural stand and reforested. Shannon-Weiner diversity and evenness indexes were used to determine species diversity and distribution, respectively. This study recorded a total of 14 462 individuals within the 1256 m² sampling plots, having Rhizophoraceae as the most abundant family with seven species that cover about 71% of both mangrove ecosystems. The vegetation analysis revealed that Ceriops tagal (70.35%) and Rhizophora mucronata (96.51%) had the highest importance value in the natural stand and reforested mangrove forests, respectively. Furthermore, these two species were also accounted for having the highest regeneration contribution among all species in each site. Shannon-Weiner diversity index revealed that the natural stand was more diverse compared to the reforested mangrove forest. However, the Shannon-Weiner evenness index showed that species in the reforested mangrove forest are more evenly distributed than species in the natural stand. Natural mangrove stands in Lebak have complex community structure and have higher regeneration capacity than the reforested mangrove forest. With this, the study suggested continuing the best practices employed for mangrove conservation in the area and crafting a strategic plan for sustainable mangrove resource utilization.

Distribution of Mangrove Species Kandelia obovata in China Using Time-series Sentinel-2 Imagery for Sustainable Mangrove Management

Mangrove management in China is converting from emphasis on occupied area to intrinsical quality. Mangrove species have varied ecological values, e.g., those having well-developed prop roots are more beneficial for coastal stabilization. The detailed distribution of mangrove species on a national scale remains a challenge, impeding species-specific applications in the ecology and management of mangroves, as well as evaluations of related Sustainable Development Goals. Although local-scale studies have explored various data sources, the variability of plant phenology is the key factor preventing their generalization from local areas to large latitudinal spans (e.g., the coast of China). The separability time period, defined by a separability metric for each scene of the image time series, provides a potential way to tackle the aforementioned problem. We conducted a case study on mapping Kandelia obovata in China based on Sentinel-2 time-series imagery, as it is a representative native mangrove species with the largest latitudinal span and tolerance to low temperatures. The proposed approach considered the separability between K. obovata and its typical co-occurring mangrove species, as well as that between K. obovata and salt marshes. The overall accuracy of the generated K. obovata map in China for 2020 reached 88.5% based on independently collected samples. The proposed approach is transferable to diverse mangrove species that inhabit a vast latitudinal span. The implications for sustainable mangrove management were discussed to reveal the benefits to precise management of mangroves, accurate biomass and carbon estimations accounting for species differences, and effective evaluation of mangrove ecosystem services.

Exploring Nature-based Solutions on Refined Waterbird Habitats Restoration in High-density Urban Area: A Case Study of the Futian Mangrove National Important Wetland in Shenzhen, China

Exploring Nature-based Solutions on Refined Waterbird Habitats Restoration in High-density Urban Area: A Case Study of the Futian Mangrove National Important Wetland in Shenzhen, China

Performance of XGBoost Ensemble Learning Algorithm for Mangrove Species Classification with Multisource Spaceborne Remote Sensing Data

Accurately and timely monitoring the spatial distribution and composition of mangrove species is critical for assessing mangroves’ health, dynamics, and biodiversity, as well as mangroves’ degradation and restoration. Recent advances in machine learning algorithms, coupled with spaceborne remote sensing technique, offer an unprecedented opportunity to map mangroves at species level with high resolution over large extents. However, a single data source or data type is insufficient to capture the complex features of mangrove species and cannot satisfy the need for fine species classification. Moreover, identifying and selecting effective features derived from integrated multisource data are essential for integrating high-dimensional features for mangrove species discrimination. In this study, we developed a novel framework for mangrove species classification using spectral, texture, and polarization information derived from 3-source spaceborne imagery: WorldView-2 (WV-2), OrbitaHyperSpectral (OHS), and Advanced Land Observing Satellite-2 (ALOS-2). A total of 151 remote sensing features were first extracted, and 18 schemes were designed. Then, a wrapper method by combining extreme gradient boosting with recursive feature elimination (XGBoost-RFE) was conducted to select the sensitive variables and determine the optical subset size of all features. Finally, an ensemble learning algorithm of XGBoost was applied to classify 6 mangrove species in the Zhanjiang Mangrove National Nature Reserve, China. Our results showed that combining multispectral, hyperspectral, and L-band synthetic aperture radar features yielded the best mangrove species classification results, with an overall accuracy of 94.02%, a quantity disagreement of 4.44%, and an allocation disagreement of 1.54%. In addition, this study demonstrated important application potential of the XGBoost classifier. The proposed framework could provide fine-scale data and conduce to mangroves’ conservation and restoration.

Soil microbial community structure, function and network along a mangrove forest restoration chronosequence

Mangrove forests have high ecological, social and economic values, but due to environmental changes and human activities, natural mangrove forests have experienced serious degradations and reductions in distribution area worldwide. In the coastal zones of southern China, an introduced mangrove species, Sonneratia apetala, has been extensively used for mangrove restoration because of its rapid growth and strong environmental adaptability. However, little is known about how soil microorganisms vary with the restoration stages of the afforested mangrove forests. Here, we examined the changes in soil physicochemical properties and microbial biomass, community structure and function, and network in three afforested S. apetala forests with restoration time of 7, 12, and 18 years and compared them with a bare flat and a 60-year-old natural Kandelia obovata forest in a mangrove nature reserve. Our results showed that the contents of soil salinity, organic carbon, total nitrogen, ammonium nitrogen, and microbial biomass increased, while soil pH and bacterial alpha diversity decreased with afforestation age. Soil microbial community structure was significantly affected by soil salinity, organic carbon, pH, total nitrogen, ammonium nitrogen, available phosphorus, and available kalium, and susceptibility to environmental factors was more pronounced in bacterial than fungal community structure. The relative abundances of aerobic chemoheterotrophy were significantly higher in 12- and 18-year-old S. apetala than in K. obovata forest, while that of sulfate-reducing bacteria showed a decreasing trend with afforestation age. The abundance of dung saprotroph was significantly higher in 12- and 18-year-old S. apetala forests than in the natural forest. With the increasing afforestation age, the modularity of microbial networks increased, while stability and robustness decreased. Our results suggest that planting S. apetala contributes to improving soil fertility and microbial biomass but may make soil microbial networks more vulnerable.

2013–2022年福建漳江口互花米草分布无人机遥感数据集

The invasion of exotic Spartina alterniflora into Chinese coastal wetlands poses a threat to biodiversity and ecosystem functions. Thus monitoring the spatio-temporal distribution of the invasion is important for the conservation/restoration and scientific management of coastal wetlands. This dataset includes S. alterniflora spatial data, derived from UAV-based RGB photos over Zhangjiang Estuary, Fujian Province from 2013 to 2022. Using a drone equipped with a visible light camera, we selected low-tide periods during the day, we captured the aerial images in the Zhangjiang Estuary wetland in Fujian Province from 2013 to 2022. Subsequently, we employed the dynamic structure-from-motion (SFM) techniques to reconstruct a three-dimensional model by mosaicking the collected aerial images to obtain a digital orthophoto image covering the study area. This process was repeated annually, resulting in a total of ten orthophoto images. Based on the classified data derived from these orthophoto images, the spatial distribution data of S. alterniflora over ten consecutive years were extracted. The high-quality UAV photos in this dataset are comprehensive and uniformly color-balanced. Located within the Zhangjiang Estuary Mangrove National Nature Reserve with coastal wetland vegetations such as mangroves and S. alterniflora, the study area is one of the most typical mangrove-S. alterniflora ecotones in China. This long-term (over ten consecutive years) and high-resolution (20 cm) image dataset for mangrove-S. alterniflora ecotone can be used in many studies including monitoring coastal wetland vegetation succession, mangrove conservation and restoration, and S. alterniflora invasion.

High-Resolution Mapping of Mangrove Species Height in Fujian Zhangjiangkou National Mangrove Nature Reserve Combined GF-2, GF-3, and UAV-LiDAR

Mangroves as an important blue carbon ecosystem have a unique ability to sequester and store large amounts of carbon. The height of mangrove forest is considered to be a critical factor in evaluating carbon sink capacity. However, considering the highly complicated nature of the mangrove system, accurate estimation of mangrove species height is challenging. Gaofen-2 (GF-2) panchromatic and multispectral sensor (PMS), Gaofen-3 (GF-3) SAR images, and unmanned aerial vehicle-light detection and ranging (UAV-LiDAR) data have the capability to capture detailed information about both the horizontal and vertical structures of mangrove forests, which offer a cost-effective and reliable approach to predict mangrove species height. To accurately estimate mangrove species height, this study obtained a variety of characteristic parameters from GF-2 PMS and GF-3 SAR data and utilized the canopy height model (CHM) derived from UAV-LiDAR data as the observed data of mangrove forest height. Based on these parameters and the random forest (RF) regression algorithm, the mangrove species height result had a root-mean-square error (RMSE) of 0.91 m and an R2 of 0.71. The Kandelia obovate (KO) exhibited the tallest tree height, reaching a maximum of 9.6 m. The polarization features, HH, VV, and texture feature, mean_1 (calculated based on the mean value of blue band in GF-2 image), had a reasonable correlation with canopy height. Among them, the most significant factor in determining the height of mangrove forest was HH. In areas where it is difficult to conduct field surveys, the results provided an opportunity to update access to acquire forest structural attributes.

Evaluation of mangrove restoration effectiveness using remote sensing indices - a case study in Guangxi Shankou Mangrove National Natural Reserve, China

As one of the most productive marine ecosystems in the coastal wetlands, mangrove forests have been severely threatened by intensive human activities. Many countries and regions have carried out mangrove restoration projects. The evaluation of mangrove restoration effectiveness is of great significance for scientific decision-making for restoration engineering and wetland management. In this study, we presented a remote-sensing-based Mangrove Restoration Effectiveness Index (MREI) to evaluate mangrove restoration effectiveness. We took the Guangxi Shankou Mangrove National Natural Reserve (GSMNNR) in China, a UNESCO Biosphere Reserve, as our study area, where four phases of afforestation were implemented during 1990-2022. The MREI was developed based on Landsat-series images by considering the change in mangrove area and the Normalized Difference Vegetation Index (NDVI) from the start year to the end year of each afforestation phase (evaluation period). We further evaluated the Persistence of Restoration Effectiveness (PRE) based on the MREI change trajectory during the whole evaluation period, and the Process-based Restoration Effectiveness Index (PREI) was developed to evaluate the restoration effectiveness at village scale. The results showed that MREI can effectively represent the trajectory of mangrove restoration and showed consistent pattern with high-spatial-resolution imagery. From 1990 to 2022, the mangrove forest area increased from 235.26 ha in 1990 to 873.27 ha in 2022, and 84.59% of the mangrove forest was converted from tidal flats in the reserve. The average value of MREI in the five evaluation phases were 0.48, 0.24, 0.29, 0.17, and 0.72, respectively. The dynamic change of MREI showed that 5.24% of the zones had poor PRE, 44.17% of the zones had excellent PRE. From the perspective of spatial distribution, the Zones with PREI values ranging from high to low were follows: Zone A, E, J, G, C, H, I (D), F, B. Overall, the high value zones of PREI were mainly distributed in the central of the Dandou Sea and the northern part of the Yingluo Bay. The low value zones were distributed in the northwest of the Dandou Sea. We expect the MREI and PREI have great potential to be applied to other regions to evaluate mangrove restoration effectiveness.

ANALISIS KANDUNGAN KARBON PADA KERAPATAN VEGETASI MANGROVE ALAMI DAN REHABILITASI DI SUAKA MARGASATWA KUALA LUPAK

Global warming is one of the principal environmental issues that have a major impact on the world and life. One of the principal causes of global warming is the increase in greenhouse gases such as carbon dioxide. The mangrove forest is a carbon-absorbing area. The Kuala Lumpur wildlife reserve includes a representative of the mangrove forest-forest ecosystem with the conservation area that boasts natural mangrove forest vegetation and rehabilitation mangroves. The study aims to estimate biomass and carbon content on the natural mangrove vegetation and rehabilitation in the Kuala Lumpur wildlife reserve. The variables observed are mangrove vegetation (natural and rehabilitation), the level of severity (seldom, moderate, dense) as much as 3 times of the deuteronomy of mangrove vegetation (1a, 2a, 3a) and the mangrove rehabilitation (1b, 2b, 3b). Biomass measurements use allometric equations with carbon content obtained from biomass by 47%. The results showed the average biomass in the natural mangrove region at 434.3 tons /ha and in the rehabilitation area had an average of 11 tons /ha. Whereas the average carbon content in natural mangrove is 204.1 tons /ha and at the rehabilitation area of 5.2 tons /ha.

Conflicts in mangrove protected areas through the actor-centred power framework - Insights from China

Mangroves as a critical ecosystem in tropical and subtropical intertidal zones are undergoing accelerated degradation. Efforts to establish protected areas have been credited as a plausible way to protect mangroves. However, the rapid expansion of protected areas has severely eroded communities' livelihoods and power balance with local authorities, creating tensions between mangrove conservation and local aquaculture development. Based on the actor-centered power framework, we analyzed local residents' reactions and resistance to the highly politicized policies in the K Mangrove National Nature Reserve in China. By revealing power dynamics hidden in multi-actor conflicts under an authoritarian regime, our research sheds new light on how conflicts arise and escalate through the strategic use of power resources and imbalanced power configuration during structural change and policy implementation. Power relations between groups of actors are reshaped from tacit complicity to opposition between the policy coalition and the interest expression coalition. The deprivation by local authorities of community-owned soft power resources significantly exacerbates the power asymmetry between coalitions and triggers the adoption of stronger power strategies by the community and the escalation of resistance intensity. Our research has important implications for better conflict management and coastal resource management under authoritarianism.

Bacterial community regulation of soil organic matter molecular structure in heavy metal-rich mangrove sediments

Heavy metals (HMs) profoundly impact soil carbon storage potential primarily through soil carbon structure. The association between HM content and soil carbon structure in mangrove sediments remains unclear, likely due to the involvement of microorganisms. In this study, surface sediments in the Futian National Mangrove Nature Reserve were sampled to investigate the chemical structure of soil organic carbon (SOC), the molecular composition of dissolved organic matter (DOM), and potential interactions with microorganisms. HMs, except for Ni, were positively correlated with soil carbon. HMs significantly reduced the alkyl C/O-alkyl C ratio, aromaticity index, and aromatic C values, but increased the labile carboxy/amide C and carbonyl C ratio in SOC. HMs also increased DOM stability, as reflected by the reduced abundance of labile DOM (lipids and proteins) and increased proportion of stable DOM (tannins and condensed aromatics). Bacteria increased the decomposition of labile DOM components (unsaturated hydrocarbons) and the accumulation of stable DOM components (lignins) under HM enrichment. In addition, the association between the bacterial groups and DOM molecules was more robust than that with fungal groups, indicating bacteria had a more significant impact on DOM molecular composition. These findings help in understanding the molecular mechanisms of soil carbon storage in HM-rich mangroves.

Methanolobus mangrovi sp. nov. and Methanolobus sediminis sp. nov, two novel methylotrophic methanogens isolated from mangrove sediments in China.

Two methylotrophic methanogens, designated strains FTZ2T and FTZ6T, were isolated from mangrove sediment sampled in Futian Mangrove Nature Reserve in Shenzhen, PR China. Cells of strains FTZ2T and FTZ6T were cocci, with diameters of 0.6-1.0 µm and 0.6-0.9 µm, respectively. Both strains grew on methanol, methylamine, dimethylamine and trimethylamine, but not on acetate, formate, H2/CO2, choline, betaine or dimethyl sulphide. Strain FTZ2T grew at 10-37 °C (optimally at 33 °C), pH 5.5-8.0 (optimally at pH 7.0) and 0-1.03 M NaCl (optimally at 0.17 M NaCl). In contrast, strain FTZ6T grew at 15-42 °C (optimally at 37 °C), pH 5.0-7.5 (optimally pH 6.5) and 0-1.03 M NaCl (optimally at 0.17 M NaCl). Both strains required magnesium for growth and were susceptible to sodium dodecyl sulphate. Biotin was required for the growth of strain FTZ2T but not of strain FTZ6T. The genomic G+C contents of strains FTZ2T and FTZ6T were 41.6 and 40.9 mol%, respectively. Phylogenetic analyses revealed that strain FTZ2T was mostly related to Methanolobus psychrotolerans YSF-03T, with 16S rRNA gene similarity of 98.6 %, an average nucleotide identity (ANI) of 82.5 %, and a digital DNA-DNA hybridization (dDDH) of 24.6 %. While strain FTZ6T was mostly related to Methanolobus vulcani PL-12/MT, with 16S rRNA gene similarity of 99.4 %, an ANI of 88.6% and a dDDH of 34.6 %. Based on phenotypic, phylogenetic and genotypic evidence, two novel species of the genus Methanolobus, Methanolobus mangrovi sp. nov. and Methanolobus sediminis sp. nov., are proposed. The type strain of M. mangrovi sp. nov. is FTZ2T (=CCAM 1276T=JCM 39396T) and the type strain of M. sediminis sp. nov. is FTZ6T (=CCAM 1277T=JCM 39397T).

Sediment Carbon Stock in Natural and Transplanted Mangroves in Bahrain, Arabian Gulf

Mangroves in the Arabian Gulf provide several biological, ecological, and environmental services. They are also considered among the largest carbon sinks. However, mangroves along the coastlines of the Arabian Gulf have degraded in recent decades, mainly due to urbanization and coastal development. Therefore, restoration and afforestation programs have been initiated to enhance the services and functions of mangrove ecosystems and as part of national targets to mitigate climate change. Increasing carbon sinks by quadrupling the current areas covered by mangroves through afforestation programs by 2035 is one of the strategies to mitigate climate change in Bahrain. The aim of the present study was to estimate the organic carbon stocks in the sediments of natural and transplanted mangroves in Bahrain. Within the protected areas of Tubli and Arad Bays, sediment samples were taken down to a depth of 70 cm from natural and transplanted mangroves as well as a bare mudflat. The findings of the present study indicated that the total sediment organic carbon concentrations at three sampling sites of natural and transplanted mangroves and the mudflat were 200.54 ± 24.52, 112.36 ± 55.51, and 81.56 ± 8.92 Mg C/ha, respectively. The natural mangroves in Tubli Bay differed considerably from those in Arad Bay (p ≤ 0.001), based on the concentrations of organic carbon in sediments. However, there was a noticeable similarity seen in the organic carbon of the mangroves in Arad Bay that were transplanted 25 years prior and the natural mangroves in Tubli Bay, indicating the importance of a long-term mangrove afforestation strategy to mitigate climate change in the Arabian Gulf.

The Relationship Between Morphometric Characteristics and The Weight of Tubuca forcipata (Subfamily: Gelasiminae) in The Mangrove Nature Reserve of Eastern Coast Resort Mendahara, Jambi Province

The objective of this study is to ascertain the pathogenic and antagonistic fungi that induce disease in avocado plants (Persea americana Mill), identify the antagonistic fungi with the greatest antagonism potential among a variety of antagonistic fungi, and elucidate the mechanism by which antagonistic fungi inhibit the growth of pathogenic fungi. From January to May 2023, this study was conducted in vitro at the Microbiology Laboratory, State University of Malang, employing a completely randomized design (CRD) comprising six replications and four interventions. The identification of mold was accomplished through macroscopically and microscopically descriptive analysis, followed by a comparison with the mold identification key book. The antagonism process was executed utilizing the dual culture method on the PDA medium, and the electron microscope (SEM) was employed to witness the antagonism mechanism. The research findings revealed that T. harzianum spp. and T. viride were identified as antagonist fungi, whereas C. aotearoa and C. gloeospoiroides were identified as pathogenic fungi. The antagonistic fungus T. viride exhibited the greatest degree of antagonism, impeding the growth of C. gloeospoiroides by 77.8%. Observed antagonism occurs when the hyphae of the antagonistic mold ensnare, entangle, and pierce those of the pathogenic mold, causing harm to the region surrounding the pathogenic mold's hyphae and subsequently impeding its growth

Blue carbon sink capacity of mangroves determined by leaves and their associated microbiome.

Mangroves play a globally significant role in carbon capture and storage, known as blue carbon ecosystems. Yet, there are fundamental biogeochemical processes of mangrove blue carbon formation that are inadequately understood, such as the mechanisms by which mangrove afforestation regulates the microbial-driven transfer of carbon from leaf to below-ground blue carbon pool. In this study, we addressed this knowledge gap by investigating: (1) the mangrove leaf characteristics using state-of-the-art FT-ICR-MS; (2) the microbial biomass and their transformation patterns of assimilated plant-carbon; and (3) the degradation potentials of plant-derived carbon in soils of an introduced (Sonneratia apetala) and a native mangrove (Kandelia obovata). We found that biogeochemical cycling took entirely different pathways for S. apetala and K. obovata. Blue carbon accumulation and the proportion of plant-carbon for native mangroves were high, with microbes (dominated by K-strategists) allocating the assimilated-carbon to starch and sucrose metabolism. Conversely, microbes with S. apetala adopted an r-strategy and increased protein- and nucleotide-biosynthetic potentials. These divergent biogeochemical pathways were related to leaf characteristics, with S. apetala leaves characterized by lower molecular-weight, C:N ratio, and lignin content than K. obovata. Moreover, anaerobic-degradation potentials for lignin were high in old-aged soils, but the overall degradation potentials of plant carbon were age-independent, explaining that S. apetala age had no significant influences on the contribution of plant-carbon to blue carbon. We propose that for introduced mangroves, newly fallen leaves release nutrient-rich organic matter that favors growth of r-strategists, which rapidly consume carbon to fuel growth, increasing the proportion of microbial-carbon to blue carbon. In contrast, lignin-rich native mangrove leaves shape K-strategist-dominated microbial communities, which grow slowly and store assimilated-carbon in cells, ultimately promoting the contribution of plant-carbon to the remarkable accumulation of blue carbon. Our study provides new insights into the molecular mechanisms of microbial community responses during reforestation in mangrove ecosystems.

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.