scholarly journals Spatiotemporal Heterogeneity of Mangrove Root Sphere under a Tropical Monsoon Climate in Eastern Thailand

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 966
Author(s):  
Sarawan Hongwiset ◽  
Chadtip Rodtassana ◽  
Sasitorn Poungparn ◽  
Suthathip Umnouysin ◽  
Akira Komiyama
Keyword(s):  
Fine Roots ◽  
Secondary Forest ◽  
River Estuary ◽  
Nutrient Budget ◽  
Available Phosphorus ◽  
Wet Season ◽  
Mangrove Root ◽  
Tropical Monsoon ◽  
Mangrove Roots ◽  
Mangrove Zonation

Mangrove ecosystems under tropical monsoon climates experience changes in environmental factors, especially seasonal variations in salinity. These changes might have direct influences on the mangrove root sphere, which plays an important role in carbon dynamics and supports mangrove growth. We aimed to elucidate how the soil properties including salinity and nutrient budget affect the mangrove roots in the wet and dry seasons across the mangrove zonation (Avicennia, Rhizophora, and Xylocarpus zones). This area is in a secondary forest at the Trat River estuary, eastern Thailand. Root mass was observed at 0–10 and 10–20 cm depths across all zones and the living roots were separated into diameter classes. The soil water salinity was measured at a 10 cm depth. We analyzed the nitrogen, phosphorus, and carbon contents in the roots and soil. Spatiotemporal changes occurred due to the vegetation zonation and the variations in salinity and the content of soil available phosphorus that caused different root sphere conditions along the distance from the river. The highest root biomass was found in the riverward Avicennia zone, which was 4.8 times higher than that of the inland Xylocarpus zone in the wet season. The root necromass distribution along the zonation showed an opposite trend to that of biomass. Among seasons, the root size-class proportion differed, with high fine roots observed during the wet season. We confirmed that the root sphere showed both spatial and temporal heterogeneity. Mangrove roots, especially fine roots, interacted with changing salinity, inundation regime, and biological processes evoked by microtopographic gradients as a consequence of mangrove zonation and seasonal rainfall. Our findings indicate how the root sphere differed by specific vegetation structure in this mangrove forest. Therefore, these might provide an ecological perspective for the mangrove rehabilitation plans to facilitate below-ground carbon stock.

scholarly journals Shifts of Bacterioplankton Metabolic Profiles along the Salinity Gradient in a Subtropical Estuary

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Hidetoshi Urakawa ◽  
Jaffar Ali ◽  
Rheannon D. J. Ketover ◽  
Spencer D. Talmage ◽  
Juan C. Garcia ◽  
...  
Keyword(s):  
Salinity Gradient ◽  
Water Discharge ◽  
River Estuary ◽  
Metabolic Profiles ◽  
Wet Season ◽  
Biolog Ecoplates ◽  
Utilization Patterns ◽  
Subtropical Estuary ◽  
Discharge Patterns ◽  
Bacterioplankton Communities

Understanding the biodegradation potential of river bacterioplankton communities is crucial for watershed management. We investigated the shifts in bacterioplankton metabolic profiles along the salinity gradient of the Caloosahatchee River Estuary, Florida. The carbon source utilization patterns of river bacterioplankton communities were determined by using Biolog EcoPlates. The number of utilized substrates was generally high in the upstream freshwater dominated zone and low in the downstream zone, suggesting a shift in metabolic profiles among bacterioplankton assemblages along the estuarine gradient. The prokaryotic cell numbers also decreased along the estuarine salinity gradient. Seasonal and site-specific differences were found in the numbers of utilized substrates, which were similar in summer and fall (wet season) and winter and spring (dry season). Bacterioplankton assemblages in summer and fall showed more versatile substrate utilization patterns than those of winter and spring communities. Therefore, our data suggest that microbial metabolic patterns in the subtropical estuary are likely influenced by the water discharge patterns created by dry and wet seasons along the salinity gradient.

scholarly journals Does the Mixture of Species change the C:N:P Ecological Stoichiometric Characteristics of fine Roots? A Case Study of Cupressus Funebris Mixed Forest

2021 ◽  
Author(s):  
Wenchun He ◽  
Yang Wang ◽  
Xiaochen Wen ◽  
Yu Wang ◽  
Baoru Xiao ◽  
...  
Keyword(s):  
Fine Roots ◽  
Environmental Changes ◽  
Mixed Forest ◽  
Chemical Properties ◽  
Available Phosphorus ◽  
Biological Factors ◽  
Nitrogen And Phosphorus ◽  
Mixed Stands ◽  
Available Nitrogen ◽  
Low Efficiency

Abstract The growth of fine roots of trees is affected by environmental changes and biological factors. At present, there have been many researches on the physiological plasticity of fine roots caused by environmental changes, but there are still few studies on the influence of biological factors on fine roots. This paper focused on the contents of carbon (C), nitrogen (N), and phosphorus (P), and their ecological stoichiometric ratios in different root orders of Cupressus funebris fine roots in 11 mixed stands with Koelreuteria paniculate or Toona sinensis at different ratios, and the effects of soil physical and chemical properties on the root chemical properties. It aimed to provide new insights into the fine-root nutrient distribution pattern and the transformation or reconstruction of low-efficiency pure forests from the standpoint of forest types. The results showed that: soil pH, and the content of available nitrogen (SAN), available phosphorus (SAP) and available potassium (SAK) differed significantly in the tested mixed forest stands. No significant differences in carbon content of fine roots were observed in different mixed stands. The content of nitrogen and phosphorus in fine roots in mixed forests showed heterogeneity. Species mixing changed the C/N, C/P and N/P of the C. funebris compared the pure stands. The "T. sinensis + C. funebris" forest alleviated the limitation of the lack of phosphorus on fine roots of C. funebris on. The principal component analysis showed that mixed stands of "T. sinensis + C. funebris" had the highest comprehensive score at ratio of "3:1". Thus, our results recommended the adoption of T. sinensis, especially at 75%, to reconstruct the low-efficiency pure C. funebris forest.

scholarly journals Topological and Metagenomic Evidence For Intensified Bacterial-Fungal Interactions in Mangrove Root Interior

2021 ◽  
Author(s):  
Zhengyuan Zhou ◽  
Ruiwen Hu ◽  
Yanmei Ni ◽  
Wei Zhuang ◽  
Zhiwen Luo ◽  
...  
Keyword(s):  
Plant Performance ◽  
Sequencing Technologies ◽  
Mangrove Root ◽  
Domain Interactions ◽  
Network Topologies ◽  
Mangrove Roots ◽  
Metagenome Sequencing ◽  
Underlying Mechanisms ◽  
Bacteria And Fungi ◽  
Fungal Interactions

Abstract Background: Plant roots host a repertoire of bacteria and fungi, whose ecological interactions could improve their functions and plant performance. However, potential interactions and underlying mechanisms remain largely unknown in root-associated microbial communities at a continuous fine-scale. Results: We analyzed microbial intra- and inter-domain network topologies, keystone taxa, and interaction-related genes across four compartments (non-rhizosphere, rhizosphere, episphere and endosphere) from a soil-mangrove root continuum, using amplicon and metagenome sequencing technologies. We found that both intra- and inter-domain networks displayed notable differences in the structure and topology across four compartments. Compared to three peripheral compartments, the endosphere was a distinctive compartment with more intensive interactions in bacterial-fungal network than in bacterial or fungal network, which could be related to three bacterial keystone taxa (Vibrio, Anaerolineae and Desulfarculaceae) detected in the endosphere as they are known to intensify inter-domain interactions with fungi and stimulate biofilm formation. Also, high abundances of genes involved in cell-cell communications by quorum sensing (rhlI, lasI, pqsH and lasR) and aerobic cobamide biosynthesis (cobG, cobF and cobA) were detected in the endosphere.Conclusions: Our results reveal intensified inter-domain interactions of endophytes in the mangrove roots, creating a distinct micro-environment to promote a biofilm life-style.

Volumetric Three-Componential Velocity Measurements (V3V) of Flow Structure Behind Mangrove-Root Type Models

2020 ◽  
Author(s):  
Amirkhosro Kazemi ◽  
Eduardo E. Castillo ◽  
Oscar Curet ◽  
Ruben Hortensius ◽  
Pothos Stamatios
Keyword(s):  
Flow Structure ◽  
Vortex Structure ◽  
Streamwise Velocity ◽  
Circular Cylinders ◽  
Complex Flow ◽  
Time Resolved ◽  
Mangrove Root ◽  
Mangrove Roots ◽  
A Chain ◽  
Complex Flow Structure

Abstract Mangrove roots produce complex flow structure interactions with their environment, which affect the nutrient, habitat and aquatic animals. Analysis of the flow structure behind the roots extends to a broad range of mangrove-inspired applications that provides understanding into complex flows encountered in unidirectional riverine flows. In this work, we modeled the mangrove roots with a cluster of rigid circular cylinders to investigate the vortex structure downstream of the models. The vortex organization of the patch of cylinder wakes was studied experimentally by time-resolved volumetric three-componential volumetric velocimetry (V3V) at Reynolds numbers 1014 and 3549. The results show that the vortex structure in the 3-D flow field reveals a regular shedding at Re = 1014, forming von Kármán vortices dominating the 3D motion. The flow structure behind rigid patches is coherent and the streamwise velocity remains unchanged. The regime for a flexible patch at Re = 3549 produces an intricate pattern where the multiple counter-rotating vortexes distorted substantially and forming a chain of rhombus-like vortex cells in the near wake. The information for the 3D flow feature provides useful information to a robust structure for Seawall erosion.

Aspects of the reproductive biology of Pseudotolithus typus (Bleeker, 1863) from qua Iboe River Estuary, Nigeria

2020 ◽  
Vol 35 (1) ◽  
pp. 57-66
Author(s):  
A.I. Nta ◽  
A.W. Akpan ◽  
A.O. Okon ◽  
I.K. Esenowo
Keyword(s):  
Reproductive Biology ◽  
Gonadosomatic Index ◽  
River Estuary ◽  
Condition Index ◽  
Mean Value ◽  
Female Dominance ◽  
Wet Season ◽  
Female Ratio ◽  
Average Fecundity ◽  
Spawning Periods

The study was conducted to assess the reproductive biology and condition index of Pseudotolithus typus in Qua Iboe Estuary using standard methods. A total of 580 fish specimen were sampled over a period of 8 months (January – August, 2018). Condition index was generally low with the highest value of 1.03 recorded in the month of April. The overall mean condition index significantly deviated (p<0.05) from the expected value of 1.0. Male-female ratio of the species showed female dominance. Significant variation (p<0.05) were observed in condition and gonadosomatic indices with peak values in the months of March and July for females. Male fish showed no seasonality in gonadosomatic index. The average fecundity ranged from 2140 eggs to 8560 eggs with mean value of 4891±641 eggs. Positive correlation was observed between fecundity and total length, body weight, standard length and gonad weight of the fish. Thus, it could be concluded that P. typus is a dual seasonal spawner having spawning periods early in the year (March) and in the peak of wet season (July). Keywords: Pseudotolithus typus, condition index, gonadosomatic index, fecundity, estuary.

scholarly journals Some Correlation Coefficients of Maize under Soil-application of Pendimethalin in Mubi and Gombe Ecologies of Nigeria

2020 ◽  
Author(s):  
I. J. Dantata ◽  
E. A. Shittu ◽  
H. J. Philip ◽  
M. Sani
Keyword(s):  
Growth Rate ◽  
Grain Yield ◽  
Sea Level ◽  
Total Nitrogen ◽  
Chemical Properties ◽  
Growth And Yield ◽  
Available Phosphorus ◽  
Wet Season ◽  
Area Index ◽  
Yield Attributes

Field experiment was carried out during the wet season of 2012 at the Teaching and Research Farm of Faculty of Agriculture, Adamawa State University, Mubi (Lat.10° 15II N and Long.13° 16II E, altitude of 696 m above sea level) and a Community based Demonstration Farm in Gombe (Lat.11° 30” N and Long.10° 20” E, altitude of 340 m above sea level). Both locations were situated in the Northern Guinea Savanna agro-ecological zone of Nigeria. The study was carried out to determine the level of correlation between weed parameters, growth and yield attributes of maize as affected by pendimethalin application. Treatments which consisted of six different rates of pendimethalin (1.0, 2.0, 3.0, 4.0, 5.0, 6.0kg a.i.ha-1) + two control checks (weed free and weedy check) were placed in the main plots as main treatment while maize cultivar SAMMAZ 17 was placed in the sub-plots as sub-treatments in a split plot design and replicated three times. Pendimethalin was pre-emergence- applied a day after sowing (DAS). Weed free check plots (control) were kept weed free by regular weeding. Similarly, all agronomic practices were adequately carried out except those under study. Data collected on weed cover score (WCS), weed fresh weight (WFW), weed dry weight (WDW), days to 50% emergence (D50E), crop injury score (CIS), crop vigour score (CVS), establishment count (EC), plant height (PH), leaf area index (LAI), crop growth rate (CGR), relative growth rate (RGR), days to 50% tasseling (D50T), 1000 grain weights (1GWTs) and grain yield (GY) were analyzed using Minitab Version 11 Statistical Software. Results revealed that WCS was significantly higher and strongly correlated with WFW, WDW but was strong and negatively associated with GY of maize in both Mubi and Gombe. D50E, D50T and LAI were positive but contributed weakly to the GY of maize in Mubi. Similarly, D50E, D50T, PH and LAI had same pattern of behavior as the former in Gombe. EC was negative and also contributed weakly to the grain yield of maize in both locations. PH, CVS, CGR, 1GWTs were positive and strongly associated with GY of maize in Mubi. The same trend was also observed for all parameters except PH which though positive it was weakly associated to the final GY of maize in Gombe. Pendimethalin did not posed any significant effect on the post- physico-chemical properties of the soils at the two experimental sites, except in soil-pH, organic carbon, available phosphorus, total nitrogen, magnesium, potassium and sodium in Mubi and available phosphorus, total nitrogen, Calcium, Magnesium and Potassium in Gombe. These soil properties were significantly influenced by rates of soil applied Pendimethalin compared to the control checks.

scholarly journals Seasonal and spatial controls on N2O concentrations and emissions in low-nitrogen estuaries: Evidence from three tropical systems

2019 ◽  
Author(s):  
Rachel Murray ◽  
Dirk Erler ◽  
Judith Rosentreter ◽  
Naomi Wells ◽  
Bradley Eyre
Keyword(s):  
Inorganic Nitrogen ◽  
River Estuary ◽  
The Other ◽  
Dissolved Inorganic Nitrogen ◽  
Wet Season ◽  
Tropical Estuaries ◽  
Dry Seasons ◽  
Low Nitrogen ◽  
Fitzroy River ◽  
Wet And Dry Seasons

AbstractEstuarine N2O emissions contribute to the atmospheric N2O budget, but little is known about estuary N2O fluxes under low dissolved inorganic nitrogen (DIN) conditions. We present high-resolution spatial surveys of N2O concentrations and water-air fluxes in three low-DIN (NO3−< 30µmol L−1) tropical estuaries in Queensland, Australia (Johnstone River, Fitzroy River, Constant Creek) during consecutive wet and dry seasons. Constant Creek had the lowest concentrations of dissolved inorganic nitrogen (DIN; 0.01 to 5.4µmol L−1of NO3−and 0.09 to 13.6µmol L−1of NH4+) and N2O (93–132% saturation), and associated lowest N2O emissions (– 1.4 to 8.4µmol m−2d−1) in both seasons. The other two estuaries exhibited higher DIN inputs and higher N2O emissions. The Johnstone River Estuary had the highest N2O concentrations (97–245% saturation) and emissions (– 0.03 to 25.7µmol m−2d−1), driven by groundwater inputs from upstream sources, with increased N2O input in the wet season. In the Fitzroy River Estuary, N2O concentrations (100–204% saturation) and emissions (0.03–19.5µmol m−2d−1) were associated with wastewater inputs, which had a larger effect during the dry season and were diluted during the wet season. Overall N2O emissions from the three tropical estuaries were low compared to previous studies, and at times water-air N2O fluxes were actually negative, indicating that N2O consumption occurred. Low water column NO3−concentration (i.e. < 5µmol L−1) appears to promote negative water-air N2O fluxes in estuary environments; considering the number of estuaries and mangrove creeks where DIN falls below this threshold, negative water-air N2O fluxes are likely common.

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