Mixed Mangrove Forest Research Articles

Climate Change Mitigation Potential and Carbon Stock Assessment of Mixed Mangrove Forest, of the Great Kwa River, Nigeria

Climate Change Mitigation Potential and Carbon Stock Assessment of Mixed Mangrove Forest, of the Great Kwa River, Nigeria

Inventorying terrestrial mammal species in mixed-mangrove forest of the Lower Kinabatangan, Sabah, Borneo, Malaysia, with special reference to a new locality record of otter civet, Cynogale bennettii

Inventorying terrestrial mammal species in mixed-mangrove forest of the Lower Kinabatangan, Sabah, Borneo, Malaysia, with special reference to a new locality record of otter civet, Cynogale bennettii

Estimation of aboveground biomass using allometric relationship between DBH and height for mixed mangrove forest in Setiu Wetland, Terengganu, Malaysia

A study was conducted to determine aboveground biomass in a mixed mangrove forest in Setiu Wetland, Terengganu, Malaysia. A total of 22 plots were established, diameter breast height (DBH) and height of each of the trees were measured and recorded. A total of three species from Rhizophoraceae and eight species from the non-Rhizophoraceae family were recorded. The highest no. of species for Rhizophoraceae is Bruguiera cylindrica with 189 individuals, meanwhile for non-Rhizophoraceae is Heritiera littoralis with 36 individuals. Linear regression between DBH to height had been done for stem allometry analysis for each species with Avicennia lanata shows good fit (r2 = 0.906). The total aboveground biomass was 5 202.23 kg ha−1. A. lanata recorded the highest (983.78 kg ha−1) total aboveground biomass because of various ranges of DBH and height. Linear regression also had been done between aboveground biomass to DBH and height. Rhizophora apiculata (Rhizophoraceae) and Excoecaria agallocha (non-Rhizophoraceae) show the highest value of regression between aboveground biomass to DBH which are r2 = 0.925 and r2 = 0.948 while B. gymnorrhiza (Rhizophoraceae) and Xylocarpus granatum (non-Rhizophoraceae) show the highest value of regression between aboveground biomass to height with r2 = 0.806 and r2 = 0.839. Overall, non-Rhizophoraceae have higher aboveground biomass as compared to Rhizophoraceae.

Development of A Model for Detection of Saline Blanks Amongst Mangrove Species on Hyperspectral Image Data

In this study we apply hyperspectral imagery to identify saline blank patterns within the mixed mangrove forest of Sunderban Bio-geographic Province, West Bengal, India. We use derivative analysis to identify hyperspectral wavelengths that are sensitive to the presence of minerals comprising saline blanks. These wavelengths have been considered for development of a novel saline blank identification model. The wavelength showing derivative value with maximum absorption in the SWIR region at 1780 nm and maximum reflection in the red region at 690 nm has been extracted for development of saline blank index. This index has been compared with the existing salinity indices and a detailed analysis has been carried out. It is found that the index outperforms existing salinity indices – normalized differential salinity index and salinity index, and accurately detects the saline blank areas of Henry Island of the Sunderbans Delta. The accuracy of pixels identified as saline blank pixels has been assessed by comparing the overall accuracy with other existing indices. Physical sampling has also been carried out and the salinity results have been compared with the image-derived results.

Attenuation of waves from boat wakes in mixed mangrove forest of rhizophora and bruguiera species in matang perak

Attenuation of waves from boat wakes in mixed mangrove forest of rhizophora and bruguiera species in matang perak

Đặc điểm phân bố và môi trường sống của loài Sâm đất (Phascolosoma arcuatum, Gray 1828) tại rừng ngập mặn Cần Giờ

The results of the study on the distribution and environmental characteristics of Peanut Worms (Phascolosoma arcuatum, Gray 1828) in Can Gio mangrove forest show that: Peanut Worms live in the areas which have flood level < 1m, flood time < 30%, the topography from 0.8m to 1.7m and in the depth from 10 cm to 30 cm. They live in the soil from silty clay loam to clay which is quite porous, high humid, from acidic to neutral, organic-rich, heavy salty and less aluminous. The average density of the Peanut Worms is 7.44 individual/m2. Peanut Worms density in mixed mangrove forest is higher than that in planting Rhizophora apiculata forest and depends on the compartments. It is forecasted that the distribution area of Peanut Worms in Can Gio mangrove forest is about 24,323 ha and the caches of Peanut Worms are about from 285,600 kg to 535,500 kg/year.

Analysis of Multiple Scattering of Radiation amongst End Members in a Mixed Pixel of Hyperspectral Data for Identification of Mangrove Species in a Mixed Stand

The Sunderban Biosphere Reserve of southern West Bengal, India offers an ideal locale where Hyperspectral Remote Sensing may be applied for mapping diverse range of mangrove plantations that are unique to this pristine ecological system. This delta is characterized by both ‘pure’ and ‘mixed’ mangrove forest patches where photons interact with multiple species within the instantaneous field of view of the hyperspectral sensor, and multiple scattering between the vegetation canopies becomes significantly nonlinear. This paper attempts to apply the principle of multiple scattering of light in naturally occurring conditions and see how best they describe the resultant mixed spectra for certain endmember distributions. It is observed that natural forests, mixed mangrove forest in this case, are better suited for non-linear scattering models as compared to linear models. The non-linear model has successfully identified areas of interaction of mangrove mixtures such as ceriops-excoecaria-phoenix, excoecaria- avicennia alba avicennia officinalis etc. in the study area.

Changes in Carbon Pool and Stand Structure of a Native Subtropical Mangrove Forest after Inter-Planting with Exotic Species Sonneratia apetala

In this study, we compared stand structure, biomass and soil carbon pools, and litterfall production between a mixed mangrove forest consisting of Aegiceras corniculatum inter-planted with the exotic Sonneratia apetala and a native monospecific forest dominated by A. corniculatum in the intertidal area of Zhanjiang, Guangdong Province, southeast China. The goal of this study was to test the hypothesis that inter-planting fast growing exotic mangrove S. apetala into subtropical native mangrove forests will significantly increase C sequestration. Although the tree heights and basal diameters of S. apetala were significantly higher than those of A. corniculatum, the density of the 12-year-old S. apetala trees in the mixed forest was much smaller than that of A. corniculatum in the monospecific forest. In contrast to several previous studies on S. apetala forests planted directly on mangrove-free mudflats, the mixed mangrove forest showed no significant difference in either standing biomass or soil carbon pools from the native monospecific mangrove forest (p = 0.294 and 0.073, respectively) twelve years after inter-planting with S. apetala. Moreover, carbon cycling was likely speeded up after inter-planting S. apetala due to higher litterfall input and lower C/N ratio. Thus, inter-planting fast-growing S. apetala into native mangrove forest is not an effective way to increase carbon sequestration in this subtropical mangrove forest. Given that exotic plant species may exert negative impact on native mangrove species and related epifauna, this fast-growing mangrove species is not suitable for mangrove plantation projects aiming mainly at enhancing carbon sequestration.

Species Diversity and Regeneration Potential of Some Mixed Mangrove Forests in Escravos Communities Delta State Nigeria

Species Diversity and Regeneration Potential of Some Mixed Mangrove Forests in Escravos Communities Delta State Nigeria

Monitoring and Assessment of Leaf Litter Dynamics in a Mixed Mangal Forest of the Cross River Estuary, Nigeria

The leaf litter decomposition of Nypa fruticans, Rhizophora racemosa and Avicennia africana were studied across a tidal gradient in a mixed mangrove forest of the Cross River estuary Nigeria. Leaf litter decomposition was measured along the tidal gradients (low, mid, high) using litter bags. A single exponential model was used to study the decomposition rates of the leaves. Leaf decomposition varied significantly (P < 0.001) among species and spatially across tidal gradients over the study period. Decomposition was fastest in A. africana and slowest in N. fruticans and spatially, it was fastest at the low tide level and slowest at the high tide level. Tidal effects were much larger than species differences in the decomposition rates. The time (days) required for the loss of half the initial dry mass (T50) of the decomposing leaves at the low, mid and high tide levels were A. africana, 46, 57 and 77, R. racemosa 69, 86 and 115, and N. fruticans 86, 99 and 115 respectively. Estimates of leaf litter turnover rates showed that the actual litter turnover based on the relative measure of leaf litterfall and biomass on the forest floor (Kt) were much shorter than the projected litter turnover based on the leaf decomposition rates (Kd). The estimated actual residence times were less than one day while the projected residence times ranged from 83 to 142 days across tidal gradients, suggesting involvement of other ecological processes in litter loss and their possible transport into the Cross River estuary. The nitrogen contents and nutritional value of the decomposing leaves increased with time during the study. The increase varied significantly (P <0.001) among species, as well as temporally (P < 0.001) and spatially (P ≤ 0.05). The average C:N ratio decreased from 27.7 to 22.1 in A. africana, 26.4 to 23.9 in R. racemosa and 32.8 to 23.6 in N. fruticans. The overall changes in nutrients during decomposition indicated net mineralization. Mangrove leaf litter dynamics, trophic value and organic matter exchange of the system have implications on the productivity of the Cross River estuary and ultimately the Gulf of Guinea. Knowledge of these processes is critical for the maintenance and long term sustainability of the mangrove and surrounding ecosystems.

Characterizing spatial and seasonal variability of carbon dioxide and water vapour fluxes above a tropical mixed mangrove forest canopy, India

The above canopy carbon dioxide and water vapour fluxes were measured by micrometeorological gradient technique at three distant stations, within the world’s largest mangrove ecosystem of Sundarban (Indian part), between April 2011 and March 2012. Quadrat analysis revealed that all the three study sites are characterized by a strong heterogeneity in the mangrove vegetation cover. At day time the forest was a sink for CO2, but its magnitude varied significantly from −0.39 to −1.33 mg m − 2 s − 1. The station named Jharkhali showed maximum annual fluxes followed by Henry Island and Bonnie Camp. Day time fluxes were higher during March and October, while in August and January the magnitudes were comparatively lower. The seasonal variation followed the same trend in all the sites. The spatial variation of CO2 flux above the canopy was mainly explained by the canopy density and photosynthetic efficiency of the mangrove species. The CO2 sink strength of the mangrove cover in different stations varied in the same way with the CO2 uptake potential of the species diversity in the respective sites. The relationship between the magnitude of day time CO2 uptake by the canopy and photosynthetic photon flux was defined by a non-linear exponential curve (R2 ranging from 0.51 to 0.60). Water vapour fluxes varied between 1.4 and 69.5 mg m − 2 s − 1. There were significant differences in magnitude between day and night time water vapour fluxes, but no spatial variation was observed.

The role of structures mangrove in invading sand-mud due to typhoon impact on coastline in Bang La (Do Son) and Dai Hop (Kien Thuy), Hai Phong

Based on study about the role of mangrove forest in Bang La (Do Son) and Dai Hop (Kien Thuy) under acting in the typhoon number two on July 31, 2005, in preventing the muddy sand ridges have investigated and studied. The mangrove forest in Bang La is almost Kandelia obovata Shuen, Lui and Yong (at the seaward edge), and mixing of Sonneratia caseolaris (L) Engl in near shore; with 5-6 year age, average size of 172 cm and 195 cm in height; 76-86 mm in diameter, average density of tree is 17500/ha. In the mixed mangrove forest of Kandelia obovata with 380 cm in height and 121 mm of diameter. Covering of 93-95% area and average density of tree is 400/ha. In Dai Hop (Kien Thuy) there are three kinds of mangrove forest from of shore to on shore in succession of those. The First, Soneratia caseolaris (L) Engl, 5-6 year old, 459 cm in height, 149.5 mm of diameter that covering of 93% area and density of 1351 tree/ha. The second consisting of Kandelia obovata Shuen, Lui and Yong with 165.4 cm of medium height, 90.6mm of diameter that covering of 92% area, density of 16100 tree/ha and the third, near shore mixed consist of mangrove with 410 cm in height, 110.85 mm in diameter, density of 613 tree/ha. The wave height measured at the seaward edge of mangrove of the forest is variation of 1-1.5 m, with wave energy of 212.306 N/m2 that pushed a big of sand-sediment penetrating to the sea shore. However, in presence of the mangrove forest, sediment-sand just has reach to distance of 36-42 m and 55-58 m from edge of the forest in Bang La and Dai Hop, respectively. One to two months later after the typhoon ended, the material from sand bars scattered everywhere in the forest by affected of the wave and tidal current and seemingly no impacts seen along shoreline.

Success rates of recruited tree species and their contribution to the structural development of reforested mangrove stands

In response to widespread global degradation of mangrove forests, many initiatives have been undertaken to reforest degraded sites. However, many of these replantings are mono- specific, raising questions regarding habitat change and reduced ecological functions in mangrove plantations compared to natural mixed mangrove forests. The main objective of this study was to determine whether colonising mangrove juveniles can be recruited into the adult tree layer and thus enhance the structural complexity of previously reforested monospecific stands. Vegetation structure of originally monospecific replanted mangrove stands (Sonneratia alba and Rhizophora mucronata) that were 8 yr old was assessed. Instantaneous juvenile (seedling/sapling) diversity and abundance were determined. Adjacent natural stands were used as reference sites. The R. mucronata stand had the same species richness as its natural reference and thus had a higher Complexity Index due to recruitment of non-planted species into the adult tree population than in a previous assessment when it was monospecific. Juvenile species richness and diversity were similar between the R. mucronata stands (reforested and natural); however, the total juvenile density was significantly higher (p < 0.05) in the natural stand (7390 ± 660 juveniles ha -1 ) than in the reforested stand (2048 ± 667 juveniles ha -1 ). In contrast, the adult vegetation layer of the S. alba reforested stand remained monospecific, suggesting 100% mortality of previously observed non-planted mangrove juveniles. Many replanted mangroves around the globe are monocultures and are thus likely to have low thresholds to pertur- bations, as they do not benefit from the 'portfolio effect' provided in mixed species stands. Successful recruitment of non-planted species into replanted monospecific mangroves stands may therefore enhance ecosystem productivity and stability. However, more research needs to be conducted on traits of different mangrove species and their contribution to ecosystem productivity and sensitivities to environmental perturbations.

Impact of four-dimensional seismic and production activities on the mangrove systems of the Niger Delta, Nigeria

Reconnaissance survey and laboratory appraisal of the mangrove system in seven communities in the Niger Delta (Nigeria) endangered by seismic and production operations revealed several alterations of soil, sediment, and vegetation. Hydrocarbon content in the range of 0.3–1.1 mg/100 g was extracted within the proximities of spill sources and seismic lines. The prospect area covered by our investigation was characterized by a mixed mangrove forest dominated by Rhizophora racemosa. It was observed that the construction of the seismic lines was responsible for the vegetal disorientation recurrent in the area. The grass, Paspalum vaginatum, and the saltwater fern, Acrostichum aureum, were found at the fringe of most dredge spoils. The characteristic tidal inundation which increases mobility of the substrate, salinity fluctuation, and anoxia may also have contributed, at least in part, to the observed despoliation of some of these species found within the vicinities of the seismic lines and hydrocarbon percolation. Extensive revegetation program is recommended to ensure an effective restoration process of this ecologically fragile zone.

Leaf-burying crabs: Their influence on energy flow and export from mixed mangrove forests ( Rhizophora spp.) in northeastern Australia

Field experiments which compared the decomposition rate of leaves of the mangrove Rhizophora stylosa Griff, in the presence and absence of the leaf-consuming crab Sesarma messa (Campbell) showed that, by burying and consuming leaves, crabs had a highly significant effect on weight loss from leaves. Seasonal measurements of the rates of leaf litter fall and leaf removal (= burial plus consumption) by crabs during day- and night-time periods of low tide in low to mid-intertidal mixed Rhizophora forest showed that crabs could remove at least 154g·m −2·yr −1 or 28% of the annual leaf fall of 556g·m −2·yr −1. Crabs consumed >78% of the leaf material within 6 h of burial. These results show that an earlier attempt to measure detrital export from mangrove forests in northeastern Australia over-estimated export by at least 22% by ignoring leaf removal by crabs. In addition, the results indicate that current models of energy flow in mangrove forests, based mainly on work in Florida, must be altered to include the leaf litter → crab trophic link in order to describe accurately the food chains of mangrove forests in the Indo-West Pacific region.