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Allometry, biomass, and productivity of mangrove forests: A review

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Abstract

We review 72 published articles to elucidate characteristics of biomass allocation and productivity of mangrove forests and also introduce recent progress on the study of mangrove allometry to solve the site- and species-specific problems. This includes the testing of a common allometric equation, which may be applicable to mangroves worldwide. The biomass of mangrove forests varies with age, dominant species, and locality. In primary mangrove forests, the above-ground biomass tends to be relatively low near the sea and increases inland. On a global scale, mangrove forests in the tropics have much higher above-ground biomass than those in temperate areas. Mangroves often accumulate large amounts of biomass in their roots, and the above-ground biomass to below-ground biomass ratio of mangrove forests is significantly low compared to that of upland forests (ANCOVA, P < 0.01). Several studies have reported on the growth increment of biomass and litter production in mangrove forests. We introduce some recent studies using the so-called “summation method” and investigate the trends in net primary production (NPP). For crown heights below 10 m, the above-ground NPP of mangrove forests is significantly higher (ANOVA, P < 0.01) than in those of tropical upland forests. The above-ground litter production is generally high in mangrove forests. Moreover, in many mangrove forests, the rate of soil respiration is low, possibly because of anaerobic soil conditions. These trends in biomass allocation, NPP, and soil respiration will result in high net ecosystem production, making mangrove forests highly efficient carbon sinks in the tropics.

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... For comparison, the belowground biomass to aboveground biomass (R:S) ratio of mangroves was 0.46 or 1:2.17 in Kerala State, India [52] and 0.38 or 1:2.60 in Samar, the Philippines [3]. Mangrove forests have a higher root: shoot ratio (R: S) (generally R:S ratios between 0.33 or 1:3 and 0.50 or 1:2 [53]) when compared to the upland forests (R:S ratios between 0.22 or 1:4.52 and 0.25 or 1:3.96 [54]). Mangrove species are capable of allocating a high proportion of their total biomass to the belowground components which could be adapted to living in the soft sediments [53]. ...
... Mangrove forests have a higher root: shoot ratio (R: S) (generally R:S ratios between 0.33 or 1:3 and 0.50 or 1:2 [53]) when compared to the upland forests (R:S ratios between 0.22 or 1:4.52 and 0.25 or 1:3.96 [54]). Mangrove species are capable of allocating a high proportion of their total biomass to the belowground components which could be adapted to living in the soft sediments [53]. Figure 5 described the root: shoot (R:S) ratio against tree diameter at breast height (DBH in cm). ...
... The ratio of BGB (R:S ratio) ranged from 0.34 to 0.58 and the average ratio of BGB to AGB was 0.44 or For comparison, the belowground biomass to aboveground biomass (R:S) r mangroves was 0.46 or 1:2.17 in Kerala State, India [52] and 0.38 or 1:2.60 in Sam Philippines [3]. Mangrove forests have a higher root: shoot ratio (R: S) (generally R: between 0.33 or 1:3 and 0.50 or 1:2 [53]) when compared to the upland forests (R: between 0.22 or 1:4.52 and 0.25 or 1:3.96 [54]). Mangrove species are capable of all a high proportion of their total biomass to the belowground components which co adapted to living in the soft sediments [53]. ...
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Mangrove ecosystems sequester and store large amounts of carbon in both biomass and soil. In this study, species diversity, the above and below-ground biomass as well as carbon stock by the mangroves in Kanhlyashay natural mangrove forest were estimated. Six true mangrove species from four families were recorded in the sample plots of the study area. Among them, Avicennia officinalis L. from the Acanthaceae family was the abundance of species with an importance value of 218.69%. Shannon–Wiener’s diversity index value (H0 = 0.71) of the mangrove community was very low compared to other natural mangrove forests since the mangrove stands in the study site possessed a low number of mangrove species and were dominated by a few species. Estimated mean biomass was 335.55 ± 181.41 Mg ha−1 (AGB = 241.37 ± 132.73 Mg ha−1, BGB = 94.17 ± 48.73 Mg ha−1).The mean overall C-stock of the mangrove stand was 150.25 ± 81.35 Mg C ha−1 and is equivalent to 551.10 ± 298.64 Mg CO2 eq. The role of forests in climate change is two-fold as a cause and a solution for greenhouse gas emissions. The result of the study demonstrated that the mangroves in Letkhutkon village have high carbon storage potential, therefore it is necessary to be sustainably managed to maintain and increase carbon storage. Climate change mitigation may be achieved not only by reducing the carbon emission levels but also by maintaining the mangrove ecosystem services as carbon sinks and sequestration.
... Mangrove forests play unique ecological functions in subtropical coastal regions [1][2][3][4]. It takes years for the ecosystem to reach the maturity phase to facilitate the provision of providing essential services, such as fisheries, timber and fuelwood production [5,6], habitat protection [7], coastal defense [8], and carbon sink production in the tropics [9][10][11]. In compliance with the Reduced Emission from Deforestation and Land Degradation In this study, the equation developed by Komiyama et al. [11] known as 'the common equation' was applied for both practical and comparison application due to the segregation of the species and the similarity of the study site conditions to that of the Asian region. ...
... It takes years for the ecosystem to reach the maturity phase to facilitate the provision of providing essential services, such as fisheries, timber and fuelwood production [5,6], habitat protection [7], coastal defense [8], and carbon sink production in the tropics [9][10][11]. In compliance with the Reduced Emission from Deforestation and Land Degradation In this study, the equation developed by Komiyama et al. [11] known as 'the common equation' was applied for both practical and comparison application due to the segregation of the species and the similarity of the study site conditions to that of the Asian region. ...
... Moreover, the equation developed by Hazandy et al. [28] focused on the even-age planted mangrove. In this study, the equation developed by Komiyama et al. [11] known as 'the common equation' was applied for both practical and comparison application due to the segregation of the species and the similarity of the study site conditions to that of the Asian region. Apart from the D and H, the wood density (ρ) is one of the important enablers in estimating aboveground biomass as it differs significantly among various mangroves species [21]. ...
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The disturbance of mangrove forests could affect climate regulation, hydrological cycles, biodiversity, and many other unique ecological functions and services. Proper biomass estimation and carbon storage potential are needed to improve forest reference on biomass accumulation. The establishment of a site-specific allometric equation is crucial to avert destructive sampling in future biomass estimation. This study aimed to develop a site-specific allometric equation for biomass estimation of a mix-mature mangrove forest at Sungai Pulai Forest Reserve, Johor. A stratified line transect was set up and a total of 1000 standing trees encompassing seven mangrove tree species were inventoried. Destructive sampling was conducted using the selective random sampling method on 15 standing trees. Five allometric equations were derived by using diameter at breast height (D), stem height (H), and wood density (ρ) which were then compared to the common equation. Simulations of each allometric equation regarding species were performed on 1000 standing trees. Results showed that the single variable (D) equation provided an accurate estimation, which was slightly improved when incorporated with the H variable. Both D and H variables, however, gave inconsistent results for large-scale data and imbalance of sampled species. Meanwhile, the best fit either for small-scale or large-scale data, as well as for imbalanced sample species was achieved following the inclusion of the ρ variable when developing the equation. Hence, excluding the H variable while including the ρ variable should be considered as an important determinant in mixed mangrove species and uneven-aged stand for aboveground biomass estimation. This valuation can both improve and influence decision-making in forest development and conservation.
... More recently Goessens et al. [30] and Otero et al. [31] estimated the aboveground biomass to range (on average) from 216 to 372 Mg ha −1 and 217 to 238 Mg ha −1 , respectively. Subsequently, by combining site-and species-specific biomass observations from the MMFR [32] with those from Thailand and Indonesia [33], Komiyama et al. [34] provided a review on the allometric equations that have proved essential for mangrove research. Recently, Adame et al. [35] claimed that carbon loss due to the clear-felling activity at the MMFR recovers to carbon gain over a period of time, with the greatest recovery rates (9.5 Mg C ha −1 yr −1 ) being in the first ten years. ...
... The NDMI was further used to retrieve canopy cover (%). Furthermore, interferometric Shuttle Radar Topographic Mission (SRTM) X/C-band (2000), TanDEM-X-band (2010-2016), and stereo WorldView-2 stereo (2016) data were used to estimate canopy height (CH), from which above ground biomass (AGB, Mg ha −1 ), consisting of stem, branch, leaf biomass, and prop roots, was derived using pre-established allometry [16,34,[47][48][49]. ...
... To estimate the belowground biomass (BGB), i.e., the carbon pool associated with roots, the data from Goessens et al. [30] were analysed for forest age of 15, 20, and 30 years and aboveground and belowground carbon pools were computed using the equations by Komiyama et al. [34]. The biomass values were then converted to carbon using a conversion factor of 0.39 [50]. ...
Article
Matang Mangrove Forest Reserve (MMFR) in peninsular Malaysia has been managed for pole and charcoal production from Rhizophora stands with a 30-year rotation cycle since 1902. The aim of this study is to estimate the carbon budget of the MMFR by considering the carbon stock of the forest, evaluated from remote sensing data (Landsat TM and ETM+, JERS-1 SAR, ALOS PALSAR, ALOS-2 PALSAR-2, SRTM, TANDEM-X, and WorldView-2) for aboveground carbon and field data for belowground carbon. This was investigated in combination with the emissions from the silvicultural activities in the production chain, plus the distribution and consumer-related activities covering the supply chain, estimated with appropriate emission factors. The aboveground biomass carbon stock of the productive forest was of 1.4 TgC, while for the protective forest (not used for silviculture) it was at least equal to 1.2 TgC. The total soil carbon of ca. 32 TgC shows the potential of the MMFR as a carbon sink. However, the commercial exploitation of mangroves also generates greenhouse gasses with an estimate of nearly 152.80 Mg C ha−1 during charcoal production and up to 0.53 Mg C ha−1 during pole production, for a total emission of 1.8 TgC. Consequently, if the productive forest alone is considered, then the carbon budget is negative, and the ongoing silvicultural management seems to be an unsustainable practice that needs a reduction in the exploited area of at least 20% to achieve carbon neutrality. However, even with the current management, and considering the protective forest together with the productive zones, the MMFR carbon budget is slightly positive, thus showing the importance of mangrove conservation as part of the management for the preservation of the carbon stock.
... It involves cutting all trees into sections and components, drying them, and weighing them. The average tree method is usually be applied only in forests with a homogeneous size distribution in the trees, as in the case of the plantations (Komiyama et al., 2008). The allometric method uses measurable dimensions such as the diameter and tree height to estimate a tree's partial or total weight. ...
... The allometric method uses measurable dimensions such as the diameter and tree height to estimate a tree's partial or total weight. Allometric equations are available and applicable for all structural forms of mangroves (Clough et al., 1997;Ross et al., 2001;Dahdouh-Guebas et al., 2005;Komiyama et al., 2008). Saenger and Snedaker (1993) had reviewed 43 AGB equations of mangroves worldwide, to derive a single, global heightbiomass and height-productivity equation. ...
... Saenger and Snedaker (1993) had reviewed 43 AGB equations of mangroves worldwide, to derive a single, global heightbiomass and height-productivity equation. Also, Komiyama et al. (2008) had described the current state of knowledge on mangrove biomass and productivity equations based on 72 published studies in detail, while , and Comley and McGuiness (2005) described the mangroves species and related site-specific equations comprehensively. Chave et al. (2005) and Komiyama et al. (2005) proposed the use of equations that are not dependent on neither site nor species. ...
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The grey mangrove Avicenna marina, constructs one of the most critical coastal ecosystems in the Kingdom of Bahrain which has been severely deteriorated by increasing anthropogenic pressures. This study aimed to assess the spatiotemporal changes in the mangrove habitat around Tubli Bay, Kingdom of Bahrain, over the last 50 years through achieving the following: (1) detect the progressive reduction in the mangrove cover using Geographic Information Science and Systems (GISs) techniques and remote sensing data, (2) estimate the changes of above-below ground (AGB-BGB) carbon sequestered in the mangroves using a GIS-based spatial analysis approach, and (3) estimate the potential carbon emission change from the loss of original mangrove habitats. Various GIS and remotely sensed data were employed in the study, including high-resolution satellite images from Worldview-3. Worldview-2, IKONOS, and QuickBird, coupled with true-color orthorectified aerial photographs. Additional data was acquired from fieldwork and the ancillary GIS maps. Image processing of the satellite data was conducted using ENVI 5.5 software. ArcGIS 10.8 was used for digitizing the mangrove areas in all satellite imagery. The final maps were used to assess and calculate mangrove area changes. The spatiotemporal process was used to calculate carbon values and estimate the amount of carbon loss due to land reclamation activities. Our results indicated that Bahrain lost more than 95% of the natural mangrove cover during the period from 1967 to 2020. The net loss in the mangrove extent area reached 280 ha during 1967–2020, as it declined from 328 ha in 1967 to 48 ha in 2020. The primary cause of the decline was land reclamation associated with urban development. The rates and causes of the loss varied both spatially as well as temporally. Due to land clearing, the total carbon stored in the mangrove habitat declined from 34932.2 Mg C ha ⁻¹ in 1967 to 5112 Mg C ha ⁻¹ in 2020. Consequently, the potential carbon Sequestration decreased from 128,200.44 Mg CO2 eq. ha-1 in 1967 to 18,761.04 Mg CO2 eq. ha ⁻¹ in 2020. Our study urges for more efficient conservation of the remaining mangroves in Bahrain to sustain their valuable ecosystem services particularly the Sequestration of carbon.
... Mangrove forests play unique ecological functions in subtropical coastal regions [1][2][3][4]. It takes years for the ecosystem to reach the maturity phase to facilitate the provision of providing essential services, such as fisheries, timber and fuelwood production [5,6], habitat protection [7], coastal defense [8], and carbon sink production in the tropics [9][10][11]. In compliance with the Reduced Emission from Deforestation and Land Degradation In this study, the equation developed by Komiyama et al. [11] known as 'the common equation' was applied for both practical and comparison application due to the segregation of the species and the similarity of the study site conditions to that of the Asian region. ...
... It takes years for the ecosystem to reach the maturity phase to facilitate the provision of providing essential services, such as fisheries, timber and fuelwood production [5,6], habitat protection [7], coastal defense [8], and carbon sink production in the tropics [9][10][11]. In compliance with the Reduced Emission from Deforestation and Land Degradation In this study, the equation developed by Komiyama et al. [11] known as 'the common equation' was applied for both practical and comparison application due to the segregation of the species and the similarity of the study site conditions to that of the Asian region. ...
... Moreover, the equation developed by Hazandy et al. [28] focused on the even-age planted mangrove. In this study, the equation developed by Komiyama et al. [11] known as 'the common equation' was applied for both practical and comparison application due to the segregation of the species and the similarity of the study site conditions to that of the Asian region. Apart from the D and H, the wood density (ρ) is one of the important enablers in estimating aboveground biomass as it differs significantly among various mangroves species [21]. ...
Article
Full-text available
The disturbance of mangrove forests could affect climate regulation, hydrological cycles, biodiversity, and many other unique ecological functions and services. Proper biomass estimation and carbon storage potential are needed to improve forest reference on biomass accumulation. The establishment of a site-specific allometric equation is crucial to avert destructive sampling in future biomass estimation. This study aimed to develop a site-specific allometric equation for biomass estimation of a mix-mature mangrove forest at Sungai Pulai Forest Reserve, Johor. A stratified line transect was set up and a total of 1000 standing trees encompassing seven mangrove tree species were inventoried. Destructive sampling was conducted using the selective random sampling method on 15 standing trees. Five allometric equations were derived by using diameter at breast height (D), stem height (H), and wood density ( ) which were then compared to the common equation. Simulations of each allometric equation regarding species were performed on 1000 standing trees. Results showed that the single variable (D) equation provided an accurate estimation, which was slightly improved when incorporated with the H variable. Both D and H variables, however, gave inconsistent results for large-scale data and imbalance of sampled species. Meanwhile, the best fit either for small-scale or large-scale data, as well as for imbalanced sample species was achieved following the inclusion of the variable when developing the equation. Hence, excluding the H variable while including the variable should be considered as an important determinant in mixed mangrove species and uneven-aged stand for aboveground biomass estimation. This valuation can both improve and influence decision-making in forest development and conservation.
... The Global Forest Resources Assessment 2020 showed that forests all over the world stored an estimated 295 billion tons of carbon in biomass (FAO 2020). On a global scale, forests in tropical zones have much higher aboveground biomass than those in temperate zones (Komiyama, Ong, and Poungparn 2008). ...
... Because of difficulties in collecting below-ground biomass data, the majority of studies on biomass estimation are all based on aboveground biomass (Lu 2006), which is the largest carbon sink in forest ecosystems. There are a lot of research works on aboveground biomass and carbon stock, including those in mangrove forests such as (Komiyama, Ong, and Poungparn 2008) and (Hoàn et al. 2018). These studies used a lot of different methods to estimate biomass. ...
Article
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Aboveground biomass and carbon stock of Rhizophora apiculata forest in Ca Mau, Vietnam. Biodiversitas 23: 403-414. Despite the small proportion of mangrove forests globally, they contribute significantly in carbon storage. Yet, biomass and carbon stock in mangrove forests might vary depending on various factors including the dominant species that occurred. This study was conducted to determine the biomass and carbon stock of a mangrove forest dominated by Rhizophora apiculata Blume in Ca Mau, Vietnam. Data were collected from 56 representative sample plots (50m x 50m), and 46 sample trees with different age classes and diameter sizes were cut down to measure the fresh biomass. The dry biomass and carbon content were analyzed in the laboratory. The average aboveground biomass and carbon stock of the individual tree and the R. apiculata forest at different diameter sizes had a significant difference and were mostly found in the stem (74.5%-79.5%). The conversion factor from fresh biomass to dry biomass was 0.56; the conversion factor from dry biomass to carbon was 0.46. The total biomass of the individual trees had a close relationship with two variables diameter at breast height (DBH) and height (Hvn) in the form of the logarithmic function: ln(Wtk) =-1,86412-1,95419*ln(Hvn) + 2,26798*ln(DBH*Hvn). The total biomass and carbon stock of the entire forest stand increased in accordance with the diameter size and age classes. The R. apiculata stand had a density of 1,040-15,800 trees/ha and a timber volume of 27.2 to 365.6 m 3 /ha. The average biomass of the R. apiculata stand was 191.1 tons/ha with a range from 49.6 to 357.4 tons/ha. The carbon stock in forest biomass ranged from 23.8 to 188.7 tons C/ha, with an average of 117.4 tons C/ha. The forest's CO2 absorption ranged from 60.0 to 691.7 tons CO2/ha, with an average of 415.9 tons/ha. The carbon stocks of trees of age class I to age class VI were 41.6 tons C/ha, 79.4 tons C/ha, 101.4 tons C/ha, 132.9 tons C/ha, 154.0 tons C/ha, and 167.4 tons C/ha, respectively.
... Mangroves are the most widespread tree communities of the Gangetic delta, and their physiology is considerably influenced by surface water salinity (Zaman et al. 2014). Therefore, salinity alteration is clearly visualized in the mangrove community by way of differential growth of aboveground biomass (AGB) of sensitive species (Komiyama et al. 2008). ...
Article
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The alterations in the salinity profile are an indirect, but potentially sensitive, indicator for detecting changes in precipitation, evaporation, river runoff , glacier retreat, and ice melt. These changes have a high impact on the growth of coastal plant species, such as mangroves. Here, we present estimates of the variability of salinity and the biomass of a stenoecious mangrove species (Heritiera fomes, commonly referred to as Sundari) in the aquatic subsystem of the lower Gangetic delta based on a dataset from 2004 to 2015. We highlight the impact of salinity alteration on the change in aboveground biomass of this endangered species that, due to different salinity profile in the western and central sectors of the lower Gangetic plain, shows an increase only in the former sector, where the salinity is dropping and low growth in the latter, where the salinity is increasing.
... This is a non-destructive method and is thus useful for estimating temporal changes in forest biomass by means of subsequent measurements. However, the site and species-specific dependencies of allometric equations pose a problem to researchers because tree weight measurement in mangrove forests is labor-intensive [9] and often risky due to presence of wild animals (e.g., Sundarban mangrove is inhabited by man eating Royal Bengal tiger.) ...
Article
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The authors estimated the above ground biomass (AGB) of Sonneratia apetala Buch.-Ham in western and central Indian Sundarbans for five successive years (2005–2010) and analysed the change of carbon stock through time. The biomass and carbon content of the species varied significantly with age and site (p\0.01). This variation may be attributed to drastically different environmental conditions prevailing in the selected sectors of Indian Sundarbans. The western sector is relatively less saline and favourable for the growth of the mangrove species. The central sector is hypersaline on account of massive siltation that prevents the mixing of fresh water of the river Ganga with the river Matla. The growth and carbon content in the AGB of the species is significantly lower in this environment.
... This is a non-destructive method and is thus useful for estimating temporal changes in forest biomass by means of subsequent measurements. However, the site and species-specific dependencies of allometric equations pose a problem to researchers because tree weight measurement in mangrove forests is labor-intensive [9] and often risky due to presence of wild animals (e.g., Sundarban mangrove is inhabited by man eating Royal Bengal tiger.) ...
Article
Full-text available
The authors estimated the above ground biomass (AGB) of Sonneratia apetala Buch.-Ham in western and central Indian Sundarbans for five successive years (2005–2010) and analysed the change of carbon stock through time. The biomass and carbon content of the species varied significantly with age and site (p\0.01). This variation may be attributed to drastically different environmental conditions prevailing in the selected sectors of Indian Sundarbans. The western sector is relatively less saline and favourable for the growth of the mangrove species. The central sector is hypersaline on account of massive siltation that prevents the mixing of fresh water of the river Ganga with the river Matla. The growth and carbon content in the AGB of the species is significantly lower in this environment.
... Mangroves are the most widespread tree communities of the Gangetic delta, and their physiology is considerably influenced by surface water salinity (Zaman et al. 2014). Therefore, salinity alteration is clearly visualized in the mangrove community by way of differential growth of aboveground biomass (AGB) of sensitive species (Komiyama et al. 2008). ...
Article
Full-text available
The alterations in the salinity profile are an indirect, but potentially sensitive, indicator for detecting changes in precipitation, evaporation, river runoff , glacier retreat, and ice melt. These changes have a high impact on the growth of coastal plant species, such as mangroves. Here, we present estimates of the variability of salinity and the biomass of a stenoecious mangrove species (Heritiera fomes, commonly referred to as Sundari) in the aquatic subsystem of the lower Gangetic delta based on a dataset from 2004 to 2015. We highlight the impact of salinity alteration on the change in aboveground biomass of this endangered species that, due to different salinity profile in the western and central sectors of the lower Gangetic plain, shows an increase only in the former sector, where the salinity is dropping and low growth in the latter, where the salinity is increasing.
... This is a non-destructive method and is thus useful for estimating temporal changes in forest biomass by means of subsequent measurements. However, the site and species-specific dependencies of allometric equations pose a problem to researchers because tree weight measurement in mangrove forests is labor-intensive [9] and often risky due to presence of wild animals (e.g., Sundarban mangrove is inhabited by man eating Royal Bengal tiger.) ...
Article
Full-text available
The authors estimated the above ground biomass (AGB) of Sonneratia apetala Buch.-Ham in western and central Indian Sundarbans for five successive years (2005–2010) and analysed the change of carbon stock through time. The biomass and carbon content of the species varied significantly with age and site (p\0.01). This variation may be attributed to drastically different environmental conditions prevailing in the selected sectors of Indian Sundarbans. The western sector is relatively less saline and favourable for the growth of the mangrove species. The central sector is hypersaline on account of massive siltation that prevents the mixing of fresh water of the river Ganga with the river Matla. The growth and carbon content in the AGB of the species is significantly lower in this environment.
... In early forest stand development, the aboveground net primary production (ANPP) of mangrove stands is gradually increasing and then declines as stands age [49]. It is also known that a high proportion of mangrove ANPP is shed as litter [50]. Young stands of planted mangroves are found to have an increasing trend of litterfall production following their stand's age, as observed in Gazi Bay, Kenya, and Tam Giang Lagoon, Vietnam [11,51]. ...
Article
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Mangrove restoration projects are now widely established, aiming to regain the carbon benefit of the mangrove ecosystem that is essential for climate change mitigation. This study aimed to investigate mangrove litter as the source of carbon in restored mangrove forests in Perancak Estuary, Bali, Indonesia, which previously experienced substantial mangrove loss due to shrimp aquaculture development. We assessed the production and decomposition of mangrove litter and associated macrozoobenthic biodiversity in restored forests with plantation age ≥14 years and intact mangrove forests as the reference. The monthly production of three groups of mangrove litter (leaf, reproductive, and wood) was assessed over 12 months. A leaf litter decomposition experiment was performed to inspect the interspecific and disturbance history variation in organic matter formation among four major mangrove species: Rhizophora apiculata, Bruguiera gymnorhiza, Avicennia marina, and Sonneratia alba. Our results showed that annual litterfall production from restored and intact mangroves in Perancak Estuary were 13.96 and 10.18 Mg ha−1 year−1, which is equivalent to approximately 6282 and 4581 kg C ha−1 year−1 of annual litterfall carbon sink, respectively. Although restored mangroves had significantly higher plant litterfall production than intact mangroves, no significant difference was detected in leaf litter decomposition and macrozoobenthic biodiversity between these forest types.
... W 0.5 is the biomass when C = 0.5 which is a critical value in the model as it defines when mangrove competition may result in tree mortality. To set W 0.5 , the aboveground (W a ) and belowground (W b ) biomass of a single Avicennia marina are first evaluated through allometric equations (Komiyama et al., 2008): ...
Article
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Mangrove forests are valuable coastal ecosystems that have been shown to persist on muddy intertidal flats through bio-morphodynamic feedbacks. However, the role of coastal conditions on mangrove behavior remains uncertain. This study conducts numerical experiments to systematically explore the effects of tidal range, small wind waves, sediment supply and coastal slope on mangrove development under sea-level rise (SLR). Our results show that mangroves in micro-tidal conditions are more vulnerable because of the gentler coastal equilibrium slope and the limited ability to capture sediment, which leads to substantial mangrove landward displacement even under slow SLR. Macro-tidal conditions with large sediment supply promote accretion along the profile and platform formation, reducing mangrove vulnerability for slow and medium SLR, but still cause rapid mangrove retreat under fast SLR. Small wind waves promote sediment accretion, and exert an extra bed shear stress that confines the mangrove forest to higher elevations with more favorable inundation regimes, offsetting SLR impacts. These processes also have important implications for the development of new landward habitats under SLR. In particular, our experiments show that landward habitat can be created even with limited sediment supply and thus without complete infilling of the available accommodation space. Nevertheless, new accommodation space may be filled over time with sediment originating from erosion of the lower coastal profile. Consistent with field data, model simulations indicate that sediment accretion within the forest can accelerate under SLR, but the timing and magnitude of accretion depend non-linearly on coastal conditions and distance from the mangrove seaward edge.
... While the mangrove soil C dynamics are complex and involve physical, biogeochemical, and ecological processes (Kristensen et al., 2008;Alongi, 2014;Bukoski et al. 2020) that still remain poorly understood, one of the most important variables determining soil C dynamics may be related to mangrove productivity. Mangroves supply their products, such as leaf litter and dead roots, to the soil C pool (Kristensen et al., 2008;Alongi, 2014;Ouyang et al., 2017), which are closely related to forest structural variables such as canopy height and above-ground biomass (AGB) (Saenger and Snedaker, 1993;Komiyama et al., 2008). Such autochthonous C accounts for a significant amount of total soil C in mangrove forests (Xiong et al., 2018;Sasmito et al., 2020). ...
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In mangrove forests, soil salinity is one of the most significant environmental factors determining forest distribution and productivity as it limits plant water uptake and carbon gain. However, salinity control on mangrove productivity through plant hydraulics has not been investigated by existing mangrove models. Here we present a new individual-based model linked with plant hydraulics to incorporate physiological characterization of mangrove growth under salt stress. Plant hydraulics was associated with mangroves' nutrient uptake and biomass allocation apart from water flux and carbon gain. The developed model was performed for two coexisting species – Rhizophora stylosa and Bruguiera gymnorrhiza – in a subtropical mangrove forest in Japan. The model predicted that the productivity of both species was affected by soil salinity through downregulation of stomatal conductance. Under low-soil-salinity conditions (< 28 ‰), B. gymnorrhiza trees grew faster and suppressed the growth of R. stylosa trees by shading that resulted in a B. gymnorrhiza-dominated forest. As soil salinity increased, the productivity of B. gymnorrhiza was significantly reduced compared to R. stylosa, which led to an increase in biomass of R. stylosa despite the enhanced salt stress (> 30 ‰). These predicted patterns in forest structures across the soil salinity gradient remarkably agreed with field data, highlighting the control of salinity on productivity and tree competition as factors that shape the mangrove forest structures. The model reproducibility of forest structures was also supported by the predicted self-thinning processes, which likewise agreed with field data. Aside from soil salinity, seasonal dynamics in atmospheric variables (solar radiation and temperature) were highlighted as factors that influence mangrove productivity in a subtropical region. This physiological principle-based improved model has the potential to be extended to other mangrove forests in various environmental settings, thus contributing to a better understanding of mangrove dynamics under future global climate change.
... Mangroves are the most widespread tree communities of the Gangetic delta, and their physiology is considerably influenced by surface water salinity (Zaman et al. 2014). Therefore, salinity alteration is clearly visualized in the mangrove community by way of differential growth of aboveground biomass (AGB) of sensitive species (Komiyama et al. 2008). ...
Article
Full-text available
The alterations in the salinity profile are an indirect, but potentially sensitive, indicator for detecting changes in precipitation, evaporation, river runoff , glacier retreat, and ice melt. These changes have a high impact on the growth of coastal plant species, such as mangroves. Here, we present estimates of the variability of salinity and the biomass of a stenoecious mangrove species (Heritiera fomes, commonly referred to as Sundari) in the aquatic subsystem of the lower Gangetic delta based on a dataset from 2004 to 2015. We highlight the impact of salinity alteration on the change in aboveground biomass of this endangered species that, due to different salinity profile in the western and central sectors of the lower Gangetic plain, shows an increase only in the former sector, where the salinity is dropping and low growth in the latter, where the salinity is increasing.
... Mangroves are the most widespread tree communities of the Gangetic delta, and their physiology is considerably influenced by surface water salinity (Zaman et al. 2014). Therefore, salinity alteration is clearly visualized in the mangrove community by way of differential growth of aboveground biomass (AGB) of sensitive species (Komiyama et al. 2008). ...
Article
Full-text available
The alterations in the salinity profile are an indirect, but potentially sensitive, indicator for detecting changes in precipitation, evaporation, river runoff , glacier retreat, and ice melt. These changes have a high impact on the growth of coastal plant species, such as mangroves. Here, we present estimates of the variability of salinity and the biomass of a stenoecious mangrove species (Heritiera fomes, commonly referred to as Sundari) in the aquatic subsystem of the lower Gangetic delta based on a dataset from 2004 to 2015. We highlight the impact of salinity alteration on the change in aboveground biomass of this endangered species that, due to different salinity profile in the western and central sectors of the lower Gangetic plain, shows an increase only in the former sector, where the salinity is dropping and low growth in the latter, where the salinity is increasing.
... This is a non-destructive method and is thus useful for estimating temporal changes in forest biomass by means of subsequent measurements. However, the site and species-specific dependencies of allometric equations pose a problem to researchers because tree weight measurement in mangrove forests is labor-intensive [9] and often risky due to presence of wild animals (e.g., Sundarban mangrove is inhabited by man eating Royal Bengal tiger.) ...
Article
Full-text available
Carbon sequestration in Sundarban freshwater mangroves.pdf
... This is a non-destructive method and is thus useful for estimating temporal changes in forest biomass by means of subsequent measurements. However, the site and species-specific dependencies of allometric equations pose a problem to researchers because tree weight measurement in mangrove forests is labor-intensive [9] and often risky due to presence of wild animals (e.g., Sundarban mangrove is inhabited by man eating Royal Bengal tiger.) ...
Article
Full-text available
The authors estimated the above ground biomass (AGB) of Sonneratia apetala Buch.-Ham in western and central Indian Sundarbans for five successive years (2005–2010) and analysed the change of carbon stock through time. The biomass and carbon content of the species varied significantly with age and site (p\0.01). This variation may be attributed to drastically different environmental conditions prevailing in the selected sectors of Indian Sundarbans. The western sector is relatively less saline and favourable for the growth of the mangrove species. The central sector is hypersaline on account of massive siltation that prevents the mixing of fresh water of the river Ganga with the river Matla. The growth and carbon content in the AGB of the species is significantly lower in this environment.
... A recent study found that the restoration of blue carbon ecosystems (BCEs) could significantly reduce global emissions by 3% and recognized as nature-based solutions (Macreadie et al., 2021). The BCEs include mangrove forests, seagrass meadows and tidal salt marshes that have been thought to play an important role in climate change mitigation and adaptation (Nellemann & Corcoran, 2009) due to their high levels of productivity coupled with their anaerobic and waterlogged sediments that can store carbon for several millenia if left undisturbed (Alongi, 2012;Komiyama et al., 2008). Additional papers soon followed that continued to highlight the important role BCEs play in climate change mitigation and adaptation. ...
Article
The Asia-Pacific blue carbon ecosystems named mangroves, seagrass meadows and salt marsh plays an important role in climate change mitigation and adaptation. However, still data gaps exist in this region to understand the blue carbon dynamic process and how future climate change will impact it. The special feature aims to fill the gaps and contributing to our knowledge from the Asia-Pacific region and to stimulate and promote future research in blue carbon research.
... Mangroves are the most widespread tree communities of the Gangetic delta, and their physiology is considerably influenced by surface water salinity (Zaman et al. 2014). Therefore, salinity alteration is clearly visualized in the mangrove community by way of differential growth of aboveground biomass (AGB) of sensitive species (Komiyama et al. 2008). ...
Article
Full-text available
The alterations in the salinity profile are an indirect, but potentially sensitive, indicator for detecting changes in precipitation, evaporation, river runoff , glacier retreat, and ice melt. These changes have a high impact on the growth of coastal plant species, such as mangroves. Here, we present estimates of the variability of salinity and the biomass of a stenoecious mangrove species (Heritiera fomes, commonly referred to as Sundari) in the aquatic subsystem of the lower Gangetic delta based on a dataset from 2004 to 2015. We highlight the impact of salinity alteration on the change in aboveground biomass of this endangered species that, due to different salinity profile in the western and central sectors of the lower Gangetic plain, shows an increase only in the former sector, where the salinity is dropping and low growth in the latter, where the salinity is increasing.
... Mangroves are intertidal wetlands that play crucial ecological roles in tropical and subtropical coastlines worldwide (16). These ecosystems have immense ecological importance due to not only their biodiversity but also their increasing association with human activities (17). Furthermore, mangroves also provide several ecosystem services, including the amelioration of wind effects and coast protection (18,19). ...
Article
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ABSTRACT Mangroves provide a variety of ecosystem services and contribute greatly to the global biogeochemical cycle. Microorganisms play important roles in biogeochemical cycles and maintain the dynamic balance of mangroves. However, the roles of bacteria in the biogeochemical cycles of mangroves and their ecological distribution and functions remain largely uncharacterized. This study thus sought to analyze and compare the ecological distributions and potential roles of bacteria in typical mangroves using 16S rRNA gene amplicon sequencing and GeoChip. Interestingly, the bacterial community compositions were largely similar in the studied mangroves, including Shenzhen, Yunxiao, Zhanjiang, Hainan, Hongkong, Fangchenggang, and Beihai mangroves. Moreover, gamma-proteobacterium_uncultured and Woeseia were the most abundant microorganisms in the mangroves. Furthermore, most of the bacterial communities were significantly correlated with phosphorus levels (P
... Mangroves are the most widespread tree communities of the Gangetic delta, and their physiology is considerably influenced by surface water salinity (Zaman et al. 2014). Therefore, salinity alteration is clearly visualized in the mangrove community by way of differential growth of aboveground biomass (AGB) of sensitive species (Komiyama et al. 2008). ...
Article
Full-text available
The alterations in the salinity profile are an indirect, but potentially sensitive, indicator for detecting changes in precipitation, evaporation, river runoff , glacier retreat, and ice melt. These changes have a high impact on the growth of coastal plant species, such as mangroves. Here, we present estimates of the variability of salinity and the biomass of a stenoecious mangrove species (Heritiera fomes, commonly referred to as Sundari) in the aquatic subsystem of the lower Gangetic delta based on a dataset from 2004 to 2015. We highlight the impact of salinity alteration on the change in aboveground biomass of this endangered species that, due to different salinity profile in the western and central sectors of the lower Gangetic plain, shows an increase only in the former sector, where the salinity is dropping and low growth in the latter, where the salinity is increasing.
... This is a non-destructive method and is thus useful for estimating temporal changes in forest biomass by means of subsequent measurements. However, the site and species-specific dependencies of allometric equations pose a problem to researchers because tree weight measurement in mangrove forests is labor-intensive [9] and often risky due to presence of wild animals (e.g., Sundarban mangrove is inhabited by man eating Royal Bengal tiger.) ...
Article
Full-text available
The authors estimated the above ground biomass (AGB) of Sonneratia apetala Buch.-Ham in western and central Indian Sundarbans for five successive years (2005–2010) and analysed the change of carbon stock through time. The biomass and carbon content of the species varied significantly with age and site (p\0.01). This variation may be attributed to drastically different environmental conditions prevailing in the selected sectors of Indian Sundarbans. The western sector is relatively less saline and favourable for the growth of the mangrove species. The central sector is hypersaline on account of massive siltation that prevents the mixing of fresh water of the river Ganga with the river Matla. The growth and carbon content in the AGB of the species is significantly lower in this environment.
... This is a non-destructive method and is thus useful for estimating temporal changes in forest biomass by means of subsequent measurements. However, the site and species-specific dependencies of allometric equations pose a problem to researchers because tree weight measurement in mangrove forests is labor-intensive [9] and often risky due to presence of wild animals (e.g., Sundarban mangrove is inhabited by man eating Royal Bengal tiger.) ...
Article
Full-text available
Change of halophytic carbon with time.pdf ----------------------------------------------------------------------------------------------------- The authors estimated the above ground biomass (AGB) of Sonneratia apetala Buch.-Ham in western and central Indian Sundarbans for five successive years (2005–2010) and analysed the change of carbon stock through time. The biomass and carbon content of the species varied significantly with age and site (p\0.01). This variation may be attributed to drastically different environmental conditions prevailing in the selected sectors of Indian Sundarbans. The western sector is relatively less saline and favourable for the growth of the mangrove species. The central sector is hypersaline on account of massive siltation that prevents the mixing of fresh water of the river Ganga with the river Matla. The growth and carbon content in the AGB of the species is significantly lower in this environment.
... There was not mangrove pole and tree. The difference of AGB was also probably because of a different environmental condition, species composition, vegetation characteristic, habitat, geographical position, climate (Komiyama et al. 2008), seasonality that affect the presence of reproductive parts of mangrove (Soares and Schaeffer-Novelli 2005), structure and age of mangrove, and nutrient (Analuddin et al. 2016b). 404 Hasidu LOAF et al. ...
Article
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This study aimed to establish an allometric model for estimation of aboveground biomass, and carbon sequestration in A. lanata mangrove forest growing in Muna Regency, Southeast Sulawesi. Research methods were done by transect and 5 quadrats with size of 100 m2 each. A total of thirteen individual trees with different sizes were harvested. While DBH and D30 were measured. The samples were separated into stems, branches, and leaves and then weighted. The sample from each fresh organs were taken and brought to the Laboratory and then oven dried at 80°C for 7 days. The allometric equations were established by using independent variables (DBH and D30), and dependent variables (Ws, Wb, Wl). The partial and overall aboveground biomasses were calculated from allometric model, while carbon stock and CO2 sequestration were estimated. The results showed that the independent variable of DBH was more applicable for estimation of Ws, Wb, Wl, and total biomasses (Mg ha-1) of A. lanata forest, which were estimated as 28.28±3.48, 6.40±0.79, 5.00±0.66, and 40.08±4.97 respectively. The carbon stock in stems (13.24±1.63 Mg ha-1) was higher than in branches (3.01±0.37 Mg C ha-1) as well as in leaves (2.35±0.31 Mg C ha-1). The total of carbon stock were estimated at about 18.83±2.33 Mg C ha-1. Meanwhile, the total of CO2 absorption by A. lanata mangrove was 43.95±5.45 Mg CO2 ha-1. Therefore a regenerated A. lanata mangrove in this in-active pond area had potentiality on carbon stock and sequestrations, although these vegetation condition was still in the growth stage.
... This is a non-destructive method and is thus useful for estimating temporal changes in forest biomass by means of subsequent measurements. However, the site and species-specific dependencies of allometric equations pose a problem to researchers because tree weight measurement in mangrove forests is labor-intensive [9] and often risky due to presence of wild animals (e.g., Sundarban mangrove is inhabited by man eating Royal Bengal tiger.) ...
Article
Full-text available
The authors estimated the above ground biomass (AGB) of Sonneratia apetala Buch.-Ham in western and central Indian Sundarbans for five successive years (2005–2010) and analysed the change of carbon stock through time. The biomass and carbon content of the species varied significantly with age and site (p\0.01). This variation may be attributed to drastically different environmental conditions prevailing in the selected sectors of Indian Sundarbans. The western sector is relatively less saline and favourable for the growth of the mangrove species. The central sector is hypersaline on account of massive siltation that prevents the mixing of fresh water of the river Ganga with the river Matla. The growth and carbon content in the AGB of the species is significantly lower in this environment. Keywords Sonneratia apetala � Indian Sundarbans � Biomass � Carbon sequestration
... This is a non-destructive method and is thus useful for estimating temporal changes in forest biomass by means of subsequent measurements. However, the site and species-specific dependencies of allometric equations pose a problem to researchers because tree weight measurement in mangrove forests is labor-intensive [9] and often risky due to presence of wild animals (e.g., Sundarban mangrove is inhabited by man eating Royal Bengal tiger.) ...
Article
Full-text available
Keora - a low saline water loving plant biomass in Sundarban.pdf
... Mangroves are the most widespread tree communities of the Gangetic delta, and their physiology is considerably influenced by surface water salinity (Zaman et al. 2014). Therefore, salinity alteration is clearly visualized in the mangrove community by way of differential growth of aboveground biomass (AGB) of sensitive species (Komiyama et al. 2008). ...
Article
Full-text available
The alterations in the salinity profile are an indirect, but potentially sensitive, indicator for detecting changes in precipitation, evaporation, river runoff , glacier retreat, and ice melt. These changes have a high impact on the growth of coastal plant species, such as mangroves. Here, we present estimates of the variability of salinity and the biomass of a stenoecious mangrove species (Heritiera fomes, commonly referred to as Sundari) in the aquatic subsystem of the lower Gangetic delta based on a dataset from 2004 to 2015. We highlight the impact of salinity alteration on the change in aboveground biomass of this endangered species that, due to different salinity profile in the western and central sectors of the lower Gangetic plain, shows an increase only in the former sector, where the salinity is dropping and low growth in the latter, where the salinity is increasing.
... This is a non-destructive method and is thus useful for estimating temporal changes in forest biomass by means of subsequent measurements. However, the site and species-specific dependencies of allometric equations pose a problem to researchers because tree weight measurement in mangrove forests is labor-intensive [9] and often risky due to presence of wild animals (e.g., Sundarban mangrove is inhabited by man eating Royal Bengal tiger.) ...
Article
Full-text available
Sundarban low saline belt mangroves with sequestered carbon.pdf
... This is a non-destructive method and is thus useful for estimating temporal changes in forest biomass by means of subsequent measurements. However, the site and species-specific dependencies of allometric equations pose a problem to researchers because tree weight measurement in mangrove forests is labor-intensive [9] and often risky due to presence of wild animals (e.g., Sundarban mangrove is inhabited by man eating Royal Bengal tiger.) ...
Article
Full-text available
Mangrove carbon storage variation with time.pdf
... Grime [70] also observed that the variation of the aboveground biomass was significantly correlated with the size of the trees. Besides, in the riverward areas, trees are constantly engaged in conflicting of tidal actions and may have an unstable substrate for nutrient uptake [71] or be subjected to higher salinity [72]. ...
Article
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Globally, with the growing importance of mangroves for providing ecosystem services and mitigating climate change, it is still uncertain whether planted mangroves can be the counterpart of natural mangroves, and thus the role of planted mangroves is still less understood. Therefore, this study aimed to assess the stand structure and carbon storage of a young mangrove plantation in Satkhira District, Bangladesh and to compare it with the natural mangrove forest (i.e., Sundarbans) to understand the potential of this young mangrove plantation as a nature-based solution to climate change. In addition, to better understand the spatial dynamics of afforested mangrove forests, we investigated and compared both above and below-ground carbon stocks between the landward and riverward sites. We collected both above (height and diameter at breast height, DBH) and belowground (i.e., coarse and fine root) data from 16 plots with a total area of 1600 m² in two paired transects, eight plots each in landward and riverward sites. Aboveground carbon stocks were estimated using the species-specific allometric models from the biophysical tree parameters (i.e., height and DBH). Besides, belowground root (≥ 20 mm) carbon was measured by direct weighting after collecting soil samples through coring. Stand structural attributes (i.e., density, basal area, and DBH) showed a significant difference between the two sites, whereas Sonneratia apetala was found as the dominant species (IV = 188.7∼207.1) in both forest sites. The mean carbon stock of this plantation was 49.1 Mg C ha⁻¹, while the mean aboveground carbon (AGC) was 37.3 Mg C ha⁻¹. The landward site contributed significantly more AGC (40.1 Mg C ha⁻¹) than the riverward (34.4 Mg C ha⁻¹) site (p<0.05). Besides, the mean belowground roots carbon (BGRC) of this plantation was 11.8 ± 1.4 Mg C ha⁻¹, where the riverward site contributed significantly more root carbon (14.3 Mg C ha⁻¹) than the landward site (9.4 Mg C ha⁻¹) (p<0.05). Tree density and basal area showed a significant positive relationship with BGRC. Although only two species were planted, after 15 years, we observed the total number of species reached nine. The carbon stock, progressive species richness in this plantation reflects the significance of young mangrove plantations in sequestering carbon to mitigate climate change and biodiversity conservation as nature-based solutions which may be useful for future coastal afforestation and restoration programs.
... Above-ground biomass and below-ground biomass (BGB) were estimated using species-specific allometric growth equations (Clough & Scott, 1989;Kauffman et al., 2016;Komiyama et al., 2005Komiyama et al., , 2008Wang et al., 2015). Given that many mangrove species are different in body size, shape and anatomy from the specific species upon which the allometric equations were developed, their AGB and BGB were calculated by common allometric equations (Supporting Information Table S1), and the results of these calculations are given in the Supporting Information ( Table S2). ...
Article
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Mangrove forests are important coastal wetlands for the blue carbon budget and play a significant role in mitigating global climate change. However, spatial patterns of carbon stocks in mangrove forests on an island scale have not been quantified owing to methodological limitations and lack of understanding of controlling factors. We took the entire Hainan Island as a case study and aimed to carry out a comprehensive investigation of the spatial patterns and driving factors of carbon stocks in mangrove forests. Southern China. 2017–2020. Mangrove forest. The upscaling method combined with field surveys and Sentinel‐2 imagery analysis were used to compare different models for optimization of mangrove ecosystem carbon stock estimations. We also used structural equation modelling (SEM) to evaluate the factors driving the distributional patterns of mangrove carbon stocks on an island scale. The current total mangrove carbon stock of the entire Hainan Island was estimated to be 703,181 Mg C (with a mean density of 192 Mg C/ha), with the above‐ and below‐ground carbon stocks averaging at 44.7 and 147.3 Mg C/ha, respectively. The mangrove carbon storage in the north‐eastern region of the island was the highest and in the west region the lowest. Sediment nitrogen content and plant species diversity had the most positive driving effects on the distribution of total carbon stock for Hainan Island mangroves. The combination of field surveys and Sentinel‐2 imagery analysis can be applied to regional‐scale estimations of carbon stocks for mangrove forests. Spatial pattens of mangrove carbon stocks vary among locations on Hainan Island, and soil nutrient (especially nitrogen) availability is the dominant factor regulating carbon stock variations along the land‐to‐sea gradient. Our findings have significant implications for better understanding the distribution of mangrove carbon stocks and quantification of the global blue carbon budget.
... Although these EVI-height relationships tend to be sitedependent, for the purpose of generality a uniform equation is applied to map annual mangrove AGB for all sites. The estimated AGB in these four mangrove sites are comparable with other estimations of subtropical mangrove forests ranging from 70.0 to 90.3 Mg DW ha −1 y −1 (Azman et al., 2021;Hickey et al., 2018;Khan et al., 2009;Komiyama et al., 2008), but overall lower than reported AGB in tropical mangroves ranging from 116.0 to 246.9 Mg DW ha −1 y −1 (Fatoyinbo & Simard, 2013;Otero et al., 2018;Salum et al., 2020;Tang et al., 2016). Although the dissimilarity among these mangrove AGB is caused by a number of biotic and abiotic factors instead of any single factor, previous studies have highlighted the important role of several factors including latitude/temperature (Saenger & Snedaker, 1993), species types (Azman et al., 2021) and stand age (Lucas The reasons why annual accumulation rates of mangrove AGB are higher over the post-2000 period than the pre-2000 period are multifaceted but at least related to the following aspects. ...
Article
Full-text available
Chinese mangroves have been recovered in area over the past two decades from previous declining trend, and about half of existing mangroves are still in their young growth stage. This provides a unique opportunity to assess mangrove conservation by examining the growth dynamics of young mangroves over different conservation periods. However, we are currently short of effective assessment tools for spatially explicit quantification of mangrove conservation effects. To fill up this gap, we proposed a novel remote sensing approach using readily available unmanned aerial vehicle (UAV) and Landsat enhanced vegetation index (EVI) data to assess the spatial evolution of aboveground biomass (AGB) of young mangroves. With the space‐for‐time hypothesis, the approach implemented with an empirical EVI‐height‐AGB equation was tested in four subtropical estuarine mangroves in the southeastern coast of China. The results indicated: (a) the UAV‐based Structure from Motion (SfM) technology served as an effective and low‐cost means for capturing the spatial heterogeneity of mangrove canopy heights; (b) a maximum stand age of 15 years could be used to define the young growth stage of mangroves, for which the EVI‐height relationships could be described by exponential equations without suffering significant spectral saturation effects; (c) mangrove forests had overall faster annual AGB accumulation during the young growth stage over the post‐2000 versus pre‐2000 conservation period. This study is one of the first attempts to develop a remote sensing approach for quantifying spatially explicit AGB accumulation rates of young mangroves. It highlights the practicability and advantage of the UAV‐SfM technology and confirms that stronger conservation efforts promote mangrove AGB accumulation over the past two decades. The developed EVI‐height‐AGB framework fueled with readily available UAV and Landsat data provides a unique tool for assessing mangrove conservation effects from landscape to regional scales. Effective assessment tools for spatially explicit quantification of mangrove conservation effects are very limited. A novel remote sensing approach using readily available UAV and Landsat enhanced vegetation index data was proposed in this study to assess the spatial evolution of aboveground biomass of young mangroves in four subtropical estuarine mangroves in the southeastern coast of China. As one of the first attempts to develop a remote sensing approach for quantifying spatially explicit AGB accumulation rates of young mangroves, this study highlights the practicability and advantage of the UAV‐based structure‐from‐motion technology and confirms that stronger conservation efforts promote mangrove aboveground biomass accumulation over the past two decades.
... Mangroves are the most widespread tree communities of the Gangetic delta, and their physiology is considerably influenced by surface water salinity (Zaman et al. 2014). Therefore, salinity alteration is clearly visualized in the mangrove community by way of differential growth of aboveground biomass (AGB) of sensitive species (Komiyama et al. 2008). ...
Article
Full-text available
The alterations in the salinity profile are an indirect, but potentially sensitive, indicator for detecting changes in precipitation, evaporation, river runoff , glacier retreat, and ice melt. These changes have a high impact on the growth of coastal plant species, such as mangroves. Here, we present estimates of the variability of salinity and the biomass of a stenoecious mangrove species (Heritiera fomes, commonly referred to as Sundari) in the aquatic subsystem of the lower Gangetic delta based on a dataset from 2004 to 2015. We highlight the impact of salinity alteration on the change in aboveground biomass of this endangered species that, due to different salinity profile in the western and central sectors of the lower Gangetic plain, shows an increase only in the former sector, where the salinity is dropping and low growth in the latter, where the salinity is increasing.
... Mangroves are the most widespread tree communities of the Gangetic delta, and their physiology is considerably influenced by surface water salinity (Zaman et al. 2014). Therefore, salinity alteration is clearly visualized in the mangrove community by way of differential growth of aboveground biomass (AGB) of sensitive species (Komiyama et al. 2008). ...
Article
Full-text available
The alterations in the salinity profile are an indirect, but potentially sensitive, indicator for detecting changes in precipitation, evaporation, river runoff , glacier retreat, and ice melt. These changes have a high impact on the growth of coastal plant species, such as mangroves. Here, we present estimates of the variability of salinity and the biomass of a stenoecious mangrove species (Heritiera fomes, commonly referred to as Sundari) in the aquatic subsystem of the lower Gangetic delta based on a dataset from 2004 to 2015. We highlight the impact of salinity alteration on the change in aboveground biomass of this endangered species that, due to different salinity profile in the western and central sectors of the lower Gangetic plain, shows an increase only in the former sector, where the salinity is dropping and low growth in the latter, where the salinity is increasing.
... This is a non-destructive method and is thus useful for estimating temporal changes in forest biomass by means of subsequent measurements. However, the site and species-specific dependencies of allometric equations pose a problem to researchers because tree weight measurement in mangrove forests is labor-intensive [9] and often risky due to presence of wild animals (e.g., Sundarban mangrove is inhabited by man eating Royal Bengal tiger.) ...
Article
Full-text available
Trend of Sonneratia Biomass in Indian Sundarbans.pdf
... Natural mortalities were accounted for by diebacks and dead trees (both standing and fallen). Generalised biomass equations for mangroves that make use of stem diameter as the dependent variable (Komiyama et al., 2005(Komiyama et al., , 2008 and localized species-specific wood densities (Gillerot et al., 2018) were applied to obtain biomass estimates. This is because there is no robust biomass relation developed yet for the mangroves in the country. ...
Article
Lamu archipelago is endowed with rich biodiversity including Kenya’s largest continuous acreage of mangroves (approx. 33,000 ha) among other ecosystems making it a hotspot for management and conservation efforts. Yet, the involvement of the local community in management in this area is still in its infancy, with threats from large-scale developments, population growth, and climate change on the rise. Here, the structural status of the mangroves around Pate Island and Kiunga Marine National Reserve (KMNR) was assessed and information applied to guide and promote community-based conservation, as well as the development of the national mangrove management plan. Stratified and random spot sampling was used to collect vegetation data and mapping undertaken to estimate the mangrove cover change between 1995 and 2014. There was a loss in mangrove cover of up to 22.6% over 19years. A substantial loss was associated with illegal selective harvesting outside the KMNR, some clear-cutting to pave way for large-scale development and natural mortality of overgrown mature trees within the KMNR. In particular, natural mortality was found to hinder natural regeneration within the KMNR. The results however showed a generally stable system with potentially sustainable levels of natural regeneration and recoveries in isolated patches. These results reveal two management actions: raising awareness of mangrove ecosystems’ ecological value and controlling old-growth harvesting in the KMNR to facilitate natural regeneration and development of young vigorous forest through gap creation. This information provides a strong foundation for conservation planning including future mangrove restoration and conservation activities. A comprehensive coordinated conservation strategy that links conservation to communities, livelihoods, and governance frameworks is recommended.
Article
Microplastics (MP) are an emerging and lesser-known pollutant that has attracted the attention of researchers around the world in recent decades. Size of PM is smaller than 5 mm and can be entered in different ways into marine environments like mangrove forests and interfere with the health of the environment and organisms. The present study reviews 53 studies in the field of microplastics in different parts (sediments and organisms) of mangrove forests. About 26% of the 53 studies was published in 2020. In most studies, MP particles were categorized based on the shape, color, size, and polymer genus. The number of microplastics per kilogram of mangrove sediments has been reported as 1.22–6390. The effect of sediment texture on the frequency of microplastic particles and the relationship between sediment pH and MP abundance were also discussed. The fiber and bright color PMs were more common in living organisms (mollusks, crustaceans, and fish). The PM particles with different genus (polypropylene, polyethylene, polystyrene, and polyethylene terephthalate) were reported for sediment samples. In sediments with smaller sizes and lower pH, microplastics have been detected more frequently. It was reported that sediments and roots of mangrove forests act as livestock and retain microplastics for a long time. The highest concentration of MP in different parts of mangrove forests (sediment and organisms) has been reported for China. Few reports were observed on microplastics in water in mangrove forests. Also, the concentration of microplastics in sediments and organisms in mangrove forests exposed to fishing, coastal tourism, urban, and industrial wastewater was higher than those in pristine areas. It is necessary to conduct comprehensive studies to monitor, control, and evaluate the MP pollution in sediments and various organisms in mangrove forests worldwide.
Article
The mangroves of the Sundaic biogeography region in Southeast Asia are ecologically diverse and highly productive. The location of mangroves close to densely populated coastlines, on the other hand, puts them in a perilous situation as socio-economic growth has intensified in the past decades. Thus, research to support conservation of remnant mangroves is urgently required. Critical information is, however, spread across numerous disciplines. Here, we use a range of sources to gain multidisciplinary inputs from as much literature as possible to summarize emerging trends for driving future research to support conservation. This narrative review begins by pointing out the unique values of the biophysical and ecosystem services of Sundaic mangroves. Subsequently, the human beneficiaries of the mangroves are explored, including indigenous sea-people who are rarely mentioned in the literature. To put mangrove degradation and loss into context, past and emerging anthropogenic pressures are evaluated to identify the threats. Key findings include the presence of persistent threats from the agriculture and aquaculture sectors. These are to be expected, but alarmingly, coal-fired power plants and inland hydrological shifts induced by dams also pose major concerns. Although community-based management is often hailed as part of the solution, studies argue that the approach should be attempted cautiously. The latest body of knowledge revealed herein is vital to inform coastal environment management and further drives the direction of research in the Sundaic and other systems globally in which similar socio-economic pressures are experienced.
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The mangrove ecological services as carbon sinks and storage are very useful in the efforts to mitigate global warming and climate change. In this study, the above and below-ground biomass, carbon stock, as well as carbon sequestration by the mangroves in Demta Bay, Papua Province, Indonesia were estimated. Allometric equations were used to determine the mangrove biomass in 36 observation plots. The biomass value was used to determine carbon stock and estimate carbon sequestration. Nine mangrove species were found in Demta Bay, with the contribution of mangrove species to biomass (AGB and BGB) in the following order: Rhizophora apiculata > Rhizophora mucronata > Bruguiera gymnorhiza > Bruguiera cylindrica > Heritiera Littoralis > Xylocarpus molucensis > Rhizophora stylosa > Avicennia marina > Sonneratia caseolaris. The average mangrove biomass was estimated at 174.20 ± 68.14 t/ha (AGB = 117.62 ± 45.68 t/ha and BGB = 56.58 ± 22.49 t/ha). The carbon stocks in mangroves at the Ambora site were higher than the Tarfia and Yougapsa sites, averaging 123.57 ± 30.49 t C/ha, 81.64 ± 25.29 t C/ha, and 56.09 ± 39.03 t C/ha, respectively. The average carbon stock in the mangrove ecosystem of Demta Bay is estimated at 87.10 ± 34.07 t C/ha or equivalent to 319.37 ± 124.92 t CO2 e/ha. The results of this study indicate that the mangrove ecosystem in Demta Bay stores quite high carbon stocks, so it is necessary to maintain it with sustainable management. Therefore, climate change mitigation is not only done by reducing the carbon emission levels but also needs to be balanced by maintaining the mangrove ecosystem services as carbon sinks and sequestration. Keywords: mangrove species; allometric equations; above-ground biomass; below-ground biomass; carbon stock; carbon sequestration
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Global atmospheric nitrogen deposition significantly affects the nutrient cycling and C–N–P stoichiometry in ecosystems. Herein, a global meta-analysis was conducted based on 898 pairwise observations to analyze the impact of nitrogen addition on plant-soil-enzyme C–N–P stoichiometry and microbial nutrient limitation in different ecosystem types (cropland, grassland, and forest), nitrogen addition intensity (0–5, 5–10, and >10 g N m⁻² yr⁻¹) and duration (0–5, 5–10, and >10yr). Results showed that nitrogen addition significantly decreased plant C:N (shoot: 16.5%, root: 27.1%, litter: 16.5%), soil C:N (5.9%), enzyme C:P (1.2%), and enzyme N:P (5.1%), whereas significantly increased soil C:P (4.9%), enzyme C:N (7.1%), vector angle (4.4%), vector length (3.9%), and plant N:P (shoot: 24.1%, root: 23.8%, and litter: 13.5%). Furthermore, nitrogen addition mainly affected the enzyme C:N and vector length in grasslands. Additionally, the changes in C:N in plants, soil, and enzymes, and vector angle and length were higher at nitrogen addition intensity of >10 g N m⁻² yr⁻¹. The changes in C:N and C:P in plant and soil were higher at nitrogen addition duration of >10 yr. Finally, the N:P in shoot, soil and enzyme, and vector angle were strongly correlated with mean annual precipitation (MAP). In conclusion, nitrogen addition significantly reduced the C:N ratio in plants and soil and increased plant N:P, and microbial C and P limitation. These effects vary with the ecosystem type, MAP, and nitrogen addition intensity and duration. The results improve our understanding of the plant-soil-microbial nutrient cycling processes in terrestrial ecosystems under global nitrogen deposition.
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By studying the structural characteristics and carbon storage of the mangrove island ecosystem in the Beibu Gulf, this study provides a scientific basis for mangrove ecological compensation in the coastal areas of Guangxi, South China Sea. On the basis of the unmanned aerial vehicle remote sensing images and a sample plot survey, the object-oriented multi-scale segmentation algorithm is used to extract the mangrove community type information, and one-way analysis of variance is conducted to analyse the structural characteristics of the mangrove community. The carbon storage and carbon density of different mangrove ecosystems were obtained based on the allometric growth equation of mangrove plants. The analysis yielded four main results. (1) The island group covers about 27.10 ha, 41.32% (11.20 ha) of which represents mangrove areas. The mangrove forest is widely distributed in the tidal flats around the islands. (2) The main mangrove types were Aegiceras corniculatum, Kandelia obovata + Aegiceras corniculatum, Avicennia marina + Aegiceras corniculatum and Avicennia marina communities. (3) Amongst the mangrove plants, Avicennia marina had the highest biomass (18.52 kg plant1), followed by Kandelia obovata (7.84 kg plant1) and Aegiceras corniculatum (3.85 kg plant1). (4) The mangrove carbon density difference was significant. Kandelia obovata had the highest carbon density (148.03 t ha1), followed by Avicennia marina (104.79 t ha1) and Aegiceras corniculatum (99.24 t ha1). The carbon storage of the mangrove island ecosystem was 1194.70 t, which was higher than in other areas with the same latitude. The carbon sequestration capacity of the mangrove was relatively strong.
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Above-ground biomass (AGB) is an important ecological variable that should be correctly measured for tree carbon storage estimation. The traditional way of measuring the AGB was to use the destructive tree-cutting method that is not cost-effective for large study areas and may cause high standard variations. Many reports demonstrated that modern terrestrial laser scanning (TLS) techniques do not require tedious fieldwork and are more accurate than the traditional methods. This research aimed to estimate AGB from a point cloud of TLS for Eucalyptus kamaldulensis 24 plants using the Qualitative surface model (QSM) and the Poisson surface reconstruction (PSR) methods. The AGB of the two methods is compared with the actual AGB using the water displacement method. The accuracy of the results was calculated with the square root of mean square error (RMSE). The RMSE value from the QSM method was 3.08 kg, and the RMSE value of the PSR method was 1.78 kg. The outcome of this study confirmed the effectiveness of the TLS techniques for AGB estimation. It is anticipated the use of the proposed method in fast-growing timber industries in Thailand.
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Mangrove forests provide important ecosystem services to the human society and nature including mitigation of climate change. The quality and quantity of ecosystem services offered by mangrove forests are however at risk when mangroves are degraded. The restoration of mangrove areas is considered as a natural solution to recover lost ecosystem services such as securing of carbon stocks. This study was set to assess the extent to which mangrove planting activities compensate for the loss of biomass carbon stocks and other structural attributes in Rufiji Delta-Tanzania through analysis of biomass carbon loss and gain as a result of conversion of mangroves forest into rice farms and planting of mangroves respectively. Circular sampling plots were established in good, degraded and restored mangrove areas where total tree heights and Diameter at Breast Height (DBH) of all standing trees were measured and recorded by species and used to compute biomass carbon stock. The mangrove species composition changed from 7 in 1989 to 2 species in degraded plots in 2016. The species dominance changed from Avicennia marina in 1989 to Rhizophora mucronata in 2016 in good mangrove plots and from A. marina and Sonneratia alba to an invasive Baringtonia racemosa in degraded plots. Bruguiera gymnorrhiza was the only mangrove species used for restoration through planting in the delta and the overall survival rate was 37%. The above-ground carbon (AGC) and below-ground carbon (BGC) for the good natural mangrove plots ranged from 28.18 – 299.43 and 16.00 – 164.51 Mg C ha⁻¹ respectively compared to 0 –150.88 and 0 – 967.01 Mg C ha⁻¹ in the degraded plots. The total biomass carbon stock in the good natural mangrove plots ranged from 44.14 – 463.94 Mg C ha⁻¹ while for the degraded plots the range was 0 – 247.89 Mg C ha⁻¹. The carbon stocks in 5, 10 and 15 year old planted mangroves were 13.65, 20.13 and 57.53 Mg C ha⁻¹ respectively. The biomass loss of 172.91 Mg C ha⁻¹ was estimated in a period of 25 years (1989-2016), equivalent to an annual loss rate of 6.9 Mg C ha⁻¹year⁻¹, demonstrating that degradation has a significant contribution to loss of carbon stocks. Nevertheless, an average of 3.8 Mg C ha⁻¹year⁻¹ was stocked by 15 years old planted mangroves, demonstrating that there is potential for the planted mangroves to compensate for the lost carbon if the anthropogenic drivers such as rice farming is controlled. These findings call for urgent collective actions among stakeholders to consider and improve the integrated management of the delta.
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Tree allometric equations are critical tool for understanding carbon storage potential and develop strategic policies to mitigate climate change. This common testing may be applicable to the world mangroves particularly, the wild forests. The present study highlights the progress on mangrove allometry in solving the problems of site-specific and species-specific relationships. This included parameters like measuring diameter at breast height which is 1.3 m from base, tree height which is the ultimate height from base to tip of the tree and first-forking height which is the height of the tree from base to the first forking—to be included as independent variables with above-ground biomass and above-ground carbon as dependent variables in developing simple and multiple linear models. The inclusion of first-forking height in mangrove allometry is the first of its kind. In this study, the mangroves of Bhitarkanika Wildlife Sanctuary have shown a greater biomass than the Mahanadi estuary proving the fact that the conserved forests are in much better health conditions than those anthropogenically stressed area in the western Bay of Bengal. The 20 best fit equations have been chosen as model equations with R2 values greater than 0.90 both for Bhitarkanika and Mahanadi mangrove ecosystem. The above-ground biomass and above-ground carbon values have drawn attention towards forest bioenergy quantification and its importance of conservation in the growing demand for energy resources worldwide.
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The present paper is an attempt to review available data on sediment biogeochemistry of the Ao Nam Bor mangrove forest on the east coast of Phuket Island, Thailand. Aspects of sedimentary carbon, sulfur and nitrogen cycling are evaluated and compared in 3 intertidal zones: 1) the low-intertidal, non-vegetated mudflat outside the forest; 2) the mid-intertidal forest zone with dense growth of Rhizophora apiculata; and 3) the high-intertidal sparsely vegetated zone with high abundance of crab burrows. By compiling data on organic carbon and nitrogen input to (e.g. litterfall, benthic primary production) and output from (e.g. crab ingestion, microbial mineralization, plant assimilation) the sediment, preliminary budgets for the 3 intertidal zones at Ao Nam Bor can be established. However, the presented budgets have serious limitations caused by a general lack of data. In those cases where no data are available from Phuket, results are either extrapolated from other mangrove forests, estimated based on assumptions or simply ignored. Furthermore, as most data on benthic carbon and nitrogen cycling used in the budgets are obtained only during the dry season, the carbon budgets most certainly do not represent annual averages, but should rather be considered dry season averages.
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Above ground tree biomass was estimated in Bruguiera parviflora, B. sexangula, and Rhizophora apiculata communities of a mangrove forest in Talidendang Besar, East Sumatra, Indonesia. The research was carried out from December 1990 to January 1991, and allometric relation method was used to estimate the above ground biomass of tree species having a diameter of 10 cm and over. The above ground biomass in this forest ranged from 42.94 to 89.68 t d.wt/ha in a B. parviflora community; 75.99 to 279.03 t d.wt/ha in a B. sexangula community; and 40.70 t d.wt/ha in a R. apiculata community.
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Mangrove forests are an integral part of tropical coastal ecosystems, particularly in northern Australia. In the Northern Territory, studies have determined the extent and species diversity of these associations but little is known of biomass or productivity. We sampled the above- and below-ground biomass of the four most abundant species, Avicennia marina, Bruguiera exaristata, Ceriops australis and Rhizophora stylosa, developed allometric relationships and examined partitioning. Unlike many other studies, we sampled below-ground biomass, which constituted a substantial proportion (0.29-0.57) of the total dry weight. Our results should be valuable in modelling potential changes in carbon allocation resulting from small- and large-scale ecosystem changes.
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The biomass of Rhizophora apiculata Bl. was measured within a 25 m2 sample plot in a mangrove at Phuket Island on the west coast of Thailand. The total biomass above the ground of this 15 years-old stand was estimated to be 159 t dry matter ha−1. The annual increment in the form of trunks, branches and prop roots was estimated to be 20 t ha−1yr−1 during the last year of growth. By means of a simple marking technique, leaf turn-over rate was found to be 0.7 yr−1 and leaf production was 6.7 t ha−1yr−1. Buds, flowers and propagules contributed very little to annual production. Total net production was estimated to be 27 t dry matter ha−1yr−1 or 6.9 g ash free dry matter m−2day−1.The biomass of prop roots, trunks, branches and leaves as well as leaf areas were determined for 1 m horizontal levels. Prop roots formed 39% of total biomass above the ground.
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Total above-ground production isusually estimated by a combination of allometry andlitter collection. However, in coastal sites that aretidally influenced, or in juvenile or dwarf forestswhere the crown bases of dominant individuals maybegin within a few decimeters of ground level,estimates of community leaf production that depend onlitter collection may not be feasible. Thus, in thispaper, we present 1) allometric equations that allowaccurate estimation of total above-ground biomass ofthree mangrove species (Rhizophora mangle, Laguncularia racemosa, and Avicennia germinans)in very small to medium size classes, and 2) analternative method of estimating total above-groundproduction that overcomes the limitations of littercollection. The method we employ to estimate mangroveproductivity is an adaptation for woody plantcommunities of a procedure introduced by Dai andWeigert (1996) for grasslands. It incorporates adetailed census of all individuals within fixedsampling plots, along with periodic observations ofmarked leaf cohorts. The method allows the comparisonof biomass allocation patterns among forests thatdiffer widely in physiognomy and physiographicsetting.The method was applied to a South Florida fringemangrove forest in the early stages of recovery fromHurricane Andrew (August 1992), and an adjacent dwarfforest which was not substantially damaged by thestorm. Total above-ground production in the fringeforest from July 1996 through June 1997 was about 3times higher than dwarf forest production,26.1 Mgha-1yr-1 vs.8.1 Mgha-1yr-1, respectively. Furthermore, when compared to the dwarf forest, fringeproduction rates were approximately eight, six, six,and two times as high as dwarf forest rates forproproots, branches, stems, and leaves, respectively. Calculations of leaf production were based on mean redmangrove leaf longevities that ranged from about 189days to 281 days, depending on cohort and site.Repeated measures analysis of variance indicated thatleaf life spans did not differ significantly betweendwarf and fringe forests, but did differ among leafcohorts.Based on reported values for similar mangrove forests,the method provided reasonable estimates ofabove-ground biomass and production, while furnishingrelevant auxiliary information on spatial and temporalvariation in leaf demographic patterns. Furthermore,the partitioning of annual production between woodytissues and leaves followed the reported trend in mostforest ecosystems.
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The objective of this study was to quantify spatial patterns in above- and belowground biomass, primary productivity, and growth efficiency along a tidal gradient in a 4700-ha mangrove forest in the Dominican Republic. We tested the hypothesis that spatial patterns of forest structure and growth following 50 years of development were associated with variations in the soil environment across the tidal gradient. Twenty-three plots were monitored from 1994 to 1998. Aboveground biomass and biomass accumulation were estimated by applying allometric regression equations derived from dimension analysis of trees harvested at our study site. Soil porewater salinity ranged from 5 to 38 g·kg-1 across the tidal gradient, and most measurements of forest biomass and productivity were inversely related to salinity. Mean standing biomass (233 ± 16.0 Mg·ha-1; range, 123.5-383.5), biomass increment (9.7 ± 1.0 Mg·ha-1 y-1; range, 3.7-18.1), annual litterfall rates (11.4 Mg·ha-1 yr-1; range, 10.2-12.8), leaf area index (LAI) (4.4 m2·m-2; range, 2.9-5.6), aboveground net primary productivity (ANPP) (19.7 Mg·ha-1 y-1; range, 15.6-25.0), and growth efficiency (1.6 ± 0.2 kg·ha -1 y-1; range, 1.0-3.6) all showed an inverse linear relationship with salinity. Fine-root biomass (≤ 2 mm) (9.7 ± 1.2 Mg·ha-1; range, 2.7-13.8) showed a weak tendency to increase with salinity, and the ratio of root to aboveground biomass increased strongly with salinity. Our results suggest that physiological stresses associated with salinity, or with some combination of salinity and other covarying soil factors, control forest structure and growth along the tidal gradient. The higher allocation of carbon to belowground resources in more saline sites apparently contributed to reductions in ANPP along the tidal gradient.
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The article presents new results on the structure and the above-ground biomass of the various population types of mangroves in French Guiana. Nine mangrove stands were studied, each composed of three to ten adjoining plots with areas that varied depending on the density of the populations. Structural parameters and indices were calculated. Individuals representative of the three groups of taxa present were felled:Avicennia germinans (L) Stearn, Rhizophora spp., and Laguncularia racemosa (L) Gaertn. The trunks, branches and leaves were sorted and weighed separately. The biomass was obtained by determining the allometric relationships, the general equation selected being of the type y = a o x a1, where the diameter (x) is the predictive variable. The total above-ground biomass varied from 31 t ha−1 for the pioneer stages to 315 t ha−1 for mature coastal mangroves, but with large variations depending on the structural characteristics at each site. The results place the Guianese mangroves among those with high biomass, although lower than those reported for Asia. Based on the relationships between structural parameters and standing biomass, in particular with the use of the “self-thinning rule”, population dynamics models are proposed.
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Because the world's forests play a major role in regulating nutrient and carbon cycles, there is much interest in estimating their biomass. Estimates of aboveground biomass based on well-established methods are relatively abundant; estimates of root biomass based on standard methods are much less common. The goal of this work was to determine if a reliable method to estimate root biomass density for forests could be developed based on existing data from the literature. The forestry literature containing root biomass measurements was reviewed and summarized and relationships between both root biomass density (Mg ha−1) and root:shoot ratios (R/S) as dependent variables and various edaphic and climatic independent variables, singly and in combination, were statistically tested. None of the tested independent variables of aboveground biomass density, latitude, temperature, precipitation, temperature:precipitation ratios, tree type, soil texture, and age had important explanatory value for R/S. However, linear regression analysis showed that aboveground biomass density, age, and latitudinal category were the most important predictors of root biomass density, and together explained 84% of the variation. A comparison of root biomass density estimates based on our equations with those based on use of generalized R/S ratios for forests in the United States indicated that our method tended to produce estimates that were about 20% higher.
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Mathematical relations that use easily measured variables to predict difficult-to-measure variables are important to resource managers. In this paper we develop allometric relations to predict total aboveground biomass and individual components of biomass (e.g., leaves, stems, branches) for three species of mangroves for Everglades National Park, Florida, USA. The Greater Everglades Ecosystem is currently the subject of a 7.8-billion-dollar restoration program sponsored by federal, state, and local agencies. Biomass and production of mangroves are being used as a measure of restoration success. A technique for rapid determination of biomass over large areas is required. We felled 32 mangrove trees and separated each plant into leaves, stems, branches, and for Rhizophora mangle L., prop roots. Wet weights were measured in the field and subsamples returned to the laboratory for determination of wet-to-dry weight conversion factors. The diameter at breast height (DBH) and stem height were also measured. Allometric equations were developed for each species for total biomass and components of biomass. We compared our equations with those from the same, or similar, species from elsewhere in the world. Our equations explained ≥93% of the variance in total dry weight using DBH. DBH is a better predictor of dry weight than is stem height and DBH is much easier to measure. Furthermore, our results indicate that there are biogeographic differences in allometric relations between regions. For a given DBH, stems of all three species have less mass in Florida than stems from elsewhere in the world.
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Growth of selected Rhizophora apiculata (Rhizophoraceae) trees was monitored from 1920 through 1981 in a 0.16 ha plot of protected forest in the Matang Mangroves. Starting in 1950, the sample was increased to include monitoring the growth of all the trees more than 10 cm dbh (diameter at 1.3 m or above prop roots). All seedlings were censused by species and removed in 1920 and recensused in 1926, 1927, and 1981. Total above-ground dry weight (biomass) of the forest was estimated using stand tables and a regression equation of biomass on dbh calculated for destructively sampled R. apiculata trees from elsewhere in the Matang Mangroves. Net primary productivity (1950–1981) was calculated from estimated biomass increments and published litter-fall rates.Rhizophora apiculata has maintained its dominance of the plot since 1920 but Bruguiera gymnorrhiza (Rhizophoraceae) and several other more shade-tolerant species have steadily increased in abundance. Between the 1920's and 1981, R. apiculata declined in relative abundance in the seedling layer while B. parviflora and B. cylindrica increased.Mean mortality rate (1950–1981) for trees more than 10 cm dbh was 3.0% per year with a range of 1.3–5.4% per year. When trees fell over and hit other trees, the damaged trees usually died within 10 years. A major cause of mortality appeared to be sapwood-eating termites.Net primary productivity averaged 17.7 t/ha/year over the 1950–1981 observation period. Biomass ranged from 270 to 460 t/ha with a mean of 409 t/ha. It is suggested that Rhizophora spp. trees greater than 50 cm dbh and mangrove forests with total above-ground biomass exceeding 300 t/ha would develop in other areas outside of the region affected by hurricanes if the forest was protected from human disturbance.
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To test the applicability of the pipe model theory to actual tree form, the frequency distribution of the thickness of woody organs in a tree was examined in 10 different species. The frequency f(D) of a certain diameter class D proved to have a definite pattern of distribution in the root, branch and trunk respectively, with only a little difference between the species. The obtained f(D)〜D curves showed that a root system could well be approximated by the assemblage of many pipes of unit thickness, a trunk by a few cones piled up one upon another, and a branch system by a geometric model intermediate between the two. The results were well consistent with the pipe model theory of tree form. As an application of the theory in forest ecology, a new method for estimating the amounts of leaves or branches of trees and stands was also proposed, based on the direct proportionality found between those amounts and the cross-sectional area of the trunk at the height just below the lowest living branch.
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OOHATA Sei-ichi (Kyoto Univ. For. Agr., Kyoto Univ., Kyoto) & SHINOZAKI Kichiro (Sci. Educ. Inst. Sakai City, Sakai). 1979. A statical model of plant form-Further analysis of the Pipe Model Theory. Jap. J. Ecol., 29 : 323-335. In the present study, the structure of stems in plant communities was analyzed as an extension of the Pipe Model Theory proposed by SHINOZAKI et al. (1964). A close correlation was found between the amount of non-photosynthetic tissue [C (z)] at the stratum z and the cumulative amount of plant weight [T (z)] from the top to that stratum. The relation between T (z) and C (z) is always linear, at least in the leafless range (trunk) in plant communities. A characteristic constant of this linear relation is herein referred to as the Specific Stress Length (SSL). This linear relation implies that the amount of nonphotosynthetic tissue increases exponentially downward. This trunk form may be physically interpreted in terms of a compressive stress distribution that is constant regardless of elevation. Statically, this form may be ideally suited for the purpose of supporting the plant body. Among the plant communities investigated, the values of SSL were always proportional to the community height. This statical model of woody tissue may be construed as a consequence of the pattern of accumulation of disused pipes that was proposed by SHINOZAKI et al. (1964).
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The consumption of mangrove leaves by herbivores before leaf fall was studied. Up to 20 percent of the leaf blade enters the food web in this manner. The influence of several environmental factors on the amount of foliage eaten before leaf fall was investigated. The quantity of leaf material eaten could not be correlated with any of the following parameters: species diversity (as species number), the distance of the plant from the upper tidal limit, plant density, season, energy value of the leaves, the presence of "protective" ants, the chloride content of leaves, or, in contrast to a previous report, pollution (high nitrogen levels). Recently leaved Xylocarpus were the only plants with no leaf damage. In all cases damage from leaf to leaf was extremely variable and obscured between-plant and, in most instances, between-species differences.
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Presents some of the results of a long-term study near Kuala Sepetang, Matang Mangrove Forest Reserve, Malaysia (started in the mid-1970s) on the carbon and nutrient budget of a mangrove ecosystem. The tree density of the 20 m × 40 m plot in the 20-yr-old stand was equivalent to 2425 stems ha⁻¹ (1975 live trees ha⁻¹). Size (girth at breast height) of Rhizophora apiculata trees ranged from 9-75.5 cm (mean 39 cm). The smallest live tree weighed 10 kg and the biggest weighed 510 kg with a mean biomass of 122 kg. About 70% of the trees were <100 kg but 30% of the bigger trees contributed to slightly more than half of the total biomass of the plot. The canopy had an average height of 21 m. The total standing biomass was 114 t C ha⁻¹; 74% of the biomass was in the trunk, 15% in the roots (10% in stilts and 5% below-ground) and 10.6% in the canopy (only 2.6% in leaves). Using allometry, net productivity was estimated at 17±5 t C ha⁻¹ yr⁻¹. If greater accuracy (than ±30%) is needed, direct measurements of root turnover and leaching from roots would be needed. Using the gas exchange method and using the mean value for a whole day's net photosynthesis measurements (averaged at 6 μmol m⁻² s⁻¹), 1.5 μmol m⁻² s⁻¹ for leaf respiration, a leaf area index of 4, and assuming respiration of the non-leaf tissues to be the same as for leaves, we estimated net productivty to be 11.35 t ha⁻¹ yr⁻¹, almost at the lower limit of the allometric estimate. -from Authors
Article
Differences in biogeochemical characteristics between three Rhizophorastylosa and three Avicenniamarina forests were examined in different coastal settings of arid Western Australia. Decomposition rates of sediment organic matter correlated with temperature, but did not differ significantly between Rhizophora (range: 46.5–52.9 mmol C m−2 per day) and Avicennia (range: 28.5–48.3 mmol C m−2 per day) forests. There were, however, clear differences in the dominance of specific carbon oxidation pathways between forest types. Rates of sulfate reduction were significantly greater in the Rhizophora (range: 12.9–28.2 mmol S m−2 per day) than in the Avicennia (range: 2.1–8.5 mmol S m−2 per day) forests, accounting for 54–100 and 20–55% of total mineralization rates in both forest types, respectively. Sulfate reduction rates correlated significantly with live root biomass, above-ground biomass and forest net primary production. Rates of oxic respiration were, on average, greater in the Avicennia forests (range: 12.7–37.4 mmol m−2 per day). Oxic respiration appeared to be a minor decomposition pathway in two of the three Rhizophora forests (range: 0.0–23.1 mmol m−2 per day). It was estimated that, on average, 50% (Avicennia) to 87% (Rhizophora) of total oxygen uptake was consumed in oxidation of reduced metabolites. Methanogenesis was not detected in any of the forests, and Mn and Fe reduction were minor carbon oxidation pathways. Rates of dissolved nitrogen and phosphorus regeneration across the sediment–water interface were slow when measurable. The percentage ratios of total sediment respiration to forest net primary production (TCOX/NPP) were low, ranging among forests between 3 and 7%. Although there may be some carbon loss via tidal export, the low TCOX/NPP ratios suggest slow rates of organic matter decomposition in relation to tree productivity. A large, slowly decomposing, pool of wood and other plant detritus may be an adaptive response, as in other tropical forests, to enhance ecosystem stability and conserve essential nutrients.
Article
Inventory data on tree weights of 104 individual trees representing 10 mangrove species were collected from mangrove forests in South-East Asia to establish common allometric equations for the trunk, leaf, above-ground and root weight. We used the measurable tree dimensions, such as dbh (trunk diameter at breast height), DR0.3 (trunk diameter at 30 cm above the highest prop root of Rhizophora species), DB (trunk diameter at lowest living branch), and H (tree height) for the independent variable of equations. Among the mangrove species studied, the trunk shape was statistically identical regardless of site and species. However, of each species, when DB2 or dbh2 or DR0.32 was selected as the independent variable. For the root weight, the common equation was derived from the allometric relationship between root weight and above-ground weight, since these two partial weights significantly correlated with each other. Based on these physical and biological parameters, we have proposed four common allometric equations for estimating the mangrove tree weight of trunk, leaf, above-ground part and root.
Article
Allometric relationships are described for estimating leaf biomass, branch biomass, stem biomass and total above-ground biomass from measurements of stem diameter (DBH) in the mangrove species Rhizophora apiculata, R. stylosa, Bruguiera gymnorrhiza, B. parviflora, Ceriops tagal var. australis and Xylocarpus granatum. A linear relationship was found when the biomass of each above-ground component was plotted against DBH on a log-log scale. The two Rhizophora species were found to have the greatest stem and total above-ground biomass for a given DBH, followed by B. parviflora, B. gymnorrhiza, C. tagal var. australis, and X. granatum, the last having a significantly lower biomass for a given DBH than the other five species. However, there was much less variation in stem volume for a given DBH amongst the six species, owing to differences in the specific gravity of their stems.
Article
A quantitative analysis was done for the root system of Xylocarpus granatum with reference to the Pipe model theory of tree form proposed by Shinozaki et al. (1964a, b). For this objective, six root systems of X. granatum were excavated using a water-pump, and the roots were weighed for respective diameter categories. A significant allometric relationship between the squared stem-base diameter and the individual root weight was seen. The coefficient of this relationship was statistically regarded to be 1.0, meaning that the individual root weight is proportional to the squared value of stem-base diameter. We also analyzed the relationship between diameter and number of roots for the six sample trees. The number of roots with a given diameter and length was calculated from the weight and the specific gravity of roots. Significant linear relationships were recognized in this relationship for the six sample trees. For all sample trees, the coefficients of relationships were statistically regarded to be - 2.0. From these analyses based on population and individual level, we conclude that the root system of X. granatum obeys the pipe model. Application of this model is helpful in the estimation of root biomass, since individual root weight can be estimated from a proportional constant and the stem-base diameter of a mangrove tree.
Article
Biomass and (leaf) litter production of stands of Rhizophora mucronata and Ceriops tagal were assessed in an East African mangrove forest. Inundation frequency of the R. mucronata stand was twice a day (on average 575 min day(-1)), whereas the C. tagal stand was inundated only during spring tides (on average 116 min day(-1)). The highest above-ground biomass (24.9 +/- 4.0 kg dry weight m(-2)) was present in the R. mucronata stand, in which leaf litter production was 2.51 +/- 1.15 g DW m(-2) day(-1). Above-ground biomass and leaf litterfall in the C. tagal stand were 4.01 +/- 0.34 kg DW m(-2) and 1.05 +/- 0.49 g DW m(-2) day(-1), respectively. There was a distinct seasonal pattern in litterfall in both stands, with lower litterfall values in the wet season. Chloride concentrations were relatively high in senescent leaves, compared with those in green leaves. The decreased litterfall during the wet periods may be related to a reduced accumulation of chloride in the leaves. The difference in inundation frequency between the R. mucronata and C. tagal stands is expected to cause a more substantial tidal export of fallen leaves from the R. mucronata stand. As nitrogen resorption before defoliation was similar for C. tagal (50.9%) and R. mucronata (50.1%), tidal flushing may cause larger nitrogen losses from the R. mucronata stand. [KEYWORDS: Australia; coast; crabs; turnover; ecology; growth; fish]
Article
Above- and below-ground biomass of A. marina were estimated on three plots with different vegetation characteristics in a subtropical mangrove woodland at Boggy Creek near Brisbane. Total photosynthetic and non-photosynthetic above-ground biomasses of mangroves in the plots were 16.2, 34.1 and 11.0 kg m-2, below-ground plus pneumatophore biomasses were 10.9, 12.1 and 12.6 kg m-2. Although the study site is in an industrialized, moderately polluted estuary, the biomass of Avicennia here is similar to that of Avicennia communities elsewhere.
Article
This allometric data set gives total biomass in kg (logtotalbiomass=2.523logGBH−1.943); total above-ground biomass (logabove-groundbiomass=2.420logGBH−1.832); total below-ground biomass (logbelow-groundbiomass=2.611logGBH−3.454) as well as stilts (logstiltbiomass=2.546logGBH−2.945); trunk (logtrunkbiomass=2.477logGBH−2.050) and leaf biomass (logleafbiomass=0.133logGBH−0.728), from girth at breast height (GBH, in cm) of the mangrove Rhizophora apiculata Blume. A comparison is made with three other previous studies. The below-ground data set is unique: there is only one other study on root biomass but the stilts were not separated from the below-ground roots. This is the second reported data set for total biomass and the two allometric regression equations are almost identical. Based on the few direct comparisons available, it is suggested that allometric equations for R. apiculata may not be very site specific but further studies would be needed to confirm this. Partitioning of biomass is very variable for the smaller trees (GBH
Article
Benthic mineralization rates and pathways were measured in two extensive shrimp ponds of the Mekong delta, Vietnam. Sediments of both ponds were unconsolidated, oxic to suboxic silt-clays of neutral pH (6.8–7.3). Free sulfides and methane were not detected in the porewater, which was dominated by NH4+ (up to 400 μM); other interstitial solutes were very variable among replicate cores, ponds, and sediment depths. Particulate C and N concentrations ranged from 2–8% and 0.15–0.36% by sediment dry weight (DW) with few depth differences between ponds. Pyrite was abundant (0.3–5.6% of sediment DW) in both ponds. Total carbon oxidation rates were not significantly different between the pond located separate from mangroves (separate pond) and the pond located within a mangrove forest (mixed pond). Fluxes of O2 and CO2 (=total carbon oxidation, TCOX) were highly variable, with slow rates of CO2 release (range: 7.7–30.5 mmol m−2 day−1) but higher rates of O2 consumption (range: 9.8–135.9 mmol m−2 day−1), especially in the separate pond. A budget of the contribution of the various diagenetic pathways to total carbon oxidation indicates that aerobic respiration accounted for 41–60% of TCOX, with active manganese and iron reduction in the mixed and separate ponds, respectively. No denitrification or methane flux was detected from sediments of either pond. Rates of sulfate reduction were slow (range: 0.94–2.73 mmol S m−2 day−1) and highly variable, accounting for 13–26% of TCOX. Rates of solute flux across the sediment–water interface were dominated by DOC, NO2−+NO3−, and Mn. There was no measurable NH4+ flux. Most light–dark bottle O2 fluxes indicated no net benthic primary productivity. The slow rates of benthic decomposition and the dominance of oxic and suboxic pathways reflect the slow rates of organic matter input, and phytoplankton and shrimp production in these extensive ponds.