Community structure and standing crop biomass of a mangrove forest in Futian Nature Reserve, Shenzhen, China

Tam, N.F.Y.; Wong, Yuk Shan; Lan, C. Y.; Chen, G.Z.

doi:10.1007/bf00029126

Cited by 79 publications

(18 citation statements)

References 14 publications

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“…All these geometric properties can be easier reflected in SAR data and thus compensate the classification of different species. Regarding the backscattering mechanism, the dominant scattering of microwave (e.g., C-band in this study) depends greatly on the mangrove height and biomass, which have been reported to vary significantly among different mangrove species [20,22,41,42]. For instance, the biomass of KO is much higher than AM, while the biomass of AC is higher than KO in the study area [41,42], which can be reflected in the backscattering coefficient of the dual-polarization C-band SAR data.…”

Section: Contributions From the Dual Polarimetric Sar Datamentioning

confidence: 73%

“…However, the Core Zone has been highly protected since 1995 [36,40], indicating minimal impacts from local human activities. Based on previous investigations of the mangrove biomass that demonstrated that the biomass of local mangrove forests did not change significantly [41,42], we assume that the two-year difference between the field data and satellite data does not have a significant impact on our study. did not change significantly [41,42], we assume that the two-year difference between the field data and satellite data does not have a significant impact on our study.…”

Section: Field Datamentioning

confidence: 96%

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Potential of Combining Optical and Dual Polarimetric SAR Data for Improving Mangrove Species Discrimination Using Rotation Forest

et al. 2018

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Classification of mangrove species using satellite images is important for investigating the spatial distribution of mangroves at community and species levels on local, regional and global scales. Hence, studies of mangrove deforestation and reforestation are imperative to support the conservation of mangrove forests. However, accurate discrimination of mangrove species remains challenging due to many factors such as data resolution, species number and spectral confusion between species. In this study, three different combinations of datasets were designed from Worldview-3 and Radarsat-2 data to classify four mangrove species, Kandelia obovate (KO), Avicennia marina (AM), Acanthus ilicifolius (AI) and Aegiceras corniculatum (AC). Then, the Rotation Forest (RoF) method was employed to classify the four mangrove species. Results indicated the benefits of dual polarimetric SAR data with an improvement of accuracy by 2-3%, which can be useful for more accurate large-scale mapping of mangrove species. Moreover, the difficulty of classifying different mangrove species, in order of increasing difficulty, was identified as KO < AM < AI < AC. Dual polarimetric SAR data are recognized to improve the classification of AI and AC species. Although this improvement is not remarkable, it is consistent for all three methods. The improvement can be particularly important for large-scale mapping of mangrove forest at the species level. These findings also provide useful guidance for future studies using multi-source satellite data for mangrove monitoring and conservation.

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Section: Contributions From the Dual Polarimetric Sar Datamentioning

confidence: 73%

Section: Field Datamentioning

confidence: 96%

Potential of Combining Optical and Dual Polarimetric SAR Data for Improving Mangrove Species Discrimination Using Rotation Forest

et al. 2018

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“…4 and 5), as opposed to the changing variation in the results displayed by the PCQM protocol, is indicative for its reliability. The fact that the basal area is less affected by the tree type (SST or MST) is also reassuring for the establishment of allometric relationships based on D 130 such as biomass (Baskerville, 1972;Suzuki and Tagawa, 1983;Woodroffe, 1985;Putz and Chan, 1986;Clough and Scott, 1989;Amarasinghe and Balasubramaniam, 1992a,b;Tam et al, 1995;Slim et al, 1996;Clough et al, 1997;Fromard et al, 1998;Komiyama et al, 2000;Ong et al, 2004). The same is true for the study of density or D 130 -related processes such as competition (Nissen and Midmore, 2002), succession (Smith III, 1992;Lugo, 1997;Duke, 2001), impact assessment (Imbert et al, 1996(Imbert et al, , 1998, or for processes that may be reflected by tree density or D 130 , such as hydrological changes (Ernst and Brooks, 2003;DahdouhGuebas et al, 2005b).…”

Section: The Pcqm+ Protocolmentioning

confidence: 99%

Empirical estimate of the reliability of the use of the Point-Centred Quarter Method (PCQM): Solutions to ambiguous field situations and description of the PCQM+ protocol

Dahdouh‐Guebas

Koedam

2006

Forest Ecology and Management

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This paper reports problems associated to the use of the Point-Centred Quarter Method (PCQM), as well as their possible solutions. Problematic settings in the application of the PCQM are amongst others due to the presence of multiple-stemmed trees (MST), to ambiguous settings for measuring the sampling point to nearest tree distance or the tree diameter, both of which may result in erroneous estimation of silvimetric variables and parameters. The analysis is based on a database of effective individual tree records including distances, diameters, and heights measured in the field in a Sri Lankan mangrove forest between 1997 and 2002, and randomly compiles a series of records that were used as PCQM sampling points. Various structural forest parameters were calculated, with particular emphasis on density and basal area.After proving that multiple-and single-stemmed trees have different silvimetric characteristics, we adopted an empirical approach to demonstrate the classical PCQM protocol applied to MST generates significantly different densities (overestimation) and basal areas (underestimation) depending on which stems are considered for measurement, and we suggest an adapted PCQM+ protocol (measurement of central stem instead of nearest stem). We test both protocols in two mangrove assemblages (one composed of Excoecaria agallocha only, and an Excoecaria agallocha/Rhizophora apiculata mixed forest) with MST proportions varying between 0% and 100%, at 5% intervals.The results indicated that the classical PCQM protocol generates density and basal area results that are strongly correlated with the MST proportion in the assemblage ( p < 0.001), whereas the PCQM+ protocol shows a robustness with no such correlations for density. For basal area the results of the PCQM+ protocol showed a weak correlation with the MST proportion, and regression-ANCOVA results indicated that they were significantly different from those of the highly sensitive PCQM protocol ( p < 0.001).Finally, we conclude by writing out the entire PCQM+ protocol, elaborating on the solutions to other common problems related to ambiguous settings for the consideration of stems or the measurement of their diameter (aerial roots, split trunks, dwarf growth, horizontally developing stems, boundary of an individual in MST, selectively cut trees or tree parts, very sparse assemblages, use of PCQM for remote sensing ground-truth), and by nevertheless highlighting the potential of the PCQM/PCQM+ approach. Although we used a mangrove forest data set, the PCQ-Method and our suggestions are widely applicable to other forest types. In addition, this paper is accompanied by the first interface that automatically processes standard PCQM-related data (regardless of forest type) to generate common silvimetric or forestry parameters elaborated in this paper, and it is freely available in Appendix C and from

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“…Mangrove diversity of each transect was calculated using Shannon Weiner Index (equation 1) (Shannon and Weaver, 1949). The above-ground biomass (AGB) of the mangrove stands was estimated using the allometric relationship between above-ground biomass, diameter at breast height (dbh) and height (Cintron and Schaeffer-Novelli, 1984;Komiyama et al, 1988;Tam et al, 1995;Komiyama et al, 2000). Equations 3 to 8 illustrate the methods used to estimate them.…”

Section: Diversity Estimationmentioning

confidence: 99%

A Preliminary Study on Vegetation Structure and Mangrove Diversity in Irakkandy Lagoon, Trincomalee

Krishnanantham¹,

Seneviratne²,

Jayamanne³

2015

JTFE

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The present study was carried out during the period from May to July 2014 to assess the vegetation pattern and to estimate biomass of the mangroves in Irakkandy Lagoon, Trincomalee. Five belt-transects of 10 m in width were laid perpendicular to the shoreline. Data were collected on tree diameter at breast height (dbh) and tree height from each sub-plot (100 m 2 ) in belt transects using standard methods. Above ground biomass, basal area and relative density of the mangroves were also estimated. Diversity and evenness of each sub-plot was calculated using Shannon-Wiener diversity index and Pielou's evenness index respectively. Results revealed that the study site is composed of 5 true mangrove species and highest density was recorded for Avicennia marina (414 trees/ha, 700 saplings/ha, 2354 seedlings/ha), followed by Lumnitzera racemosa, Excoecaria agallocha, Rhizophora apiculata and Heritiera littoralis. The greatest mangrove diversity (1.28) was observed in subplot 1 of transect 2. The least mangrove diversity (0) was found in transect 5. There is a significant difference among transects concerning the diversity and evenness (P<0.05). The results showed that Avicennia marina was the dominant species with Height (H) and dbh of 3.65±1.43 m and 5.06±1.07 cm respectively, followed by Lumnitzera racemosa (3.36±1.19 m and 5.81±1.06 cm, Excoecaria agallocha (4.92±2.45 m and 5.31±1.93 cm), Rhizophora apiculata (4.56±1.70 m and 4.89±0.96 cm) and Heritiera littoralis (8.80±0.849 m and 26.50±4.95 cm). The above ground biomass of Lumnitzera racemosa was recorded as 8334.89 kg/ha and Avicennia marina was recorded as 1361.13 kg/ha. Species diversity (H') of whole mangrove area studied was 0.86 and evenness (E) was 0.54. It reveals that Irakkandy Lagoon consists of fairly high biological diversity (Diversity index=0.86) of mangroves and extremely valuable for stability of the ecosystem.

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Community structure and standing crop biomass of a mangrove forest in Futian Nature Reserve, Shenzhen, China

Cited by 79 publications

References 14 publications

Potential of Combining Optical and Dual Polarimetric SAR Data for Improving Mangrove Species Discrimination Using Rotation Forest

Potential of Combining Optical and Dual Polarimetric SAR Data for Improving Mangrove Species Discrimination Using Rotation Forest

Empirical estimate of the reliability of the use of the Point-Centred Quarter Method (PCQM): Solutions to ambiguous field situations and description of the PCQM+ protocol

A Preliminary Study on Vegetation Structure and Mangrove Diversity in Irakkandy Lagoon, Trincomalee

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