scholarly journals Re-colonizing Mangrove species in tsunami devastated habitats at Nicobar Islands, India

Check List ◽  
2011 ◽  
Vol 7 (3) ◽  
pp. 253 ◽  
Author(s):  
Prabakaran Nehru ◽  
Paramasivam Balasubramanian
Keyword(s):  
Mangrove Forests ◽  
Bruguiera Gymnorrhiza ◽  
Anthropogenic Pressures ◽  
Mangrove Species ◽  
Mangrove Vegetation ◽  
Colonization Process ◽  
The Common ◽  
Nicobar Islands ◽  
First Time

Mangrove habitats are crucial for maintaining the biodiversity of coastal ecosystem. Climatic change, sea level rise and anthropogenic pressures are the major threats to mangrove forests. The Nicobar Islands comprised one of the pristine mangrove stands in India. The mega earthquake of >9 M and subsequent tsunami during 2004 caused destruction of over 70% of mangrove vegetation in Nicobar Islands. The present study was carried out in the Central Nicobar Group of Islands (Camorta, Nancowry, Katchall and Trinkat), where tsunami has entirely wiped out the mangrove vegetation. Re-colonization started on its own course. We enumerated nine species of mangrove plants and 30 species of mangrove associates from the surveyed locations. Lumnitzera racemosa has been recorded for the first time from the study area. Rhizophora mucronata and Bruguiera gymnorrhiza were the common pioneer mangrove species. Long-term monitoring of re-colonization process will help us in understanding succession of mangrove forests. 

scholarly journals KEANEKARAGAMAN JENIS MANGROVE DI DESA MENDALOK KECAMATAN SUNGAI KUNYIT KABUPATEN MEMPAWAH

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Syahrul Muharamsyah ◽  
M Sofwan Anwari ◽  
Hafiz Ardian
Keyword(s):  
Mangrove Forest ◽  
Avicennia Marina ◽  
Raw Material ◽  
Mangrove Forests ◽  
Bruguiera Gymnorrhiza ◽  
Mangrove Species ◽  
Rhizophora Stylosa ◽  
Sonneratia Caseolaris ◽  
Rhizophora Apiculata ◽  
Bruguiera Cylindrica

Mangrove forests are unique ecosystems that have ecological, biological and socio-economic functions. The function of mangrove forests on the environment is very important especially in the coastal and oceanic regions. Mangrove forests providers of wood, leaves as raw material for medicines, and natural dye. This study aims to inventory the diversity of species of mangrove vegetation in Mendalok Village, Sungai Kunyit Subdistrict, Mempawah Regency. The benefits of this study are to provide the data on mangrove forest vegetation as basic data for local government and related agencies in efforts to protect and preserve mangrove forests in Mendalok Village, Sungai Kunyit Subdistrict, Mempawah Regency. Inventory the tree in mangrove forest used a line with measured 200 meters. There are 6 lines and the distance between the lines as far as 100 meters. The lines of observation are placed by purposive sampling. The results of research found 11 types of species and consisted of 6 genera. The genera are Avicennia, Bruguiera, Ceriops, Rhizophora, Soneratia and Xylocarpus. The species found were Avicennia alba, Avicennia marina, Bruguiera cylindrica, Bruguiera gymnorrhiza, Bruguiera parviflora, Ceriops decandra, Rhizophora apiculata, Rhizophora mucronata, Rhizophora stylosa, Sonneratia caseolaris, Xylocarpus mollucensis. Diversity of mangrove species in Mendalok Village, Sungai Kunyit Subdistrict, Mempawah Regency was high and should be maintained for conservation and ecotourism area. Keywords : conservation, ecotourism, mangrove, Mendalok Village

scholarly journals Kondisi mangrove di pesisir timur pulau Jemaja Kepuluan Anambas

2020 ◽  
Vol 7 (2) ◽  
pp. 70
Author(s):  
Wahyudi Andrito ◽  
Syafruddin Nasution ◽  
Efriyeldi Efriyeldi
Keyword(s):  
East Coast ◽  
Good Condition ◽  
Canopy Cover ◽  
Coastal Areas ◽  
Average Density ◽  
Survey Method ◽  
Mangrove Forests ◽  
Bruguiera Gymnorrhiza ◽  
Mangrove Species ◽  
Sea Levels

 Mangrove ecosystems are one of three important ecosystems in the coastal areas that supports global warming mitigation efforts. The existence of mangrove forests is needed to reduce the increased CO2 concentrations in the atmosphere. However, the rise of the water temperatures and sea levels indirectly affects the presence and condition of mangrove forests in coastal areas. The purpose of this study is to determine the condition of the mangrove community on the East Coast of Jemaja, Anambas Archipelagoes Regency. The survey method  was used in this study and a series survey activities were conducted for a quadrant transect with a size of 10m by 10m in December 2019 - March 2020.The result shown that the five mangrove species were identified, such as Rhizophora apiculata, R. mucronata, Bruguiera gymnorrhiza, Ceriops tagal and Xylocarpus granatum. R. apiculata dominates with an important value index of 123.12%. While, the average density of mangroves and saplings in the study area was 3155 ± 785 individuals/ha and the average canopy cover was 84.03 ± 3.11%. With this finding, it can be concluded that the condition of mangroves in the East Coast of Jemaja is very dense and still in a good condition.

scholarly journals UNDERSTANDING THE STATUS AND CHALLENGES OF MANGROVE CONSERVATION IN CENTRAL VIETNAM: CASE STUDY IN DUY XUYEN DISTRICT, QUANG NAM PROVINCE

2019 ◽  
Vol 128 (3B) ◽  
Author(s):  
Nguyen Thi Hong Mai ◽  
Nguyen Quang Tan ◽  
Nguyen Hoang Khanh Linh
Keyword(s):  
Development Strategy ◽  
Local Community ◽  
Current Status ◽  
Mangrove Forests ◽  
Economic Activities ◽  
Mangrove Species ◽  
Central Vietnam ◽  
The Status ◽  
Mangrove Conservation

Abstract: While mangrove forests support large surrounding populations and diverse economic activities, mangrove areas in Central Vietnam are decreasing. This study, thereforce, aims to understand the current status and threats facing mangrove conservation and development. A survey of 52 respondents was conducted in Duy Xuyen district, the largest area of mangrove forests of Quang Nam province. The results show that 17 mangrove species belong to 11 families, in which 8 significant species and 9 minor species were found in this site. The distribution of species was uneven with dominated by Nipah palms (Nypafruticans Wurmb). Although the mangrove species had several useful functions including protection against wind, wave break and serving tourism development, mangrove areas have been decreasing from 26.39ha to 18.22ha during period of 1999-2018. In which, 67.3% of respondents argued that the conversion of mangroves to aquaculture is one of the main causes of mangrove loss. The study also provided some suggestions related to a long-term development strategy for both government and local community, especially who are directly involving in the mangrove for their livelihoods.Keywords: Central Vietnam, development strategy, mangrove forests, livelihoods

scholarly journals MANGROVE FOREST EFFECT ON THE COASTLINE IN RANGSANG ISLAND RIAU PROVINCE

2020 ◽  
Vol 3 (1) ◽  
pp. 29-37
Author(s):  
Paulinus ◽  
Mubarak Mubarak ◽  
Efriyeldi Efriyeldi
Keyword(s):  
Image Data ◽  
Landsat Image ◽  
Sampling Location ◽  
Landsat 8 ◽  
Mangrove Forests ◽  
Bruguiera Gymnorrhiza ◽  
Mangrove Species ◽  
Rhizophora Apiculata ◽  
Xylocarpus Granatum ◽  
Avicennia Alba

The study was conducted in May-June 2019 on Rangsang Island. This study aims to determine the effect of mangrove forests on coastline found on the island of Rangsang in Riau Province. The sampling location was determined by purposive sampling, namely 3 station points, namely Segomeng Village, Tanjung Kedabu Village, and Sungai Gayung Kiri Village. Landsat image data analyzed at the Oceanographic Physics Laboratory of the Department of Marine Sciences, Faculty of Fisheries and Maritime Affairs, University of Riau. To find out the area of ​​mangroves using Landsad 5 TM satellite imagery and Landsat 8 OLI Tirs imagery and analyzed using Er Mapper Software, Envi 4.5 and Arcgis 10.3. Calculation of the structure of the mangrove community is carried out using the line plot plot method. The results of the analysis of the vast landsat image of mangroves in the coastal areas of Rangsang Island in 1997, 2002, 2007, 2013, 2019 were respectively 11,093 ha, 10,807 ha, 10,393 ha, 10,121 ha and 9,971 ha. Changes in the coastline indicate the occurrence of abrasion and accretion, where the highest abrasion occurs at station three with an average of -7.6 m/year and accretion occurs at station one with an average of 2.68 m / year. Mangrove density at station one is 2266.7 ind / ha and at station two that is 1466.7 ind / ha. Mangrove species found were Rhizophora apiculata, Rhizophora mucronata, Avicennia alba, Sonneratia ovata, Bruguiera gymnorrhiza, and Xylocarpus granatum.

scholarly journals Continuous Wavelet Analysis of Leaf Reflectance Improves Classification Accuracy of Mangrove Species

2019 ◽  
Vol 11 (3) ◽  
pp. 254 ◽  
Author(s):  
Yi Xu ◽  
Junjie Wang ◽  
Anquan Xia ◽  
Kangyong Zhang ◽  
Xuanyan Dong ◽  
...  
Keyword(s):  
Wavelet Analysis ◽  
Classification Accuracy ◽  
Vegetation Index ◽  
Hyperspectral Data ◽  
Continuous Wavelet ◽  
Mangrove Forests ◽  
Bruguiera Gymnorrhiza ◽  
Species Classification ◽  
Successive Projections Algorithm ◽  
Mangrove Species

Due to continuous degradation of mangrove forests, the accurate monitoring of spatial distribution and species composition of mangroves is essential for restoration, conservation and management of coastal ecosystems. With leaf hyperspectral reflectance, this study aimed to explore the potential of continuous wavelet analysis (CWA) combined with different sample subset partition (stratified random sampling (STRAT), Kennard-Stone sampling algorithm (KS), and sample subset partition based on joint X-Y distances (SPXY)) and feature extraction methods (principal component analysis (PCA), successive projections algorithm (SPA), and vegetation index (VI)) in mangrove species classification. A total of 301 mangrove leaf samples with four species (Avicennia marina, Bruguiera gymnorrhiza, Kandelia obovate and Aegiceras corniculatum) were collected across six different regions. The smoothed reflectance (Smth) and first derivative reflectance (Der) spectra were subjected to CWA using different wavelet scales, and a total of 270 random forest classification models were established and compared. Among the 120 models with CWA of Smth, 88.3% of models increased the overall accuracy (OA) values with an improvement of 0.2–28.6% compared to the model with the Smth spectra; among the 120 models with CWA of Der, 25.8% of models increased the OA values with an improvement of 0.1–11.4% compared to the model with the Der spectra. The model with CWA of Der at the scale of 23 coupling with STRAT and SPA achieved the best classification result (OA = 98.0%), while the best model with Smth and Der alone had OA values of 86.3% and 93.0%, respectively. Moreover, the models using STRAT outperformed those using KS and SPXY, and the models using PCA and SPA had better performances than those using VIs. We have concluded that CWA with suitable scales holds great potential in improving the classification accuracy of mangrove species, and that STRAT combined with the PCA or SPA method is also recommended to improve classification performance. These results may lay the foundation for further studies with UAV-acquired or satellite hyperspectral data, and the encouraging performance of CWA for mangrove species classification can also be extended to other plant species.

scholarly journals Vegetation Structure and Damage Level Mangrove Forest in Manomadehe Island, Subdistrict South Jailolo, North Maluku Province

2021 ◽  
Vol 21 (1) ◽  
pp. 222
Author(s):  
Salim Abubakar ◽  
Riyadi Subur ◽  
Masykhur Abdul Kadir ◽  
Rina Rina ◽  
Adi Noman Susanto ◽  
...  
Keyword(s):  
Relative Density ◽  
Vegetation Structure ◽  
Mangrove Forest ◽  
Mangrove Forests ◽  
Mangrove Species ◽  
Rhizophora Stylosa ◽  
Xylocarpus Granatum ◽  
Sonneratia Alba ◽  
Mangrove Vegetation ◽  
Ceriops Tagal

Mangrove forest is a natural resource typical of tropical coasts, which has multiple benefits with a very broad impact when viewed from social, economic and ecological aspects. Management of natural resources must be very prudent because it takes a long time to be able to recover when damage / extinction has occurred. The purpose of this study was to determine the composition of mangrove species, the structure of mangrove forest vegetation (species density, relative density of species, frequency of species, relative frequency of species, species cover, relative cover of species and important values) and to determine the level of damage. Extraction of mangrove vegetation using the "spot check" method. The transects are drawn perpendicular to the coastline along the mangrove vegetation. The composition of mangrove species were 7 species, namely Rhizophora apiculata, R. stylosa, Bruguirea gymnorrhiza, Ceriops tagal, Sonneratia alba, Xylocarpus granatum and Aegiceras floridum. In the vegetation structure, the highest density and relative density were found in Rhizophora stylosa and the lowest was Xylocarpus granatum. The highest species and relative frequencies were Rhizophora stylosa, R. apiculata and the lowest were Bruguiera gymnorrhiza. The highest type and closure were Sonneratia alba and the lowest was Ceriops tagal. Meanwhile, the highest importance was in Sonneratia alba and the lowest was Xylocarpus granatum. Overall, the density value of mangrove species on Manomadehe Island is 2796 trees / ha so that the condition of the mangrove forests on Manomadehe Island is still in the good category (very dense).

Common allometric equations for estimating the tree weight of mangroves

2005 ◽  
Vol 21 (4) ◽  
pp. 471-477 ◽  
Author(s):  
Akira Komiyama ◽  
Sasitorn Poungparn ◽  
Shogo Kato
Keyword(s):  
Wood Density ◽  
Allometric Equations ◽  
Root Weight ◽  
Mangrove Forests ◽  
Mangrove Species ◽  
Trunk Diameter ◽  
Mangrove Tree ◽  
Pipe Model ◽  
Independent Variable ◽  
The Common

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, ρ (wood density of tree trunk) differed significantly among the species. A common allometric equation for trunk weight was derived, when dbh2H or DR0.32H was selected as the independent variable and wood density was taken into account. The common allometric equations for the leaf and the above-ground weight were also derived according to Shinozaki's pipe model and its extended theory. The common allometric relationships for these weights were attained with given ρ 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.

scholarly journals Long-term effects of oil pollution in mangrove forests (Baixada Santista, Southeast Brazil) detected using a GIS-based multitemporal analysis of aerial photographs

2012 ◽  
Vol 60 (2) ◽  
pp. 159-170 ◽  
Author(s):  
Luciana Cavalcanti Maia Santos ◽  
Marília Cunha-Lignon ◽  
Yara Schaeffer-Novelli ◽  
Gilberto Cintrón-Molero
Keyword(s):  
Mangrove Forest ◽  
Oil Pollution ◽  
Aerial Photographs ◽  
Residual Effects ◽  
Structural Development ◽  
Mangrove Forests ◽  
Long Term Effects ◽  
Mangrove Vegetation ◽  
Multitemporal Analysis

Oil spills are potential threats to the integrity of highly productive coastal wetlands, such as mangrove forests. In October 1983, a mangrove area of nearly 300 ha located on the southeastern coast of Brazil was impacted by a 3.5 million liter crude oil spill released by a broken pipeline. In order to assess the long-term effects of oil pollution on mangrove vegetation, we carried out a GIS-based multitemporal analysis of aerial photographs of the years 1962, 1994, 2000 and 2003. Photointerpretation, visual classification, class quantification, ground-truth and vegetation structure data were combined to evaluate the oil impact. Before the spill, the mangroves exhibited a homogeneous canopy and well-developed stands. More than ten years after the spill, the mangrove vegetation exhibited three distinct zones reflecting the long-term effects of the oil pollution. The most impacted zone (10.5 ha) presented dead trees, exposed substrate and recovering stands with reduced structural development. We suggest that the distinct impact and recovery zones reflect the spatial variability of oil removal rates in the mangrove forest. This study identifies the multitemporal analysis of aerial photographs as a useful tool for assessing a system's capacity for recovery and monitoring the long-term residual effects of pollutants on vegetation dynamics, thus giving support to mangrove forest management and conservation.

scholarly journals FLORISTIC DIVERSITY AND STRUCTURAL CHARACTERISTICS OF MANGROVE FOREST OF RAJA AMPAT, WEST PAPUA, INDONESIA

REINWARDTIA ◽  
2014 ◽  
Vol 14 (1) ◽  
pp. 171
Author(s):  
Suhardjono Prawiroatmodjo ◽  
Kuswata Kartawinata
Keyword(s):  
Diversity Index ◽  
Structural Characteristics ◽  
Basal Area ◽  
Economic Benefits ◽  
Mangrove Forests ◽  
Bruguiera Gymnorrhiza ◽  
Importance Value ◽  
Mangrove Species ◽  
Rhizophora Apiculata ◽  
West Papua

We studied  the floristic compostion and structure of mangrove forests and mangrove species distribution at the Raja Ampat Regency, West Papua  We sampled the forests using (10x10 m) quadrats to record trees and saplings  laid out contiguously along 9 transects of 60 – 450 m long,  stretching perpendicularly from the coastlines or riverbanks to the landward borders. Seedlings were sampled using a 1x1 m subplot nested in each quadrat.  The transects were established on the islands of  Batanta (6), Salawati  (2). and Waigeo (1).  Within quadrats and transects we recorded 17 mangrove species of trees with density of 768 stems/ha and basal area of  37.82 m2/ha and tree height of  10 – 30 m.   Two species possessed  the highest importance value  (IV) , frequency, density and basal area  i.e. Rhizophora apiculata (IV=168.06 %) and  Bruguiera gymnorrhiza (IV=67.18).  They also showed the highest similarity in their distribution,  indicating highest degree of association.  The mangrove at Raja Ampat may, therefore,  be designated as the Rhizophora apiculata-Bruguiera gymnorrhiza Association. Other species with highest degree of distributional similarities but with low densities, basal areas and importance values were Barringtonia racemosa, Excoecaria agallocha, Hibiscus tiliaceus, Inocarpus fagifera,  Lumnitzera littorea and Sterculia shillinglawii,  of which four of them are not  true mangrove species, usually growing on less saline and more solid soils. The floristic composition of the transects in the three islands showed relatively high similarities of about 70 % and at higher similarities the transects in Batanta Island formed four groups, Salawati Island two groups and Waigeo Island one group.The Bray-Curtis polar ordination  resulted in four groups  of transects, which were related to the habitat  conditions and the length of the transects. Species diversity in the islands was very low, where the  Shannon diversity index  ranged  from  0.19 to 0.64 giving  the average  of 0.42. Rhizophora apiculata and Bruguiera gymnorrhiza  were gregenerating well and in the future they will remain dominant.  The mangrove forests of the Raja Ampat Islands by any means should be maintained as green belts and  protected from all kinds of destruction and should be made into conservation areas in order to sustain its ability to provide ecological services  and non-destructive economic benefits.

scholarly journals Evaluation of the Continuous Monitoring of Land Disturbance Algorithm for Large-Scale Mangrove Classification

2021 ◽  
Vol 13 (19) ◽  
pp. 3978
Author(s):  
Katie Awty-Carroll ◽  
Pete Bunting ◽  
Andy Hardy ◽  
Gemma Bell
Keyword(s):  
Continuous Monitoring ◽  
Large Scale ◽  
Data Availability ◽  
Mangrove Forests ◽  
Mangrove Species ◽  
Land Disturbance ◽  
Long Term Monitoring ◽  
The Impact ◽  
Term Monitoring

Mangrove forests are of high biological, economic, and ecological importance globally. Growing within the intertidal zone, they are particularly vulnerable to the effects of climate change in addition to being threatened on local scales by over-exploitation and aquaculture expansion. Long-term monitoring of global mangrove populations is therefore highly important to understanding the impact of these threats. However, data availability from satellites is often limited due to cloud cover. This problem can be mitigated using a season-trend modelling approach such as Continuous Monitoring of Land Disturbance (COLD). COLD operates by using every available observation on a pixel-wise basis, removing the need for whole cloud free images. The approach can be used to better classify land cover by taking into account the underlying seasonal variability, and can also be used to extrapolate between data points to obtain more accurate long term trends. To demonstrate the utility of COLD for global mangrove monitoring, we applied it to five study sites chosen to represent a range of mangrove species, forest types, and quantities of available data. The COLD classifier was trained on the Global Mangrove Watch 2010 dataset and applied to 30 years of Landsat data for each site. By increasing the period between model updates, COLD was successfully applied to all five sites (2253 scenes) in less than four days. The method achieved an overall accuracy of 92% with a User’s accuracy of 77% and a Dice score of 0.84 for the mangrove class. The lowest User’s accuracy was for North Kalimantan (49.9%) due to confusion with mangrove palms. However, the method performed extremely well for the Niger Delta from the 2000s onwards (93.6%) despite the absence of any Landsat 5 data. Observation of trends in mangrove extent over time suggests that the method was able to accurately capture changes in extent caused by the 2014/15 mangrove die-back event in the Gulf of Carpentaria and highlighted a net loss of mangroves in the Matang Forest Reserve over the last two decades, despite ongoing management. COLD is therefore a promising methodology for global, long-term monitoring of mangrove extent and trends.

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