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•Organic carbon burial rates and sources were assessed across Papuan mangroves.•Organic carbon burial rates ranged between 0.21 and 1.19 Mg C ha−1 yr−1.•Soil organic carbon stocks in ...the top 50 cm varied between 62 and 179 Mg C ha−1.•Soil organic carbon stocks are sourced from autoch- and alloch-thonous sources.
Mangrove organic carbon is primarily stored in soils, which contain more than two-thirds of total mangrove ecosystem carbon stocks. Despite increasing recognition of the critical role of mangrove ecosystems for climate change mitigation, there is limited understanding of soil organic carbon sequestration mechanisms in undisturbed low-latitude mangroves, specifically on organic carbon burial rates and sources. This study assessed soil organic carbon burial rates, sources and stocks across an undisturbed coastal mudflat and mangrove hydrogeomorphological catena (fringe mangrove and interior mangrove) in Bintuni Bay, West Papua Province, Indonesia. 210Pb radionuclide sediment dating, and mixing model of natural stable isotope signatures (δ 13C and δ15N) and C/N ratio were used to estimate organic carbon burial rates and to quantify proportions of allochthonous (i.e., upland terrestrial forest) and autochthonous (i.e., on-site mangrove forest) organic carbon in the top 50 cm of the soil. Burial rates were in the range of 0.21–1.19 Mg C ha−1 yr−1. Compared to the fringe mangroves, organic carbon burial rates in interior mangroves were almost twice as high. Primary productivity of C3 upland forest vegetation and mangroves induced soil organic carbon burial in interior mangroves and this was consistent with the formation of the largest organic carbon stocks (179 ± 82 Mg C ha−1). By contrast, organic carbon stored in the fringe mangrove (68 ± 11 Mg C ha−1) and mudflat (62 ± 10 Mg C ha−1) soils mainly originated from upland forests (allochthonous origin). These findings clearly indicate that carbon sequestered and cycling in mangrove and terrestrial forest ecosystems are closely linked, and at least a part of carbon losses (e.g., erosion) from terrestrial forests is buried in mangrove ecosystems.
Globally, carbon‐rich mangrove forests are deforested and degraded due to land‐use and land‐cover change (LULCC). The impact of mangrove deforestation on carbon emissions has been reported on a ...global scale; however, uncertainty remains at subnational scales due to geographical variability and field data limitations. We present an assessment of blue carbon storage at five mangrove sites across West Papua Province, Indonesia, a region that supports 10% of the world's mangrove area. The sites are representative of contrasting hydrogeomorphic settings and also capture change over a 25‐years LULCC chronosequence. Field‐based assessments were conducted across 255 plots covering undisturbed and LULCC‐affected mangroves (0‐, 5‐, 10‐, 15‐ and 25‐year‐old post‐harvest or regenerating forests as well as 15‐year‐old aquaculture ponds). Undisturbed mangroves stored total ecosystem carbon stocks of 182–2,730 (mean ± SD: 1,087 ± 584) Mg C/ha, with the large variation driven by hydrogeomorphic settings. The highest carbon stocks were found in estuarine interior (EI) mangroves, followed by open coast interior, open coast fringe and EI forests. Forest harvesting did not significantly affect soil carbon stocks, despite an elevated dead wood density relative to undisturbed forests, but it did remove nearly all live biomass. Aquaculture conversion removed 60% of soil carbon stock and 85% of live biomass carbon stock, relative to reference sites. By contrast, mangroves left to regenerate for more than 25 years reached the same level of biomass carbon compared to undisturbed forests, with annual biomass accumulation rates of 3.6 ± 1.1 Mg C ha−1 year−1. This study shows that hydrogeomorphic setting controls natural dynamics of mangrove blue carbon stocks, while long‐term land‐use changes affect carbon loss and gain to a substantial degree. Therefore, current land‐based climate policies must incorporate landscape and land‐use characteristics, and their related carbon management consequences, for more effective emissions reduction targets and restoration outcomes.
We present blue carbon (C) assessment from 255 plots covering undisturbed and land‐use change‐affected mangroves (0‐, 5‐, 10‐, 15‐ and 25‐year‐old post‐harvest as well as 15‐year‐old aquaculture ponds) across West Papua Province, Indonesia. Undisturbed mangroves stored total ecosystem C‐stocks of 182–2,730 (1,087 ± 584) Mg C/ha, with variation driven by hydrogeomorphic settings. Forest harvesting did not significantly affect soil C‐stocks, despite increased dead wood density, but it removed nearly all live biomass. Aquaculture conversion removed 60% of soil and 85% of live biomass C‐stocks. Mangroves left to regenerate for 25 years reached the same level of biomass carbon compared to undisturbed forests.
Many watersheds in Manokwari are classified as flood-prone areas with a frequency of more than 1 flood per year. Limited rain stations and climate stations make it difficult to the zoning of ...flood-prone areas. This study aims to utilize remote sensing data and hydrodynamic models to zone flood-prone areas in watersheds (DAS). The research was conducted in the Wosi Watershed - Manokwari Regency - West Papua Province. The data used in this research is DEMNAS topographic data, Climate Hazards Group Infrared Precipitation with Stations (CHIRPS) data acquired 1996 – 2020, Sentinel 2 imagery acquired 21 September 2020, and river maps. The peak flow in the Wosi watershed was analyzed using rational methods and flood hazard zoning was analyzed using HEC-RAS. The research showed that the Wosi River was not able to accommodate the peak flow at various return periods, consequently, the Wosi River had the potential for flooding every year. The results of this study are relevant to actual events, therefore remote sensing data and hydrodynamic models can be used to analyze peak flow and flood hazard zoning.Keywords: Climate Hazards Group Infrared Precipitation with Stations, DEMNAS, HEC-RAS, Satellite Imagery, Sentinel 2.
The effects of El Nino-Southern Oscillation events on catches of Bigeye Tuna (Thunnus obesus) in the eastern Indian Ocean (EIO) off Java were evaluated through the use of remotely sensed ...environmental data (sea-surface-height anomaly SSHA, sea-surface temperature SST, and chlorophyll-a concentration), and Bigeye Tuna catch data. Analyses were conducted for the period of 1997-2000, which included the 1997-98 El Nino and 1999-2000 La Nina events. The empirical orthogonal function (EOF) was applied to examine oceano-graphic parameters quantitatively. The relationship of those parameters to variations in catch distribution of Bigeye Tuna was explored with a generalized additive model (GAM). The mean hook rate was 0.67 during El Nino and 0.44 during La Nina, and catches were high where SSHA ranged from -21 to 5 cm, SST ranged from 24 degree C to 27.5 degree C, and chlorophyll-a concentrations ranged from 0.04 to 0.16 mg m super(-3). The EOF analysis confirmed that the 1997-98 El Nino affected oceanographic conditions in the EIO off Java. The GAM results indicated that SST was better than the other environmental factors (SSHA and chlorophyll-a concentration) as an oceanographic predictor of Bigeye Tuna catches in the region. According to the GAM predictions, the highest probabilities (70-80%) for Bigeye Tuna catch in 1997-2000 occurred during oceanographic conditions during the 1997-98 El Nino event.
ABSTRAKWilayah pesisir sebagai kawasan peralihan yang menghubungkan ekosistem darat dan ekosistem laut, sangat rentan terhadap kerusakan dan perubahan yang diakibatkan oleh berbagai aktifitas manusia ...di darat maupun di laut. Kabupaten Indramayu merupakan salah satu wilayah di Pesisir Utara Jawa Barat yang mengalami kerusakan paling parah diantara seluruh kabupaten di wilayah pesisir Utara Jawa Barat serta memiliki penggunaan lahan pesisir yang cukup lengkap mulai dari pemukiman, persawahan, tambak, dan industri (PLTU dan MIGAS)..Besarnya perubahan garis pantai yang meliputi abrasi dan sedimentasi diturunkan dari data citra satelit Landsat wilayah pesisir Kabupaten Indramayu tahun 1994-2009 dengan metode komposit RGB 4, 5, 7 dan Metode AGSO kemudian dilakukan proses digitasi.. Luas abrasi di 11 Kecamatan Pesisir Indramayu dari tahun 1994 – 2009 sebesar 3900,41 Ha dengan laju abrasi rata-rata sebesar 23,64 Ha/ tahun dan Luas sedimentasi sebesar 650,29 Ha dengan laju sedimentasi rata-rata sebesar 4,81 Ha/tahun. Hasil perhitungan regresi terhadap rasio lahan penduduk untuk tahun 2015 sebesar 0,07 Ha/ jiwa dan menurun pada tahun 2025 menjadi 0,05 Ha/jiwa .Rasio lahan petani untuk tahun 2015 sebesar 0,66 Ha/petani dan menurun menjadi 0,55 Ha/petani di tahun 2025.Kata Kunci : Pesisir indramayu, citra satelit, abrasi dan sedimentasi, Rasio lahanABSTRACTCoastal areas as a transitional region connecting the land ecosystems and marine ecosystems, are vulnerable to damage and changes caused by various human activities on land and at sea. Indramayu regency is one of the areas in the North Coast of West Java is the most severely damaged among all districts in the northern coast of West Java and has a coastal land use complete enough from residential areas, wet rice fields, ponds, and industrial (power plant and Gas). The number of change in coastal line include erosion and sedimentation derived from Landsat satellite image data coastal areas of Indramayu district in 1994-2009 with the composite method RGB 4, 5, 7 and methods AGSO then do the digitization process. The extent of abrasion in 11 districts of the coastal Indramayu from 1994 - 2009 are 3900.41 hectares with average abrasion rate of 23.64 ha / year and sedimentation area of 650.29 hectares with an average sedimentation rate of 4.81 ha / year. Results of regression calculations to land ratio for the 2015 population of 0.07 ha / life and decreased in 2025 to 0.05 hectares /life .Rasio farmers' fields for 2015 of 0.66 ha / farmer and decreased to 0.55 Ha / farmers in 2025. Keywords: Coastal area of indramayu, satellite imagery, erosion and sedimentation, land Ratio
The growth and starch accumulation processes of sago palm with age in the natural forest were investigated in South Sorong, West Papua, Indonesia. The surveyed natural forest seemed to be a nearly ...pure sago palm forest and have reached the climax forest stage. The sucker density was lower than that of the cultivated garden, and the trunk density (trunks of 0.5 m or more) was almost equal. In addition, the trunk length at the flowering stage was longer than that in the cultivated garden, and the trunk frequency during the flowering to the dying/dead stage was higher. In the natural forest, it was difficult to estimate palm age, thus the number of leaf scars and leaves (No. LS + L) was used as an index of palm age. Until the No. LS + L was about 80 (about 10 m in trunk length), there was almost no increase in the percentages of dry matter and starch in the pith. However, afterward, these percentages and the starch content of the pith increased rapidly. The average starch content at the harvest stage was about 360 kg, but its variation was large among the individuals. The sago palms in the natural forest had lower percentages of dry matter and starch in the pith even at the optimal harvest stage, and the starch productivities per trunk length, fresh weight, and volume were lower than those of the cultivated sago palms.
Slope length and steepness factor index (LS) is one of the parameters for the Universal Soil Loss Equation (USLE) to estimate soil erosion. Currently, several methods for LS analysis, i.e. ...Wischmeier-Smith, Moore-Nieber, and Desmet – Govers. This study aims to compare the Wischmeier-Smith method, Moore–Nieber method, and Desmet–Govers method to analyze LS in the watershed in Manokwari – West Papua. This research consists of 4 main stages, i.e. data inventory, watershed boundary delineation, LS analysis, and LS comparison. The research showed that the Wischmeier-Smith method gave a higher LS value than the Moore – Nieber method and the Desmet – Govers method. Meanwhile, the Desmet – Gover method gives a lower average LS value than the Wischmeier-Smith method and the Moore – Nieber method. Based on the T-test, the LS produced by the Wischmeier-Smith, Moore-Nieber, and Desmet–Govers methods has significant differences in analyzing LS in the watershed in Manokwari – West Papua. Keywords: Desmet – Govers, Moore – Nieber, Universal Soil Loss Equation, Watershed, Wischmeier-Smith
This study aims to test how the HR recruitment system is carried out by Perumda Tirta Mangkaluku Palopo City in an effort to improve employee performance and also to find out what obstacles are faced ...by Perumda Mangkaluku City of Palopo in recruiting employees in an effort to improve the performance of its employees. The data analysis used in this study is using a quantitative method using simple linear regression analysis, conducting field studies such as (observations, interviews and documentation) which are carried out at the location of the research object The results of this research show that this recruitment system is very influential in improving employee performance at Perumda Tirta Mangkaluku City of Palopo because there is a science or a way of how to regulate the relationship between the roles of resources owned by individuals effectively and efficiently and can be used optimally so as to achieve the common goals of the company. So the process of hiring employees at Perumda Tirta Mangkaluku, Palopo City really fits the company's needs.
Trees are significant components of ecosystems built by several widespread species. For instance, Papua forest is known to comprise abiotic and biotic elements. Also, certain plants have grown in ...popularity to a point where they are discovered almost everywhere. The purpose of this study, therefore, was to investigate tree diversity, distribution, and the importance of conservation. Data were collected in four locations using a total of 24 sample plots spread across Idoor, Karst, Persemaian, and Torembi, where seven, four, seven, and five plots were allocated, respectively. These forests formed a mixed natural plantation comprising 76 species from 35 families. Furthermore, Idoor and Karst generated the highest species diversity and varied significantly compared to Persemaian, while Torembi showed similarities with the other three locations. This condition formed three ecosystem communities across Persemaian, Karst, Idoor, and Torembi. Also, the composition of the dominant species showed variations at the seedling and sapling levels believed to structure the understory, while the pole and tree levels characterized the overstory. The total species status was described as critically endangered (CR) of two species, vulnerable (VU) of six species, least concern (LC) of 28 species, and data deficient (DD) species. Therefore, location management is advised to not only pay significant attention in terms of economic benefits but also ecological, including the provisions for ex-situ and in-situ conservation to support sustainable forest management.
Faktor panjang dan kemiringan lereng (LS) merupakan parameter utama pada sejumlah model prediksi erosi. Sejumlah peneliti didunia telah mengembangkan algoritma untuk menganalisis LS berdasarkan data ...Digital Elevation Model (DEM). Penelitian ini bertujuan untuk membandingkan nilai LS pada 2 (dua) Daerah Aliran Sungai (DAS) di Kabupaten Manokwari Provinsi Papua Barat berdasarkan analisis beberapa data DEM resolusi menengah, yaitu DEM Space Shuttle Radar Topography Mission (SRTM), ASTER Global DEM, Jaxa’s Global ALOS 3D World, dan Copernicus DEM. Nilai LS dihitung menggunakan metode Desmet – Govers. Hasil penelitian menunjukkan LS yang dianalisis menggunakan DEM Copernicus memberikan nilai yang lebih tinggi dibandingkan LS yang dihasilkan dari DEM SRTM, ASTER Global DEM, dan Jaxa’s Global ALOS 3D World, sedangkan LS yang dihasilkan dari data ASTER Global DEM memberikan nilai lebih rendah. Berdasarkan uji F dan uji korelasi pearson, LS hasil analisis metode Desmet – Govers dan DEM SRTM, ASTER Global DEM, Jaxa’s Global ALOS 3D World, dan Copernicus DEM memiliki perbedaan yang signifikan dengan tingkat korelasi lemah hingga sedang
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