Judul: The Effectiveness of Mangrove Rehabilitation in Rambut Island, Kepulauan Seribu Administrative Regency
Abstrak: Ekosistem mangrove adalah ekosistem yang mendapatkan pengaruh dari air laut dan air darat. Ekosistem mangrove di Pulau Rambut mengalami kerusakan karena adanya abrasi dan pencemaran lingkungan (tumpahan minyak dan sampah). Oleh karena itu, perlu dilakukan upaya pemulihan ekosistem (rehabilitasi ekosistem mangrove). Tujuan penelitian ini adalah untuk menilai efektivitas rehabilitasi mangrove, faktor yang mempengaruhi efektivitas rehabilitasi, dan rekomendasi pengelolaan ekosistem mangrove yang berkelanjutan. Jenis data yang dikumpulkan dalam penelitian adalah data primer dan data sekunder. Data primer meliputi data ekologi (sintasan, pertumbuhan, tutupan relatif, dan kualitas air) dan data sosial ekonomi (persepsi dan partisipasi masyarakat) sedangkan data sekunder meliputi data program rehabilitasi dari Balai Konservasi Sumber Daya Alam Daerah Khusus Ibukota Jakarta dan studi pustaka. Analisis data menggunakan analisis linier berganda, Analisis Komponen Utama, analisis kelompok, dan analisis efektivitas rehabilitasi. Efektivitas rehabilitasi mangrove dari sembilan stasiun tergolong efektif, faktor yang paling berpengaruh terhadap efektivitas rehabilitasi adalah sintasan mangrove, salinitas, dam metode tanam., Mangrove ecosystem is an ecosystem that is influenced by salt water and fresh water. The mangrove ecosystem in Rambut Island is damaged due to abrasion and environmental pollution (oil spills and garbage). Therefore, it is necessary to make efforts to restore the ecosystem (mangrove ecosystem rehabilitation). This study aimed to examine the effectiveness value of mangrove rehabilitation, the factors that influence the rehabilitation, and recommendations for sustainable management of mangrove ecosystems. The types of data were primary data and secondary data. Primary data included ecological data (survival, growth, relative cover, and water quality) and socioeconomic data (community perception and participation), while secondary data included rehabilitation program data from the DKI Jakarta BKSDA and literature studies. Data analysis used multiple linear analysis, Principal Component Analysis (PCA), Cluster Analysis (CA), and analysis of rehabilitation effectiveness. The effectiveness of mangrove rehabilitation from nine stations is classified as effective; the most influential factors on the effectiveness of rehabilitation are mangrove survival, salinity, and planting methods.
Keyword: Mangrove, Efektivitas, Rehabilitasi

Judul: Effectiveness of mangrove rehabilitation on pramuka island, seribu archipelago.
Abstrak: Mangrove ecosystem damage is generally caused by human activities, although it is undeniable, nature also has a considerable role. The damage will cause a reduction or even disappearance of system functions and benefits of mangrove for the community and the surrounding environment. To restore the damaged mangrove, it is necessary to attempt rehabilitation through mangrove management on Pramuka Island, Seribu Archipelago. The purpose of this study was (1) to examine the factors that determine the success of the rehabilitation of mangrove ecosystems on Pramuka Island, Seribu Archipelago, (2) to assess the effectiveness of the rehabilitation of mangrove ecosystems and the factors supporting the success and failure on Pamuka Island, Seribu Archipelago, and (3) to arrange the recommendations to improve the effectiveness of the rehabilitation of mangrove ecosystems on Pramuka Island, Seribu Archipelago. Assessment of mangrove rehabilitation success rate on Pramuka Island was done by analyzing several indicators of using an effectiveness index with taking into account also the environmental parameters of water quality such as temperature, flow velocity, salinity, pH, DO, TSS, nitrate, potassium, BOD5. Indicators of effectiveness of mangrove include eco-biologi indicators of mangrove rehabilitation that includes survival, growth and percent cover; and social indicators that include public participation and public perception. Results of this study showed that the majority of mangroves on Pramuka Island are the saplings, while for trees and seedlings only a small fraction. All existing mangrove rehabilitation was the result of the different planting years, only two trees ware considered a pre-existing natural mangrove long ago. Based on the measurement results, mangrove rehabilitation on Pramuka Island had a relative cover between 0.03 to 2.82%; growth of 13.33 to 32.50 cm/yr; and survival rate of 3.02 to 67.36%. Environmental conditions in the area of rehabilitation of mangrove waters are shallow water reef around the island stretches to a distance of about 500 m from the shoreline and the water quality is suitable for mangroves. Values of water quality measurements include temperature from 31.7 to 35 °C; flow velocity 0.1-0.3 m/s; TSS 4-16 mg/l; pH 7.54 to 8.20; salinity 25-28 psu; DO from 7.6 to 9.4 mg/l; nitrate from 0.039 to 0.156 mg/l; orthophosphate 0.002 to 0.283 mg/l; potassium 0.272 to 0.698; and BOD5 from 2.00 to 4.60 mg/l. Based on social conditions, all the people (100%) know about mangroves, both the function and existence. 60% of people also know that the mangrove on Pramuka Island is managed by TNKpS. In addition, people also take a role and participate in themanagement of the mangrove. Approximately 80% of respondents said had been involved in management efforts, including by contributing to maintain, not destroy the existence of mangroves and mangrove occasional cleaning of garbage. Community involvement is in line with the perceived benefits. 80% of vii respondents said that the mangroves are considered to lessen the blow of the waves, erosion and add coolness on the beach. Community involvement in management efforts can be improved if people know and can take advantage of direct utilization of mangrove like to candied fruit, wood utilization, etc.. So far there is no direct use
Keyword: mangrove ecosystem, TNKpS, ehabilitation, effectiveness

Judul: Approximation of the Median of Poisson Distribution Using the Relation of Poisson-Gamma Distribution
Abstrak: A major drawback of median is that median cannot usually be defined in closed form, even in the cases where their distribution functions are known. This study gives an approximation of the closed form for the median of the Poisson distribution by using the relation of Poisson-Gamma distribution. The approximation uses elementary techniques based on the monotonicity of certain sequences involving tail probabilities of the Poisson distribution and the Central Limit Theorem. Furthermore, a closed form expression for the mean absolute deviation 􀜧|􀜰􀰒 􀵆 􀜯􀝁􀝀􁈺􀜰􀰒􁈻| is also studied. The median is relevant because of the fact that it minimizes the mean absolute deviation of a Poisson random variable (􀜰􀰒􁈻 by considering median as central tendency.
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