Judul: Produktifitas serasah mangrove dan potensi kontribusi unsur hara di perairan mangrove Pulau Panjang Banten
Abstrak: As a transition zone between land and sea, coastal zone is inhabited by various ecosystems, such as mangrove ecosystem. Mangrove ecosystem is considered for its ecological importance. The objective of this research was to investigate the characteristic of mangroves habitat based on water quality parameters, to determine productivity and leaves decomposition rate of litterfall, and to study nutrients (C, N, P) contribution potency of litterfall production in Panjang Island, Banten. This study was carried out in the mangrove forest, Panjang Island, Banten Province, from April to June 2010 using vegetation analysis, litterfall decomposition rate analysis and nutrients production of litterfall analysis. Principal Component Analysis was performed to analyse water chemical physical parameters. Data were collected using direct measurement and sampling in the field then followed by laboratory analyses. Results showed that contribution of one principal component to total diversity was 32.81%, 2 principal components were 55.01% and 3 principal components were 75.74%. Mangrove in Panjang Island produced a litterfall productivity average of 0.346 gram/m2/day. It exhibited the productivity of mangrove in Panjang Island is slightly lower than other mangrove forests due to low density and young plantation. The nutrient contribution potency of litterfall (C, N, and P) respectively were 0.528 g-C/m2/day; 0.00353 g-N/m2/day and 0.00076 g-P/m2 /day.
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Judul: Produktifitas Srasah Mangrove dan Potensi Kontribusi Unsur Hara di Perairan Mangrove Tanjung Api-Api Sumatera Selatan
Abstrak: Ekosistem mangrove merupakan salah satu bentuk ekosistem pesisir yang unik dan memiliki fungsi ekologis dan ekonomis yang sangat bermanfaat di lingkungan pesisir. Penelitian ini bertujuan untuk mengetahui karakteristik habitat mangrove Tanjung Api-Api berdasarkan parameter kualitas perairan dan substratnya serta mengkaji produksi serasah, laju dekomposisi serasah dayn dan kontribusi potensi unsur hara (C,N, P) dari produksi serasah mangrove Tanjung Api-Api. Pengambilan sampel untuk analisis vegetasi mangrove dilakukan dengan menggunakan metoda plot transek gratis. Guguran serasah (litter-fall) ditangkap dengan menggunakan litter-trap. Pengukuran laju dekomposisi serasah dilakukan secara eksperimental di lapangan dengan menggunakan kantong serasah (litter-bag. Analisis data vegetasi mangrove meliputi: Kerapatan Jenis, Kerapatan Relatif, Frekuensi Jenis, Frekuensi Relatif, Basal Area, Penutupan Jenis atau Dominasi, Dominasi relatif dan nilai Penting (NP). Untuk menentukan variasi karakteristik fisika kimia perairan stasiun pengamatan dan keterkaitannya dengan jenis dan kerapatan mangrove digunakan Corespondent Analysis atau CA. Hasil Penelitian menunjukkan bahwa kawasan mangrove Tanjung Api-Api didominasi oleh jenis Avicennia marina dan Sonneratia caseolaris dengan karakteristik perairan untuk Stasiun I (daerah laut) dicirikan oleh suhu, salinitas, DO dan pH yang tinggi, Stasiun II (mulut muara) lebih dicirikan oleh nilai TOM dan TSS yang tinggi, sedangkan Stasiun III (sungai) dicirikan oleh parameter fisika kimia air dengan nilai yang lebih rendah dibandingkan dengan stasiun-stasiun yang berada di daerah laut dan muara. Produksi rata-rata serasah di lokasi penelitian sebesar 2,99 g/m2/hari, dengan kontribusi potensi unsur hara C, N dan P masing-masing adalah 0,788 g-C/m2/hari; 0,0225 g-N/m2/hari dan 0,0022 g-P/m2/hari. Proses dekomposisi serasah serasah daun mangrove menunjukkan tingkat yang lebih tinggi di daerah perairan bila dibandingkan dengan daerah daratan. Serasah daun S. caseolaris lebih cepat terdekomposisi dibandingkan dengan serasah daun A. Marina
Keyword: South Sumatera, Mangrove, Litter productivity, Nutrient, Decomposition

Judul: Construction of Strongly Optimal Binary Linear Code with Minimum Distance 9 and 11
Abstrak: A binary linear code of length n over q F is a subspace of n q F . A code has three parameters that attached to it, namely length, dimension, and minimum distance. A code with length n, dimension k and minimum distance d is often called [n, k, d ]-code. Usually, when two parameters are given, then we want to find a code that has the best value for the last parameter. Based on Gilbert- Varshamov bound, if a [n, k, d ]-code exists and can not be expanded, we call it a strongly optimal code. In this paper, we construct strongly optimal code with minimum distance 9 and 11. In constructing the code, we created a theorem and algorithm based on Gilbert-Varshamov bound before we implement the algorithm to MAPLE programming language. Because of computational limitations, the program can only construct up to k = 10 for d = 9 and k = 12 for d = 11.
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