Judul: Studi Autekologi dan pengaruh invasi akasia (Acacia nilotica) (L.) Willd. ex Del. terhadap eksistensi savanadan strategi penanganannya di Tamana Nasional Baluar Banyuwangi Jawa Timur
Abstrak: Tujuan yang ingin dicapai dari penelitian ini adalah untuk: (a). Mengetahui autekologi meliputi; siklus hidup, fenologi, produksi biji, pemancaran biji, dan struktur tagakan A. nilotica di Taman Nasional Baluran, (b). Mengetahui derajat invasi A. nilotica di Taman Nasional Baluran dan upaya yang telah dilakukan), (c). Mengetahui pengaruh invasi A. nilotica terhadap komposisi spesies, Indeks Keanekaragaman Spesies (H'), Indeks Similaritas (IS), asosiasi spesies, biomasa tumbuhan bawah dibandingkan dengan daerah yang belum terinvasi A. nilotica.
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Judul: Understory Vegetation Diversity and Forage  Plants Availability in Bekol and Balanan Savanna, Baluran National Park
Abstrak: Akasia berduri (Vachellia nilotica) adalah salah satu tumbuhan yang berada di Taman Nasional Baluran yang bersifat invasif dan memengaruhi komposisi savana di kawasan tersebut. Penelitian bertujuan mengetahui keanekaragaman spesies tumbuhan bawah, sifat invasif dan mengkaji spesies pakan satwa yang mampu berkompetisi pada lingkungan penelitian. Pengambilan data analisis vegetasi didapatkan dengan metode kuadrat. Plot utama dengan ukuran 50 m × 50 m dibuat pada tiga kawasan, yaitu kawasan savana terinvasi rendah, tinggi, dan bebas invasi. Setiap plot utama dibuat 15 petak contoh yang berukuran 1 m × 1 m. Parameter tumbuhan bawah yang diamati adalah jumlah individu dan spesies. Pada savana terinvasi rendah ditemukan sembilan spesies dari tujuh famili dan pada savana terinvasi tinggi ditemukan sembilan spesies dari enam famili. Nilai indeks keragaman jenis (H’) pada savana Balanan invasi rendah bernilai 1,62 dan pada invasi tinggi sebesar 1,74, sedangkan pada savana Bekol yang terbebas invasi sebesar 1,24. Vegetasi yang menyusun ketiga kawasan cenderung berbeda dengan nilai indeks kesamaan Sorenson (IS) sebesar 4.05 hingga 14.65. Jumlah spesies pakan pada kawasan invasi tinggi lebih rendah dibandingkan dengan kawasan lainnya., Thorny acacia (Vachella nilotica) is one of the invasive plants species in Baluran National Park (BNP) which affects the vegetation composition in its savanna. This study aims to determine the diversity of understory species and its invasiveness, as well as to examine the availability of forage plant species that are able to compete with the other understory species in the research plot. This study was conducted in three areas that is high invaded, low invaded, and uninvaded areas from V. nilotica. The vegetation composition was described by vegetation analysis. Main plot with a size of 50 m × 50 m has been made in three areas with five replicate plots were selected for each location resulting in total of 15 plots were studied. The uninvaded area has the highest number of understory species compare against the high invaded and low invaded areas. The value of the species diversity index (H') in high invaded, low invaded, and uninvaded areas are 1,74; 1,62; and 1,24 respectively. The understory composition within the three areas were tends to be different based on Sorenson Similarity Index (IS) with a range of values 4.05 to 14.65. The high invasion area has the lowest number of forage plants species compared to other areas.
Keyword: animal feed, invasion, quadrat method, Vachellia nilotica, vegetation analysis

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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