Judul: Perkembangan Bakteri dan Mikoriza Arbuskula Pada Rizosfer Johar di Tanah Pascatambang Batu Bara
Abstrak: Rizosfer merupakan zona kecil sekitar perakaran yang terbentuk karena adanya eksudat akar yang dapat mempengaruhi aktivitas mikroorganisme. Proses penambangan menyebabkan perubahan sifat-sifat tanah termasuk tanah di area rizosfer. Perbaikan sifat-sifat tanah diperlukan dengan menambah bahan pembenah tanah. Tujuan dari penelitian adalah untuk 1) menganalisis populasi mikoriza arbuskula dan bakteri pada rizosfer johar pada media tanah pascatambang batubara dan diberi berbagai perlakuan bahan pembenah tanah 2) menganalisis pengaruh dosis Al dan Fe yang mempengaruhi perkembangan mikoriza arbuskula dan bakteri. Rancangan percobaan yang digunakan adalah rancangan acak lengkap (RAL) dengan petak terbagi (split plot design). Pemberian bahan pembenah tanah berupa faba, kompos dan kapur dapat meningkatkan jumlah spora FMA, persentase kolonisasi spora, dan jumlah populasi bakteri. Penambahan 2 mM Al dan 0,25 mM Fe berpengaruh positif terhadap jumlah spora FMA dan jumlah bakteri. Korelasi antara jumlah spora FMA dan jumlah bakteri sangat rendah.
Keyword: faba, kapur, kompos, logam berat, spora

Judul: Populasi Mikoriza Arbuskula dan Bakteri pada Rizosfer Bibit Trembesi (Samanea saman (Jacq.) Merrill) di Media Pascatambang Batubara
Abstrak: Kegiatan pertambangan dapat memberikan dampak negatif terhadap daerah rizosfer sehingga dapat memengaruhi tingkat kesuburan tanahnya. Salah satu teknik yang telah banyak dikembangkan dalam perbaikan dan peningkatan kualitas tanah adalah penggunaan bahan amelioran dan FMA. Penelitian ini bertujuan untuk: (1) menganalisis jumlah spora FMA dan bakteri pada rizosfer bibit S. saman; (2) menganalisis pemberian dosis Al dan Fe terhadap perkembangan spora FMA dan bakteri pada rizosfer bibit S. saman, dan (3) mengidentifikasi karakteristik morfologi bakteri. Rancangan percobaan adalah rancangan acak lengkap dengan petak terbagi. Perlakuan yang diberikan adalah FMA, bahan ameliorant tanah (kompos, kapur, dan faba) serta penambahan kadar Al dan Fe. Hasil penelitian menunjukkan bahwa FMA, amelioran faba 10% serta penambahan 2 mM Al dan 0,25 mM Fe mampu meningkatkan kepadatan spora FMA pada bibit S. saman. Pemberian amelioran berupa kompos 5% dan kapur 0,5% mampu meningkatkan jumlah bakteri pada bibit S. saman. Ditemukan 7 karakteristik morfologi bakteri yang berbeda.
Keyword: meliorant, bottom ash, correlation, fly ash, toxicit

Judul: Thermal Characteristics and Dynamics of Tropical Cyclone over Western North Pacific Ocean: A Case Study of Typhoon Songda (Chedeng) 2011
Abstrak: The frequent occasion of Tropical Cyclone (TC) over Western North Pacific (WNP) Ocean lies from 10˚N to 26˚N and 121˚E to 170˚E. Sources of TC development come from warm ocean temperature where latent heat is released during condensation processes and subsequently concentrated in the boundary layer. Relative humidity at 850-700 hPa is responsible to produce the most intense storm. Meanwhile, weak vertical wind shear between 850-200 hPa is one of the dynamical factors that lead to the development of TC. Pressure level of 850-200 hPa is chosen to minimize the thermodynamic effect in the lower troposphere. Typhoon Songda (Chedeng in the Philippines) or TSC lasted from May 18th to 30th, 2011 and strengthened into powerful Super Typhoon stage between May 24th and 27th. Long curving track and the exhibition of all sequences of TC life cycle, TSC is then considered as an ideal case of TC. The objective of the study with case of TSC is to investigate the role of thermal characteristics and dynamics on TC intensity. The research is carried out by using Advanced Research of Weather Research and Forecasting model (WRF ARW model) version 3.3. Two domains are employed in the model. The first domain situate from 02˚N to 40˚N and 118˚E to 149˚E and cover spatial resolution () of 33.1 km. The second domain situate from 09˚N to 27˚N and 119˚E to 132˚E with of 11 km. Timestep of the model () is 120 seconds. The model is supported by the following physical parameterization, i.e., Yonsei University Scheme (YSU) in the boundary layer, Kain-Fritsch scheme (KF) in the cumulus, and WRF Single-Moment 3-class scheme in the microphysics. Initial meteorological condition prior to the formation of the cyclone is generated using WRF ARW standard-release model. Sensitivity of the model output is obtained from a selected single-parameter change scenarios, namely, 10 % to 20 % decrease and increase of wind shear initial data at 850-200 hPa, and by 10 % to 20 % decrease of relative humidity initial data at 850-700 hPa. The result showed that the negative correlations between wind shear and intensity are found in wind shear scenarios. Wind shears of 10 ms-1 which lead to strengthening of the wind intensity in the early period of Typhoon development are found in wind shear scenarios. The effect of wind shear changes on wind intensity is statistically significant in the 20 % wind shear scenarios. During mature stage, weak wind intensity occurred when wind shear increase as given in the WRF standard-release and the 20 % decreasing scenario. Different situation is found in the 20 % increasing scenario where wind shear tend to weak and lead to strong wind intensity at this stage. Meanwhile, the reduction of moisture supply at 850-700 hPa resulting from 20 % decreasing relative humidity play a major role in the weakening of wind intensity and reduces mechanical energy of the cycle process as much as 300 J kg-1.
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