Judul: Analysis of Arbuscular Mycorrhizal Fungi and Bacterial Populations in the Mycohizosphere of Manglid Seedlings (Manglietia glauca Bl.) in an Organic Pot
Abstrak: Mikorhizosfer merupakan daerah di sekitar akar tumbuhan yang bermikoriza dan dapat memengaruhi kehidupan berbagai mikroorganisme di dalamnya. Penelitian ini bertujuan untuk (1) menganalisis jumlah spora Fungi Mikoriza Arbuskula (FMA), populasi, dan karakter morfologi bakteri pada mikorhizosfer semai manglid yang tumbuh pada media tanah marginal dengan menggunakan wadah pot organik dengan komposisi dan ukuran bahannya berbeda; (2) menganalisis perkembangan FMA dan populasi bakteri pada media tanam dan pot organik. Rancangan percobaan yang digunakan adalah rancangan acak lengkap (RAL) pola faktorial dua faktor, yaitu komposisi dan ukuran bahan pot organik. Interaksi antara kedua perlakuan berpengaruh positif terhadap perkembangan spora FMA pada media tanam, jumlah kolonisasi mikoriza, serta jumlah koloni bakteri pada media tanam. Komposisi koran 70%, kompos 30%, cocopeat 0% menunjukkan hasil tertinggi untuk perkembangan spora FMA dan kolonisasi FMA. Koloni bakteri yang ditemukan terkarakterisasi ke dalam delapan morfologi berbeda dan didominasi oleh genus Bacillus.
Keyword: bakteri, FMA, komposisi, manglid, mikorhizosfer

Judul: Study of Arbuscular Mycorrhizal and Bacterial Populations on Mycorrhizosphere of Mahagony (Swietenia macrophylla King.) Seedlings in Organic Pots
Abstrak: Mikorhizosfer merupakan zona tanah di sekitar perakaran tumbuhan yang bermikoriza dan umumnya terdapat banyak mikroorganisme. Penelitian ini bertujuan untuk : (1) menganalisis jumlah spora fungi mikoriza arbuskula (FMA), populasi dan karakter morfologi bakteri pada mikorhizosfer semai mahoni yang tumbuh pada media pascatambang pasir silika dengan wadah pot organik dengan komposisi dan ukuran bahan yang berbeda; (2) menganalisis perkembangan fungi mikoriza arbuskula FMA dan populasi bakteri pada media tanam dan pot organik. Rancangan percobaan yang digunakan adalah Rancangan Acak Lengkap (RAL) yang terdiri atas dua perlakuan, yaitu komposisi dan ukuran bahan pot organik. Hasil penelitian menunjukkan komposisi pot organik mampu mempengaruhi keberadaan spora FMA. Komposisi pot organik 50% koran, 35% kompos, dan 15% cocopeat menunjukkan hasil terbaik untuk perkembangan spora FMA dan koloni bakteri, perkembangan spora FMA dan populasi koloni bakteri dalam media tanam lebih baik dibandingkan dengan perkembangan spora FMA dan koloni bakteri dalam pot organik. Terdapat tujuh karakter morfologi koloni bakteri berbeda yang didominasi oleh bundar, berbenang, rata, dan berwarna putih.
Keyword: arbuscular mycorrhizal fungi (AMF), bacteria, correlation, mahagony, rhizosphere

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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