Judul: Identifikasi cendawan mikoriza arbuskula dari rizosfer aquilaria spp.
Abstrak: Aqularia spp. merupakan genus utama penghasil gaharu. Intensitas perburuan yang tidak terkendali menyebabkan Aquilaria spp. menjadi salah satu tanaman langka. Oleh karena itu, pelestarian Aquilaria spp. sebagai sumber plasma nutfah perlu dilakukan untuk mencegah kepunahan. Cendawan mikoriza arbuskula (CMA) telah digunakan sebagai inokulum dalam peningkatan pertumbuhan Aquilaria spp., tetapi informasi keberadaan CMA pada rizosfer Aquilaria spp. belum dilaporkan. Penelitian ini bertujuan mengidentifikasi CMA pada rizosfer Aquilaria spp. Contoh rizosfer tanah dan akar Aquilaria spp. diambil dari empat lokasi, yaitu Carita (A. malaccensis), Ciapus (A. filaria), Cifor (A. crasna dan A. malaccensis ), dan Bantar Kemang (A. beccariana, A. crasna, dan A. malaccensis ). Pewarnaan akar menggunakan metode Phillips dan Hayman (1970) yang dimodifikasi. Contoh tanah yang diambil segera dikeringudarakan untuk digunakan sebagai biakan pot dengan Pueraria javanica sebagai tanaman inang. Spora diisolasi dari biakan pot dengan menggunakan metode tuang saring basah dilanjutkan dengan sentrifugasi. Hasil dari penelitian ini menunjukkan struktur koloni CMA pada akar Aquilaria spp. berupa hifa eksternal, hifa internal, hifa gelung, arbuskula dan vesikula. Seluruh struktur koloni CMA pada akar Aquilaria spp. menunjukkan adanya asosiasi tanaman dengan CMA. Spora CMA yang berhasil diisolasi dan diidentifikasi dari rizosfer empat spesies Aquilaria spp. (tujuh contoh tanah) berupa empat spesies CMA, yaitu Glomus sp.1, Glomus sp.2 , Gigaspora albida, dan Scutellospora sp.
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Judul: Respon cendawan mikoriza arbuskula pada aquilaria spp.
Abstrak: Aquilaria malaccensis dan A. microcarpa merupakan tanaman penghasil gaharu yang pengadaannya dalam bentuk bibit perlu ditingkatkan. Cendawan mikoriza arbuskula (CMA) diharapkan mampu meningkatkan pertumbuhan bibit. Penelitian ini bertujuan mengetahui respons CMA pada bibit A. malaccensis dan A. microcarpa. Inokulum CMA yang digunakan ialah Glomus sp. ACA, Glomus sp. ZEA, Glomus clarum, Entrophospora sp., dan Gigaspora sp. Kolonisasi CMA pada akar A. malaccensis dan A. microcarpa terjadi sebelum minggu ke-7 setelah inokulasi. Inokulasi CMA efektif meningkatkan tinggi bibit , diameter batang, dan bobot kering total A. malaccensis dan A. microcarpa.
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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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