Judul: Dinamika Kandungan Klorofil dan LAI Tumbuhan Prunus avium dalam Ekosistem Karst Ciampea
Abstrak: Chlorophyll is the primary photosynthesis pigment of plants. The level of chlorophyll content of plant can be affected by external factors, such as light, temperature, and carbon dioxide. Karst is a unique topography that formed by water flow on carbonate rocks. One of the plant that can be found in the karst ecosystem was Prunus avium. Prunus avium is a major species of karst ecosystem. The purpose of this research was to determine the level of chlorophyll and leaf area index (LAI) in Prunus avium at the different influence of altitude and environmental factors. The level of chlorophyll was measured by SPAD Chlorophyll meter in each altitude on the same characteristic of Prunus tree. The results showed that the chlorophyll was inversely with altitude, LAI and environmental factors. The highest level of chlorophyll that found at 175 mdpl of altitude was 34.32 and the lowest 355 mdpl of altitude was 25.18. LAI showed the highest values 3.32 at 355 mdpl. Based on the statistical analysis, the environmental factors that affected the level of chlorophyll are light intensity, temperature, humidity and wind speed (p<0.05).
Keyword: Bogor Agricultural University (IPB), LAI, Prunus avium, karst, chlorophyll

Judul: Struktur dan komposisi tegakan serta sistem perakaran tumbuhan pada kawasan karst di Taman Nasional Bantimurung-Bulusaraung, Resort Pattunuang-Karaenta
Abstrak: Plants in Karst Area have different characteristics and distinctive when compared with plants of other forest ecosystem. The purpose of research is to assessing the composition and stand structure and root system of plants in karst areas in Bantimurung-Bulusaraung National Park, Resort Pattunuang-Karaenta. This observation plots determined by purposive sampling based on the representation of the stand. Three sample plots lines with the size of 20 m x 100 m each were constructed in the research site. The research was spread out on four habitats that are on hill base, slopes, summit with considerable soil cover, and summit with very little soil cover. The number of species on the research area is amounted 108 species of seedlings and understorey plants, 108 species saplings, 63 species poles and 78 species trees. Horizontal structure inverted J-shaped and vertical structure of the stand consist of four strata (B, C, D, and E strata). Overall, the spatial distribution patterns have a clumped distribution pattern. Uniform distribution pattern is only found in Palaquium obovatum species of pole on slopes and Dracontomelon dao species of tree on base. Pterospermum celebicum has the highest value of shoot-root ratio on the hill base, index root binding highest value with category of moderate (1.5-3.5) on hill base and index root anchoring highest value with the high category (>1.0) on summits with considerable soil cover.
Keyword: Bogor Agricultural University (IPB), stand structure, root system, stand composition

Judul: Peramalan Indeks Harga Saham Gabugan dengan Metode Deret Waktu Fuzzy Berbasis Rerata
Abstrak: Indeks Harga Saham Gabungan (IHSG) adalah suatu nilai yang menggambarkan kinerja gabungan saham-saham yang tercatat pada Bursa Efek Indonesia. Data IHSG merupakan data deret waktu yang dapat dicatat dalam format harian. Data IHSG dapat digunakan investor dalam membuat keputusan untuk membeli, menahan atau menjual saham yang dimilikinya. Oleh karena peran penting data IHSG, maka perlu dilakukan peramalan. Metode peramalan yang tepat akan menghasilkan nilai prediksi IHSG yang baik sehingga dapat memberikan keuntungan bagi investor. Data yang digunakan dalam penelitian ini adalah data IHSG harian periode 1 November 2018 s.d. 5 April 2019. Metode yang digunakan untuk meramalkan nilai IHSG dalam penelitian ini adalah ARIMA dan Deret Waktu Fuzzy (DWF) berbasis rerata. Peramalan dengan metode DWF berbasis rerata menghasilkan nilai RMSEP sebesar 27.279 sedangkan metode ARIMA menghasilkan nilai RMSEP sebesar 41.664. Nilai RMSEP metode DWF berbasis rerata lebih kecil dibandingkan metode ARIMA, sehingga dapat disimpulkan metode DWF berbasis rerata lebih baik daripada metode ARIMA dalam meramalkan nilai IHSG.
Keyword: ARIMA, Deret Waktu Fuzzy, IHSG, peramalan