Faculty of Mathematics and Natural Sciences

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EFEKTIVITAS SERBUK BIJI KELOR (Moringa oleifera) DALAM MENURUNKAN KANDUNGAN KLORIDA DAN KEKERUHAN PADA AIR SUMUR GALI DI KOTA DUMAI
(2-03-07) Jannah, Raihanil; Anita, Sofia
Moringa oleifera is one of the natural coagulants in Indonesia. This study was conducted to see the effectiveness of moringa seed powder as natural coagulant as an alternative to coagulant chemical that has negative effect. This research was conducted for well water samples in Kelurahan Purnama, Sukajadi and Tanjung Palas in Dumai City. The parameters analyzed were chloride and turbidity as well as some additional parameters. Turbidity was analyzed using a turbidimetry method, while chloride was analyzed using a UV-Vis spectrophotometer. The results indicated that moringa seed powder could decrease turbidity and chloride in three kelurahans turbidity was of 62.06%, 60.51%, and 19.05%; while chloride was of 43.59%, 48.93%, and 50.50%. Based on paired t-test method (P = 0.05), moringa seed powder are effective to decrease chloride and turbidity on wells water in Kelurahan Purnama, Sukajadi and Tanjung Palas in Dumai City. Based on PERMENKES RI No. 492/MENKES/PER/IV/2010 about drinking water quality, chloride concentration was the limit of requirements for drinking water, but not for turbidity.
PEMANFAATAN LEMPUNG ALAM MAREDAN SEBAGAI KATALIS HETEROGEN UNTUK PENGHILANGAN METILEN BIRU MELALUI PROSES FENTON
(2-04-07) Hendru, Hendru; Awaluddin, Amir
Methylene blue, commonly used dye in textile industry, is harmful to living organism and environment due to its resistance for degradation. The most effective method for dyestuff removal is heterogeneous catalyst based on Fenton reaction to produce OH radical. In this study, Maredan Clay (LM) can be used as a heterogeneous catalyst. The results of catalyst preparation were characterized by X-ray Diffraction (XRD), Fourier Transformed Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). Characterization results showed that catalyst contained quartz, kaolinite, muscovite and hematite minerals with morphology like irregular spheres. LM give optimum result in methylene blue removal under conditions of pH = 3, H2O2 = 6.7 mM, Fe-LM = 0.75 g/L, initial concentration = 50 ppm, at room temperature
KEANEKARAGAMAN LICHEN SEBAGAI BIOINDIKATOR PENCEMARAN UDARA DI KOTA PEKANBARU PROVINSI RIAU
(2012-10-14) Panjaitan, Desi Maria; Fitmawati; Martina, Atria
Lichen have been widely used as bioindicator of air quality. The aims of this study were to know the relationship between certain lichen with traffic volume and influence of traffic volume to lichen diversity and accumulation of Pb and Cr in lichen thalus. There were 20 species from 6 families found from all sampling sites. The highest traffic volume was observed in Jl. Jend. Sudirman, Jl. Arifin Ahmad and Jl. Adi Sucipto respectively. Lichen diversity increased with greater volume of traffic, and was highest at Jl. Adi Sucipto (17 species), Jl. Arifin Ahmad (12 species) and Jl. Jend. Sudirman (11 species). Dirinaria picta was found in all sampling sites and has the highest presence percentage among the observed lichens. The highest accumulation of Pb (4.48±0.18 ppm ) and Cr (1.00 ±0.14 ppm) in D. picta thalus was found at Jl. Jend. Sudirman. The lowest accumulation of Pb (2.03±0.03 ppm) and Cr (0.61±0.13 ppm) in D. picta thalus was found at Jl. Adi. Sucipto. The analysis of Spearmans correlation showed the positive correlation between traffic volume and accumulation of Pb and Cr on lichen thalus at Jl. Jend. Sudirman and Jl. Arifin Ahmad, while negative correlation was shown at Jl. Adi Sucipto. Spearman’s correlation showed negative correlatiom for traffic volume and accumulation of Cr in lichen thalus in all sampling sites.
PENYELESAIAN MASALAH TRAVELING SALESMAN DENGAN PEMROGRAMAN DINAMIK
(2012-10-14) Mustafsiroh; Gamal, M. D. H; Natsir, M.
Traveling salesman problem ia a problem in graph theory. This problem can be solved by enumurating all possible Hamilton circuit. Then we calculate the length of rute of each circuit, and then we choose the shortest circuit. For a large n, many of Hamilton circuits are examined. We discuss traveling salesman problem using dinamic programming to ﬁnd optimal solution.
MEMBUKTIKAN KETAKSAMAAN ERDŐS-MORDELL DENGAN MENGGUNAKAN JARAK BERTANDA
(2012-10-14) Wahidah, Riva Atul; Mashadi; Hasriati
We discuss prove the Erdős-Mordell Inequality. We will use signed distances from the sides of a triangle to prove that Erdős-Mordell Inequality not only to interior point of triangle, but also to exterior point of triangle. Here we detail a method proposed by Dergiades, N. Forum Geom. 4: 67–68 (2004).
Biomasa Karbon Mikroba dan Aktivitas Enzim Selulolitik di Cagar Biosfer Giam Siak Kecil-Bukit Batu: Status Hara Karbon
(2012-10-25) Yunita, Melda; Zul, Delita; Fibriati, Bernadeta Leni
Giam Siak Kecil-Bukit Batu Biosphere Reserve is a peatland ecosystem consisting higher biodiversity of flora, fauna and soil microbes. Most of this areas have been converted into industrial forest plantation, oil palm plantation, agricultural activities, and settlement. This activity will decrease vegetation number and influence microbial population and activities at the end. Changing of the microbial at those population and activities will affect rate the impact of C cycle in peatland. This research aim was to analyze the impact of land use changes to microbial carbon biomass, cellulolytic bacterial cells number, and rate of cellulolytic enzymes activity (celllulase and β-glucosidase). Soil samples were taken from six different locations in Giam Siak Kecil-Bukit Batu Biosphere Reserve, namely primary forest (as a control), secondary forest, fourteen years old rubber plantation, fourty to sixty years old rubber plantation, twelve years old oil palm plantation, and three years old oil palm plantation. Soil physical and chemical characteristics varied in every location ranging from 28.25-31.25 ( o C) for soil temperature, dry weight 14.35-33.10 (%); water content 72.07-83.30 (%); bulk density 0.06-0.33 (g/cm 1 3 ) and 3.5 for soil pH. The lowest number of microbial carbon biomass was shown in the twelve years old oil palm plantation (240.29 µg C/hour/g soil) and the highest was in the primary forest (963.95 µg C/hour/g soil). The lowest number of cellulolytic bacterial cells number was shown in the primary forest (2.4·10 3 CFU/g soil) and the highest was in the fourty to sixty years old rubber plantation (1.3·10 4 CFU/g soil). The lowest number of cellulase activity was shown in the primary forest (0.67 µg/hour/g soil) and the highest was in the fourty to sixty years old rubber plantation (4.17 µg/jam/g tanah). The lowest number of β-glucosidase activity was shown in the 3 years old oil palm plantation (5.92 µmol PNP/hour/g soil) and the highest was in the fourty to sixty years old rubber plantation (27.45 µmol PNP/hour/g soil). Generally, land use changes govern the biomass microbial carbon biomass, cellulolytic bacterial number, and rate of cellulolytic enzymes activity in Giam Siak Kecil-Bukit Batu Biosphere Reserve.
PENENTUAN TOTAL FENOLIK, ASAM ASKORBAT DAN AKTIVITAS ANTIOKSIDAN TANAMAN KAILAN (Brassica oleracea var. Alboglabra) YANG DIRAWAT DENGAN EKSTRAK TANAMAN TERFERMENTASI
(2012-11-20) Murniati, S; Jose, C; Hendra, R
Kailan (Brassica oleracea var. Alboglabra) is a family of cabbages (Brasicaceae) which contain nutrients and high antioxidant activities. The cultivation system organically and conventionally can influence the nutrients and antioxidant contents. In this study, the total phenolic content, flavonoid, ascorbic acid, and antioxidant activity of ethanolic of kailan extract were carried out. Fresh weight and height of the plant as well as the percentage of damaged leaves of kailan were determine too as physical analysis. There were three different watering treatments on cultivation of kailan such as, organic kailan treated with Fermented Plant Extract (FPE), control (just water) and conventional treatment. FPE was prepared from mixture of rumput paitan (Paspalum conjugatum B), babadotan (Ageratum conyzoides L), and effective microorganism 5 (EM5). The results showed that the weight of plant, the height of plant and percentage of damaged leaves were not significantly different in all treatments. Total phenolic of organic kailan (6,866 AGE mg/g dry weight) was not significantly different from conventional treatment (6,396 AGE mg/g dry weight). Conventional kailan (0,343 QE mg/g dry weight) has the highest flavonoid content. The highest ascorbic acid content was given by organic (0,589 AAE mg/gr dry weight) and conventional kailan (0,448 AAE mg/g dry weight). For antioxidant activities, all treatments gave the same inhibition on free radical in FTC assay, and IC value in DPPH assay. Antioxidant activity in FRAP assay from conventional kailan (0,132 mol/g) could reduce Fe3+ become Fe2+ more efficient than other treatments. IC50 value in NO radical scavenging assay of organic kailan (4,009 mg/ml) was not significantly different from control treatment. This study showed that the cultivation of kailan organically by using FPE treatment could increase the total phenolic, flavonoid content, ascorbic acid and antioxidant activity and thus it could be used as alternative for replacing the pesticide.
PENENTUAN FENOLIK, VITAMIN C DAN AKTIVITAS ANTIOKSIDAN TANAMAN SELADA (Lactuca sativa L.) YANG DIRAWAT DENGAN EKSTRAK TANAMAN TERFERMENTASI
(2012-11-20) Reno Raisandi, Mohd; Jose, Christine; Hendra, Rudi
Lettuce (Lactuca sativa L) can serve as a source of vitamins, minerals and natural antioxidants. The cultivation system organically and conventionally can influence the nutrients and antioxidant contents. In this study, the total phenolic, flavonoid, vitamin C content, antioxidant activity and flavonoid composition of lettuce extract were carried out. Fresh weight and percentage of damaged leaves of lettuce were determine too as physical analysis. Two different treatment (FPE and control) were used for organic lettuce. The results showed that the fresh weight of plants were not significantly different. Organic lettuce with FPE treatment (5,10%) had lower (P0,05) percentage of leaves damaged than control treatment (18,23%). Compared to conventional lettuce, organic lettuce with FPE (9,873 GAE mg/g) and control (9,000 GAE mg/g) treatment had a significantly (P0,05) higher content of phenolic. Organic lettuce with FPE treatment showed higher flavonoid (10,681 QE mg/g) and vitamin C (0,460 AAE mg/g) content. For antioxidant activities, organic lettuce with FPE treatment gave the best FRAP (0,234 mmol Fe2+/g), FTC (55,05%), DPPH (482,33 g/mL) and NO radical scavenging (4,619 mg/mL) values. Determination of flavonoid composition showed that lettuce extracts didn’t contain standards of flavonoid compound (quercetin, catechin, naringin, and rutin). Lettuce extracts could be contained other flavonoid compounds. From this study, it can be concluded that the percentage of phenolic and vitamin C might be contributed to the antioxidant activity and the amount of total phenolic and vitamin C content which might be influenced by the cultivation system.
CALYMPERACEAE (MUSCI) PADA BEBERAPA TIPE VEGETASI DI KAWASAN CAGAR BIOSFER GIAM SIAK KECIL-BUKIT BATU PROVINSI RIAU
(2013-03-01) Fastanti, Fandri Sofiana; Fitmawati; Sofiyanti, Nery
Giam Siak Kecil-Bukit Batu Biosphere Reserve is a conservation area in Riau Province, characterized by its peat swamp forest. This area posses a unique biological diversity, including mosses (Musci). One family of Musci that can adapt in this area is Calymperaceae. This group has unique morphological structure and vegetative reproduction which make them can survive in this area. However, in spite of their uniques, the data of this group is inadequate and diversity of moss from this biosphere reserve had been not reported yet. The aims of this study are to identify, characterize, and classify Calymperaceae diversity of Giam Siak Kecil-Bukit Batu Biosphere Reserve. All of the specimens in this study were collected from six sites, that are grouped based on their vegetation types, i.e. natural forest, industrial plant forest, rubber forest, rubber plantations, oil palm plantations and home gardens. Total of 11 species belongs to 4 genera were recorded
Biomassa Nitrogen (N) Mikroba dan Aktivitas Urease Tanah di Cagar Biosfer Giam Siak Kecil-Bukit Batu: Sebagai Status Hara Nitrogen
(2013-03-04) Komariah, Siti; F, Bernadeta Leni; Zul, Delita
Giam Siak Kecil-Bukit Batu Biosphere Reserve (GSK-BB) is one of the peatland ecosystem that most of the regions have been converted into oil palm plantations, industrial forest plantation, and settlement. Environmental conditions disrupted by land conversion will affect the population, diversity and activity of soil microbes. This research aim was to analyze the impact of land use changes to nitrogen fixation bacterial cells number, microbial nitrogen biomass and urease activity in peatlands. Nitrogen fixation bacterial cells number was calculated by using a Total Plate Count (TPC) method, concentration of microbial N biomass was determined by using Chloroform Fumigation Extraction (CFE) and rate of urease activity was determined by quantifying ammonia released during an incubation by adding buffer solution. The result of physical and chemical characteristic of the soil ranged from 3.5 for pH, temperature 28.25-31.25oC, dry weight 21.20-42.86%, water content 63.2- 78.8% and bulk density 0.10-0.34 g/cm3. Cells number of nitrogen fixation symbiotic bacteria ranged from 3⋅2-4⋅9⋅103 CFU/g soil and cells number of nitrogen fixation non- symbiotic bacteria ranged from 3⋅2-9⋅3⋅102 CFU/g soil. Microbial N biomass varied ranging from 1.15-4.29 μg N/g soil and urease activity varied ranging from 3.66-39.28 μg NH4+/g dry weight soil/h. Based on the results obtained, it can be described that the soil quality in the GSK-BB Biosphere Reserve is still capable enough to support the sustainability of soil biological processes
MORFOMETRIK DAN MERISTIK IKAN IKAN PARANG – PARANG (Chirocentrus dorab Forsskal, 1775) DI PERAIRAN BENGKALIS
(2013-03-04) Fitriadi, A. F; Elvyra, R; Yusfiati
The aim of this study is to determine the morphometric and meristic of the parang- parang fish (Chirocentrus dorab) male and female in Bengkalis waters and also view the status of the fish growth. The method used is survey method. The number of samples collected was as many as 60 Chirocentrus dorab, consisting of 15 males in range of 448-680 cm and 15 females in range of 466-690 cm for Bengkalis Strait, and 15 males in range of 365-581 cm and 15 females in range of 370-590 cm for Malacca strait. The result of t test shows significant differences for male fish characters which are PSSA, TK, TB, TPE, PDSV, PM, JMTI, LB and for female which are PS, PSSA, TK, TB, TPE, PDSA, PDSV, PSEB, PM, JMTI, and LB. From the result, it is show that there are no differences beetwen beetwen Chirocentrus dorab male and female in their meristic characters
KEANEKARAGAMAN DAN BIOMASSA RAYAP TANAH DI HUTAN ALAM DAN HUTAN TANAMAN INDUSTRI (HTI) PADA LAHAN GAMBUT DI KAWASAN BUKIT BATU, RIAU
(2013-03-04) Ayu, Febri; Muhammad, Ahmad; Salbiah, Desita
The conversion of peat swamp forest into industrial pulpwood (Acacia crassicarpa) plantation forest (“HTI”) has been suspected to cause substantial change in biodiversity, such as might be reflected in termite assemblages. This study was carried out to investigate how such conversion affects subterranean termites diversity and biomass. The study area was conducted at Bukit Batu District, Riau Province. Termite sampling was done in September and October 2011 at four natural forest sites in Bukit Batu Wildlife Reserve and four HTI sites situated near the former. Termites were systematically sampled with the help of a transect of 100 m drawn on each site. We used 10 square subplots (1 m x 1 m) situated along the transect with a regular interval of 10 m, and termites were extracted down to 10 cm deep beneath the peat surface. Nine species were found, consisting of eight genera, four subfamilies and two families. Termite species found only under natural forest were Microcerotermes dubius, Bulbitermes flavicans, Nasutitermes proatripennis and Ceylonitermes indicola. Species encountered only under HTI was Coptotermes curvignathus. Four species occurring in both land use types were Capritermes semarangi, Capritermes mohri, Schedorhinotermes malaccensis and Parrhinotermes aequalis (Sørensen Similarity Index = 61.54%). Termite biomass was relatively small, with only 0.53 ± 0.41 gr/m2 and 0.29 ± 0.19 gr/m2 under natural forest and HTI, respectively, and there was no significant difference between them
TOTAL POPULASI MIKROBA DAN AKTIVITAS PROTEASE PADA TANAH GAMBUT DI CAGAR BIOSFER GIAM SIAK KECIL - BUKIT BATU RIAU
(2013-03-04) Marliyana, Siti; Zul, Delita; Fibriarti, Bernadeta Leni
Giam Siak Kecil-Bukit Batu (GSK-BB) Biosphere Reserve is one of peatland areas located in Riau Province that consist of conserved area and productive area. Most of these areas have been changed as oil palm plantation, industrial forest plantation, agriculture, and settlement. This research aim was to analyze land use change affect to microbial cells in GSK-BB Biosphere Reserve by analyzing physical and chemical characteristics of soil, quantifying microbial cells and determinating of protease activity. Physical and chemical characteristics of soil were measured by employing standard methods, microbial cells was quantified by using of total plate count method and protease activity was measured by using colorimetric method. Soil samples were taken from six different locations, namely primary forests (as a control), secondary forest, 14 years old rubber plantation, 40-60 years old rubber forests, 12 years old palm oil plantation, and 3 years old oil palm plantation. Soil physical and chemical characteristics varied in every location ranging from 3,5 for soil pH; temperature 28,25- 31,25oC; dry weight 14,70-34,70%; bulk density 0,08-0,38 g/cm3 and soil conductivity 8,75-20,5 me/100 g. Copiotropic bacterial cell number ranges from 7,05±0,85x104- 44±6,48x104 CFU/g soil. Oligotropic bacterial cell number ranges from 10,5±0,57x104-40,0±2,16x104 CFU/g soil. Proteolytic bacterial cell number ranges from 0,5±0,08x104 -4,6±0,53x104 CFU/g soil. Fungal cell number ranges from 2,42±0,78x103- 16,0±2,94x103 CFU/g soil. Actinomycetes cell number ranges from 4,00±1,15x103 - 9,25±1,70x103 CFU/ g soil. Protease activity ranges from 2,28-5,78 g tyrosine/ g soil/ hour. The results of this research show that land use changes influence the dry weight, bulk density, soil conductivity and microbial cells number.
AKTIVITAS ANTIBAKTERI EKSTRAK DAUN PEPAYA (Carica papaya L.) TERHADAP Escherichia coli DAN Salmonella typhi
(2013-03-04) Anggrahini, Dian ND.; Roza, Rodesia M.; Fitmawati
Papaya (Carica papaya L.) is a plant which had been used by society since long time ago as a traditional medicine. It was predicted that there was antibacterial substances in papaya, so it can be used as antibiotic substitutes. The aims of this study were to know the extraction method and concentration of Carica papaya L. against the test bacteria. Carica papaya L. leaf extract were made by maceration method, grinding method, boiling fresh leaf method, and boiling dry leaf method. The test bacteria were E. coli and S. typhi. The inhibition zone was determined for concentration ranging from 10% to 100% (10%, 25%, 50%, 75%, 100%). Antibacterial activity test was done using paper disc and agar well methods. The result showed that Carica papaya L. leaf extract had antibacterial activities against E. coli and S. typhi that was showed by zone of inhibition. Maceration method with agar well was the most effective extraction method against of E. coli and S. typhi. The bigest zone of inhibition was showed in concentration 100%. The maceration method with agar well demonstrated the highest activity against E. coli (17±1 mm zone of inhibition) and S. typhi (15±0,5 mm zone of inhibition)
LAJU DEKOMPOSISI SERASAH DALAM DUA SISTEM BUDIDAYA KARET PADA LAHAN GAMBUT DI KAWASAN RIMBO PANJANG, RIAU
(2013-03-04) Anggrini, Maimona; Muhammad, Ahmad; Fatonah, Siti
This study focused on two smallholder rubber systems in Riau, i.e. “rubber jungle” and “rubber garden,” which have contrasting vegetative structure. Owing to the absence of weeding, rubber jungle may become as dense as 1100-1200 trees/ha, consisting of around 28.80% non-rubber trees. In rubber garden, stand density is retained at usually 500-600 trees/ha and as monospecific stands. Such differences have been suspected to affect decomposition process beneath each system. The purpose of this study was to determine and compare the rate of litter decomposition and nutrient changes in rubber forest and rubber garden. This research has been done throughout the period of February-August 2012 (180 days) on a peatland area situated at Rimbo Panjang, Kampar Regency, Riau. Dried naturally-fallen rubber leaves were used as litter, which was exposed to field conditions in nylon litter bags. In both rubber growing systems, litter rapidly lost substantial amount of its mass (averagely 34.59%) during the first 30 days, but the decomposition slowed down thereafter until the end of the experiment on the 180th day, where the average remaining litter mass was 43.13% of the initial mass. Litter decomposition rate in earlier phase was 1.16%/day and slowed down to 0.32%/day to the 180th day. C/N ratio declined through time, starting from 40.41 to 27.42. P content did not change much through time, while K fluctuated slightly. In contrast, Ca increased in earlier phase to the middle of decomposition process and decreased afterwards. Mg decreased though time
POTENSI ALELOPATI EKSTRAK DAUN Pueraria javanica TERHADAP PERKECAMBAHAN DAN PERTUMBUHAN ANAKAN GULMA Borreria alata (Aublet) DC
(2013-03-04) Murtini, Ika; Fatonah, Siti; Izda, Mayta Novaliza
The allelopathic substances are organic agents which are produced and released by a plant that cause alteration on the neighboring plants. The characteristics of allelopathic substances usually inhibit germination of other species and sometimes will reduce the plant growth. This research was aimed to determine the effect of Puararia javanica leaf extract and also to determine optimum concentration on seed germination and growth of weeds Borreria alata in field condition. This experiment used to extract concentration 0, 2, 6, 18 and 54%. The experiment showed that germination and growth of Borreria alata were reduced by leaf extract of Puararia javanica. The highest germination and growth inhibition at concentrations of the leaf extract 54% respectively are 50% and 60.27%
MORFOMETRIK DAN MERISTIK IKAN BUNTAL PISANG (Tetraodon lunaris) DI PERAIRAN LAUT DAN PAYAU KABUPATEN BENGKALIS
(2013-03-04) Syahrozi; Yusfiati; Elvyra, Roza
There are two kinds of morfologi, morfometrics and meristic. Morfometrics is characteristics which are associated with part size of fish body such as the total and standart length. Meristics is characteristics which are connected to the number of body part of fish such as the number of scales on the lateral line, the number of hard and sof dorsal fins. Morfometrics and meristic study of puffer fish (Tetraodon lunaris) was conducted at Bengkalis and Sungai Pakning waters. The aim of this study is to know the differentes between of morfometrics and meristics of puffer fish in waters with different salinity condition. This study was conducted from September to November 2012. Fish sampling was carried was at Bengkalis and Sungai Pakning waters which has 50 samples for each location. Research data was analyzed using excel and SPSS program. The total length of puffer fish in Bengkalis and Sungai Pakning ranges 45-160 mm and 45-151 mm. Puffer fish growth status in the both locations of research is positive allometrik, negative allometrik and isometric. There are no differences in shown puffer fish morfometrics character ratio between Bengkalis and Sungai Pakning waters.The T- test result shows character growth JSAPSE / PT significantly different between both locations of this research. There are no differences in puffer fish meristics for both locations, Bengkalis and Sungai Pakning waters
INVENTARISASI JENIS-JENIS IKAN DI SUNGAI SINGINGI KABUPATEN KUANTAN SINGINGI
(2013-03-04) Zalmi, G.; Elvyra, R.; Yusfiati
Singingi river has an important role as one of freshwater fishery resources in Kuantan Singingi. Therefore data and information relating to fish species are needed. The objective of this study is to create inventory of fish species in Singingi river, Kuantan Singingi. The research is conducted by survey method. The samples of fish consist of three individual from each species. The samples of fish were preserved with formalin 4%, 10% and alcohol 70%. Identification of fish was carried in Zoology laboratory, Biology Department, Faculty of Mathematic and Science, Riau University. Fishes founded in Singingi river consists of 4 orders, 13 family, 23 genera, and 38 species. They are family Cyprinidae (21 species), Cobitidae (3 species), Anabantidae (2 species), Channidae (2 species), Bagridae (2 species), Balitoridae (1 species), Belontiidae (1 species), Mastacembelidae (1 species), Akysidae (1 species), Clariidae (1 species), Pangasidae (1 species), Siluridae (1 species), Synbranchidae (1 species)
LAJU PRODUKSI SERASAH DALAM DUA SISTEM BUDIDAYA KARET PADA LAHAN GAMBUT DI KAWASAN RIMBO PANJANG, RIAU
(2013-03-04) Nanda, Fristya; Muhammad, Ahmad; Fatonah, Siti
The contrasting difference in the vegetation structure of two smallholder rubber growing systems, namely “rubber jungle” and “rubber garden,” has been suspected to affect nutrient cycling in both systems. In this study, we focused on litter production, which roughly reflects the rate of nutrient return to the soil. The objective of the present study has been to assess litter production and composition in both types of rubber growing systems. Our study sites were situated in a peatland area at Rimbo Panjang, Kampar Regency, Riau, where we selected four rubber jungle plots and four rubber garden. Three litter traps (each 1 x 1 x 1 m) were systematically set up beneath rubber stands in a regular interval of 30 m within each selected plot. Trapped litter was collected weekly for 26 consecutive weeks between February and August 2012. Litter samples were dried up to their constant dry weight before weighing and analyzed after their components (leaves, flower and fruits, others). They were also analyzed on a monthly basis for their contents of C, N, P, K Ca, and Mg. In both systems, litter production was strongly correlated with monthly rainfall volume (r2= 0.91 and 0.95in rubber jungle and rubber garden, respectively). Litter production rate was 71.56 g/m2/month or 8587,2 kg/ha/yr in rubber jungle and 65.36 g/m2/month or 7843,2 kg/ha/yr in rubber garden. There was, however, no significant difference between them. Litter averagely consisted of about 60% leaves, 7% flowers and fruits, and 33% other components. Leaf mass varied significantly between rubber jungle and rubber garden, while the mass of flowers and fruits and other components did not. Leaf mass also fluctuated following rainfall, which peaking in March and July. Flower and fruit mass increased from February to August, while the mass of other components decreased during the same period. C/N ratio in litter of both systems influenced by rainfall, in which litter produced during wetter months had slightly smaller C/N ratio, but the correlation between both variables was insignificant. Through litter production trees in both rubber growing systems returned N, P, K, Ca and Mg with the average rate of 125.05 kg/ha/yr, 9.94 kg/ha/yr, 29.71 kg/ha/yr, 77.99 kg/ha/yr and 29.88 kg/ha/yr, respectively
AKTIVITAS ANTIBAKTERI EKSTRAK DAUN BENALU (Scurulla sp) YANG TUMBUH PADA BEBERAPA INANG TERHADAP PERTUMBUHAN Salmonella typhi
(2013-03-04) Nasution, Pebriana; Roza, Rodesia Mustika; Fitmawati
Scurulla sp as arboreal parasitic plant that hold and absorb its nutrient from host. During nutrient absorption, all of metabolites (include secondary metabolites) which produce by the host will be also absorbed. For this reason Scurulla sp must have capability to develop strategies to adapt. Different host are estimated to produce different secondary metabolite. The aims of this study is to know the best solvent between water and methanol to reduce the antibacterial activity of leaf extracts Scurulla sp from different hosts (Coffea arabica, Theobroma cacao, Diospyros nigra) and to know the concentration exctract of Scurulla sp against S. typhi. The method used in this research is the experimental method in the laboratory. There are 5 concentration variations. This extraction performed used methanol and water, and were used series of dilution 10%, 25%, 50%, 75%, and 100%. The exctract than was tested by paper disc diffusion and agar wells method, then incubated for 24-72 hours at room temperature. Observations were made by measuring the area which of inhibition. The results showed the inhibition of the solvent methanol has the inhibition area is bigger than the solvent water at all concentrations. Extract of Scurulla sp from Coffea arabica host, Theobroma cacao host and Diospyros nigra host showed the highest in a 100% concentration. The lowest concentration of 10% is characterized by no area of the inhibition on all hosts with the methanol and water solvents

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