BIOTROPIA - The Southeast Asian Journal of Tropical Biology
Not a member yet
547 research outputs found
Sort by
TAXOMETRICS CLASSIFICATION (HIERARCHICAL AND ORDINATION) OF AQUATIC AND SEMI-AQUATIC MOSSES: A PRELIMINARY MODEL TO BRYODIVERSITY MANAGEMENT
Get PDFBryodiversity is naturally serving the ecosystems sustainably. It serves the environments by preventing natural disaster (flooding), maintaining the quality of the water body and filter or treats the pollutants naturally. Efficient bryodiversity management is needed for environmental cost cutting and have a cost-effective management strategy. To achieve this, cluster and principal component analyses (PCA) were manipulated to produce the linkage distance between the OTUs and identify the important groups of characters, respectively. In return, it becomes a guideline for bryoflora and environmental managements. In this study, 23 OTUs and 156 characters were analyzed. The output from the reliability and item analysis showed that the data set is highly reliable (Cronbach’s alpha = 0.9627). From the cluster analysis, it showed that 5 clustered groups (manageable units) could be derived from the produced phenogram. This is based on the nearest neighbour amalgation rule and Euclidean distances. As for the principal component analysis, three factors were derived and explained 75.1064% of the variation with 56.0485%(PC1), 11.7346%(PC2) and 7.3233%(PC3), respectively. The ordination showed that 5 manageable units were derived from PC1 and 3 manageable units for PC2 and PC3, respectively. In conclusion, conservation should precede any biodiversity management plans.  Keywords: aquatic mosses, semi-aquatic mosses, cluster analysis, principal component analysis (PCA), classification Â
SEEDBANK AND SEEDLING EMERGENCE CHARACTERISTICS OF WEEDS IN RICEFIELD SOILS OF THE MUDA GRANARY AREA IN NORTH-WEST PENINSULAR MALAYSIA
Get PDFTlie experiment was conducted in the glasshouse of UPM from March 2003 to June 2004 to determine the soil seedbank in the ricefields ot\u27Muda rice granary area in Peninsular Malaysia. Six soil cores of 5 cm in diameter and 10 cm depth were sampled from each of 24 fields. All samples from each individual field were bulked and placed in plastic trays of 38 x 25 x 10 cm. Soil was moistened as required and emergence of weed seedlings were recorded over period of one year. After one year, remaining seeds were separated, removed and identified. The total seed bank was estimated at 1136.48 million/ha of which 62.35% (708.60 million seedlings ha"1) germinated within 12 months and 37.65% (427.88 million seeds ha"1) remained ungerminated. Total of 20 taxa were recognized. Based on importance value (I.V.) the five most dominant species in terms of emerged seedling were Fimbristylis miliacea, Leplochloa chinensis, LitJwigia hyssopifolia, Cyperus difformii and C. iria. Of the remaining seeds the five dominant species with decreasing trend in ranking were F. miliacea, Scirpus lateriflonis, Monochoria vagina/is, L. hyssopifolia and L. chinensis. Ranking of total seed reserves (seedlings+ remaining seeds) were similar to emerged seedling indicating that emerged seedlings reflect the actual weed flora in the Muda area. Among the dominant species F. miliacea accounted for 58.07% of emerged seedlings, 79.31% of remaining seeds and 66.07% of total seed bank. Total seedling emergence of all species was higher in the first observation in April 2003 and cumulative seedling emergence showed no clear peaks. Key words : Seedbank, seedling emergence, weeds, ricefield soils, Malaysi
SOIL AS A FACTOR INFLUENCING THE MANGROVE FOREST COMMUNITIES IN TALIDENDANG BESAR, RIAU
Get PDFOne transect of 10 m x 900 m was constructed perpendicular to the sea edge to know the pattern ofmangrove forest communities from the sea edge through the inland area. Then, one sample plot of 50 m x 50 mwas established at each forest community to explore its vegetation structure and soil characteristics. The results show that in Talidendang Besar area, there are three mangrove forest communities stretchingfrom the sea edge to the inland, namely Bruguiera parviflora, B. sexangula and B. sexangula-Nypa fruticans.The soil factors such as pH.EC (electrical conductivity), % K, % Na, C-organic, N-total, NH4 (ammonia), andCEC (cation exchange capacity) were regarded important in influencing the pattern of the mangrove forestcommunities
OPTIMIZATION OF CELLULASE PRODUCTION WITH PENICILLIUM NALGIOVENSE Sll GROWN ON PRETREATED WHEAT POLLARD
Get PDFThe cellulase production with Penicillium nalgiovense S11 on wheat pollard was enhanced using substrate pretreatments, i.e.: (i) mechanic process by Wiley milling, (ii) reducing sugars removal by water soaking, and (iii) chemical pretrcatment by 0.5% NaOH soaking at 100°C. The enzyme production stated as enzyme activities of all prctrcated substrates were higher than the untreated substrate. Although soaking with water showed significant increase in enzyme activities, the highest CMCase (EC 3.2.1.4), FPase (filter papcrase) and p-glucosidase (EC 3.2.1.21) were observed on NaOH pretreated pollard. The NaOH prctreatment also enhanced the enzyme production by increasing substrate concentration from 2 to 4%. The optimal incubation time in the cellulase production on 4% NaOH-pretrcated pollard was observed on the fifth day. Addition of 250 ppm glucose also increased the enzyme activities. The optimal treatments increased the specific activities of CMCase, FPase, and |3-glucosidase into 60, 4, and 198 times, respectively, as compared to the specific activities on 2% unpretreated pollard. Keywords :  Cellulase production/ pollard pretreatments/ water soaking/ NaOH soakin
PRODUCTION AND UTILIZATION OF CELLULASE FROM TRICHODERMA VIRIDE
No full text An appropriate preservation technology for forage such as silage needs to be developed in order to overcome the shortage of tropical forage during the dry season. A good quality of silage is obtained by decreasing the fibre contents (Neutral Detergent Fibre, Acid Detergent Fibre and lignin). The research was conducted in two stages: 1). Production and activity test of crude enzymes from Trichoderma viride and 2). Comparative test using crude enzymes from Trichoderma viride strain QM 9414 (CETV) and commercial cellulase (Cellulase “Onozuka R-10â€, heidelberg) on rice straw silage. The treatments were arranged as follows : P0=Untreated rice straw silage, P1=Treated with commercial cellulase at 10 IU kg-1, P2= Treated with CETV at 3.8 IU kg-1, P3=Treated with CETV at 7.6 IU kg-1 and P4= Treated with CETV at 11.4 IU kg-1 of fresh rice straw. All treatments were enriched with 5% molasses. The result of the research indicated that: 1). The activity of crude enzymes from Trichoderma viride strain QM 9414 (CETV) was 1.52 IUml-1. 2). The addition of both enzymes did not decrease dry matter of rice straw silage; however, organic matter significantly decreased (
EFFECT OF LIGHT QUALITIES AND STORAGE PERIODS ON THE GERMINATION OF PENNISETUM POLYSTACHION SEEDS*)
Get PDFSeeds of the yellowish inflorescence strain of Pennisetum polystachion, collected from the field in Indonesia, were kept in the dark for 30 days, then germinated in 12-h light and 24-h light under various light qualities, namely, white, black, blue, red and far-red. There was no effect of photo-period to seed germination. Percent of seed germination under white, red, far-red, blue and dark were 49, 43, 22, 11 and 2%, respectively. White and red light did not cause any difference to seed germination. Seeds kept in 12-h light alternating with 12-h dark and 24-h dark for 15 and 30 days were tested for germination. Results showed that light condition during seed storage did not effect seed germination. Long storage period resulted in more seed germination. During seed germination test, effect of light played a great role on increasing seed germination
ANTAGONISTIC EFFECT OF THREE FUNGAL ISOLATES TO AFLATOXIN-PRODUCING^spergiY/HS/JavHS
Get PDFAflatoxin contamination in preharvest peanuts can be controlled among others by using antagonistic fimgi to aflatoxin-producing fungi. Aspergillus flavus is one of the fungal species where certain strains can produce aflatoxin. Informations regarding the type of interactions between antagonistic fungi and toxigenic A. flavus, and the effects of culture filtrates of the test fungi on the growth and aflatoxin production of toxigenic A. flavus are necessary, before antagonistic fungi could be used as biocontrol agent. Three fungal isolates (nontoxigenic A. flavus BIO 2127, A. niger BIO 2129 and Trichoderma harzianum BIO 19130) were tested for their antagonistic properties against toxigenic A. flavus BIO 2132 using direct and indirect confrontation methods. On direct confrontation method, four kinds of agar media were used, i.e PDA (Potato Dextrose Agar), MEA 1% (Malt Extract Agar 1%), SMKYA (Sucrose 200 g, MgSO47H2O 0.5 g, KNO3 3 g, yeast extract 7 g, and block agar AA 20 g), and the mixture of MEA 1 % + SMKYA (1:1). The results indicated that the type of interactions between toxigenic A. flavus either with nontoxigenic A. flavus or with T. harzianum was B type. In this type of interaction, the growth of both toxigenic A. flavus and the test fungi inhibited each other (mutual inhibition) with the zone of inhibition 2 mm. Culture filtrates derived from nontoxigenic A. flavus and A. niger grown on ME 1%, SMKY and ME 1% + SMKY inhibited the growth (based on dry weight) of toxigenic A. flavus, except culture filtrates derived from T. harzianum grown on SMKY and ME 1% + SMKY media stimulated the growth of toxigenic A. flavus. Culture filtrates of nontoxigenic A. flavus, A. niger and T. harzianum inhibited aflatoxin B\ production of toxigenic A. flavus. Culture filtrates of A. niger and T. harzianum with conidial concentrations of IxlO6, 2xl06 and 3xl06 per ml inhibited aflatoxin B, production up to 100%. The percentage of inhibition of aflatoxin Bi production increased with the increase of conidial concentrations of nontoxigenic A. flavus. The highest percentage of inhibition of aflatoxin BI production (62.5%) was obtained from conidial concentration of 3xl06 per ml. Aspergillus niger was the most potential fungus in inhibiting the growth of toxigenic A. flavus, either on agar media or on culture filtrates of test fungi. Culture filtrate of A. niger was also the most potential filtrate in inhibiting aflatoxin BI production of toxigenic A. flavus.Keywords:   Antagonistic effect / Aspergillus flavus I Aspergillus niger I Trichoderma harzianum I aflatoxi
EFFECT OF MANCOZEB 80% CONCENTRATIONS ON THE GROWTH OF CENOCOCCUM GEOPHILUM FR. UNDER IN VITRO CONDITION
Get PDFFungicides, such as Mancozeb 80% are used in nurseries to prevent the plant root against pathogenic fungi. These fungicides may have negative impacts on beneficial organisms such as ectomycorrhizal fungi. Cenococcum geophilum is an important ectomycorrhizal fungus associated with some forest trees species. An in vitro experiment was conducted in laboratory condition. Cenococcum geophilum was cultured on solid Modified Melin Nokrans’ (MMN) medium containing Mancozeb 80 % at different concentrations (0, 50, 100, 200, 300, 400, 500, 600, 700, 800, 900, and 1000 μM). A completely randomized design was used with 8 replicates Petri dishes. Mancozeb 80 % decreased the growth of mycelia of C. geophilum. The radial growth of mycelia was not inhibited by Mancozeb 80 % at 0 to 400 μM concentrations. Fungi-static effect of Mancozeb 80 % was found at 500 to 600 μM concentrations, meanwhile fungi-toxic effect of Mancozeb 80 % was obtained at concentration more than 700 μM. A lethal level of Mancozeb 80% to the growth of C. geophilum was not found.  Key word : fungicide/Mancozeb 80 % /Cenococcum geophilum/fungi-static, fungi-toxic Â
INTEGRATION OF NPP SEMI MECHANISTIC - MODELLING, REMOTE SENSING AND CIS IN ESTIMATING CO2 ABSORPTION OF FOREST VEGETATION IN LORE LINDU NATIONAL PARK
Get PDFNet Primary Production, NPP, is one of the most important variables characterizing the performance of an ecosystem. It is the difference between the total carbon uptake from the air through photosynthesis and the carbon loss due to respiration by living plants. However, field measurements of NPP are time-consuming and expensive. Current techniques are therefore not useful for obtaining NPP estimates over large areas. By combining the remote sensing and GIS technology and modelling, we can estimate NPP of a large ecosystem with a little ease. This paper discusses the use of a process based physiological sunshade canopy models in estimating NPP of Lore Lindu National Park (LLNP). The discussion includes on how to parameterize the models and how to scale up from leaf to the canopy. The version documented in this manuscript is called NetPro Model, whicha potential NPP model where water effect is not included yet. The model integrates CIS and the use of Remote Sensing, and written in Visual Basic 6.0 programming language and Map Objects 2.1. NetPro has the capability of estimating NPP of Cs vegetation under present environmental condition and under future scenarios (increasing [CO2], increasing temperature and increasing or decreasing leaf nitrogen level). Based on site-measured parameterisation of VaM* (Photosynthetic capacity), /JjRespiration) and leaf nitrogen ONi), the model was run under increasing CO2 level and temperature and varied leaf nitrogen. The output of the semi-mechanistic modelling is radiation use efficiency (?). Analysis of remote sensing data give Normalized Difference Vegetation Index (NDVI) and related Leaf Area Index (LAI) and traction of absorbed Photosynthetically Active Radiation (/M>AK). Climate data are obtained from 12 meteorological stations around die parks, which includes global radiations, minimum and maximum temperature. CO2 absorbed by vegetation (Gross Primary Production, GPP) is then calculated using the above variables and parameters with the following equation:estimating NPP, while ecosystem respiration is set as a function of temperature for estimating NEE. Under present condition, the net absorption of CO> by the vegetation of Lore Lindu National Park (NPP) is 1330.31 gCm"2year"\u27 and at double CO2 and temperature increased of 3.5 "C, it increased by 23 %, reaching 1638.80 gCm\u272 year\u271.Key words : NPP Semi-mechanistic model, photosynthesis, carbon sequestration, net primary-production, tropical fores