Papers by Ardhini Maharning
Scripta Biologica, Sep 1, 2017
The research objectives were to investigate nematode community response to decomposing plant litt... more The research objectives were to investigate nematode community response to decomposing plant litter of varying proportions, and to measure the litter decomposition rate. This greenhouse experiments included three treatments of decomposing plant litter with proportions of 30:70, 50:50, and 70:30 (leaf litter to stem-paddy litter, weight to weight), and two controls (commercial organic fertilizers and no-organic matter). We applied the prepared plant litter and organic fertilizers on the surface of the agricultural sandy soil. Soil samples were taken after two, seven, 14, 28, 49, and 77 days to follow nematode temporal changes. Nematodes were assigned to functional groups and family level of a taxon. We used Anova to test the significance of nematode abundance among the treatments, exponential decay model to measure decomposition rates of the plant litter, and canonical correspondence analysis to investigate the correlation of varying plant proportion and nematode community composition. The results showed that nematode functional groups and family did not differ among soils of various plant litter proportions. Bacterivorous Rhabditidae and Cephalobidae, fungivorous Aphelenchidae, and fungivorous-root feeder Tylenchidae inhabited plant litter amended soils. Their abundance, however, differed significantly (p<0.001) and revealed two temporal patterns, i.e., linear (50:50) and unimodal (30:70 and 70:30). No nematodes were observed in organic fertilizer amended soil and no-organic matter soil. Nematode community composition changed over time according to the litter proportion, in which by the end of experiments, community of 50:50 and 30:70 were the least similar (r: 0.57 of axis-1 and 0.54 of axis-2, CPV: 89.06). We concluded that all litter proportions retained similar quality and supported the growth of similar nematode groups. The litter proportion, however, appeared to influence nematode abundance, their temporal patterns, and community compositions.
Biodiversitas Journal of Biological Diversity
Luckyana DR, Puspitasari IGAAR, Maharning AR. 2020. Bacterial (9A2H) enhancement alters the nemat... more Luckyana DR, Puspitasari IGAAR, Maharning AR. 2020. Bacterial (9A2H) enhancement alters the nematode community structure and decomposition pathway of amended nutrient-limited soil. Biodiversitas 21: 4813-4820. This study examined the influence of paddy litter amendment and bacterial enhancement of nutrient-limited soil on the nematode community structure and investigated the decomposition rate of the litter due to the treatment. We applied a microcosm-based approach using sand as the medium, including the following treatments: no-bacteria, 9A-autotrophic-bacteria, 2H-heterotrophic-bacteria, and 9A-2H-mix-bacteria, with five replicates. The litter bag experiment and exponential decay model estimated the litter decomposition rate in the microcosm. The soil samples and litter bags were retrieved after days 21, 42, and 63. The structure, enrichment, channel index (CI), and canonical correspondence analysis were employed to investigate the nematode community response. Bacterial enhancement shifted the nematode community and the soil food web toward the dominant bacterial pathway by day 63 (CI: 0), with a slightly less structured food web that was supported by bacterivorous nematodes mostly related to available nutrients. These changes coincided with soil organic carbon and nitrogen increases over time. Our experiments showed that paddy litter amendment and the 9A, 2H, and 9A-2H-mix bacterial enhancements improved nutrient-limited soil, according to the analysis of the nematode community, its composition, and the food web conditions determining nutrient mobility and availability. However, these factors have no impact on the litter decay rate.
Vegetation types are an above-ground component that plays an important role in shaping soil commu... more Vegetation types are an above-ground component that plays an important role in shaping soil community through their different life history. Plant organic material as the main source for the below-ground community is available at various time and amount based on plant growth. The objective of this study was to compare the bacteria and nematode functional diversity on soil planted with five plant types. These greenhouse experiments are selected Oryza sativa L. (grass), Amaranthus sp. (herb), Solanum lycopersicum (L.) Karst. (shrub), Citrus reticulata Blanco (tree), and Arachis hypogaea L. (legume). To create seven treatments, control and plant mixture were included. Soil samples and plants were collected after five weeks for bacteria and nematode enumerations, plant biomass and specific leaf area measurements. Plant growth was followed approximately every two weeks. The bacteria were separated into the heterotrophic or autotrophic group and nematodes were classified into their functional group after identification. Canonical Correspondence Analysis was used to investigate the correlation between plant types and the soil organism composition. The preliminary results showed that the plant types determined the soil bacteria and nematode composition, except for O. sativa and S. lycopersicum with the greatest similarity of composition (eigenvalue: 0.33 and 0.24, correlation: 0.80, cumulative variance: 84.1 %). This was consistent with stem growth rate, leaf growth rate, specific leaf area and plant biomass allocation. Strong to medium correlations were observed between soil organisms and aboveground plant biomass allocation (r =-0.81), plant growth rate (r =-0.59) and leaf growth rate (r =-0.46) indicating below-ground resources most likely influenced soil food web development.
Applied Soil Ecology, 2009
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Papers by Ardhini Maharning