scholarly journals Effects of Water Content and Mesh Size on Tea Bag Decomposition

Ecologies ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 175-186
Author(s):  
Taiki Mori ◽  
Ryota Aoyagi ◽  
Hiroki Taga ◽  
Yoshimi Sakai
Keyword(s):  
Water Content ◽  
Large Scale ◽  
Mixed Forest ◽  
Mesh Size ◽  
Field Studies ◽  
Decomposition Rates ◽  
Essential Information ◽  
Litter Bag ◽  
Rooibos Tea ◽  
Water Contents

The tea bag method provides a replicable and standardized method to study the effect of environmental variables on the decomposition of standard litter, which enables comparison of organic matter decomposition rates on a large scale. However, it remains uncertain whether tea bag decomposition in response to wetness is representative of that of local litters. We performed incubation experiments to examine whether the effect of soil water on tea bag decomposition becomes inhibitory at higher water contents, as is the case in local leaf litters. In addition, we performed field studies in a mixed forest and cedar plantation in Japan to compare two litter bag mesh sizes: 0.25-mm mesh, the size previously used by a major manufacturer of tea bags (Lipton), and nonwoven bags with mesh sizes finer than 0.25 mm, which are currently produced by Lipton. Both green tea and rooibos tea exhibited higher decomposition rates at higher water contents, but decomposition was inhibited at the highest water content; this was in contrast to our hypothesis based on a field observation but consistent with conceptual models of local litters. The nonwoven tea bags did not show lower decomposition rates, despite the finer mesh size. Rather, the nonwoven rooibos tea bags exhibited slightly higher decomposition rates than the 0.25-mm mesh bags in the cedar plantation, possibly due to a greater abundance of microorganisms that decompose litters in the nonwoven bags, due to the decrease in predation by mesofauna. Our findings provide essential information for future studies of tea bag decomposition.

scholarly journals Effects of water content and mesh size on tea bag decomposition

2020 ◽  
Author(s):  
Taiki Mori ◽  
Ryota Aoyagi ◽  
Hiroki Taga ◽  
Yoshimi Sakai
Keyword(s):  
Water Content ◽  
Large Scale ◽  
Mixed Forest ◽  
Mesh Size ◽  
Decomposition Rates ◽  
Litter Bags ◽  
Essential Information ◽  
Litter Bag ◽  
Rooibos Tea ◽  
Water Contents

AbstractThe tea bag method was developed to provide uniform litter bags that enable comparison of organic matter decomposition rates on a large scale. However, it remains uncertain whether tea bag decomposition in response to wetness is representative of that of natural litters. We performed incubation experiments to examine whether the effect of soil water on tea bag decomposition becomes inhibitory at higher water contents, as was demonstrated in natural leaf litters. In addition, we performed field studies in a mixed forest and cedar plantation in Japan to compare two litter bag mesh sizes: 0.25-mm mesh, the size previously used by a major manufacturer of tea bags (Lipton), and nonwoven bags with mesh sizes finer than 0.25 mm, which are currently produced by Lipton. Both green tea and rooibos tea exhibited higher decomposition rates at higher water contents, but decomposition was inhibited at the highest water content, consistent with conceptual models of natural litters. The nonwoven tea bags did not show lower decomposition rates, despite the finer mesh size. Rather, the nonwoven rooibos tea bags exhibited slightly higher decomposition rates than the 0.25-mm mesh bags in the cedar plantation, possibly due to a greater abundance of microorganisms that decompose litters in the nonwoven bags, due to the decrease in predation by mesofauna. Our findings provide essential information for future studies of tea bag decomposition.

Decoupled water and iron enrichments in the cratonic mantle: A study on peridotite xenoliths from Tok, SE Siberian Craton

2020 ◽  
Vol 105 (6) ◽  
pp. 803-819
Author(s):  
Luc S. Doucet ◽  
Yongjiang Xu ◽  
Delphine Klaessens ◽  
Hejiu Hui ◽  
Dmitri A. Ionov ◽  
...  
Keyword(s):  
Water Content ◽  
Siberian Craton ◽  
Lithospheric Mantle ◽  
Large Scale ◽  
Basaltic Magma ◽  
Mantle Xenoliths ◽  
Spinel Peridotite ◽  
Peridotite Xenoliths ◽  
Cratonic Mantle ◽  
Water Contents

Abstract Water and iron are believed to be key constituents controlling the strength and density of the lithosphere and, therefore, play a crucial role in the long-term stability of cratons. On the other hand, metasomatism can modify the water and iron abundances in the mantle and possibly triggers thermo-mechanical erosion of cratonic keels. Whether local or large scale processes control water distribution in cratonic mantle remains unclear, calling for further investigation. Spinel peridotite xenoliths in alkali basalts of the Cenozoic Tok volcanic field sampled the lithospheric mantle beneath the southeastern margin of the Siberian Craton. The absence of garnet-bearing peridotite among the xenoliths, together with voluminous eruptions of basaltic magma, suggests that the craton margin, in contrast to the central part, lost its deep keel. The Tok peridotites experienced extensive and complex metasomatic reworking by evolved, Ca-Fe-rich liquids that transformed refractory harzburgite to lherzolite and wehrlite. We used polarized Fourier transform infrared spectroscopy (FTIR) to obtain water content in olivine, orthopyroxene (Opx), and clinopyroxene (Cpx) of 14 Tok xenoliths. Olivine, with a water content of 0–3 ppm H2O, was severely degassed, probably during emplacement and cooling of the host lava flow. Orthopyroxene (49–106 ppm H2O) and clinopyroxene (97–300 ppm H2O) are in equilibrium. The cores of the pyroxene grains, unlike olivine, experienced no water loss due to dehydration or addition attributable to interaction with the host magma. The water contents of Opx and Cpx are similar to those from the Kaapvaal, Tanzania, and North China cratons, but the Tok Opx has less water than previously studied Opx from the central Siberian craton (Udachnaya, 28–301 ppm; average 138 ppm). Melting models suggest that the water contents of Tok peridotites are higher than in melting residues, and argue for a post-melting (metasomatic) origin. Moreover, the water contents in Opx and Cpx of Tok peridotites are decoupled from iron enrichments or other indicators of melt metasomatism (e.g., CaO and P2O5). Such decoupling is not seen in the Udachnaya and Kaapvaal peridotites but is similar to observations on Tanzanian peridotites. Our data suggest that iron enrichments in the southeastern Siberian craton mantle preceded water enrichment. Pervasive and large-scale, iron enrichment in the lithospheric mantle may strongly increase its density and initiate a thermo-magmatic erosion. By contrast, the distribution of water in xenoliths is relatively “recent” and was controlled by local metasomatic processes that operate shortly before the volcanic eruption. Hence, water abundances in minerals of Tok mantle xenoliths appear to represent a snapshot of water in the vicinity of the xenolith source regions.

Ecological and physiological investigations in continental Antarctic cryptogams II. Moisture relations and photosynthesis of lichens near Casey Station, Wilkes Land

1991 ◽  
Vol 3 (3) ◽  
pp. 273-278 ◽  
Author(s):  
L. Kappen ◽  
M. Breuer
Keyword(s):  
Water Content ◽  
Thick Layer ◽  
Net Photosynthesis ◽  
Field Studies ◽  
Optimum Water Content ◽  
Continental Antarctica ◽  
Wilkes Land ◽  
Quantum Flux ◽  
Optimum Water ◽  
Water Contents

In the second of three field studies on the ecology and physiology of lichens on Clark Peninsula, Wilkes Land, Antarctica, photosynthetic activity due to natural and artificial soaking of lichen thalli was investigated. Gravimetric measurements were used to quantify water uptake by lichens in contact with snow or ice. Quantum flux density under a 15 cm thick layer of snow can reach light saturation for net photosynthesis of Usnea sphacelata at temperatures around 0°C. Measurements with a steady-state CO2 diffusion porometer in the field reveal that, in Usnea antarctica, Umbilicaria decussata, and U. aprina, the optimum water content for net photosynthesis was 75–115 % d.wt. after the thalli were sprayed with water or submerged. The depression of net photosynthesis at super-optimal water content was strong in these species. In naturally soaked Usnea sphacelata this depression was less apparent. The water content resulting from contact with snow is frequently near the optimum for photosynthesis. In lichens of continental Antarctica it seems that super-optimal water contents are the exception rather than the rule.

Mapping global water projects: improving access to donor investment information on the web

Water Policy ◽  
2003 ◽  
Vol 5 (3) ◽  
pp. 203-212
Author(s):  
J. Lisa Jorgensona
Keyword(s):  
Water Resources ◽  
Web Sites ◽  
Large Scale ◽  
Technical Assistance ◽  
Water Withdrawal ◽  
Small Scale ◽  
Water Projects ◽  
Essential Information ◽  
Water Project ◽  
The Web

This paper discusses a series of discusses how web sites now report international water project information, and maps the combined donor investment in more than 6000 water projects, active since 1995. The maps show donor investment:  • has addressed water scarcity,  • has improved access to improvised water resources,  • correlates with growth in GDP,  • appears to show a correlation with growth in net private capital flow,  • does NOT appear to correlate with growth in GNI. Evaluation indicates problems in the combined water project portfolios for major donor organizations: •difficulties in grouping projects over differing Sector classifications, food security, or agriculture/irrigation is the most difficult.  • inability to map donor projects at the country or river basin level because 60% of the donor projects include no location data (town, province, watershed) in the title or abstracts available on the web sites.  • no means to identify donor projects with utilization of water resources from training or technical assistance.  • no information of the source of water (river, aquifer, rainwater catchment).  • an identifiable quantity of water (withdrawal amounts, or increased water efficiency) is not provided.  • differentiation between large scale verses small scale projects. Recommendation: Major donors need to look at how the web harvests and combines their information, and look at ways to agree on a standard template for project titles to include more essential information. The Japanese (JICA) and the Asian Development Bank provide good models.

Effects of Trust and Threat Messaging on Academic Cheating: A Field Study

2021 ◽  
pp. 095679762097751
Author(s):  
Li Zhao ◽  
Jiaxin Zheng ◽  
Haiying Mao ◽  
Xinyi Yu ◽  
Jiacheng Ye ◽  
...  
Keyword(s):  
Field Study ◽  
Academic Integrity ◽  
Large Scale ◽  
Theoretical Foundation ◽  
Empirical Evaluation ◽  
Psychological Theory ◽  
Field Studies ◽  
Educational Institutions ◽  
Academic Cheating ◽  
College Classrooms

Morality-based interventions designed to promote academic integrity are being used by educational institutions around the world. Although many such approaches have a strong theoretical foundation and are supported by laboratory-based evidence, they often have not been subjected to rigorous empirical evaluation in real-world contexts. In a naturalistic field study ( N = 296), we evaluated a recent research-inspired classroom innovation in which students are told, just prior to taking an unproctored exam, that they are trusted to act with integrity. Four university classes were assigned to a proctored exam or one of three types of unproctored exam. Students who took unproctored exams cheated significantly more, which suggests that it may be premature to implement this approach in college classrooms. These findings point to the importance of conducting ecologically valid and well-controlled field studies that translate psychological theory into practice when introducing large-scale educational reforms.

scholarly journals Holocene vegetation, fire and land use dynamics at Lake Svityaz, an agriculturally marginal site in northwestern Ukraine

2021 ◽  
Author(s):  
Christoph Schwörer ◽  
Erika Gobet ◽  
Jacqueline F. N. van Leeuwen ◽  
Sarah Bögli ◽  
Rachel Imboden ◽  
...  
Keyword(s):  
Bronze Age ◽  
Human Impact ◽  
Central Europe ◽  
Large Scale ◽  
Mixed Forest ◽  
Fire Risk ◽  
Late Glacial ◽  
Future Climate Change ◽  
Agricultural Activity ◽  
Fire Dynamics

AbstractObserving natural vegetation dynamics over the entire Holocene is difficult in Central Europe, due to pervasive and increasing human disturbance since the Neolithic. One strategy to minimize this limitation is to select a study site in an area that is marginal for agricultural activity. Here, we present a new sediment record from Lake Svityaz in northwestern Ukraine. We have reconstructed regional and local vegetation and fire dynamics since the Late Glacial using pollen, spores, macrofossils and charcoal. Boreal forest composed of Pinus sylvestris and Betula with continental Larix decidua and Pinus cembra established in the region around 13,450 cal bp, replacing an open, steppic landscape. The first temperate tree to expand was Ulmus at 11,800 cal bp, followed by Quercus, Fraxinus excelsior, Tilia and Corylus ca. 1,000 years later. Fire activity was highest during the Early Holocene, when summer solar insolation reached its maximum. Carpinus betulus and Fagus sylvatica established at ca. 6,000 cal bp, coinciding with the first indicators of agricultural activity in the region and a transient climatic shift to cooler and moister conditions. Human impact on the vegetation remained initially very low, only increasing during the Bronze Age, at ca. 3,400 cal bp. Large-scale forest openings and the establishment of the present-day cultural landscape occurred only during the past 500 years. The persistence of highly diverse mixed forest under absent or low anthropogenic disturbance until the Early Middle Ages corroborates the role of human impact in the impoverishment of temperate forests elsewhere in Central Europe. The preservation or reestablishment of such diverse forests may mitigate future climate change impacts, specifically by lowering fire risk under warmer and drier conditions.

scholarly journals Graph Convolutional Network for Drug Response Prediction Using Gene Expression Data

Mathematics ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 772
Author(s):  
Seonghun Kim ◽  
Seockhun Bae ◽  
Yinhua Piao ◽  
Kyuri Jo
Keyword(s):  
Gene Expression ◽  
Gene Expression Data ◽  
Large Scale ◽  
Drug Response ◽  
Response Prediction ◽  
Biological Data ◽  
Expression Data ◽  
Convolutional Network ◽  
Essential Information ◽  
Protein Protein Interaction

Genomic profiles of cancer patients such as gene expression have become a major source to predict responses to drugs in the era of personalized medicine. As large-scale drug screening data with cancer cell lines are available, a number of computational methods have been developed for drug response prediction. However, few methods incorporate both gene expression data and the biological network, which can harbor essential information about the underlying process of the drug response. We proposed an analysis framework called DrugGCN for prediction of Drug response using a Graph Convolutional Network (GCN). DrugGCN first generates a gene graph by combining a Protein-Protein Interaction (PPI) network and gene expression data with feature selection of drug-related genes, and the GCN model detects the local features such as subnetworks of genes that contribute to the drug response by localized filtering. We demonstrated the effectiveness of DrugGCN using biological data showing its high prediction accuracy among the competing methods.

scholarly journals Spatial variation and mechanisms of leaf water content in grassland plants at the biome scale: evidence from three comparative transects

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ruomeng Wang ◽  
Nianpeng He ◽  
Shenggong Li ◽  
Li Xu ◽  
Mingxu Li
Keyword(s):  
Spatial Variation ◽  
Water Content ◽  
Large Scale ◽  
Life Forms ◽  
Important Variable ◽  
Leaf Water ◽  
Leaf Water Content ◽  
Desert Grassland ◽  
Large Spatial Scale ◽  
Grassland Plants

AbstractLeaf water content (LWC) has important physiological and ecological significance for plant growth. However, it is still unclear how LWC varies over large spatial scale and with plant adaptation strategies. Here, we measured the LWC of 1365 grassland plants, along three comparative precipitation transects from meadow to desert on the Mongolia Plateau (MP), Loess Plateau, and Tibetan Plateau, respectively, to explore its spatial variation and the underlying mechanisms that determine this variation. The LWC data were normally distributed with an average value of 0.66 g g−1. LWC was not significantly different among the three plateaus, but it differed significantly among different plant life forms. Spatially, LWC in the three plateaus all decreased and then increased from meadow to desert grassland along a precipitation gradient. Unexpectedly, climate and genetic evolution only explained a small proportion of the spatial variation of LWC in all plateaus, and LWC was only weakly correlated with precipitation in the water-limited MP. Overall, the lasso variation in LWC with precipitation in all plateaus represented an underlying trade-off between structural investment and water income in plants, for better survival in various environments. In brief, plants should invest less to thrive in a humid environment (meadow), increase more investment to keep a relatively stable LWC in a drying environment, and have high investment to hold higher LWC in a dry environment (desert). Combined, these results indicate that LWC should be an important variable in future studies of large-scale trait variations.

scholarly journals Assessment of Leaf Litter Decomposition in a Pine and Beech Mixed Forest: Case Study in Northern Spain

2020 ◽  
Vol 3 (1) ◽  
pp. 25
Author(s):  
David Candel-Pérez ◽  
J. Bosco Imbert ◽  
Maitane Unzu ◽  
Juan A. Blanco
Keyword(s):  
Chemical Composition ◽  
Forest Management ◽  
Leaf Litter ◽  
Litter Decomposition ◽  
Mixed Forest ◽  
Decomposition Process ◽  
Tree Canopy ◽  
Natural State ◽  
Nutrient Cycles ◽  
Decomposition Rates

The promotion of mixed forests represents an adaptation strategy in forest management to cope with climate change. The mixing of tree species with complementary ecological traits may modify forest functioning regarding productivity, stability, or resilience against disturbances. Litter decomposition is an important process for global carbon and nutrient cycles in terrestrial ecosystems, also affecting the functionality and sustainability of forests. Decomposition of mixed-leaf litters has become an active research area because it mimics the natural state of leaf litters in most forests. Thus, it is important to understand the factors controlling decomposition rates and nutrient cycles in mixed stands. In this study, we conducted a litter decomposition experiment in a Scots pine and European beech mixed forest in the province of Navarre (north of Spain). The effects of forest management (i.e., different thinning intensities), leaf litter types, and tree canopy on mass loss and chemical composition in such decomposing litter were analysed over a period of three years. Higher decomposition rates were observed in leaf litter mixtures, suggesting the existence of positive synergies between both pine and beech litter types. Moreover, a decomposition process was favoured under mixed-tree canopy patches. Regarding thinning treatments significant differences on decomposition rates disappeared at the end of the study period. Time influenced the nutrient concentration after the leaf litter incubation, with significant differences in the chemical composition between the different types of leaf litter. Higher Ca and Mg concentrations were found in beech litter types than in pine ones. An increase in certain nutrients throughout the decomposition process was observed due to immobilization by microorganisms (e.g., Mg in all leaf litter types, K only in beech leaves, P in thinned plots and under mixed canopy). Evaluating the overall response in mixed-leaf litters and the contribution of single species is necessary for understanding the litter decomposition and nutrient processes in mixed-forest ecosystems.

MITIGATION YIELD SCALED METHANE EMISSION FROM RICE GROWN IN WATER STRESS CONDITIONS WITH BIOCHAR AND SILICATE AMENDMENTS

2021 ◽  
Author(s):  
MUHAMMAD ASLAM ALI ◽  
SANJIT CHANDRA BARMAN ◽  
MD. ASHRAFUL ISLAM KHAN ◽  
MD. BADIUZZAMAN KHAN ◽  
HAFSA JAHAN HIYA
Keyword(s):  
Water Stress ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Field Capacity ◽  
Saturated Soil ◽  
Rice Grain ◽  
Standing Water ◽  
Water Contents ◽  
Soil Water Contents

Climate change and water scarcity may badly affect existing rice production system in Bangladesh. With a view to sustain rice productivity and mitigate yield scaled CH4 emission in the changing climatic conditions, a pot experiment was conducted under different soil water contents, biochar and silicate amendments with inorganic fertilization (NPKS). In this regard, 12 treatments combinations of biochar, silicate and NPKS fertilizer along with continuous standing water (CSW), soil saturation water content and field capacity (100% and 50%) moisture levels were arranged into rice planted potted soils. Gas samples were collected from rice planted pots through Closed Chamber technique and analyzed by Gas Chromatograph. This study revealed that seasonal CH4 emissions were suppressed through integrated biochar and silicate amendments with NPKS fertilizer (50–75% of the recommended doze), while increased rice yield significantly at different soil water contents. Biochar and silicate amendments with NPKS fertilizer (50% of the recommended doze) increased rice grain yield by 10.9%, 18.1%, 13.0% and 14.2%, while decreased seasonal CH4 emissions by 22.8%, 20.9%, 23.3% and 24.3% at continuous standing water level (CSW) (T9), at saturated soil water content (T10), at 100% field capacity soil water content (T11) and at 50% field capacity soil water content (T12), respectively. Soil porosity, soil redox status, SOC and free iron oxide contents were improved with biochar and silicate amendments. Furthermore, rice root oxidation activity (ROA) was found more dominant in water stress condition compared to flooded and saturated soil water contents, which ultimately reduced seasonal CH4 emissions as well as yield scaled CH4 emission. Conclusively, soil amendments with biochar and silicate fertilizer may be a rational practice to reduce the demand for inorganic fertilization and mitigate CH4 emissions during rice cultivation under water stress drought conditions.

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