A study on bioluminescence and photoluminescence in the earthworm Eisenia lucens

2016 ◽  
Vol 15 (2) ◽  
pp. 175-180 ◽  
Author(s):  
O. Pes ◽  
A. Midlik ◽  
J. Schlaghamersky ◽  
M. Zitnan ◽  
P. Taborsky
Keyword(s):  
Soil Layer ◽  
Organic Soil ◽  
Lines Of Evidence

Eisenia lucens is a bioluminescent earthworm found in the organic soil layer of decomposing wood. Many lines of evidence indicate that riboflavin stored in coelomycetes plays an important role in this glowing reaction.

scholarly journals Heavy metals in the organic soil layer of beech forests in Serbia

2005 ◽  
pp. 55-67 ◽  
Author(s):  
Ratko Kadovic ◽  
Olivera Kosanin ◽  
Snezana Belanovic ◽  
Milan Knezevic
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Soil Layer ◽  
Forest Litter ◽  
Organic Soil ◽  
Organic Horizon ◽  
Beech Forests ◽  
Metal Contents ◽  
Level I ◽  
And Migration

During the last decades, forest ecosystems have been strongly exposed to the effect of different harmful pollutants, especially from the atmosphere. Harmful substances from the air, in addition to the direct effect on forest trees, also deposit in the soil, and have an adverse effect on soil chemistry and pedogenetic processes. The results of previous studies in Serbia (Kadovic, Knezevic, 2002, 2004) show some specificities regarding the accumulation and migration of heavy metals in the soil. The highest concentrations were found in the layers of forest litter and in the surface organo-mineral horizons. This paper presents the results of the study of heavy metal contents (Zn, Mn, Cu, Fe, Cd, Pb, Ni and Cr) in the organic horizon (forest litter) of beech forests in Serbia. The study of the heavy metal content in the organic horizon (forest litter) is very significant primarily in the aim of monitoring the trend of their migration through the soil profile and the effect on the soil properties and genesis. The soil quality in beech forests in Serbia was assessed within the Project ICP Forest, Level I, by the methodology UN/ECE-EC, 2000.

scholarly journals The net exchange of methane with high Arctic landscapes during the summer growing season

2014 ◽  
Vol 11 (1) ◽  
pp. 1673-1706 ◽  
Author(s):  
C. A. Emmerton ◽  
V. L. St. Louis ◽  
I. Lehnherr ◽  
E. R. Humphreys ◽  
E. Rydz ◽  
...  
Keyword(s):  
Soil Temperature ◽  
Stream Water ◽  
Soil Layer ◽  
Organic Soil ◽  
High Arctic ◽  
Carbon Dioxide Flux ◽  
Gas Diffusion ◽  
Growing Seasons ◽  
Consumption Rates ◽  
Chamber Measurements

Abstract. High Arctic landscapes are essentially vast cold deserts interspersed with streams, ponds and wetlands. These landscapes may be important consumers and sources of the greenhouse gas methane (CH4), though few measurements exist from this region. To quantify the flux of CH4 (FCH4) between the atmosphere and desert and wetland landscapes on northern Ellesmere Island, Canada, we made static chamber measurements at both locations over five growing seasons and eddy covariance (EC) measurements at the wetland in 2012. Chamber measurements revealed that desert soils consumed CH4 (−1.37 ± 0.10 mg-CH4 m−2 d−1) whereas the wetland emitted CH4 (+0.22 ± 0.19 mg-CH4 m−2 d−1). Desert CH4 consumption rates were positively correlated with soil temperature among years, and were similar to temperate locations, likely because of suitable landscape conditions for soil gas diffusion. Wetland FCH4 varied closely with stream discharge entering the wetland and hence extent of soil saturation. Landscape-scale FCH4 measured by EC was +1.27± 0.18 mg-CH4 m−2 d−1 and varied with soil temperature and carbon dioxide flux. FCH4 measured using EC was higher than using chambers because EC incorporated a arger, more saturated footprint of the wetland. Using EC FCH4 and quantifying the mass of CH4 entering and exiting the wetland in stream water, we determined that methanogenisis within wetland soils was the dominant source of FCH4. Low FCH4 at the wetland was likely due to a shallow organic soil layer, and thus limited carbon resources for methanogens. Considering the prevalence of dry soils in the high Arctic, our results suggest that these landscapes cannot be overlooked as important consumers of atmospheric CH4.

scholarly journals First Report of Cryptocline taxicola Infecting Pacific Yew (Taxus brevifolia) in Eastern North America

Plant Disease ◽  
2001 ◽  
Vol 85 (8) ◽  
pp. 922-922 ◽  
Author(s):  
Vladimir Vujanovic ◽  
Marc St-Arnaud
Keyword(s):  
North America ◽  
Soil Layer ◽  
Organic Soil ◽  
Botanical Garden ◽  
The United States ◽  
Taxus Baccata ◽  
Conidial Suspension ◽  
Taxus Brevifolia ◽  
Rock Outcrops ◽  
First Report

To our knowledge, this is the first report of Cryptocline taxicola (Allesch.) Petrak (Coelomycetes) on Pacific yew (Taxus brevifolia Nuttall) and the first observation of the fungus infecting living needles. C. taxicola is known to occur on needles of Taxus baccata in Europe (on T. baccata var. fastigiata) and North America (Vermont) (on T. baccata var. canadensis) (2). In August 1999 and 2000, chlorotic and necrotic current and second-year needles of Pacific yew were observed to have fruiting bodies, sometimes greater than 400 per needle, on the upper surface. Acervuli were circular to subcircular, yellowish, surrounded by brown circles, subcuticular to intraepidermal, at first covered, later exposed by the fissure of the cuticule, and 150 to 350 μm wide. Hyphae in host tissue were septate, brownish, and 3 to 4.5 μm in diameter. Conidiophores were phialidic, cylindrical, hyaline, 10 to 20 × 2.5 to 4.5 μm. Mature conidia were ellipsoidal to oval, truncate at the base, obtuse at the apex, hyaline to slightly pigmented, 8 to 17 × 4 to 5 μm. From these symptomatic needles, C. taxicola was often isolated (>85%) on potato dextrose agar. Koch's postulates were completed for C. taxicola by spraying current-year living needles, on one twig of each of separate plants (five) of T. brevifolia with a conidial suspension of 4 × 103 conidia per ml. Five control twigs were sprayed with sterile, distilled water. Twigs were covered with black sterile plastic bags and incubated outdoors for 24 h, when the bags were removed. Within 3 weeks, inoculated needles exhibited chlorotic and necrotic symptoms similar to those originally observed, but symptoms were never observed on control twigs. The fungus was reisolated (91%) only from the symptomatic needles. T. brevifolia trees growing in the Montreal Botanical Garden (Quebec, Canada) are clones originating from the Pacific Coast of the United States. We found that Pacific yew was colonized more frequently on the dry rock outcrops in the Alpine and Chinese Garden tree plantations. We believe that inappropriate stand selection, unfavorable humid conditions, and a thin organic soil layer may predispose Pacific yew to infection by this fungal species. A similar effect has been reported in Europe (1) for Cryptocline pseudotsugae causing serious levels of disease in a Pseudotsuga menziesii plantations. References: (1) T. L. Cech. Forstschutz Aktuell. 25:13, 2000. (2) G. Morgan-Jones. Can. J. Bot. 51:309, 1973.

Postfire root distribution of Scots pine in relation to fire behaviour

2008 ◽  
Vol 38 (2) ◽  
pp. 353-362 ◽  
Author(s):  
Evgeniya Smirnova ◽  
Yves Bergeron ◽  
Suzanne Brais ◽  
Anders Granström
Keyword(s):  
Fine Root ◽  
Root Function ◽  
Soil Layer ◽  
Organic Soil ◽  
Tree Canopy ◽  
Fire Intensity ◽  
Root Production ◽  
Fine Root Production ◽  
Root Dynamics ◽  
Coarse Roots

Fire can potentially have a large direct impact on tree roots and, thus, contribute to reduced vitality. Tree canopy status after fire should have an impact on the postfire production of fine roots, further affecting root function. We analyzed the standing crop of live and dead roots in Pinus sylvestris L. with varying degrees of crown scorch, 1 year after fire in northern Sweden. On the burned sites, total Pinus live fine-root biomass was 74% of that at the control sites, and it was only 19% of the control for roots <2 mm, indicating an 80% reduction due to fire. Root mortality was highest for high-scorch trees, but this was probably due to greater depth of burn in the organic soil for these trees and not to higher fire intensity per se. Fine-root production was also assessed by an ingrowth experiment. This showed relatively similar fine-root production in both control trees and fire-damaged trees, indicating a high allocation to root growth for the damaged trees, to make up for lost root function. Root dynamics after fire are related to a number of factors, and direct effects are determined by the depth of burn in the organic soil layer. Indirect, long-lasting effects could be due mainly to girdling of coarse roots close to tree stems and canopy loss.

scholarly journals Foxes fertilize the subarctic forest and modify vegetation through denning

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jessica A. Lang ◽  
James D. Roth ◽  
John H. Markham
Keyword(s):  
Plant Species ◽  
Plant Diversity ◽  
Inorganic Nitrogen ◽  
Soil Layer ◽  
Plant Species Richness ◽  
Organic Soil ◽  
The Arctic ◽  
Organic Layer ◽  
Red Foxes ◽  
Higher Plant

AbstractEcosystem engineers modify habitats through processes other than trophic interactions, such as by regulating soil nutrients, and can influence resource availability and quality for other organisms. Predator-mediated elemental cycling may be especially important in determining plant diversity and growth in ecosystems where soil fertility and primary productivity are low. Red foxes (Vulpes vulpes L.), top predators in the Subarctic, could engineer local ecosystems through denning, which could create biogeochemical hotspots of nutrients due to continual input of feces, urine and prey remains. We examined soil and vegetation characteristics on red fox dens and paired control sites in woodland habitats near the Arctic treeline in Manitoba, Canada. The organic soil layer on den sites had 81% more inorganic nitrogen and 250% more extractable phosphorus than in control areas. Denning also increased soil respiration and pH in the organic layer, suggesting improved soil quality and nutrient availability for plants. By enriching nutrients and disturbing soils through digging, den sites had a higher plant species ß-diversity and a greater cover of erect woody shrubs (Salix spp.), grasses (Leymus mollis (Trinius) Pilger) and weedy ephemerals compared to control sites, resulting in a regional increase in plant species richness. Our research highlights the importance of considering impacts of predators other than through their consumption of prey, and provides insight into the role of red foxes in modifying plant diversity and productivity in the Subarctic.

scholarly journals Surface-applied or incorporated biochar and compost combination improves soil fertility, Chinese cabbage and papaya biomass

Biochar ◽  
2021 ◽  
Author(s):  
Justine Cox ◽  
Nguyen V. Hue ◽  
Amjad Ahmad ◽  
Kent D. Kobayashi
Keyword(s):  
Soil Ph ◽  
Chinese Cabbage ◽  
Agricultural Soils ◽  
Soil Layer ◽  
Nutrient Retention ◽  
Tropical Soils ◽  
Organic Soil ◽  
Chicken Manure ◽  
Total N ◽  
Surface Application

AbstractMany Hawaiian agricultural soils are acidic with low-nutrient retention; therefore, organic soil amendments are often used to improve soil properties and increase yields. Amendments can be incorporated for annual crops, but perennial orchards need surface application to avoid damaging surface roots. Pot trials compared responses to incorporated (IBC) or surface-applied (SBC) combination of hardwood biochar and chicken manure compost (4% v/v of each amendment) added to an Andisol and Oxisol. Soil pH was increased by 0.4–1.1 units in IBC and by 0.2–0.5 for SBC in the 0–10 cm soil layer. Both SBC and IBC increased soil total N, extractable P, Ca and Mg in the 0–10 cm soil layer. Soil pH, total C and extractable Ca were also higher in the 10–20 cm soil layer for IBC soil, indicating movement and/or leaching of amendments. Chinese cabbage biomass was 18–70% higher in the IBC and 14–47% higher in the SBC than that in the unamended soil, while papaya biomass was 23% and 19% higher in SBC and IBC, respectively. There was a greater response in the more acidic Andisol soil, with larger improvements in soil pH, plant nutrient uptake and root biomass than the Oxisol. Surface application was as effective in increasing plant growth as the incorporated amendment, providing evidence for farm scale assessment. Biochar and compost are recommended for use in tropical soils, and surface application may be beneficial to annual and perennial crops.

scholarly journals High Rate of N2 Fixation by East Siberian Cryophilic Soil Bacteria as Determined by Measuring Acetylene Reduction in Nitrogen-Poor Medium Solidified with Gellan Gum

2009 ◽  
Vol 75 (9) ◽  
pp. 2811-2819 ◽  
Author(s):  
Shintaro Hara ◽  
Yasuyuki Hashidoko ◽  
Roman V. Desyatkin ◽  
Ryusuke Hatano ◽  
Satoshi Tahara
Keyword(s):  
Acetylene Reduction ◽  
Soil Bacteria ◽  
Soil Layer ◽  
Organic Soil ◽  
Gellan Gum ◽  
Growth Potential ◽  
High Rate ◽  
Acetylene Reduction Activity ◽  
Bacterial Microbiota ◽  
Taiga Forest

ABSTRACT For evaluating N2 fixation of diazotrophic bacteria, nitrogen-poor liquid media supplemented with at least 0.5% sugar and 0.2% agar are widely used for acetylene reduction assays. In such a soft gel medium, however, many N2-fixing soil bacteria generally show only trace acetylene reduction activity. Here, we report that use of a N2 fixation medium solidified with gellan gum instead of agar promoted growth of some gellan-preferring soil bacteria. In a soft gel medium solidified with 0.3% gellan gum under appropriate culture conditions, bacterial microbiota from boreal forest bed soils and some free-living N2-fixing soil bacteria isolated from the microbiota exhibited 10- to 200-fold-higher acetylene reduction than those cultured in 0.2% agar medium. To determine the N2 fixation-activating mechanism of gellan gum medium, qualitative differences in the colony-forming bacterial components from tested soil microbiota were investigated in plate cultures solidified with either agar or gellan gum for use with modified Winogradsky's medium. On 1.5% agar plates, apparently cryophilic bacterial microbiota showed strictly distinguishable microbiota according to the depth of soil in samples from an eastern Siberian Taiga forest bed. Some pure cultures of proteobacteria, such as Pseudomonas fluorescens and Burkholderia xenovorans, showed remarkable acetylene reduction. On plates solidified with 1.0% gellan gum, some soil bacteria, including Luteibacter sp., Janthinobacterium sp., Paenibacillus sp., and Arthrobacter sp., uniquely grew that had not grown in the presence of the same inoculants on agar plates. In contrast, Pseudomonas spp. and Burkholderia spp. were apparent only as minor colonies on the gellan gum plates. Moreover, only gellan gum plates allowed some bacteria, particularly those isolated from the shallow organic soil layer, to actively swarm. In consequence, gellan gum is a useful gel matrix to bring out growth potential capabilities of many soil diazotrophs and their consortia in communities of soil bacteria.

scholarly journals Natural 15N abundance in two nitrogen saturated forest ecosystems at Solling, Germany

2012 ◽  
Vol 49 (No. 11) ◽  
pp. 515-522 ◽  
Author(s):  
S. P Sah ◽  
R. Brumme
Keyword(s):  
Soil Water ◽  
Soil Depth ◽  
Mineral Soil ◽  
Soil Layer ◽  
Organic Soil ◽  
Soil Horizon ◽  
Nitrification Rate ◽  
Seepage Water ◽  
Natural Occurrence ◽  
N Enrichment

This research deals with a comparative study of two different N-saturated forests: 1. beech forest and 2. spruce forest at the same locality of \solling, Central Germany. The present results show that <sup>15</sup>N natural occurrence in the rainfall (both above and below canopy) at Solling site is similar (&delta;<sup>15</sup>N = &ndash;15&permil; to +19&permil;) to other sites of the world (such as NITREX sites, USA etc.). Furthermore, <sup>15</sup>N values in the soil water ranged from &ndash;4.32 (&plusmn; 2.09) to +5&permil; (&plusmn; 1.47), which also corresponds to NITREX sites and other sites of Europe and USA. In both forests, &delta;<sup>15</sup>N enrichment of both NH<sub>4</sub>-N and NO<sub>3</sub>-N showed a decreasing trend of their values from bulk precipitation to the upper soil layer, but increasing in the deeper soil layer again. An increase in the <sup>15</sup>N enrichment of soil water from upper soil depth to lower soil depth was observed in our study and it is assumed to be due to the strong net nitrification taking place in the upper layer (organic surface layer) of soil. The soils at both sites showed characteristic low (negative) &delta;<sup>15</sup>N values in the upper organic layers, strongly increasing to positive &delta;<sup>15</sup>N values in the mineral soil. In the lower depths of mineral soil horizons of both stands, an increase in &delta;<sup>15</sup>N values was found to culminate at +3 to +5&permil;. In contrast to the mineral soil horizon, in the organic soil horizon (0 to 6 cm depth) of both sites there was almost a similar or slight decrease in &delta;<sup>15</sup>N values with depth. This is attributed to the high nitrification rate in the organic soil horizon, resulting in excessive seepage water NO<sub>3</sub>-output at both sites (especially at the spruce site).

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