INFLUENCES OF SEASONAL TEMPERATURE ON NITROGEN AND SULFUR MINERALIZATION/IMMOBILIZATION IN A MAPLE-BIRCH FOREST FLOOR IN CENTRAL ONTARIO

1989 ◽  
Vol 69 (3) ◽  
pp. 501-514 ◽  
Author(s):  
N. W. FOSTER
Keyword(s):  
Soil Temperature ◽  
Ammonium Nitrate ◽  
Key Words ◽  
Forest Floor ◽  
Late Summer ◽  
Seasonal Temperature ◽  
Net Mineralization ◽  
Net Release ◽  
Sulfur Mineralization ◽  
Absorbing Roots

Net mineralization of sulfur (S) and nitrogen (N) and nitrification in an F(Oe) horizon were examined over a 16-wk period (May to September) with (a) buried bags, (b) lysimeters and (c) closed flasks at 10, 20 or 30 °C. The amount of [Formula: see text] plus [Formula: see text] extracted from soil held at 33 kPa tension over 16 wk, when extrapolated to the mass of soil in the field, was 30 kg ha−1 N and 9 kg ha−1[Formula: see text] at constant 20 °C in the flasks, and 33 kg ha−1 N and 4 kg ha−1[Formula: see text] in buried bags (mean daily temperature 15.2 °C). On the basis of lysimeter data there was a net release of only 8 kg ha−1 N and a net retention of 3 kg ha−1[Formula: see text] under field conditions, with fluctuating temperature and moisture and actively absorbing roots. Nitrate recovered from the three types of experiment was equivalent to 18, 36, and 4 kg ha−1 N, respectively. Mineralization appeared to be particularly sensitive to temporal changes in average daily temperatures in the field. The late-summer peak in mean daily forest-floor temperature triggered a shift from net mineralization to net immobilization of N. Key words: Soil temperature, forest floor, sulfate, ammonium, nitrate

scholarly journals FEEDING AND REPRODUCTIVE ACTIVITY OF THE COPEPODS Drepanopus forcipatus AND Calanus australis DURING LATE SUMMER ON THE SOUTHERN PATAGONIAN SHELF (ARGENTINA, 47°-55°S)

2014 ◽  
Vol 62 (4) ◽  
pp. 295-314 ◽  
Author(s):  
Julieta Carolina Antacli ◽  
Marina E. Sabatini ◽  
Ricardo I. Silva ◽  
Daniel R. Hernández ◽  
Andrés J. Jaureguizar ◽  
...  
Keyword(s):  
Diet Composition ◽  
Feeding Activity ◽  
Food Pellet ◽  
Late Summer ◽  
Reproductive Activity ◽  
Seasonal Temperature ◽  
Patagonian Shelf ◽  
Adult Females ◽  
Female Reproductive Status ◽  
Potential Food

Drepanopus forcipatus and Calanus australis are key planktonic copepods on the southern Patagonian shelf. Their feeding and reproductive patterns and population status were investigated during late summer, when environmental conditions may be critical. The presence of food in the gut and food-pellet length were recorded in adult females and the most abundant copepodite stages. Diet composition was also studied in adult females. Female reproductive status was evaluated by gonad staging. Despite generally low feeding conditions and decreasing seasonal temperature, both copepods fed to some degree. The most numerous copepodites and adult females of both species showed similarly low feeding activity. About half of the adult females of the two species and C5s of C. australis contained food in their guts, but the proportion of fed C4-females of D. forcipatus was much lower. All copepods were generally feeding at low or intermediate levels. Gonad stage distribution and population structure showed low but still ongoing reproduction in both species. Gut content findings suggest a preference for smaller nanoplanktonic particles, especially dinoflagellates by D. forcipatus, and for autotrophic prey, particularly large diatoms by C. australis. The feeding and reproduction patterns of the two copepods were likely influenced by the distributions of potential food resources and temperature.

scholarly journals Dynamic of nitrogen and dissolved organic carbon in an alpine forested catchment: atmospheric deposition and soil solution trends

2019 ◽  
Vol 34 ◽  
pp. 41-66 ◽  
Author(s):  
Raffaella Balestrini ◽  
Carlo Andrea Delconte ◽  
Andrea Buffagni ◽  
Alessio Fumagalli ◽  
Michele Freppaz ◽  
...  
Keyword(s):  
Soil Solution ◽  
Forest Ecosystem ◽  
Forest Floor ◽  
Mineral Soil ◽  
Chemical Species ◽  
Organic N ◽  
Seasonal Temperature ◽  
Inorganic N ◽  
Forest Floor Leachates ◽  
Throughfall Deposition

A number of studies have reported decreasing trends of acidifying and N deposition inputs to forest areas throughout Europe and the USA in recent decades. There is a need to assess the responses of the ecosystem to declining atmospheric pollution by monitoring the variations of chemical species in the various compartments of the forest ecosystem on a long temporal scale. In this study, we report on patterns and trends in throughfall deposition concentrations of inorganic N, dissolved organic N (DON) and C (DOC) over a 20-year (1995–2015) period in the LTER site -Val Masino (1190 m a.s.l.), a spruce forest, in the Central Italian Alps. The same chemical species were studied in the litter floor leachates and mineral soil solution, at three different depths (15, 40 and 70 cm), over a 10-year period (2005–2015). Inorganic N concentration was drastically reduced as throughfall and litter floor leachates percolated through the topsoil, where the measured mean values (2 µeq L-1) were much lower than the critical limits established for coniferous stands (14 µeq L-1). The seasonal temperature dependence of throughfall DOC and DON concentration suggests that the microbial community living on the needles was the main source of dissolved organic matter. Most of DOC and DON infiltrating from the litter floor were retained in the mineral soil. The rainfall amount was the only climatic factor exerting a control on DOC and N compounds in throughfall and forest floor leachates over a decadal period. Concentration of SO4 and NO3 declined by 50% and 26% respectively in throughfall deposition. Trends of NO3 and SO4 in forest floor leachates and mineral soil solution mirrored declining depositions. No trends in both DON and DOC concentration and in DOC/DON ratio in soil solutions were observed. These outcomes suggest that the declining NO3 and SO4 atmospheric inputs did not influence the dynamic of DON and DOC in the Val Masino forest. The results of this study are particularly relevant, as they are based on a comprehensive survey of all the main compartments of the forest ecosystem. Moreover, this kind of long-term research has rarely been carried out in the Alpine region.

Seasonal Changes in the Germination Responses of Buried Witchgrass (Panicum capillare) Seeds

Weed Science ◽  
1986 ◽  
Vol 34 (1) ◽  
pp. 22-24 ◽  
Author(s):  
Jerry M. Baskin ◽  
Carol C. Baskin
Keyword(s):  
Seasonal Changes ◽  
Late Summer ◽  
Late Spring ◽  
Seasonal Temperature ◽  
Temperature Changes ◽  
Late Autumn ◽  
Buried Seeds ◽  
Autumn And Winter

Buried seeds of witchgrass (Panicum capillare L., # PANCA) exposed to natural seasonal temperature changes in Lexington, KY, for 0 to 35 months exhibited annual dormancy/nondormancy cycles. Seeds were dormant at maturity in early October. During burial in late autumn and winter, fresh seeds and those that had been buried for 1 and 2 years became nondormant. Nondormant seeds germinated from 76 to 100% in light at daily thermoperiods of 15/6, 20/10, 25/15, 30/15, and 35/20 C, while in darkness they germinated from 1 to 24%. In late spring, seeds lost the ability to germinate in darkness, and by late summer 63 to 100% of them had lost the ability to germinate in light. As seeds became nondormant, they germinated (in light) at high (35/20, 30/15 C) and then at lower (25/15, 20/10, and 15/6 C) temperatures. As seeds reentered dormancy, they lost the ability to germinate (in light) at 15/6 C and at higher thermoperiods 2 to 3 months later.

Soil sulphate changes in the presence and absence of growing plants

1960 ◽  
Vol 11 (3) ◽  
pp. 339 ◽  
Author(s):  
JR Freney ◽  
K Spencer
Keyword(s):  
Relative Intensity ◽  
Water Soluble ◽  
Rhizosphere Microorganisms ◽  
Organic Sulphur ◽  
Sulphate Sulphur ◽  
Net Mineralization ◽  
Modifying Effect ◽  
Sulphate Water ◽  
Net Release ◽  
Extractable Soil

To determine whether sulphate addition to sulphur-deficient soils affects mineralization of organic sulphur, an experiment was conducted in undrained pots with five soils of differing properties. Initial and final extractable soil sulphate (water-soluble and adsorbed), and sulphur taken up by Phalaris tuberosa L., were measured. Where plants were grown, mobilization of the organic sulphur occurred at the nil, 4 p.p.m., 12 p.p.m., and 36 p.p.m. levels of sulphate sulphur addition in four out of the five soils. In the fifth soil, a lateritic krasnozem, only at the nil and 4 p.p.m. levels was there any net release of sulphate. All five soils immobilized added sulphate at the 108 p.p.m. level. In the absence of plants, with one exception, no net mineralization of organic sulphur occurred following additions of sulphate. In the pots without added sulphate there was slight mineralization (less than under plants) in all soils but the lateritic krasnozem. The modifying effect of growing plants is obviously of great significance in the cycling of sulphur in soil. The relative intensity of immobilization and mineralization was affected by the presence of growing plants. This effect was probably due to the activities of rhizosphere microorganisms.

scholarly journals Soil organic carbon dynamics along a climatic gradient in a southern Appalachian spruce–fir forest

2007 ◽  
Vol 37 (7) ◽  
pp. 1161-1172 ◽  
Author(s):  
C.E. Tewksbury ◽  
H. Van Miegroet
Keyword(s):  
Soil Temperature ◽  
Residence Time ◽  
Mean Residence Time ◽  
Forest Floor ◽  
Elevation Gradient ◽  
Mineral Soil ◽  
Carbon Dynamics ◽  
Effect Of Temperature ◽  
Degree Days ◽  
Soil C

A field study was conducted in a high-elevation spruce–fir ( Picea rubens Sarg. – Abies fraseri (Pursh.) Poir) forest in the Great Smoky Mountains National Park to assess the effect of temperature on soil C storage and dynamics. In eight plots along an elevation gradient (1500–1900 m), we measured soil temperature, forest floor and mineral soil C, litter decomposition, soil respiration, and forest floor mean residence time. Mean annual soil temperature and annual degree-days above 5 °C were inversely correlated with elevation. Total soil C (166–241 Mg·ha–1) showed no trend with elevation, while forest floor C accumulation (16.3–35.9 Mg·ha–1) decreased significantly with elevation. Carbon dynamics did not follow a consistent elevation pattern; however, the cooler upper elevations showed the lowest C turnover as indicated by the lowest needle decomposition rate (k = 0.0231·year–1) and the longest mean residence time of forest floor C (22 years). Mean annual CO2efflux from the soil (1020–1830 kg C·ha–1·year–1) was negatively correlated with mean annual soil temperatures and annual degree-days above 5 °C. This gradient study offers useful insights into C release patterns under future warming scenarios, and suggests that the highest elevation may be most susceptible to global warming.

Productivity and nutrient cycling in taiga forest ecosystems

1983 ◽  
Vol 13 (5) ◽  
pp. 747-766 ◽  
Author(s):  
Keith Van Cleve ◽  
Lola Oliver ◽  
Robert Schlentner ◽  
Leslie A. Viereck ◽  
C. T. Dyrness
Keyword(s):  
Nutrient Cycling ◽  
Soil Temperature ◽  
Forest Floor ◽  
Black Spruce ◽  
Lignin Content ◽  
Mineral Soil ◽  
Forest Types ◽  
Interior Alaska ◽  
Taiga Forest ◽  
Tree Production

This paper considers the productivity and nutrient cycling in examples of the major forest types in interior Alaska. These ecosystem properties are examined from the standpoint of the control exerted over them by soil temperature and forest-floor chemistry. We conclude that black spruce Piceamariana (Mill.) B.S.P. occupies the coldest, wettest sites which support tree growth in interior Alaska. Average seasonal heat sums (1132 ± 32 degree days (DD)) for all other forest types were significantly higher than those encountered for black spruce (640 ± 40 DD). In addition, black spruce ecosystems display the highest average seasonal forest-floor and mineral-soil moisture contents. Forest-floor chemistry interacts with soil temperature in black spruce to produce the most decay-resistant organic matter. In black spruce the material is characterized by the highest lignin content and widest C/N (44) and C/P (404) ratios. Across the range of forest types examined in this study, soil temperature is strongly related to net annual aboveground tree production and the annual tree requirement for N, P, K, Ca, and Mg. Forest floor C/N and C/P ratios are strongly related to annual tree N and P requirement and the C/N ratio to annual tree production. In all cases these controls act to produce, in black spruce, the smallest accumulation of tree biomass, standing crop of elements, annual production, and element requirement in aboveground tree components.

Effect of zinc on cadmium concentration in the tissue of durum wheat

1994 ◽  
Vol 74 (3) ◽  
pp. 549-552 ◽  
Author(s):  
M. Choudhary ◽  
L D. Bailey ◽  
C. A. Grant
Keyword(s):  
Ammonium Nitrate ◽  
Durum Wheat ◽  
Key Words ◽  
Triticum Turgidum ◽  
Cadmium Concentration ◽  
Growth Chamber ◽  
Monoammonium Phosphate ◽  
Chamber Study ◽  
Soil Temperatures

The addition of zinc at 20 mg kg−1 to soils in a growth chamber study reduced the shoot Cd concentration of two durum wheat (Triticum turgidum L. var durum) lines at 10 °C, 16 °C, and 22 °C soil temperatures while additions of ammonium nitrate (NH4NO3) and monoammonium phosphate (NH4H2PO4) increased shoot Cd concentrations. Applying Zn with NH4NO3 or NH4H2PO4 reduced shoot Cd concentrations of the plants to levels comparable to the control. Key words: Cd, durum wheat, ammonium nitrate, monoammonium phosphate, Zn

scholarly journals Seasonal temperature waves in the ground, nonperiodic case

2021 ◽  
Vol 274 ◽  
pp. 04010
Author(s):  
Vsevolod Krepkogorskij
Keyword(s):  
Soil Temperature ◽  
Time Lag ◽  
Seasonal Temperature ◽  
Earth Surface ◽  
Temperature Deviation ◽  
Temperature Changes ◽  
The Earth ◽  
Periodic Law ◽  
Temperature Waves ◽  
Different Depths

Seasonal fluctuations in soil temperature at a depth of several meters are considered. It is assumed that the temperature of the earth surface changes strictly periodically. Then, according to the Fourier law, the soil temperature at depth will also change periodically with a smaller amplitude and time lag. What happens if we let the temperature on the surface deviate from the strict periodicity at some point in time? How will the nature of soil temperature fluctuations change at depth? Two types of deviations of the surface temperature from the periodic law are considered: 1) A sharp cold snap. For 30 days, the temperature of the earth surface is -30оC and 2) Warm winter. It is assumed that the temperature of the earth surface is zero during the winter months. Graphs of temperature changes at different depths in both cases are plotted. Conclusions are drawn about the duration of the period of noticeable deviations and the magnitude of the temperature deviation from the normal value.

Soil temperatures and suckering response of trembling aspen (Populus tremuloides Michx.) following disposal of hog on winter-logged cutblocks

2004 ◽  
Vol 80 (6) ◽  
pp. 687-693 ◽  
Author(s):  
Timothy Conlin ◽  
Dave Cheyne ◽  
John Dymond
Keyword(s):  
British Columbia ◽  
Soil Temperature ◽  
Key Words ◽  
Populus Tremuloides ◽  
Growing Season ◽  
Soil Warming ◽  
Wood Residue ◽  
Application Rates ◽  
Soil Temperatures ◽  
Temperature Levels

Bark and wood residue, commonly referred to as "hog fuel" or "hog," from a portable pulp chipper was deposited on aspen cutblocks in replicated 10 x 10 m treatment plots during winter logging operations in northeastern British Columbia. The treatments emulated disposal of hog under conditions that simulated on-site chipping operations. Three different rates of hog disposal were applied; 34, 68 and 102 kg m-2, and three cutblocks were treated, one each during February of 1997, and March of 1998 and 1999. We originally hypothesized that the deposition of hog would lower soil temperatures in the treated plots and reduce aspen sucker density during the following growing season. However, our observations showed an initial lag in soil warming in the treatments followed by temperature levels that rose above that exhibited in the control plots. Higher soil temperatures were correlated with greater rates of hog disposal. Increased suckering was not observed in response to higher soil temperatures and stem densities decreased as hog application rates increased. Key words: in-woods, on-site, chipping, Populus tremuloides, hog fuel, soil temperature

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