Total fluoride in Guangdong soil profiles, China: Spatial distribution and vertical variation

2007 ◽  
Vol 33 (3) ◽  
pp. 302-308 ◽  
Author(s):  
L. Zhu ◽  
H.H. Zhang ◽  
B. Xia ◽  
D.R. Xu
Keyword(s):  
Spatial Distribution ◽  
Soil Profiles ◽  
Vertical Variation

Spatial distribution and vertical variation of arsenic in Guangdong soil profiles, China

2006 ◽  
Vol 144 (2) ◽  
pp. 492-499 ◽  
Author(s):  
H.H. Zhang ◽  
H.X. Yuan ◽  
Y.G. Hu ◽  
Z.F. Wu ◽  
L.A. Zhu ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Soil Profiles ◽  
Vertical Variation

Effect of drought on ericoid mycorrhizae in wild blueberry (Vaccinium angustifolium Ait.)

2003 ◽  
Vol 83 (3) ◽  
pp. 583-586 ◽  
Author(s):  
E. Jeliazkova and D. Percival
Keyword(s):  
Spatial Distribution ◽  
Soil Depth ◽  
Block Design ◽  
Soil Profiles ◽  
Root Weight ◽  
Vaccinium Angustifolium ◽  
Ericoid Mycorrhizae ◽  
Randomized Complete Block Design ◽  
Influence Of Water ◽  
Wild Blueberry

To evaluate the influence of water exclusion on the mycorrhizal coloni zations in wild blueberry, and to examine the spatial distribution of mycorrhizae among roots of wild blueberry plants that were in both the vegetative and cropping stages of production, a randomized complete block design was used. The mycorrhizal coloniz a tions were equally distributed throughout upper and lower soil profiles in both stages of production. Nevertheless, soil moisture levels in water exclusion treatments were as much as 50% lower than the control, drought stress had no effect on mycorrhizal colonization levels or on any other of the measured responses. Root weight and volume decreased as soil depth increased from 0-7.5 to 7.5-15 cm. Key words:

Spatial Distribution of Nearshore Fish in the Vicinity of Two Thermal Generating Stations, Nanticoke and Douglas Point, on the Great Lakes

1978 ◽  
Vol 35 (6) ◽  
pp. 885-892 ◽  
Author(s):  
C. K. Minns ◽  
J. R. M. Kelso ◽  
W. Hyatt
Keyword(s):  
Spatial Distribution ◽  
Thermal Stratification ◽  
Lake Erie ◽  
Temperature Response ◽  
Incident Radiation ◽  
Fish Distribution ◽  
Lake Huron ◽  
Vertical Variation ◽  
Pelagic Communities ◽  
Key Words Temperature

At Nanticoke, Lake Erie, 1974, mean fish density varied considerably, range 162–14 204/10 000 m3, as estimated by digital acoustic fish enumeration. At Douglas Point, Lake Huron, 1975, mean density varied less, range 108–671/10 000 m3. At both sites fish densities were generally greatest in the shallowest, 3–5 m, depths. At Nanticoke, where the nearshore has low relief, there were no distinguishable communities. At Douglas Point, where depth increases rapidly offshore, there was evidence of benthic and pelagic communities. There was no evidence of altered fish distribution in relation to temperature. At Nanticoke there was no vertical variation in temperature and no vertical response was to be expected. At Douglas Point there was thermal stratification present in the summer and there was no apparent response. The influence of incident radiation was uncertain because of the effects of diurnal migrations. At both locations fish were clustered horizontally to varying degrees in the spring and fall, while in the summer fish were distributed more evenly. Densest clusters were usually in the vicinity of the turbulent discharge at both locations. The lack of temperature response and the similarity of Nanticoke with situations at nearby streams on Lake Erie suggest that the fish are responding to currents and perhaps topography. Key words: temperature, acoustic enumeration, topography, light

scholarly journals Vertical and horizontal distribution of pollination systems in cerrado fragments of central Brazil

2007 ◽  
Vol 50 (3) ◽  
pp. 503-514 ◽  
Author(s):  
Fernanda Quintas Martins ◽  
Marco Antônio Batalha
Keyword(s):  
Spatial Distribution ◽  
Significant Variation ◽  
Horizontal Distribution ◽  
Bee Pollination ◽  
Vertical Variation ◽  
Pollination System ◽  
Cerrado Vegetation ◽  
Central Brazil ◽  
Vertical And Horizontal Distribution ◽  
Pollination Systems

In fragments of the cerrado, we determined the frequency of pollination systems and analyzed their spatial distribution. We placed 38 transects, sampling 2,280 individuals and 121 species. As expected in Neotropical regions, bee-pollination was the most frequent pollination system. We found a decrease in the frequency of plants pollinated by beetles towards the fragment interior. Similarly, we found significant variation in relation to height just for the bats; there was an increase in the frequency of plants pollinated by bats towards the higher heights. In general, we found no horizontal and vertical variation in the pollination systems, probably as consequence of the more open physiognomy of the cerrado vegetation.

scholarly journals Spatial distribution of pH in the soil profiles of representative soil series from rice producing area, district Sheikhupura

2018 ◽  
Vol 37 (1) ◽  
pp. 28-34
Author(s):  
Ghulam Nabi ◽  
◽  
Humair Ahmed ◽  
Ijaz Ali ◽  
◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Soil Profiles ◽  
Soil Series

scholarly journals Trickle irrigation systems affect spatial distribution of roots of banana crop

2020 ◽  
Vol 24 (5) ◽  
pp. 325-331
Author(s):  
Edvaldo B. Santana Junior ◽  
Eugênio F. Coelho ◽  
Jailson L. Cruz ◽  
João B. R. da S. Reis ◽  
Diego M. de Mello ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Flow Rate ◽  
Root Length ◽  
Root Length Density ◽  
Soil Profiles ◽  
Trickle Irrigation ◽  
Irrigation Systems ◽  
Sprinkler Systems ◽  
Lateral Lines ◽  
Distribution Of Roots

ABSTRACT Trickle irrigation has been largely used for banana in Brazil, mainly due to the increase in water and fertilizer use efficiency. These irrigation systems have different options concerning number, type and flow rate of emitters as well as for hydraulics, number and location of lateral lines. The small area of soil wetted by these systems limits root spatial distribution of crops. This study aimed to evaluate the effect of different trickle irrigation systems on the root spatial growth and root spatial distribution of banana cv. Prata Gorutuba. Root length density and root length were evaluated in soil profiles of three micro-sprinkler systems, with emitter flow rates of 35, 53 and 70 L h-1 and of two drip irrigation systems, with one and two lateral lines per crop row. Trickle irrigation systems influence root spatial distribution, favoring a greater or smaller distribution of roots at different depth and distance from the plant according to micro-sprinkler flow rate and to the number of lateral lines per crop row. The effect on root spatial distribution is more accentuated for micro-sprinkler systems than for drip systems. The majority of the total root length (80%) was observed in the soil profiles from 0.33 to 0.57 m depth and at distances from the plants of 0.75 to 0.83 m.

scholarly journals Which are important soil parameters influencing the spatial heterogeneity of <sup>14</sup>C in soil organic matter?

2016 ◽  
Author(s):  
Stephan John ◽  
Gerrit Angst ◽  
Kristina Kirfel ◽  
Sebastian Preusser ◽  
Carsten W. Mueller ◽  
...  
Keyword(s):  
Organic Matter ◽  
Spatial Distribution ◽  
Soil Organic Matter ◽  
Microbial Biomass ◽  
Organic Carbon ◽  
Soil Texture ◽  
Soil Parameters ◽  
Soil Profiles ◽  
Fine Silt ◽  
Distribution Of Roots

Abstract. Radiocarbon (14C) analysis is an important tool that can provide information on the dynamics of organic matter in soils. Radiocarbon concentrations of soil organic matter (SOM) however, reflect the heterogeneous mixture of various organic compounds and are affected by different chemical, biological, and physical soil parameters. These parameters can vary strongly in soil profiles and thus affect the spatial distribution of the apparent 14C age of SOM considerably. The heterogeneity of SOM and its 14C signature may be even larger in subsoil horizons, which are thought to receive organic carbon inputs following preferential pathways. This will bias conclusions drawn from 14C analyses of individual soil profiles considerably. We thus investigated important soil parameters, which may influence the 14C distribution of SOM as well as the spatial heterogeneity of 14C distributions in soil profiles. The suspected strong heterogeneity and spatial variability, respectively of bulk SOM is confirmed by the variable 14C distribution in three 185 cm deep profiles in a Dystric Cambisol. The 14C contents are most variable in the C horizons because of large differences in the abundance of roots there. The distribution of root biomass and necromass and its organic carbon input is the most important factor affecting the 14C distribution of bulk SOM. The distance of the soil profiles to a beech did not influence the horizontal and vertical distribution of roots and 14C concentrations. Other parameters were found to be of minor importance including microbial biomass-derived carbon and soil texture. The microbial biomass however, may promote a faster turnover of SOM at hot spots resulting in lower 14C concentration there. Soil texture had no statistically significant influence on the spatial 14C distribution of bulk SOM. However, SOM in fine silt and clay sized particles (< 6.3 µm) yields slightly higher 14C concentrations than bulk SOM particularly at greater soil depth, which is in contrast to previous studies where silt and clay fractions contained older SOM stabilized by organo-mineral interaction. 14C contents of fine silt and clay correlate with the microbial biomass-derived carbon suggesting a considerable contribution of microbial-derived organic carbon. In conclusion, 14C analyses of bulk SOM mainly reflect the spatial distribution of roots, which is strongly variable even on a small spatial scale of few meters. This finding should be considered when using 14C analysis to determine SOM.

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