Growth of a sitka spruce plantation: Spatial distribution and seasonal fluctuations of lengths, weights and carbohydrate concentrations of fine roots

1977 ◽  
Vol 47 (2) ◽  
pp. 463-485 ◽  
Author(s):  
E. D. Ford ◽  
J. D. Deans
Keyword(s):  
Spatial Distribution ◽  
Fine Roots ◽  
Sitka Spruce ◽  
Seasonal Fluctuations

An In-Situ Rainwater Collection and Infiltration System to Improve Plant-Available Water and Fine Root Growth for Drought Resistance

2020 ◽  
Vol 36 (5) ◽  
pp. 807-814
Author(s):  
Xiaolin Song ◽  
Xiaodong Gao ◽  
Paul Reese Weckler ◽  
Wei Zhang ◽  
Jie Yao ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Root Growth ◽  
Root System ◽  
Drought Resistance ◽  
Fine Roots ◽  
Soil Depth ◽  
List Type ◽  
Available Water ◽  
Plant Available Water

HighlightsAn in-situ rainwater collection and infiltration (RWCI) method is a rainwater catchment utilization techniqueRWCI is advantageous for increasing sustainable plant-avaibale water to increase drought resistanceRWCI significantly increased the amount of water and nutrients in the rhizosphere for uptake by apple tree rootsABSTRACT. A two-year field experiment was undertaken to determine the spatial distribution of plant-available water and roots in soil profiles under two rainfall control systems—an in-situ rainwater collection and infiltration (RWCI) method and a semi-circular basin (SCB)—in apple orchards in the Loess Plateau of China. The results showed that the RWCI treatments with a soil depth of 40 cm (RWCI40), 60 cm (RWCI60), and 80 cm (RWCI80) significantly increased plant-available water in different seasons and depths and increased root growth of apple trees in the experimental soil profile (0–200 cm). At 0–200 cm soil depth, then RWCI treatments had significantly higher (91.86%-110.01%) mean plant-available water storage (PAWS) than the SCB treatment in both study years (2015 and 2016). From 0–120 cm soil depth, the RWCI60 treatment had significantly higher growing season mean PAWS than RWCI40 and RWCI80; however, RWCI80 had the highest from 120–200 cm. From 0–60 cm, the RWCI treatments had 25.84%-36.86% a smaller proportion of root system than the SCB treatment. However, from 60–120 cm, the proportion of root system increased by 131.53% (RWCI40), 157.95% (RWCI60) and 129.98% (RWCI80), relative to SCB. From 0–200 cm, the RWCI treatments had 1.49–1.94 times more root dry weight density than the SCB treatment. The highest concentration of fine roots occurred in the RWCI treatments. Thus, RWCI enabled roots to absorb more water and nutrients from a wider wetted area and improved drought resistance. Keywords: Drought resistance, Fine roots, Loess Plateau, Plant-available water, Spatial distribution.

Growth analysis of four nursery-grown conifer species

1968 ◽  
Vol 46 (11) ◽  
pp. 1389-1395 ◽  
Author(s):  
R van den. Driessche
Keyword(s):  
White Spruce ◽  
Sitka Spruce ◽  
Douglas Fir ◽  
Extension Growth ◽  
Seasonal Patterns ◽  
Seasonal Fluctuations ◽  
Conifer Species ◽  
Relative Growth ◽  
Stem Extension ◽  
Net Assimilation

Annual pattern of relative growth rate (RGR) and stem extension growth were examined in four 1-year-old conifer species grown at two nurseries. Net assimilation rate (NAR) and needle area ratio (F) were calculated for a 14-day period in June. Seasonal patterns of RGR in Douglas fir and Sitka spruce were similar, but RGR of white spruce was lower and showed a different pattern. Seasonal fluctuations in RGR may have been associated with changes in rate of stem extension growth in Douglas fir and Sitka spruce, but not in white spruce or hemlock. Differences in NAR had a greater effect on RGR than differences in F during June. In particular, low RGR was mainly due to low NAR in white spruce.

Population dynamics and spatial distribution of monogeneans on the gills of Oreochromis mossambicus (Peters, 1852) from two lakes of the Limpopo River System, South Africa

2010 ◽  
Vol 85 (2) ◽  
pp. 146-152 ◽  
Author(s):  
G.N. Madanire-Moyo ◽  
M.M. Matla ◽  
P.A.S. Olivier ◽  
W.J. Luus-Powell
Keyword(s):  
Spatial Distribution ◽  
Dominant Species ◽  
Parasite Species ◽  
Parasitic Infection ◽  
River System ◽  
Oreochromis Mossambicus ◽  
Seasonal Fluctuations ◽  
Parasite Abundance ◽  
Gill Parasite ◽  
The Mean

AbstractAn investigation was conducted into the parasitic infection of an indigenous cichlid, Oreochromis mossambicus, collected seasonally from the Nwanedi-Luphephe dams of the Limpopo River System from July 2007 to April 2009. Of 157 host specimens examined, 115 (73.25%) were infected by at least one gill parasite. In all, 1565 monogenean specimens were collected, belonging to five different species and two genera: Cichlidogyrus (C. halli, C. sclerosus, C. tilapiae and C. dossoui) and Scutogyrus (S. longicornis). Infracommunities were poor, with only 27 (17.20%) hosts harbouring four of the five species observed. Cichlidogyrus halli was the dominant species, with a prevalence of 73.25%. Prevalence values for each of the other four species were less than 50%. The mean intensities for each of the five species were low ( < 8 parasites/host). The parasite abundance and intensity levels were not influenced by either the sex or the size of the host. The abundance of all parasite species except for S. longicornis exhibited seasonal fluctuations, reaching peaks in winter and summer. The spatial distribution of each parasite was studied on different regions of the gill, and positive associations among some species were revealed.

A comparison of the fine root component of a pure and a mixed coniferous stand

1988 ◽  
Vol 18 (11) ◽  
pp. 1416-1426 ◽  
Author(s):  
H. M. McKay ◽  
D. C. Malcolm
Keyword(s):  
Fine Roots ◽  
Standing Crop ◽  
Fine Root ◽  
Sitka Spruce ◽  
Nitrogen And Phosphorus ◽  
Mixed Stands ◽  
Method Of Calculation ◽  
The Mean ◽  
Phosphorus And Potassium ◽  
Nitrogen Phosphorus

Fine roots were sampled at monthly intervals during 1984–1985 in pure plots of Sitka spruce (Piceasitchensis (Bong.) Carr.) and mixed plots of Scots pine (Pinussylvestris L.) and Sitka spruce established on an upland heath in 1969. Both types of planting had received phosphorus and potassium fertiliser but no nitrogen. The mean standing crop of live roots (<2 mm diameter) in the top 5 cm of pure spruce plots was 112 g • m−2, almost double that of mixed stands (37 g • m−2 of spruce plus 20 g • m−2 of pine). Necromass was 80% of total mass in both stand types. Concentrations of nitrogen and phosphorus were greater in pure plots than in mixed plots, but fine root capital of nitrogen, phosphorus, and potassium was greater in pure spruce than in mixed plots (biomass and necromass contained 11, 2, and 5 and 45, 4, and 7 kg • ha−1 of nitrogen, phosphorus, and potassium, in pure plots, and 7, 1, and 3 and 30, 3, and 3 kg • ha−1 of nitrogen, phosphorus, and potassium in mixed plots, respectively). Production of fine roots in pure and mixed stands was estimated at 181 and 97 g • m−2•year−1 or 715 and 367 g • m−2•year−1, respectively, depending on the method of calculation. Fine roots of pure plots were highly concentrated in the top 3 cm. In mixture, spruce roots had a less extreme vertical distribution and pine roots were more evenly distributed down to 9 cm.

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