Fine-root distribution of coniferous plantations in relation to site in southern Buenos Aires, Argentina

1992 ◽  
Vol 22 (11) ◽  
pp. 1575-1582 ◽  
Author(s):  
Adrián Ares ◽  
Norman Peinemann

A study was conducted to determine the amounts and vertical distribution of fine roots <2 mm as a function of site quality in a temperate, hilly zone of Argentina. Fine roots were sampled in autumn from 0.2-ha plots established in 12 coniferous plantations of Pinushalepensis Mill., Pinusradiata D. Don, Cedrusdeodara (D. Don) G. Don, and Cupressussempervirens L.f. horizontalis, located in Sierra de la Ventana, southern Buenos Aires. Generally, root density was found to be higher under low-growth stands. The distance from a tree sometimes had an effect on root density, but no clear pattern within stands could be observed. Root density commonly decreased with depth, but slight irregularities in some profiles were observed. Site quality and soil type influenced root distribution. Belowground biomass up to a depth of 50 cm ranged from 1600 to 9800 kg•ha−1 in high-growth stands and from 5400 to 40 700 kg•ha−1 in low-growth stands. Soil organic matter content provided the best correlation with root density. A possible practical implication would be the use of indices related to vertical distribution of organic matter, among other variables, as complementary estimators of effective depth of rooting. The results strongly suggest that trees maintain a large fine-root system in poor sites at the expense of aboveground growth.

2008 ◽  
Vol 23 (4) ◽  
pp. 202-205 ◽  
Author(s):  
Gabriel Dumm ◽  
Lauren Fins ◽  
Russell T. Graham ◽  
Theresa B. Jain

Abstract This study describes soil horizon depth and fine root distribution in cores collected at two distances from the boles of Douglas-fir and ponderosa pine trees at a study site in a central Idaho forest. Concentration and content of fine roots extracted from soil cores were compared among species, soil horizons, tree size, and distance from bole. Approximately 80% of litter and humus samples contained no fine roots. The highest fine root content and concentrations of fine roots occurred in deep mineral soil for both species (1.24 g and 2.82 g/l for Douglas-fir and 0.98g and 2.24 g/l for ponderosa pine, respectively). No statistically significant differences were found in fine root content or concentration between species in any of the four soil horizons. Tree size was not a significant factor in fine root distribution in this study. Significant variables were horizon, distance from bole, and interactions among tree size, location of sample, and soil horizon. This study, which was part of a larger US Forest Service study to develop a predictive model of postfire tree mortality, provides baseline information that may be useful in predicting postfire damage to fine roots.


2014 ◽  
Vol 1 ◽  
Author(s):  
Pavel Krasilnikov ◽  
Norma Eugenia García Calderón ◽  
Rosalía Ramos Bello ◽  
Héctor Manuel Ortega Escobar

The chinampas agriculture is a traditional land use practice in the Valley of Mexico since Pre-Hispanic time. The chinampas soils were constructed by excavation of lake sediments that resulted in the creation of a system of islands separated by channels. The agricultural productivity of these artificial soils was high; also the land use practices included forestry, fish breeding and hunting. Nowadays, the chinampas soils are affected by excessive salinity. We studied 10 representative soil profiles in the chinampas zone of Mexico City in order to characterize their properties and origin, to provide their classification, and to evaluate soil salinization, vertical distribution of the salts and their chemical composition. The soils are characterized by a layered structure, uniform dark grey colour, irregular vertical distribution of organic carbon and clay, and high percentage of carbon. Some soils show an increase in organic matter with depth, and other profiles have maximum organic matter content in the surficial layers and in the subsoil. The dynamics of sedimentation resulted in the decrease in organic matter in the upper layers of lacustrine sediments, because of recent increase in erosion rate and consequent increase in the proportion of mineral particles in the sediments. Most probably high organic matter content in surficial layers of some soils is due to excavation and accumulation of organic-rich subsoil material in the course of digging the channels. The concentration of soluble salts in superficial horizons, expressed as electric conductivity, varies in a wide range from 5 to almost 50 dS·m<sup>-1</sup>. The salts concentrate mainly in the superficial layers of soils. The abundance of the cations of soluble salts is Na<sup>+</sup>&gt;Mg<sup>2+</sup>&gt;Ca<sup>2+</sup>&gt;K<sup>+</sup> and that of the anions is SO<sub>4</sub><sup>2-</sup>&gt;Cl<sup>-</sup>&gt;HCO<sub>3</sub><sup>-</sup>&gt;CO<sub>3</sub><sup>2-</sup>. The alkaline reaction of soils is caused by exchangeable Na rather than by free sodium carbonates. The restoration of chinampas requires a complex approach, combining soil, water and ecosystems remediation.


1978 ◽  
Vol 8 (3) ◽  
pp. 265-279 ◽  
Author(s):  
J. P. Kimmins ◽  
B. C. Hawkes

The vertical distribution of fine-root biomass, its chemical content, and the vertical distribution of overstory root tips were measured in a mature white spruce – subalpine fir stand (Piceaglauca (Moench) Voss – Abieslasiocarpa (Hook.) Nutt.) growing on an infertile sandy soil near Prince George, British Columbia, during July and August, 1975. The study was part of a larger project which described the biomass and chemical content of the tree and minor vegetation. The objective of the project was to provide information on nutrient losses accompanying whole-tree logging and to estimate the possible consequences of such losses for future tree production. Questions concerning the magnitude of the soil nutrient capital available to the vegetation indicated the need for information on the exploitation of the soil by the roots. This paper reports the results of an investigation of the fine roots. Living fine roots (<6.4 mm) of overstory trees and understory plants were sampled separately from 11 soil pits to an average depth of 94 cm. Overstory fine-root biomass was estimated to be about 1870 kg/ha of which 67% was in the forest floor (LFH horizon) and the Ae horizon. The average combined depth of these two horizons was only 8.3 cm, but they contained 88% of the overstory root tips sampled. The 3.3-cm-thick forest floor alone contained half of the fine-root biomass and approximately 70% of the overstory root tips. Understory fine-root biomass was estimated to be about 7880 kg/ha of which 69% was in the forest floor and the Ae horizon. The concentrations of N, P, K, Ca, and Mg generally decreased with increasing depth, while Fe and Al exhibited the opposite pattern.The marked concentration of fine-root biomass and root tips in the forest floor is interpreted as reflecting the very low nutrient status of the mineral soil on the study site. The high value of fine-root biomass for understory vegetation results from the open structure of the stand and is thought to reflect the great importance of this vegetation in nutrient cycling on the study site. The biomass data, together with root chemical concentration data, are consistent with the hypothesis that the forest floor is the major source of several of the macronutrients for the vegetation on the site.


2019 ◽  
Vol 94 (3) ◽  
pp. 843-855 ◽  
Author(s):  
David Montejo-Martínez ◽  
Víctor F. Díaz-Echeverría ◽  
Gilberto Villanueva-López ◽  
Deb R. Aryal ◽  
Fernando Casanova-Lugo ◽  
...  

Forests ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 562 ◽  
Author(s):  
Huijuan Bo ◽  
Chunyan Wen ◽  
Lianjun Song ◽  
Yatao Yue ◽  
Lishui Nie

Stand density directly affects the distribution of ecological factors such as light, heat, and water in forest communities and changes the diversity and structure of undergrowth species, thereby affecting soil health. Fine roots can provide water and nutrients to plants rapidly in the fierce competition of soil resources, so as to get rid of environmental factors. This study examined the fine-root responses of the Populus tomentosa clone S86 to three stand densities (plant × row spacing: 2 × 2 m, 4 × 3 m, 4 × 5 m). We measured the biomass, morphology, and nitrogen content of lower- (1–3 order) and higher-order (>3 order) fine roots, and analyzed soil chemical properties in 10–30 cm. The soil from the density (2 × 2 m) stands showed lower soil organic matter content, available nitrogen, available phosphorous, and available potassium than others. Obviously, lower and higher-order fine roots were different: biomass of the >3 order accounted for 77–87% of the total biomass, 1–3-order fine-root diameter around 0.28–0.38 mm, while >3-order fine root were 1.28–1.69 mm; the length of 1–3-order fine root was longer than the >3 order, and root length density, specific root length, and nutrient content between the 1–3 and >3 orders were different. At 2 × 2 m, 1–3-order fine-root biomass was the highest, 132.5 g/m3, and the 1–3-order fine-root length, diameter, surface, root length density was also the highest; at the same time, the 1–3-order fine-root total nitrogen and organic matter content was also the highest, while the >3 order was highest under 4 × 3 m or 4 × 5 m. The findings of this study show that stand density affected the available nutrient content of the soil. When soil resources were poor, the biomass, morphology, and chemical content of fine roots were adjusted to increase the nutrient absorption rate, particularly in the lower-order roots.


Soil Research ◽  
1983 ◽  
Vol 21 (2) ◽  
pp. 165 ◽  
Author(s):  
GR Davis ◽  
WA Neilsen ◽  
JG Mcdavitt

Root distribution of Pinus radiata was studied on five diverse soils. Root concentration to 80 cm was most closely correlated with soil organic matter content. Considerable differences in the proportion of roots at different depths were found.


1993 ◽  
Vol 8 (2) ◽  
pp. 62-66 ◽  
Author(s):  
Wayne D. Shepperd

Abstract Logging activities cause significant compaction on skid trails in commercial aspen harvest areas. Bulk density increases have persisted up to 12 yr following harvest. Compaction of the upper 0.2 m of an undisturbed mineral soil profile increased with each succeeding pass of a tractor where later passes contributed less to the total compaction effect. Compaction effects were similar under wet soil conditions. High organic matter content in the upper mineral soil profile may have decreased the magnitude of compaction effects. Root damage can occur without apparent disruption of the soil profile, especially to fine roots and those in saturated soils. West. J. Appl. For. 8(2):62-66.


Sign in / Sign up

Export Citation Format

Share Document