Organic matter dynamics of fine roots in plantations of slash pine (Pinuselliottii) in north Florida

1986 ◽  
Vol 16 (3) ◽  
pp. 529-538 ◽  
Author(s):  
Henry L. Gholz ◽  
Laurel C. Hendry ◽  
Wendell P. Cropper Jr.

Seasonal patterns of live, dead, and unknown viability fine (diameter, ≤10 mm) roots of pine and other vegetation in a young and old slash pine stand were sampled using monthly soil coring over a 24-month period. A distinct unimodal pattern for roots <1 mm in diameter in the surface soil was observed. Live roots increased in the spring to a peak in midsummer and then declined. Larger roots and roots deeper in the soil showed less distinct seasonal patterns, although maximum and minimum annual biomass values were sometimes significantly different. Decomposition of fine roots in buried mesh bags averaged 15–20% per year for roots <5 mm in diameter. An analysis of seasonal dynamics and decompositon rates were combined to construct organic matter budgets for the forest floor and soil. Estimated net root production for roots ≤10 mm in diameter was 590 and 626 g m−2 year−1 in the young and old stand, respectively. Root turnover contributed 214 and 452 g m−2 year−1 to detrital pools on the two sites, with the balance of production accumulating as standing root biomass or lost in decomposition. Root production and turnover rates decreased with increasing root diameter; most production was from roots <1 mm. Pine root production was greater and nonpine production was less in the older stand than in the younger stand. Compared with other temperate and boreal forests, root biomass was high and net root production relatively low. The low production:biomass ratio may be characteristic of low latitude (warm) and (or) low nutrient forest types.

2013 ◽  
Vol 59 (3) ◽  
Author(s):  
Bohdan Konôpka ◽  
Jozef Pajtík ◽  
Miriam Maľová

AbstractFine roots (defined by a maximum diameter of 2 mm) and assimilatory organs are the compartments which rotate carbon much faster than any other tree part. We focused on quantification of fine roots in young European beech and Norway spruce trees growing under the same ecological conditions. Standing stock of fine roots was estimated by soil coring during 2009 - 2012. Fine root production was established by the in-growth bag method. Standing stock and productions of fine roots were comparable in both tree species. The quantity of fine root biomass (at a soil depth of 0 -50 cm) varied inter-annually between 6.08 and 7.41 t per ha in the beech and from 5.10 to 6.49 t per ha in the spruce stand. Annual production of fine roots (soil depth of 0 - 30 cm) was between 1.11 and 1.63 t ha-1 in beech and between 0.95 and 1.54 t.ha-1 in spruce. We found that fine root standing stock at the beginning of each growing season was related to climatic conditions in the previous year. Annual fine root production was influenced by the climatic situation of the current year. In general, a maximum standing stock of fine roots as well as a relatively slow fine root turnover is expected in young forest stands. Whereas production of fine roots prevailed over mortality in a favorable year (sufficiency of precipitations and slightly above-average temperatures in 2010), there was a reverse situation in an unfavorable year (drought episodes in 2011). We concluded that although both forest types represented contrasting turnovers of assimilatory organs (once a year and once in 5 years in beech and spruce respectively), fine root turnover rates were very similar (approx. once per four years).


2020 ◽  
Vol 25 (1) ◽  
pp. 24-29
Author(s):  
Krishna Prasad Bhattarai ◽  
Tej Narayan Mandal ◽  
Tilak Prasad Gautam

The present study was conducted to understand the effect of altitude on the nutrient concentration, nutrient stock, and uptake in the fine root of the Terai Sal forest (TSF) and Hill Sal forest (HSF) in eastern Nepal. Annual mean fine root biomass in 0-30 cm soil depth was found higher in HSF (6.27 Mg ha-1) than TSF (5.05 Mg ha-1). Conversely, fine root production was higher in TSF (4.8 Mg ha-1 y-1) than HSF (4.12 Mg ha-1 y-1). Nitrogen, phosphorus, and potassium content in fine roots were slightly higher in TSF than HSF. Nutrient concentration in fine roots of smaller size (<2 mm diameter) was nearly 1.2 times greater than that of larger size (2–5 mm diameter) in both forests. In HSF total stock of different nutrients (kg ha-1) in fine root was 55.62 N, 4.99 P, and 20.15 K whereas, these values were 49.49 N, 4.14 P, and 19.27 K only in TSF. However, total nutrient uptake (kg ha-1y-1) by fine root (both size classes) was greater in TSF (48.5 N, 4.3 P, and 18.6 K) than HSF (36.9 N, 3.3 P, and 13.5 K). The variability in fine root nutrient dynamics between these two forests was explained by the differences in fine root biomass and production which were influenced by the combined effect of varied altitude and season. The fine root, as being a greater source of organic matter, the information on its nutrient dynamics is inevitable for the management of soil nutrients in the forest ecosystem.


1987 ◽  
Vol 17 (8) ◽  
pp. 909-912 ◽  
Author(s):  
W. A. Kurz ◽  
J. P. Kimmins

Fine root production rates are most commonly calculated from periodic measurements of live and dead fine root biomass. The accuracy of production estimates based on this method is very sensitive to violations of the inherent assumptions, particularly the assumption that the processes of fine root production and mortality are temporally separate. A simple model was used to simulate data for a variety of seasonal patterns of live and dead fine root biomass. Fine root production and mortality rates were calculated from these simulated data using two different computational methods. Comparison of the calculated rates with the known rates (the rates used to generate the seasonal patterns) revealed that violations of the above assumptions can result in inaccurate rate estimates. When fine root production and mortality occur simultaneously within a sampling interval, the calculated production rate will greatly underestimate the true value. Additional error in the rate estimates may result from sampling error associated with the fine root biomass data. The model suggested that sampling error can cause either overestimation or underestimation of fine root production.


1987 ◽  
Vol 17 (4) ◽  
pp. 330-333 ◽  
Author(s):  
Katherine C. Ewel ◽  
Wendell P. Cropper.Jr. ◽  
Henry L. Gholz

Respiration of live roots was the single largest contributor to soil CO2 evolution in two mature slash pine (Pinuselliottii) plantations. Root respiration accounted for 51% of soil CO2 evolution at the 9-year-old plantation and 62% at the 29-year-old plantation. Additional estimates, calculated from data recorded from two small trenched plot sites at the 29-year-old plantation and based on possible variations in initial root biomass and subsequent decomposition rates, also averaged 62% of soil CO2 evolution. Specific root respiration averaged 0.40 g•g−1•year−1, varying from 0.34 to 1.70 g•g−1•year−1. Plots with larger proportions of fine roots had faster soil CO2 evolution rates.


2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Hans Å. Persson

The spatial and temporal dynamics of tree fine roots were investigated in six boreal forests types in Eastern Sweden, close to the Swedish Forsmark and Laxemar nuclear power plants. Four dry and two wet forest types were included in the study. The amount of live and dead fine roots in terms of dry weight was estimated in soil cores. The live/dead ratios of fine roots (<1 mm in diameter) decreased with depth; very low ratios were observed in two wet forest sites. The proportions of dead fine roots to the total amounts of fine roots in the mineral soil horizons of those wet sites were 63 and 86%. The corresponding proportions in the mineral soil in dry forest sites were 45 and 45% and 49 and 48% at Forsmark and Laxemar, respectively. Sequential soil core sampling demonstrated a high variation in live and dead amounts of fine roots during the growth period. A high accumulation of carbon from dead tree fine root was found in all six forest types, in particular in the wet forest sites, but also in deeper soil horizons. Consequently, substantial amounts of organic matter from dead fine roots are continuously accumulated in the soil in boreal forests.


2019 ◽  
Vol 6 (2) ◽  
pp. 180890 ◽  
Author(s):  
Zhanyi Wang ◽  
Jing Jin ◽  
Yanan Zhang ◽  
Xiaojuan Liu ◽  
Yongling Jin ◽  
...  

The impacts of large herbivores on plant communities differ depending on the plants and the herbivores. Few studies have explored how herbivores influence root biomass. Root growth of vegetation was studied in the field with four treatments: sheep grazing alone (SG), cattle grazing alone (CG), mixed grazing with cattle and sheep (MG) and no grazing (CK). Live and total root biomasses were measured using the root ingrowth core and the drilling core, respectively. After 2 years of grazing, total root biomass showed a decreasing trend while live root biomass increased with time during the growing seasons. Belowground net primary production (BNPP) among the treatments varied from 166 ± 32 to 501 ± 88 g m −2 and root turnover rates (RTR) varied from 0.25 ± 0.05 to 0.70 ± 0.11 year −1 . SG had the greatest BNPP and RTR, while the CG had the smallest BNPP and RTR. BNPP and RTR of the MG treatment were between those of the CG and SG treatments. BNPP and RTR of the CK were similar to MG treatment. Compared with other treatments, CG had a greater impact on dominant tall grasses species in communities. SG could decrease community diversity. MG eliminated the disadvantages of single-species grazing and was beneficial to community diversity and stability.


2013 ◽  
Vol 49 (4) ◽  
pp. 556-573 ◽  
Author(s):  
M. D. JESSY ◽  
P. PRASANNAKUMARI ◽  
JOSHUA ABRAHAM

SUMMARYUnderstanding the growth dynamics of fine roots and their contribution to soil organic carbon and nutrient pools is crucial for estimating ecosystem carbon and nutrient cycling and how these are influenced by climate change. Rubber is cultivated in more than 10 million hectare globally and the area under rubber cultivation is fast expanding due to socio-economic reasons, apart from the importance given to this species for eco-restoration of degraded lands. An experiment was conducted to quantify fine root production, fine root turnover and carbon and nutrient cycling through fine roots in rubber plantations with different soil nutrient status and rainfall pattern. Fine root production was estimated by sequential coring and ingrowth core methods. Fine root decomposition was determined by the litter bag technique. Carbon and nutrient contents in fine roots were determined and their turnover was computed. Fine root biomass in the top 0–7.5-cm soil layer showed significant seasonal fluctuation and the fluctuations were particularly wide during the transition period from the dry season to the rainy season. Fine root production estimated by the different methods was significantly higher at the lower fertility site and during the higher soil moisture stress year. Fine root turnover ranged from 1.04 to 2.29 year−1. Root carbon and nutrient status showed seasonal variation and lower status was observed during the rainy season. The annual recycling of C, N, P, K, Ca and Mg through fine roots ranged from 590 to 1758, 30 to 85, 3 to 12, 13 to 31, 11 to 35 and 6 to 13 kg ha−1, respectively. Substantial quantities of carbon and nutrients were recycled annually in rubber plantations through fine roots. When soil moisture and nutrient stress were more severe, fine root production, turnover and carbon and nutrient recycling through fine roots were higher.


1996 ◽  
Vol 26 (8) ◽  
pp. 1326-1336 ◽  
Author(s):  
R.W. Ruess ◽  
K. Van Cleve ◽  
J. Yarie ◽  
L.A. Viereck

Fine root production and turnover were studied in hardwood and coniferous taiga forests using three methods. (1) Using soil cores, fine root production ranged from 1574 ± 76 kg•ha−1•year−1 in the upland white spruce (Piceaglauca (Moench) Voss) stand to 4386 ± 322 kg•ha−1•year−1 in the floodplain balsam poplar (Populusbalsamifera L.) stand, accounting for 49% of total production for coniferous stands and 32% of total production for deciduous stands. Fine root turnover rates were higher in floodplain (0.90 ± 0.06 year−1) stands than in upland (0.42 ± 0.10 year−1) stands. Across all sites, the ratio of fine root turnover to litter fall averaged 2.2 for biomass and 2.8 for N. Both values were higher in floodplain stands than in upland stands, and in coniferous stands than in deciduous stands. (2) The C budget method showed that C allocation to fine roots varied from 150 to 425 g C•m−2•year−1 and suggested that soil respiration was more dependent on C derived from roots than from aboveground inputs. The C allocation ratio (C to roots: C to litter fall) was inversely correlated with litter-fall C and varied from 0.3 to 69.5; there was a tendency for higher proportional belowground allocation in coniferous stands than in deciduous stands and the highest levels were at the earliest successional sites. (3) Estimates of apparent N uptake (Nu), N allocation to fine roots, and fine root production based on N budget calculations showed that annual aboveground N increments exceeded Nu estimates at half the sites, indicating that the method failed to account for large amounts of N acquired by plants. This suggests that plant and (or) mycorrhizal uptake of soil organic N may be more significant to ecosystem N cycling than mineral N turnover by the soil microbial biomass.


2004 ◽  
Vol 20 (2) ◽  
pp. 221-224 ◽  
Author(s):  
Xiaoyong Chen ◽  
Derek Eamus ◽  
Lindsay B. Hutley

Fine roots and their turnover represent a dynamic aspect of below-ground biomass (BGB) and nutrient capital in forest ecosystems, and account for a significant fraction of net primary productivity (NPP) (Cuevas 1995, Vogt et al. 1990). On a weight basis, coarse roots contribute more to total ecosystem biomass than fine roots, but they account for only a small portion of annual root production (Eamus et al. 2002). Despite the fact that fine roots may compose less than 2% of total ecosystem biomass, they may contribute up to 40% of total ecosystem production (Vogt et al. 1990). Therefore, estimates of root production, like estimates of root biomass, should differentiate between coarse- and fine-root production.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 541d-541
Author(s):  
Christina Wells ◽  
David Eissenstat ◽  
Michael Glenn

Damage to the root system by soil insects and pathogenic fungi is difficult to assess and often goes unnoticed until a tree exhibits significant decline above ground. In this study, below-ground imaging technology was used to quantify fine root turnover in peach and to determine what percentage of root death may be caused by soil pests in an apparently healthy orchard. The study was conducted on six 15-year-old `Loring' peach trees on Halford rootstock in Kearneysville, W.Va. Five root observation tubes were placed in the soil beneath each tree in Apr. 1996. Each tube was randomly assigned one of five soil drench treatments: Lorsban 4E insecticide, Ridomil 2E fungicide, a combination of both pesticides, 1/10th strength Hoagland's solution, or water. A portable VCR and camera system were used to record images of fine roots (<1 mm diameter) growing along the tubes at biweekly intervals from May 1996 through Nov. 1997. The images were used to construct a database of life history information for more than 1500 individual roots. Peach root survivorship was influenced by root diameter and pesticide treatment. Fine roots on tubes receiving either of the pesticide treatments had higher survivorship than roots on control tubes for all diameter classes. The effect was most pronounced for white roots <0.5 mm in diameter, whose survivorship during the growing season was increased by 45% when both insecticide and fungicide were applied. These results suggest that a substantial fraction of fine root death may be caused by interactions with the soil fauna.


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