Fine root biomass within experimental canopy gaps: evidence for a below-ground gap

1993 ◽  
Vol 4 (4) ◽  
pp. 571-574 ◽  
Author(s):  
C. J. Wilczynski ◽  
S. T. A. Pickett
2005 ◽  
Vol 21 (4) ◽  
pp. 427-434 ◽  
Author(s):  
H. Asbjornsen ◽  
N. Velázquez-Rosas ◽  
R. García-Soriano ◽  
C. Gallardo-Hernández

Although fire is occurring at greater frequencies and spatial scales in the moist tropics, few studies have examined the ecological impacts of fire in tropical montane cloud forest (TMCF). This study, conducted in the Chimalapas region of Oaxaca, Mexico, documents changes in live tree biomass, live fine-root biomass, and fallen and standing dead wood 4 y following deep ground fires occurring in TMCF during the 1997–98 El Niño Southern Oscillation event. Forests growing on two different substrates (metamorphic and sedimentary) and having three different statures (mean canopy heights: 20–30 m, 15–20 m and 4–6 m) were assessed within six paired plots established on adjacent burned and unburned forest sites. Total live tree biomass was 82% and 88% lower for burned TMCF growing on metamorphic and sedimentary substrates, respectively, compared with unburned TMCF. Nearly 100% of the living biomass was killed in elfin TMCF located on exposed sedimentary limestone at the highest elevations. Live fine-root biomass in the upper organic soil horizon of burned TMCF sites was 49% lower on metamorphic substrates and 77% lower on sedimentary substrates compared with unburned sites. The amount of total dead wood was 3- to 14-fold greater in burned forests compared with unburned forests. These results suggest that first-time fires in relatively undisturbed TMCF can cause dramatic changes in live above- and below-ground biomass at levels greatly exceeding values reported for most lowland tropical rain forests. These patterns may be attributed to the slower decomposition rates and thick organic soils typical of TMCF, combined with the relatively fast drainage associated with steep topography and, in some locations, sedimentary limestone-derived substrates.


2002 ◽  
Vol 50 (1) ◽  
pp. 31 ◽  
Author(s):  
D. Eamus ◽  
X. Chen ◽  
G. Kelley ◽  
L. B. Hutley

Below-ground biomass of a Eucalyptus savanna forest was estimated following trenching to depths of 2 m around 16 mature trees in a tropical savanna of north Australia. Correlations among below-ground and various components of above-ground biomass were also investigated. In addition, root morphology was investigated by fractal analyses and a determination of an index of shallow-rootedness was undertaken. Total root biomass was 38.4 t ha–1, including 1 t ha–1 of fine roots. About 77–90% of total root biomass was found in the upper 0.5 m of soil. While fine-root biomass density was approximately constant (0.1 kg m–3) in the top soil, irrespective of distance from a tree stem, coarse-root biomass showed large variation with distance from the tree stem. Significant positive correlations among total root biomass, total above-ground biomass, diameter at breast height, leaf biomass and leaf area were obtained. It is likely that total root biomass can be reasonably accurately estimated from aboveground biomass and fine-root biomass from tree leaf area. We present equations that allow the prediction of belowground biomass from above-ground measures of tree size. Root morphology of two evergreen and two deciduous species was compared by the use of three parameters. These were the fractal dimension (d), which describes root system complexity; a proportionality factor (α), which is the ratio of the cross-sectional area before and after branching; and two indices of shallow-rootedness (ISR). Roots were found to be amenable to fractal analyses. The proportionality factor was independent of root diameter (Dr) at any branching level in all tree species examined, indicating that branching patterns were similar across all root sizes. The fractal dimension (d) ranged from 1.15 to 1.36, indicating a relatively simple root structure. Mean d was significantly different between E. tetrodonta (evergreen) and T. ferdinandiana (deciduous); however, no significant differences were found among other pairs of species. Terminalia ferdinandiana had the highest ISR, while Planchonia careya (deciduous) had the lowest. In addition, differences in ISR between P. careya and the other three species were significant, but not significant among E. miniata, E. tetrodonta and T. ferdinandiana. There were clear relationships among above-ground tree stem diameter at breast height, stem base diameter, and horizontal and vertical proximal root diameter. By the use of mean values of and stem diameter, we estimated the total crosssectional area of root and root diameter-class distribution for each species studied.


2005 ◽  
Vol 21 (5) ◽  
pp. 483-492 ◽  
Author(s):  
Marina Röderstein ◽  
Dietrich Hertel ◽  
Christoph Leuschner

Litter production from above-ground (leaves, twigs, fruits, flowers) and below-ground (roots) plant organs is an important component of the cycling of carbon and nutrients in forests. Tropical montane forests possess comparatively large quantities of fine-root biomass, suggesting that litter production by dying fine roots may represent a major component of total litter production. In a comparative study in three tropical montane forests of southern Ecuador at 1890, 2380 and 3060 m elevation, we measured leaf-fall by litter trapping and fine-root litter production by sequential soil coring and fine-root biomass and necromass analysis for about 1 y with the objectives (1) to quantify annual above- and below-ground litter production, and (2) to investigate elevational differences in litter production. Leaf litter mass decreased to less than a third (862 to 263 g m−2 y−1) with increasing elevation (1890 m to 3060 m), whereas fine-root litter production increased by a factor of about four (506 to 2084 g m−2 y−1). Thus, the ratio of leaf to fine-root litter shifted by an order of magnitude in favour of fine-root litter production between 1890 to 3060 m. Fine-root litter production was not synchronized with leaf litterfall and was seasonal only at 3060 m with mortality peaks in the drier and the wetter periods. We conclude that dying fine roots represent a very important fraction of total litterfall in tropical montane forests that can exceed the quantity of leaf litter. At 3060 m, the largest part of the organic material on top of the soil must originate from dying fine roots but not from fallen leaves.


2013 ◽  
Vol 36 (7) ◽  
pp. 645-654 ◽  
Author(s):  
Yun-Ke LIU ◽  
Chuan FAN ◽  
Xian-Wei LI ◽  
Yin-Hua LING ◽  
Yi-Gui ZHOU ◽  
...  

2021 ◽  
Vol 130 ◽  
pp. 108031
Author(s):  
Wen Li ◽  
Yifei Shi ◽  
Dandan Zhu ◽  
Wenqian Wang ◽  
Haowei Liu ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tina Unuk Nahberger ◽  
Gian Maria Niccolò Benucci ◽  
Hojka Kraigher ◽  
Tine Grebenc

AbstractSpecies of the genus Tuber have gained a lot of attention in recent decades due to their aromatic hypogenous fruitbodies, which can bring high prices on the market. The tendency in truffle production is to infect oak, hazel, beech, etc. in greenhouse conditions. We aimed to show whether silver fir (Abies alba Mill.) can be an appropriate host partner for commercial mycorrhization with truffles, and how earthworms in the inoculation substrate would affect the mycorrhization dynamics. Silver fir seedlings inoculated with Tuber. aestivum were analyzed for root system parameters and mycorrhization, how earthworms affect the bare root system, and if mycorrhization parameters change when earthworms are added to the inoculation substrate. Seedlings were analyzed 6 and 12 months after spore inoculation. Mycorrhization with or without earthworms revealed contrasting effects on fine root biomass and morphology of silver fir seedlings. Only a few of the assessed fine root parameters showed statistically significant response, namely higher fine root biomass and fine root tip density in inoculated seedlings without earthworms 6 months after inoculation, lower fine root tip density when earthworms were added, the specific root tip density increased in inoculated seedlings without earthworms 12 months after inoculation, and general negative effect of earthworm on branching density. Silver fir was confirmed as a suitable host partner for commercial mycorrhization with truffles, with 6% and 35% mycorrhization 6 months after inoculation and between 36% and 55% mycorrhization 12 months after inoculation. The effect of earthworms on mycorrhization of silver fir with Tuber aestivum was positive only after 6 months of mycorrhization, while this effect disappeared and turned insignificantly negative after 12 months due to the secondary effect of grazing on ectomycorrhizal root tips.


Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 823
Author(s):  
Anna Zielonka ◽  
Marek Drewnik ◽  
Łukasz Musielok ◽  
Marcin K. Dyderski ◽  
Dariusz Struzik ◽  
...  

Forest ecosystems significantly contribute to the global organic carbon (OC) pool, exhibiting high spatial heterogeneity in this respect. Some of the components of the OC pool in a forest (woody aboveground biomass (wAGB), coarse root biomass (CRB)) can be relatively easily estimated using readily available data from land observation and forest inventories, while some of the components of the OC pool are very difficult to determine (fine root biomass (FRB) and soil organic matter (SOM) stock). The main objectives of our study were to: (1) estimate the SOM stock; (2) estimate FRB; and (3) assess the relationship between both biotic (wAGB, forest age, foliage, stand density) and abiotic factors (climatic conditions, relief, soil properties) and SOM stocks and FRB in temperate forests in the Western Carpathians consisting of European beech, Norway spruce, and silver fir (32 forest inventory plots in total). We uncovered the highest wAGB in beech forests and highest SOM stocks under beech forest. FRB was the highest under fir forest. We noted a considerable impact of stand density on SOM stocks, particularly in beech and spruce forests. FRB content was mostly impacted by stand density only in beech forests without any discernible effects on other forest characteristics. We discovered significant impacts of relief-dependent factors and SOM stocks at all the studied sites. Our biomass and carbon models informed by more detailed environmental data led to reduce the uncertainty in over- and underestimation in Cambisols under beech, spruce, and fir forests for mountain temperate forest carbon pools.


2003 ◽  
Vol 33 (5) ◽  
pp. 847-853 ◽  
Author(s):  
Sylvia E Welke ◽  
Graeme D Hope ◽  
Gary A Hunt

The effect of timber harvesting on the biomass, nutrient standing crop, and decomposition of fine roots (<2 mm) was studied in a high elevation, Engelmann spruce (Picea engelmannii Parry ex Engelm.) – subalpine fir (Abies lasiocarpa (Hook.) Nutt.) forest. Root dynamics were compared in openings of different sizes. The sequential core method was used to collect fine root samples over 4 years. Differences in fine root biomass between opening sizes were most significant for the active fine root portion and were most pronounced in the fall compared with the spring. Active fine root biomass was significantly lower in the 10-ha clearcuts (164 kg/ha) compared with control plots (275 kg/ha). Furthermore, active fine root biomass was often lower in the 1.0-ha opening than in the 0.1-ha and control plots. A similar trend was established for inactive fine root biomass, although this was not consistent over sampling years. Nutrient concentrations of K, but no other elements, were higher in control plots. Nutrient standing crops, however, followed trends observed in fine root biomass. In the 10-ha clearcuts, the largest changes in fine root biomass occurred at the edge of the opening. The findings suggest that small (<10 ha) cutblocks may maintain greater fine root longevity.


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