Juniperusoccidentalis juvenile foliage: advantages and disadvantages for a stress-tolerant, invasive conifer

1995 ◽  
Vol 25 (3) ◽  
pp. 470-479 ◽  
Author(s):  
P.M. Miller ◽  
L.E. Eddleman ◽  
J.M. Miller
Keyword(s):  
Fine Root ◽  
Fine Root Biomass ◽  
Semiarid Environment ◽  
Advantages And Disadvantages ◽  
Physiological Processes ◽  
Use Of Resources ◽  
Adult Trees ◽  
Large Trees ◽  
Nitrogen Concentrations ◽  
Below Ground

Physiological processes for juvenile and adult foliage of Juniperusoccidentalis Hook. were compared to evaluate the advantages and disadvantages of juvenile foliage for a stress-tolerant, invasive conifer. Above- and below-ground biomass allocation and monthly measurements (April through October) of gas exchange, water relations, foliar nitrogen concentrations, and growth were made for juvenile and small-adult trees in the field in central Oregon. Compared with small adults, juveniles have greater allocations to foliage and fine-root biomass, higher rates of CO2 assimilation, leaf conductance, and transpiration, and lower investments of biomass and nitrogen per unit of foliar area. Juvenile foliage is less costly to produce than adult foliage. The suite of physiological processes associated with juvenile awl-like foliage should enhance establishment and early growth of J. occidentalis. However, high rates of water loss, which are associated with high rates of CO2 assimilation of juvenile foliage, appear to be a liability for large trees in the semiarid environment of eastern Oregon. Once established, the transition to a more conservative use of resources associated with adult scale-like foliage is consistent with the stress-tolerant strategy of long-lived evergreen trees.

Deep ground fires cause massive above- and below-ground biomass losses in tropical montane cloud forests in Oaxaca, Mexico

2005 ◽  
Vol 21 (4) ◽  
pp. 427-434 ◽  
Author(s):  
H. Asbjornsen ◽  
N. Velázquez-Rosas ◽  
R. García-Soriano ◽  
C. Gallardo-Hernández
Keyword(s):  
Root Biomass ◽  
Dead Wood ◽  
Fine Root ◽  
Fine Root Biomass ◽  
Ecological Impacts ◽  
Soil Horizon ◽  
Tree Biomass ◽  
Ground Biomass ◽  
Below Ground ◽  
Live Tree

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.

scholarly journals Root biomass and root fractal analyses of an open Eucalyptus forest in a savanna of north Australia

2002 ◽  
Vol 50 (1) ◽  
pp. 31 ◽  
Author(s):  
D. Eamus ◽  
X. Chen ◽  
G. Kelley ◽  
L. B. Hutley
Keyword(s):  
Root Biomass ◽  
Fine Root ◽  
Fine Root Biomass ◽  
Root Diameter ◽  
Above Ground Biomass ◽  
Breast Height ◽  
Ground Biomass ◽  
Fractal Analyses ◽  
Below Ground ◽  
Tree Stem

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.

Altered growth and fine root chemistry of Betula papyrifera and Acer saccharum under elevated CO2

2003 ◽  
Vol 33 (5) ◽  
pp. 842-846 ◽  
Author(s):  
William FJ Parsons ◽  
Brian J Kopper ◽  
Richard L Lindroth
Keyword(s):  
Condensed Tannins ◽  
Acer Saccharum ◽  
Fine Root ◽  
Fine Root Biomass ◽  
Total Biomass ◽  
Betula Papyrifera ◽  
Northern Hardwood Forests ◽  
Nitrogen Concentrations ◽  
Root Starch ◽  
Root Chemistry

We investigated the effects of CO2 enrichment on fine root chemical composition of two tree species common to northern hardwood forests. Two-year-old Betula papyrifera and 3-year-old Acer saccharum saplings were grown under ambient (400 µmol·mol–1) and elevated (700 µmol·mol–1) CO2 in a glasshouse experiment. In both species, root/shoot ratios and fine root percentages (of total biomass) were unaltered by CO2 enrichment. Tissue nitrogen concentrations decreased in the fine roots, and consequently, C/N ratios increased with elevated CO2. In birch, only condensed tannins increased with CO2 enrichment, while root starch levels were conserved. In maple, neither condensed tannins nor hydrolysable tannins were positively influenced by elevated CO2. Both fine root biomass and chemistry responses of the tree saplings may be related to their successional status.

Above- and below-ground litter production in three tropical montane forests in southern Ecuador

2005 ◽  
Vol 21 (5) ◽  
pp. 483-492 ◽  
Author(s):  
Marina Röderstein ◽  
Dietrich Hertel ◽  
Christoph Leuschner
Keyword(s):  
Fine Roots ◽  
Root Biomass ◽  
Fine Root ◽  
Fine Root Biomass ◽  
Litter Production ◽  
Montane Forests ◽  
Tropical Montane Forests ◽  
Root Litter ◽  
Southern Ecuador ◽  
Below Ground

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.

scholarly journals Fine root biomass and morphology in a temperate forest are influenced more by the nitrogen treatment approach than the rate

2021 ◽  
Vol 130 ◽  
pp. 108031
Author(s):  
Wen Li ◽  
Yifei Shi ◽  
Dandan Zhu ◽  
Wenqian Wang ◽  
Haowei Liu ◽  
...  
Keyword(s):  
Root Biomass ◽  
Temperate Forest ◽  
Fine Root ◽  
Treatment Approach ◽  
Fine Root Biomass ◽  
Nitrogen Treatment
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