Root biomass and surface area in three successional tropical forests

1982 ◽  
Vol 12 (3) ◽  
pp. 699-704 ◽  
Author(s):  
Cory W. Berish
Keyword(s):  
Costa Rica ◽  
Surface Area ◽  
Tropical Forests ◽  
Soil Type ◽  
Fine Roots ◽  
Root Biomass ◽  
Large Diameter ◽  
Area Index ◽  
Root Area ◽  
Root Area Index

Total root biomass and surface area of fine roots (<5 mm diameter) were determined to a depth of 85 cm in 1-, 8-, and 70-year-old tropical forests on the same soil type (Typic Dystrandept) at Turrialba, Costa Rica. Root biomass and root area index (RAI) increased with age: biomass = 219, 1291, and 1555 g/m2, and RAI = 1.34, 4.66, and 5.28 in the 1-, 8-, and 70-year-old stands, respectively. Fine roots were most concentrated in the surface 5 cm of soil at all three sites, but especially so in the 70-year-old stand. The 1- and 8-year-old vegetations had proportionally more fine roots below 25 cm than the 70-year-old vegetation, but lacked the large-diameter roots characteristic of the 70-year-old stand.

Biomass and leaf area in contrasting lodgepole pine forests

1984 ◽  
Vol 14 (2) ◽  
pp. 259-265 ◽  
Author(s):  
John A. Pearson ◽  
Timothy J. Fahey ◽  
Dennis H. Knight
Keyword(s):  
Leaf Area ◽  
Fine Roots ◽  
Lateral Root ◽  
Root Biomass ◽  
Basal Area ◽  
Pine Forests ◽  
Total Biomass ◽  
Area Index ◽  
Sapwood Area ◽  
Dimension Analysis

Bole, branch, foliage, root crown, and lateral root biomass of Pinuscontorta ssp. latifolia (Engelm. ex Wats.) Critchfield forests in southeastern Wyoming were estimated by a combination of aboveground dimension analysis, belowground planar intersect sampling, and soil coring. Total biomass of six stands ≥75 years old ranged from 123 to 180 Mg/ha, and roof:shoot ratios were much higher in two very dense stands than in four more open stands. Average proportions of biomass in boles, branches, foliage, woody roots, and fine roots were 61, 7, 6, 20, and 6%, respectively. Leaf area index ranged from 4.5 to 9.9. Leaf area per unit sapwood area ranged from 0.20 to 0.57 m2/cm2in stands of different densities, ages, and sites. Sapwood area was a more precise predictor of foliage biomass than was basal area for the low to moderate density stands, but was marginally inferior to basal area for two high density stands (>9000 trees/ha).

A Comparison of Planting Stock Characterization with Root Area Index, Volume and Dry Weight

1985 ◽  
Vol 61 (2) ◽  
pp. 64-70 ◽  
Author(s):  
G. D. Racey
Keyword(s):  
Picea Glauca ◽  
Dry Weight ◽  
High Light Intensity ◽  
Root Volume ◽  
Volume Determination ◽  
Area Index ◽  
Root Area ◽  
Nursery Stock ◽  
Volume Estimates ◽  
Root Area Index

Volume, area and weight methods for characterizing tops and roots of coniferous nursery stock were compared for accuracy, reproducibility and practicality using 60 seedling samples of red pine (Pinus resinosa Ait.), white pine (Pinus strobus L.) and white spruce (Picea glauca (Moench) Voss). Root volume estimates as determined by the volume displacement method were as accurate and reproducible as root area index estimates determined by the rhizometer. Root volume determination was faster than root area index while producing information of comparable quality and usefulness. White roots measured by a rhizometer can be underestimated by as much as 50% when a high light intensity is used. Dry weight is a reliable indicator of biomass but is time consuming compared with either root volume or root area index.

scholarly journals A simple model of P uptake by crops as a possible basis for P fertilizer recommendations.

1990 ◽  
Vol 38 (3A) ◽  
pp. 317-332 ◽  
Author(s):  
M. van Noordwijk ◽  
P. de Willigen ◽  
P.A.I. Ehlert
Keyword(s):  
Crop Production ◽  
Field Experiments ◽  
Mechanistic Model ◽  
P Uptake ◽  
Area Index ◽  
Soil P ◽  
Root Area ◽  
Fertilizer Recommendations ◽  
P Fertilizer ◽  
Root Area Index

In the Netherlands the Pw value, based on an extraction of soil P with water, is used as a basis for P-fertilizer recommendations for arable crops. Using a simple, mechanistic model of P transport in the soil the Pw value required for adequate P uptake by crops can be calculated on the basis of daily uptake requirements, root area index, P-adsorption isotherms and total amount of P taken up during a growing season. Calculated Pw values for adequate uptake are in the same range as the present recommendation scheme based on field experiments. Possible refinements of the model are discussed. For each soil the Pw value can be calculated that corresponds to the P concentrations in the soil solution according to standards set to reduce environmental pollution. The model predicts that, unless the root area index of non-cereal crops is considerably improved, these standards cannot be met in the plough layer without affecting crop production levels. Calculations show that the present method of determining the Pw value yields a reasonable compromise between a measurement of intensity and capacity of P supply in the soil. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Mitral tetrahedron as a geometrical surrogate for chronic ischemic mitral regurgitation

2005 ◽  
Vol 289 (3) ◽  
pp. H1218-H1225 ◽  
Author(s):  
Hsi-Yu Yu ◽  
Mao-Yuan Su ◽  
Yih-Sharng Chen ◽  
Fang-Yue Lin ◽  
Wen-Yih Isaac Tseng
Keyword(s):  
Mitral Regurgitation ◽  
Surface Area ◽  
Left Ventricular ◽  
Ischemic Mitral Regurgitation ◽  
Volume Index ◽  
Left Ventricular Ejection ◽  
Area Index ◽  
Ventricular Ejection Fraction ◽  
Cutoff Values ◽  
Chronic Ischemic Mitral Regurgitation

The present study tests the hypothesis that a mitral tetrahedron (MT) is a useful geometrical surrogate for assessment of chronic ischemic mitral regurgitation (CIMR). Fifty-eight subjects were divided into three groups on the basis of left ventricular ejection fraction (LVEF) and the presence or absence of CIMR: LVEF ≥0.5 and negative CIMR ( group 1, n = 28), LVEF <0.5 and negative CIMR ( group 2, n = 12), and LVEF <0.5 and positive CIMR ( group 3, n = 18). MT was defined by its four vertices at the anterior annulus, posterior annulus, and medial and lateral papillary muscle roots, determined by MRI at peak systole. The results showed no clear cutoff values of MT parameters between groups 2 and 1. In contrast, all MT indexes were significantly different between groups 3 and 2 ( P < 0.05), and significant cutoff values differentiated the two groups. A scoring system employing parameters of the whole MT confirmed the absence of CIMR with total edge length index <268 mm/BSA1/3, total surface area index <2,528 mm2/BSA2/3, and volume index <5,089 mm3/BSA (where BSA is body surface area). The sensitivity, specificity, and positive and negative predictive values were 1.00. This preliminary study demonstrates that MT might serve as a good geometrical surrogate for assessing CIMR. The derived geometrical criteria of MT may be useful in surgical correction of CIMR.

Fine root biomass and nutrient content in a black spruce peat soil with and without alder

1998 ◽  
Vol 78 (1) ◽  
pp. 163-169 ◽  
Author(s):  
J. S. Bhatti ◽  
N. W. Foster ◽  
P. W. Hazlett
Keyword(s):  
Fine Roots ◽  
Root Biomass ◽  
Fine Root ◽  
Black Spruce ◽  
Peat Soil ◽  
Chemical Properties ◽  
Nutrient Content ◽  
Fine Root Biomass ◽  
Boreal Peatlands ◽  
Strong Positive Relationship

Vertical distribution of fine root biomass and nutrient content was examined within a black spruce (Picea mariana) stand growing on a boreal peat soil in northeastern Ontario. The influence of site physical and chemical properties on fine root biomass production was assessed. More then 80% of the fine roots were present in moss plus the top 10 cm of peat where nutrients and aeration are most favourable. The fine root biomass (W/V) was significantly higher with alder (5.9 kg m−3) (Alnus rugosa) as understory vegetation compared to non-alder locations (2.9 kg m−3). Total nutrient content in fine roots was 54, 3.2, 5.4, 63 and 5.7 kg ha−1 on the alder site and 20, 1.4, 2.3, 28 and 4.2 kg ha−1 of N, P, K, Ca, and Mg on the non-alder site, respectively. The mass (W/V) of nutrients in fine roots was strongly dependent upon the availability of nutrients in the peat. Fine root content had a strong positive relationship with peat available P and exchangeable K contents suggesting that P and K may be limiting nutrients for black spruce in this peat soil. Key words: Nitrogen, phosphorus, potassium, boreal peatlands, aeration, water table

scholarly journals Intra and inter annual variation in a seagrass meadow on the Caribbean coast of Costa Rica: 2009-2015

2018 ◽  
Vol 66 (3) ◽  
pp. 1149 ◽  
Author(s):  
Margarita Loría-Naranjo ◽  
Jimena Samper-Villarreal ◽  
Marylaura Sandoval-Siles ◽  
Jorge Cortés
Keyword(s):  
Costa Rica ◽  
Leaf Area ◽  
Turnover Rate ◽  
Seagrass Meadow ◽  
Seagrass Beds ◽  
Seagrass Bed ◽  
Monitoring Methods ◽  
Caribbean Coast ◽  
Area Index ◽  
The Caribbean

Seagrass beds are an important ecosystem on the Caribbean coast of Costa Rica. At Cahuita National Park (CNP) a seagrass bed at Perezoso has been monitored continually since 1999 within the CARICOMP program. Thalassia testudinum is the dominant seagrass species, in some cases mixed with Syringodium filiforme. The results from the 2009 to 2015 monitoring period are presented here, and contrasted with data before 2009. Total (above and below ground tissue) mean biomass of T. testudinum was higher (1 255.4 ± 146.0 gm-2) than biomass before 2009, with an increasing tendency. However, productivity (1.5±0.59 gm-2d-1) and turnover rate (4.3 ± 1.22 %d-1) were lower than previous monitoring periods. In this period, mean leaf area diminished considerably (4.9 ± 2.30 m2), but leaf area index (LAI) increased (1.9 ± 0.80 m2leafm-2) in comparison to prior monitoring. Productivity, density, turnover rate, LAI and biomass showed intra-annual variations; while mean biomass of T. testudinum did not vary significantly among years. No correlations were found between water salinity, temperature and clarity with seagrass measurements. However, most seagrass parameters were strongly correlated with precipitation. These results highlight the effect of external environmental agents acting on the ecosystem. CNP presents a long-term stable seagrass meadow. However, there are indirect signals, such as high biomass and above-ground biomass proportion, along with low productivity and LAI, which point to a nutrient increment in Perezoso’s seagrass bed. To continue protecting this seagrass bed, it is necessary to improve monitoring methods, and seagrass beds should be included in national conservation policies and monitoring programs.

scholarly journals Bacillus thuringiensis in caterpillars and associated materials collected from protected tropical forests in northwestern Costa Rica

2014 ◽  
Vol 54 (2) ◽  
pp. 265 ◽  
Author(s):  
César Rodríguez-Sánchez ◽  
Ana Sittenfeld ◽  
Daniel H. Janzen ◽  
Ana M. Espinoza
Keyword(s):  
Costa Rica ◽  
Bacillus Thuringiensis ◽  
Tropical Forests

Soil organic carbon stabilization in dry tropical forests of Costa Rica

Geoderma ◽  
2009 ◽  
Vol 152 (1-2) ◽  
pp. 95-103 ◽  
Author(s):  
Klaus Lorenz ◽  
Rattan Lal ◽  
Juan J. Jiménez
Keyword(s):  
Costa Rica ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Tropical Forests ◽  
Carbon Stabilization ◽  
Dry Tropical Forests
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