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  • 1
    Electronic Resource
    Electronic Resource
    Current Status and Potential Applications of Drug Delivery Balloon Catheters (1995)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of interventional cardiology 8 (1995), S. 0 
    Details
    ISSN: 1540-8183
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1540-8183.1995.tb00566.x
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  • 2
    Electronic Resource
    Electronic Resource
    The net carbon flux due to deforestation and forest re-growth in the Brazilian Amazon: analysis using a process-based model (2004)
    Oxford, UK : Blackwell Science Ltd
    Global change biology 10 (2004), S. 0 
    Details
    ISSN: 1365-2486
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Geography
    Notes: We developed a process-based model of forest growth, carbon cycling and land-cover dynamics named CARLUC (for CARbon and Land-Use Change) to estimate the size of terrestrial carbon pools in terra firme (nonflooded) forests across the Brazilian Legal Amazon and the net flux of carbon resulting from forest disturbance and forest recovery from disturbance. Our goal in building the model was to construct a relatively simple ecosystem model that would respond to soil and climatic heterogeneity that allows us to study the impact of Amazonian deforestation, selective logging and accidental fire on the global carbon cycle. This paper focuses on the net flux caused by deforestation and forest re-growth over the period from 1970 to 1998. We calculate that the net flux to the atmosphere during this period reached a maximum of ∼0.35 PgC yr−1 (1 PgC= 1 × 1015 gC) in 1990, with a cumulative release of ∼7 PgC from 1970 to 1998. The net flux is higher than predicted by an earlier study (Houghton et al., 2000) by a total of 1 PgC over the period 1989–1998 mainly because CARLUC predicts relatively high mature forest carbon storage compared with the datasets used in the earlier study. Incorporating the dynamics of litter and soil carbon pools into the model increases the cumulative net flux by∼1 PgC from 1970 to 1998, while different assumptions about land-cover dynamics only caused small changes. The uncertainty of the net flux, calculated with a Monte-Carlo approach, is roughly 35% of the mean value (1 SD).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1529-8817.2003.00765.x
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  • 3
    Electronic Resource
    Electronic Resource
    Biologically Active Neuropeptide Y Analogs (1990)
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 611 (1990), S. 0 
    Details
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1749-6632.1990.tb48919.x
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  • 4
    Electronic Resource
    Electronic Resource
    Mechanisms for changes in soil carbon storage with pasture to Pinus radiata land-use change (2003)
    Oxford, UK : Blackwell Science Ltd
    Global change biology 9 (2003), S. 0 
    Details
    ISSN: 1365-2486
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Geography
    Notes: In this study, we simulated pasture to Pinus radiata land-use change with the Generic Decomposition And Yield (G'DAY) ecosystem model to examine mechanisms responsible for the change in soil carbon (C) under pine. We parameterized the model for paired sites in New Zealand. Our simulations successfully reproduced empirical trends in ecosystem productivity and soil inorganic nitrogen (N), and modeled an increase in soil C and a small decline in soil N after 30 years under pine. We determined the mechanisms contributing to soil C change based on an established hypothesis that attributes increases in soil C storage to three main factors: increased ecosystem N inputs relative to outputs, increased C/N ratios in plant and soil, or a shift of N from plant to soil. The mechanisms we attributed to the simulated increase in soil C under pine were increased soil C inputs through tree litterfall, and an increase in the soil C/N ratio. In the first 7 years following pine establishment, a decline in soil C was simulated; this was matched by a decline in soil N. The simulated longer-term increase in soil C with afforestation by pine contrasts with results from published field studies, which show either a decline or no change in soil C under pine. The discrepancy between measured and simulated changes in soil C was attributed to the G'DAY model overestimating the transfer of litter C into the mineral soil.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2486.2003.00659.x
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  • 5
    Electronic Resource
    Electronic Resource
    Effects of filter type and extraction efficiency on nitrogen mineralization measurements using the aerobic leaching soil incubation method (1995)
    Springer
    Biology and fertility of soils 20 (1995), S. 197-204 
    Details
    ISSN: 1432-0789
    Keywords: Aerobic incubation ; N mineralization ; N extraction efficiency ; Tropical forest soils ; Soil moisture levels
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Aerobic incubation of soils with sequential leachings to extract mineralized N is often used to determine N mineralization potential and N availability in the laboratory. This study used tropical forest soils with differing mineralogy and texture to address: (1) the effects of filter type and equilibration time on soil moisture and N mineralization and (2) the N extraction efficiency of 0.01 M CaCl2, minus-N nutrient solution (containing 0.004 M CaCl2) and 2 M KCl. Use of glass microfiber filters compared to cellulose acetate or polyethersulfone membrane filters resulted in a lower moisture content for both low-and high-clay soils. However, filter type did not affect N mineralization. Under 47 kPa suction, soil moisture equilibration occurred between 240 and 360 min regardless of filter type. Extraction efficiency for mineralized N using 0.01 M CaCl2 or minus-N nutrient solution was lower in forest soils of smectitic mineralogy and soils with a higher proportion of macroaggregates. However, with the exception of allophanic soils, the cumulative amount of N mineralized measured in a long-term incubation for approximately 1 year was not different when either a leaching or an unleached incubation method was used. These results indicate that researchers may wish to conduct preliminary evaluations to determine whether their incubation method will achieve a desired uniform moisture level and N extraction efficiency.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00336558
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  • 6
    Electronic Resource
    Electronic Resource
    Foliage litter quality and annual net N mineralization: comparison across North American forest sites (1997)
    Springer
    Oecologia 111 (1997), S. 151-159 
    Details
    ISSN: 1432-1939
    Keywords: Key words Litter quality ; Lignin:N ratio ; Nitrogen mineralization ; Climate ; Forests and grasslands
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The feedback between plant litterfall and nutrient cycling processes plays a major role in the regulation of nutrient availability and net primary production in terrestrial ecosystems. While several studies have examined site-specific feedbacks between litter chemistry and nitrogen (N) availability, little is known about the interaction between climate, litter chemistry, and N availability across different ecosystems. We assembled data from several studies spanning a wide range of vegetation, soils, and climatic regimes to examine the relationship between aboveground litter chemistry and annual net N mineralization. Net N mineralization declined strongly and non-linearly as the litter lignin:N ratio increased in forest ecosystems (r 2 = 0.74, P 〈 0.01). Net N mineralization decreased linearly as litter lignin concentration increased, but the relationship was significant (r 2 = 0.63, P 〈 0.01) only for tree species. Litterfall quantity, N concentration, and N content correlated poorly with net N mineralization across this range of sites (r 2 〈 0.03, P = 0.17–0.26). The relationship between the litter lignin:N ratio and net N mineralization from forest floor and mineral soil was similar. The litter lignin:N ratio explained more of the variation in net N mineralization than climatic factors over a wide range of forest age classes, suggesting that litter quality (lignin:N ratio) may exert more than a proximal control over net N mineralization by influencing soil organic matter quality throughout the soil profile independent of climate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004420050219
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  • 7
    Electronic Resource
    Electronic Resource
    Soil Aggregation and Organic Matter Mineralization in Forests and Grasslands: Plant Species Effects (1998)
    Springer
    Soil Science Society of America journal 62 (1998), S. 1081-1089 
    Details
    ISSN: 1435-0661
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Larix decidua Miller], red oak [Quercus rubra L.], red pine [Pinus resinosa Ait.], white pine [Pinus strobus L.], and Norway spruce [Picea abies (L.) Karst]) and one containing six grass species (big bluestem [Andropogon gerardi Vitm.], indiangrass [Sorghastrum nutans (L.) Nash], prairie sandreed [Calamovilfa longifolia (Hook) Scrib.], switchgrass [Panicum virgatum L.], little bluestem [Schizachyrium scoparium (Michx.) Nash.], and sideoats grama [Bouteloua curtipendula (Michx.) Torr.]). The grass monocultures are burned annually. Souls were wet sieved into four size classes (〉2000, 250–2000, 53–250, and 〈53μm). Unsieved soil was incubated aerobically for 30 and 387 d to examine C and net N mineralization. For tree species, aggregate weighted mean diameter (WMD) differed between species (P=0.01), and correlated positively with fungal biomass (r=0.56). Large macroaggregate (〉2000 μm) C concentration ranged from 15 to 26 g kg–1, and was lowest for Norway spruce and red oak (P=0.07). Aggregate WMD correlated weakly (and negatively) with potentially mineralizable N (r=0.57) and in situ net N mineralization (r=0.49). Grass species had no effect on aggregate-size distribution or organic matter concentration in spite of twofold differences in root biomass and threefold differences in N cycling rates. Species-induced changes in soil aggregation explained little of the variation in whole-soil C and N cycling rates, and therefore unlikely to be an important mechanism explaining species effects on ecosystem processes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/
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