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- Nicolás, César, et al.
(författare)
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Type and quantity of organic amendments determine the amount of carbon stabilized in particle-size fractions of a semiarid degraded soil
- 2017
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Ingår i: Arid Land Research and Management. - : Informa UK Limited. - 1532-4982 .- 1532-4990. ; 31:1, s. 14-28
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Tidskriftsartikel (refereegranskat)abstract
- A 9-month lab experiment was carried out with three different amendments (vine pruning wastes, PW; composted vine pruning wastes, cPW; and sewage sludge, SS) added at three different rates (90, 180, and 240 t ha−1, dry weight) in order to test whether the type or the quantity of the amendments applied to a semiarid, degraded soil determined the Corg accumulation in its particle-size fractions (coarse sand, 200–2,000 µm; fine sand, 63–200 µm; silt, 2–63 µm; and clay, 0.1–2 µm). All amendments, independently of their C/N ratios, resulted in similar Corg content and accumulation in coarse sand and silt-sized fractions after 9 months. In the clay-sized fraction, enrichment in Corg produced the incorporation of particles from this particle-size fraction into the silt-sized fraction. Likewise, increasing the application rates of the amendments led to larger Corg contents into the particle-size fractions of all amended soils except for the clay-sized fraction. The application of SS resulted in lower basal respiration-to-Corg ratios in the clay-sized fraction than the application of PW and cPW, suggesting a higher protection of the Corg in the SS treatment. These results indicate that organic amendments from woody plants with C/N ratios higher than 30, such as PW, favor Corg accumulation in the fine sand-sized fractions. Furthermore, our findings suggest that the application rate of such amendments, rather than the C/N ratios and amendment origin (from sludge or woody plants), is the key factor for promoting Corg accumulation in the silt-sized fractions of semiarid degraded soils.
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| 2. |
- Wang, XP, et al.
(författare)
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Evapotranspiration of Artemisia ordosica vegetation in stabilized arid desert dune in Shapotou, China
- 2004
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Ingår i: Arid Land Research and Management. - : Informa UK Limited. - 1532-4982 .- 1532-4990. ; 18:1, s. 63-76
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Tidskriftsartikel (refereegranskat)abstract
- More than 40 years of revegetation using mainly Artemisia ordosica, Hedysarum scoparium, and Caragana korshinskii at Shapotou Desert Experimental Research Station near Lanzhou has established a dwarf-shrub and herbaceous cover on the stabilized sand dunes. The evapotranspiration (ET) of the xerophyte dwarf-shrub A. ordosica plant vegetation was measured by the autoweighing lysimeter method during the growing seasons from 1990 to 1995, and 2002 on the southeast edge of the Tengger Desert at Shapotou, China. The study showed that the average ET rates were 0.88 mm d(-1), and they varied from 0.6 mm d(-1) to 1.31 mm d(-1) during the 7-year experimental period from 1990 to 1995, and 2002. The ratios of ET/Precipitation (P) varied from 69.8% to 120.9% with an average of 90.9%. The higher ET/P value in 1991 was associated with the properties of intra year distribution of rainfall events, and resulted in soil moisture depletion. The correlation between the accumulative P and the accumulative ET was quite high. For the years 1990, 1993, and 1995, the relationship between the accumulative ET and the accumulative P had a closed linear relationship, resulting from the higher intensity of monthly P exceeding 40% of the overall P during the growing season. Whatever the variation in the monthly P, statistics showed that the relationship between the accumulative P and ET could be expressed as an equation, ET=0.8003 P+5.8914, with a correlation coefficient of R-2=0.9035. Results suggest that in areas similar to Shapotou it is practical to establish an artificial protection belt using xerophytic shrubs.
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| 5. |
- Björck, Martin, et al.
(författare)
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Plasminogen Activator Inhibitor-1 Levels and Activity Decrease After Intervention in Patients with Critical Limb Ischaemia
- 2013
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Ingår i: European Journal of Vascular and Endovascular Surgery. - : Elsevier BV. - 1078-5884 .- 1532-2165. ; 46:2, s. 214-222
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Tidskriftsartikel (refereegranskat)abstract
- Patients with peripheral arterial occlusive disease (PAOD), in particular critical limb ischaemia (CLI), carry a high risk of thrombotic events. We hypothesised that patients undergoing conservative, endovascular, or open surgical treatment for CLI have increased levels of plasminogen activator inhibitor-1 (PAI-1), leading to a prothrombotic state. The objective was to determine levels of PAI-1 in patients with acute or chronic PAOD/CLI. Thirty-two patients with a median age of 74 (49–90) years were included. Three underwent thrombolysis for acute limb-threatening ischaemia. Twenty-six patients with chronic ischaemia received endovascular (n = 20) or open (n = 6) surgical treatment. Three were treated conservatively. Biomarkers and ankle brachial index (ABI) were measured before and up to 1 month after intervention. Patency was studied with repeated duplex ultrasound. Ankle pressure and ABI improved after intervention (p < .001). C-reactive protein (CRP) increased from a median of 7.90 mg/L at baseline to 31.5 on day 1 (p < .001), 28.0 on day 6 (p < .001), and returned to baseline levels on day 30. PAI-1 antigen and activity decreased from day 6 and onwards post-intervention compared with baseline (p < .05). A great individual variability in PAI-1 antigen and activity was observed. Although most actively treated patients had normal PAI-1 activity, 11/29 (38%) were above that level of normality at baseline, 10/24 (42%) on day 1, 3/23 (13%) on day 6, and 5/27 (19%) on day 30 after intervention. Endovascular and open surgical treatment resulted in improved ankle pressure and ABI. The intervention was followed by a transient increase in CRP and a sustained reduction in PAI-1 levels and activity.
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