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Sari?JuutinenEmail author Tuula?Larmola Rainer?Remus Edith?Mirus Wolfgang?Merbach Jouko?Silvola Jürgen?Augustin 《Biology and Fertility of Soils》2003,38(1):10-14
The contribution of Phragmites australis (Cav.) Trin. ex Steud. (common reed) litter as an origin of CH 4-C was studied in a microcosm experiment. 14C-labelled, dried and ground P. australis root and shoot litter was buried in waterlogged, planted or non-planted fen microcosms. The evolution of 14CO 2 and 14CH 4 from the pots was monitored during the 35-day experiment. The 14C activity in the shoots and roots of the plants, soil, and inundation water was also analysed at the end of the experiment. Up to 40% of the released CH 4-C originated from the added litter, whereas the rest originated from old soil organic matter. The comparison of planted and non-planted pots suggested that the contribution of recent plant-derived C (i.e. root exudates) to CH 4 emission was negligible. The proportion of litter-derived CH 4-C was significantly higher in the planted pots, suggesting that the presence of plants enhanced the formation of CH 4 from litter. The major part of the initial 14C activity was recovered from the soil. About 3% was recovered from the inundation water, about 10% was emitted as CO 2, and only <0.01% as CH 4. However, these results demonstrated that plant litter and old soil organic matter are the major sources of CH 4-C in fens during the early growth stage of P. australis. 相似文献
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Pekka Vähäoja Petteri Piltonen Anna Hyvönen Jouko Niinimäki Jorma Jalonen Toivo Kuokkanen 《Water, air, and soil pollution》2005,165(1-4):313-324
This study focuses on the biodegradability measurements of tall oil-based wood preservatives and their raw materials in groundwater as determined by the respirometric BOD OxiTop method. Certain substances were also analyzed in standard conditions described by OECD 301 F. Results show that creosote oil, a traditional wood preservative, does not biodegrade at all in groundwater over a period of 28 days, while tall oil and linseed oil biodegrade to some degree (13.4% and 14.8%, respectively). On the other hand, degrees of biodegradation of linseed oil, tall oil and creosote oil in the extra mineral and microbe including conditions described by OECD 301 F were 72.9%, 54.3% and 24.9% after 28 days, respectively. Studied raw materials of tall oil-based wood preservative production biodegrade to some degree in groundwater (variability from 11.9% to 18%) and quite effectively in OECD 301 F test (variability from 39% to 71.7%) over a period of 28 days. Abiotic degradation may also be significant with the studied substances. 相似文献
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An epidemiological and genetic study on registered diseases in Finnish Ayrshire cattle. III. Metabolic diseases 总被引:1,自引:0,他引:1
The epidemiology of clinical ketosis, hypocalcaemia and hypomagnesaemia was examined. In addition, the genetic variability of ketosis and parturient paresis was investigated. The data set consisted of the lactation records of 70,775 Finnish Ayrshire dairy cows. Each cow was under observation for 2 days before and for 305 days after calving. Lactation incidence rates (%) were: ketosis 6.0, parturient paresis 3.8, non-parturient paresis 0.6, hypomagnesaemic tetany, outdoor 0.6, and indoor 0.2. These diseases formed 22 % of all first treatments by veterinarians during farm visits. 92 % of the cases of ketosis occurred with 8 weeks of parturition, with the highest occurrence 3–5 weeks after calving. Four % of cases of parturient paresis occurred before, and 45 % within 24 h after calving. When cases were categorized by month of calving the risk of ketosis was higher during indoor feeding (October-April) than during outdoor feeding (May-September). The risk of parturient paresis did not significantly vary with month of calving. The occurrence of ketosis increased with parity up to the 4th and decreased thereafter. The occurrence of parturient paresis increased with parity. Both the increase in herd milk yield and the increase in individual milk yields were positively associated with the occurrence of ketosis and parturient paresis. The cows with a history of the reproductive tract infection had a higher risk of contracting ketosis. Heritability estimates for ketosis in various parity groups were from 1.6 % to 4.1 % on the binomial scale (corresponding to 7.3 %–14.4 % on the normal scale), and for parturient paresis from 3.5 to 10.5% (corresponding from 18.3 % to 27.4 %). The genetic correlation between ketosis and parturient paresis, and these and current milk production for all material were insignificant. 相似文献
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Schmidt TB Brown MS Larson RL Kleiboeker SB Olson KC Keisler D Carroll JA Berg EP 《American journal of veterinary research》2006,67(7):1192-1198
OBJECTIVE: To determine the effect of dietary supplemental lipoic acid (LA) on serum concentrations of metabolic hormones and acute-phase proteins of steers challenged with infectious bovine rhinotracheitis virus (IBRV). ANIMALS: 32 steers. PROCEDURES: Steers were randomly assigned to 4 treatments: negative control (NC; no LA, no IBRV challenge), control (CON; no LA, IBRV challenge), 16 mg of LA/kg of body weight (BW)/d plus IBRV challenge (LA16), and 32 mg of LA/kg of BW/d plus IBRV challenge (LA32). Following a 21-day adaptation period, CON, LA16, and LA32 steers received IBRV (2 mL/nostril [day 0]); NC steers received saline (0.9% NaCl) solution. Blood samples, nasal swab specimens, BW, and rectal temperatures were obtained 0, 1, 3, 5, 7, 14, and 21 days after challenge. Serum was analyzed for concentrations of haptoglobin, amyloid-A, leptin, and anti-IBRV antibodies. RESULTS: Steers fed LA32 began gaining BW by day 7, whereas BW of CON and LA16 steers declined. Serum haptoglobin concentration of LA32 steers was lower than that of CON and LA16 steers on day 7. Serum neutralization titers for 30 of 32 steers were negative for anti-IBRV antibodies before challenge; however, all steers (including NCs) had antibodies on day 21. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that LA supplementation augmented certain aspects of the immune response; LA32 steers had a more rapid recovery from IBRV viral challenge than did others. 相似文献