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1

Warming effects on plant growth, soil nutrients, microbial biomass and soil enzymes activities of two alpine meadows in Tibetan Plateau

100%
Li N., Wang G. X., Gao Y. H., Wang J. F.
Polish Journal of Ecology
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2011
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tom 59
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nr 1
The aim of this study was to assess initial effects of warming on the plant growth, soil nutrient contents, microbial biomass and enzyme activities of two most widespread ecosystem types: swamp meadow (deep soil, high water content) and alpine meadow (poor soil, low water content), in the hinterland of the Qinghai-Tibet Plateau (altitude 4600–4800 m a.s.l.) The temperature of air and upper soil layer was passively enhanced using open-top chambers (OTCs) (50 cm high with 60 cm at opening and constructed of 6 mm thick translucent synthetic glass) from 2006 to 2008. The use of OTCs clearly raised temperature and decreased soil moisture. In warmed plots, monthly mean air temperature was increased by 2.10oC and 2.28oC, soil moisture of 20 cm soil layer was decreased by 2.5% and 3.9% in alpine meadow and swamp meadow, respectively. Plant biomass significantly increased by 31% in alpine meadow and 67% in swamp meadow. Warming also affected soil microbial biomass C and N at both meadows. In swamp meadow, warming caused the decrease of soil organic carbon and total nitrogen in 0–5 cm layer and an increase in 5–20 cm. While in alpine meadow, these soil parameters increased in 0–5 cm layer and decreased in 5–20 cm layer. The effects of warming on enzyme activities differed depending on the enzyme and the meadow ecosystem. In general, enzyme activities were higher in the upper soil layers (0–5 cm) than in the lower soil layers (5–20 cm). The experiment results exhibited that warming improved the soil biochemical and microbiological conditions in high- mountain meadows, at least in the short term.
2

Dietary effects of n-6:n-3 polyunsaturated fatty acid ratios on antioxidant status of the liver in goslings

88%
Wang M. Z., Ding L. Y., Wang J. F., Yu L. H., Wang H. R.
Journal of Animal and Feed Sciences
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2012
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tom 21
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nr 2
The objective of this study was to investigate the effects of dietary n-6:n-3 polyunsaturated fatty acid (PUFA) ratios on the oxidative stress of the liver in goslings. A total of 160 healthy Yangzhou geese was randomly divided into 4 groups, and each group was fed on diets with different n-6:n-3 PUFA ratios: A (12:1), B (9:1), C (6:1), and D (3:1), respectively. The liver was separated and antioxidant functions were evaluated on days 42, 56, and 70. The results showed that the activities of total superoxide dismutase, glutathione peroxidase, and catalase decreased when the geese aged, and were highest on d 42 in each group (P<0.05). The activities of these enzymes increased as the n-6:n-3 PUFA ratios decreased and were highest in the 3:1 group at all tested ages (P<0.05). It was also observed that the levels of H2 O2, malondialdehyde (MDA), and nitric oxide (NO) in liver tissue tended to increase with age, and were relatively higher on d 70. Furthermore, the levels of H2 O2, MDA, and NO decreased as n-6:n-3 PUFA ratios decreased and were lowest at 3:1 and 6:1 at all studied ages (P<0.05). Overall, diets containing comparatively low n-6:n-3 PUFA ratios, such as 3:1 or 6:1, could increase antioxidant function and decrease hepatocyte damage in liver tissue.
3

The effects of n-6:n-3 polyunsaturated fatty acid ratios on serum protein and immunoglobulins in the Yangzhou goose

88%
Wang M. Z., Ding L. Y., Wang J. F., Yu L. H., Wang H. R.
Journal of Animal and Feed Sciences
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2012
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tom 21
|
nr 2
This study was conducted to investigate the effects of n-6:n-3 polyunsaturated fatty acid (PUFA) ratios on serum protein and immunoglobulins in growing geese. One hundred and sixty healthy Yangzhou geese were randomly divided into 4 groups: diets were designed as 12:1, 9:1, 6:1, and 3:1, respectively, by varying dietary n-6:n-3 PUFA ratios. Protein and immunoglobulin levels were measured on d 42, d 56, and d 70. The experimental results showed that total protein was highest in group 6:1 on d 42 (P<0.05), albumin, in group 12:1 on d 56 (P<0.05), and globulin, in group 6:1 on d 42 (P<0.05). No significant difference was detected in the albumin/globulin ratio (A/G ratio) among groups (P>0.05); however, the numerical value of the A/G ratio of group 3:1 was higher than in any of the other groups at all sampling ages. On d 56 and 70, IgA and IgM were highest in group 3:1, whereas IgG was highest in group 6:1, and these values were significantly higher than in the other groups (P<0.05). Overall, diets containing low n-6:n-3 PUFA ratios could increase the serum A/G ratio, IgA, IgG, and IgM, in the Yangzhou goose on days 56 and 70.
4

Plant traits response to grazing exclusion by fencing assessed via multiple classification approach: a case from a subalpine meadow

64%
Li W. J., Liu S. S., Li J. H., Zhang R. L., Rang K. Z. C., Zhou H. K., Yao B. Q., Wang J. F.
Polish Journal of Ecology
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2019
|
tom 67
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nr 1
Using multiple classification approach to examine plant traits response to grazing and fencing (as without access to grazing) is rare. Here we used multiple classification approach to examine plant diversity, productivity and species traits response to grazing and fencing over a three-year period on the eastern part of the Qing-Hai Tibetan Plateau. The results showed that most common species response to the fence was poorly noticeable. The fencing meadows compared to those under long-term free grazing are characterized by significantly higher total species richness, but species richness declined with sampling years gradually, regardless of grazing or fencing. The correlation showed that species richness was negatively associated with mean annual temperature significantly, suggesting that abiotic factors (e.g. annual temperature) could also play important roles in driving species richness in this subalpine meadow. Total aboveground biomass was not associated with mean annual temperature and rainfall. The fencing meadow demonstrated higher community aboveground biomass relative to the grazing ones, especially the abundance of legume and graminoids increased, while the proportions of sedge decreased, suggested that grazing disturbance favours the increase of reproductive success of sedge (e.g. Kobresia humilis) in this subalpine meadow. Growth form-based analyses combined with canopy height categories should be recommended to reveal general rules and mechanisms relating to grazing.
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