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The Effect of Different Improving Measures on Nutrients and Its Ecological Stoichiometry of Degenerated Leymus Chinensis Steppe

Author: LiZaoXia
Tutor: BaoYinTaoGeTao
School: Inner Mongolia University
Course: Ecology
Keywords: Degenerated grassland Improved measures Community Nutrient Stoichiometric ratio
CLC: S543.9
Type: Master's thesis
Year: 2011
Downloads: 92
Quote: 3
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Abstract


Natural recovery, rake, shallow plowing and sowing the L. chinensis four grassland improvement measures to deal with Leymus chinensis steppe community characteristics degradation after 26 years of below-ground biomass, soil, plants and roots of nutrients and its chemical stoichiometry were analyzed and outside the fence grazing plots as a control to explore the impact of different improvement measures on community nutrients and their stoichiometric conditions more conducive to human understanding of the law of succession and direction to optimize the existing improvement measures, improvement of the grass toward in the desired direction, and comparison of different ameliorative measures, provide a scientific basis for the restoration and improvement of degraded pasture and grassland productivity, the best way to seek restoration of degraded grassland. The main findings are as follows: 1, soil organic matter, the full effect nutrients and available nutrient content in the different treatments are reduced with the increase of soil depth, the significant difference between treatments gradually along with the increase of soil depth disappeared, outside the bar significantly lower than the improvement measures in the column, the column overall highest natural recovery. 2, nutrient stoichiometric ratio column improvement measures no significant difference (p = 0.05); under different soil indicators relationship, soil nitrogen and available nitrogen in the natural recovery to achieve significant positive correlation, total phosphorus significant positive correlation (p = 0.05) and available phosphorus in harrow and bar outside control; each treatment soil nitrogen content N / P limit is greater than the soil phosphorus column of each treatment is mainly affected by soil C / N limitations of soil nitrogen content of soil organic matter smaller effect, but the C / P and C / N is just the opposite. Improved treatment community biomass, density and litter than the bar significantly increased (p = 0.05). Aboveground biomass and litter column each treatment natural restore gt; the harrow gt; shallow plowing gt; the reseeding sheep, a higher proportion of natural recovery and harrow quality forage; community density of natural recovery GT; rake gt ; sowing the L. chinensis gt; shallow plowing. Different Improving Measures on plant nitrogen content is greater than the phosphorus content, the overall nitrogen content of the column in the external control and natural recovery was significantly higher than the other three improvement measures, different processing plant phosphorus content little difference (p = 0.05); come to the ground by the N / P as a whole are nitrogen deficiency state, harrow, shallow plowing and sowing L. chinensis than natural recovery is more serious. 5, the order of the total biomass of different ameliorative measures underground natural restore gt; the harrow gt; the shallow plowing deleted gt; sowing chinensis GT; outside the fence, most of the below-ground biomass of each treatment are concentrated in the surface soil, with the soil layer depth increases, the sharp decrease in biomass. Different treatment on the ground / underground biomass: column outside the control column was significantly higher than the improvement measures, the improvement measures in the fence between the ground / below-ground biomass was no significant difference (p = 0.05). 6 different ameliorative measures Root Nitrogen and phosphorus content of the column in the external control and natural recovery was significantly higher than the other three treatments; roots natural recovery column in the external control and nitrogen deficiency conditions than shallow plowing sowing chinensis and harrow more serious . 7, compared with the native Leymus chinensis steppe, soil organic matter and total phosphorus content overall than the native communities to improve; total nitrogen content and the stoichiometric ratio (N / P, C / N and C / P) compared with the native communities in decline; processing plant nitrogen content and N / P compared with native communities is reduced; plant phosphorus content than the native communities have reduced both increased.

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CLC: > Agricultural Sciences > Crop > Fodder crops,pasture > Perennial grass forages > Other
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