| This study is financed by Nature Science Fund of Hei Longjiang province (C200811).Thymus mandschuricus, a kind of woody ground cover plant, which is planted in Maoer Mountain of Northeast Forest University. This paper is to study the growth influence on different trampling for Thymus mandschuricus, physiology, bio-chemical metabolism, the impact of physicochemical properties for soil of seedbed and the characteristics of clone growth. The results are as follows;(1) Different levels of trampling have significant effect on height, leaf density and biomass of root, stem and leaf of Thymus mandschuricus. Plant height is decreasing with the trample strength increased. Compared with the contrast, Mild trampled plots were not distinctive, but moderate and severe trampling plants plots were significantly difference with the comparison, particularly severe violations, with the numbers of trampling increased, plant height, leaf density decreased rapidly to the fifth trampling they were reduced 24.1% and 51.2% respectively. The biomass of root, stem and leaf was decreased respectively by 37.8%, 54.8%,38.3%.(2) With the frequency of trampling and intensity increased, soil compactness showed a upward tendency. After the 5th moderate and heavy trampling, the soil compaction is up to 0.401,0.531 kp, compared with the comparison have significantly different. Increased soil compaction lead to decreasing of water infiltration and soil water, and soil PH is increased. The content of soil nutrient (Nitrogen, Phosphorus, Kalium) showed downward trend, which was significantly difference and influenced plant growth. As intensity of trampling increased, the soil Nitrogen content of three different levels of trampling was decreased by 0.14,0.08,0.10 g /kg respectively. Phosphorus content was decreased byl 1.49,2.23,5.43 g/kg; Kalium content was decreased by 23.68,13.59,11.91 g/kg.(3) With trampling intensity increased, MDA, soluble sugar, protein, and proline of Thymus mandschuricus increased, and was increased respectively by 129.9%,215.5%, 92.2%,173.9%respectively with severe trampling stress.After mild trampling, Thymus mandschuricus had a little influence on the normal growth and appreciation character, and it was recovered within 4-7d. However, moderate and severe had serious impact, particularly under severe trampling, the serious damage to the plant stems, leaves and flowers wither and fall seriously, soil surface surrounding plant roots harden seriously, even seriously affected the physiological indices, so it can't be completed in the life cycle and lead to death in the growing season. (4) During the growing season, the stem length of the mother plants, the second and third ramet stems of Thymus mandschuricus in original habit were increased by 2.3,1.7,1.8 cm respectively, the length of cultivated were increased by 7.1,8.7,13.1 cm. The better growing conditions will promote the speed of clone growth. We suggest that the planting density is 16/m2 in landscape applications and the coverage is more than 65% in 2-3 months, and this can reach a very good scenery. The flowering period of cultivated plant will be longer about 20d.(5) The clonal growth of Thymus mandschuricus is creeping stems clone. The growth rate of stems biomass showed significantly difference between the mother plant and the offspring ramet. The biomass growth of the second ramet reached maximum,19.38g from July to September.In the growth season, the sprout ability of new root of offspring ramet and the growth speed are all better than mother plant. The root biomass of mother plant and the second and third ramet stems were increased by 7.11,11.57,11.81 g respectively from July to September. The second-class ramet stems had the similar cases with the third-class, and this situation is most favourable for offspring independent growth of Thymus mandschuricus clonal growth.
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