Study On The Restoration Effects Of Enclosed Pasture In The National Project Of Pastureland Rehabilitation Areas In A-Ba County

The A-Ba county already completed the national project of pastureland rehabilitation in 2003, 2004and 2005, This experiment have studied on the restoration effects about fenced pasture (include grazingprohibition and resting grazing) of this project (to facilitate better compared study and analysis, This testalso increased two fenced pasture of 2002, as a supplement).in the trial we selected grazing grass of nofenced as a control in outside on the project area. According to Compared the changes of diversity ofcommunity, quantitative structure of community and rules of soil nutrients variety in the plots of grazingprohibition, resting grazing and grazing control, we aimed to know the influence of fenced grazingprohibition and resting grassland to the restoration of the degenerated grassland. The results showed:1. After fencing grazing prohibition and rest grazing in grazing pastureland, changes of speciesdiversity of each plot as follow: rest grazing＞forbidden grazing＞grazing control. The species diversity ofplant community in the fenced plot had decreasing trend as the increase of fence years, but the variationtrend of community richness and uniformity was consistent in all the fenced plots.2. After through fencing grazing prohibition and rest grazing in the degenerated grassland, theabove-ground biomass was increased significantly, the forbidden grazing and rest grazing were significantdifferent from the control (p＜0.01), and with the years of fence increasing, increased amounts of theaboveground biomass was also greater gradually., The above-ground biomass in forbidden grazing plotsfrom 2002 to 2005 as following: 8224.1 kg/hm~2, 6093.1 kg/hm~2,4792.3kg/hm~2,4152.1 kg/hm~2, and increasedby average of 87.67%, 74%, 68.07% and 50.36% respectively more than control; and in rest grazing plotswere 6383.2 kg/hm~2,5382.7 kg/hm~2,4532.3 kg/hm~2 sequentially(no rest grazing in 2002), respectively,compared with the control increased 82.29%,88.77% and 64.13%.This result showed that grazingprohibition and rest grazing could significantly enhanced the aboveground biomass of the pastureland.3. After through fencing grazing prohibition and rest grazing, the total coverage of plant community,height of community were significantly increased, and forbidden grazing and rest grazing plots weredifferent from the control (p＜0.05). From 2002 to 2005, the height of community in forbidden grazing plotswere 33.62cm,25.15 cm,21.67 cm,17.29 cm, increased 85.11%, 76.98%, 45.73%, 36.79% respectively more than the control, and with the fence year increasing, the height of community of forbidden grazingplots also increased. And the height of community in rest grazing plots were: 24.53 cm, 23.32 cm, 21.18cm(no rest grazing plot in 2002), respectively, compared with their respective controls, increased72.62%,56.83%,67.56%.4. After through fencing grazing prohibition and rest grazing, the dominance of plant communitychanged obviously, the dominance of excellent forage (Kobresia setchwanenesis,Kobresia Pygmaea,Etymus nutans)began to increased, but the dominance of miscellaneous grass plants(Potentilla anserina,Polygonum vivparum,Saussuren japonica) and the poisonous plant (Oxytropis ransuensis,Ranunculusbrotherusii,Anemone rivularis) decreased gradually, and with the fence year increasing, the configurationof meadow plant community changed significantly, the plant of Gramineous and kobresia communitybegan to occupy the dominant position, and some miscellaneous grass and poisonous plant even began todisappear, such as Ranunculus brotherusii, Anemone rivularis, Polygonum vivparum.5. Fenced Forbidden grazing and rest grazing could significantly improve organic content in surfacesoil of pastureland (0-15 cm).The soil organic content was significant different in forbidden grazing, restgrazing and control plots (p＜0.05), and the soil organic content of fenced plots increased gradually.Meanwhile, total phosphorus, total nitrogen content of soil in fenced plots had varying degrees of elevationthan the control, but the increase of total potassium content were smaller; the content of soil availablenutrient (consist of available nitrogen, potassium and phosphorus) in the fenced plots increased obviously,and the increased amounts of available nutrient were consistent with the fencing year; but the soil pH hasnot significantly change.6. The study results showed that forbidden grazing and rest grazing can improve grassland vegetationand soil nutrient on the pastureland effectively, according to fencing on grazing degenerated grassland,the interference of grazing was eliminated, then the grassland could recuperate effectively, began toimprove and restore, the plant species and amounts, species diversity, aboveground biomass, grass-height,the total vegetation coverage were all increased; and the quality of grassland were improved significantly,and excellent forage plants increased gradually, species and amounts of poisonous plant began to decreased.Therefore, based on the above results, we can see that the fencing grasslands in the areas of pasturelandrehabilitation project were resumed effectively.