| Phyllostachys nidularia Munro f.nidularia has become an important substitute for wood due to its early growth,rapid growth and renewal,high yield,high nutritional value of bamboo shoot and high added value.There are 358,700 mu of bamboo forest resources in Liangping District,of which 130,000 mu are Phyllostachys nidularia Munro f.nidularia,and over 100,000 mu are Phyllostachys nidularia Munro f.nidularia inefficient forest(accounting for 66.7% of the entire chongqing Phyllostachys nidularia Munro f.nidularia inefficient forest)..However,the existing bamboo forest area in Liangping can’t satisfy the needs of the development of industrialization,so low renovate the efficiency of Phyllostachys nidularia Munro f.nidulariaforest can effectively ease the contradiction between supply and demand of bamboo resources.This paper takes low-efficiency of Phyllostachys nidularia Munro f.nidularia in zhushan town of Liangping,as the research object,Chongqing.Research the implementation of artificial promote update technology(including opened,scarification,secondary fertilization,bamboo forest structure adjustment,pest control,etc.),before carrying out comparative analysis in October 2015 and November 2017 after the project implementation related data,points on the comprehensive evaluation of different elevation transform technology implementation of dialogue between bamboo forest of inefficient production,hair bamboo bamboo shoots back rate and the effect after transforming forestry comprehensive benefits.The main research results are as follows::(1)Elevation gradient has significant effects on field water capacity,organic matter,alkali-hydrolyzable nitrogen,available phosphorus and available potassium(P < 0.05).It has significant effects on soil bulk density,soil p H,soil porosity,soil temperature and soil moisture,but not to a significant level.In general,as elevation increases,soil organic matter,alkali-hydrolyzable nitrogen,available phosphorus,available potassium,field water capacity and temperature all decrease to varying degrees,while soil p H increases,while soil bulk density,soil moisture and soil porosity do not change uniformly.The implementation of low-efficiency forest transformation technology of White bamboo had significant effects on soil field water capacity,organic matter,alkali-hydrolyzable nitrogen,available phosphorus and available potassium(P < 0.05),and had significant effects on soil bulk density,soil p H,soil porosity,soil temperature and soil moisture,but not to a significant level.The effective soil organic matter,alkaloid nitrogen,available phosphorus,available potassium,soil porosity,and field water capacity increased by 7.46% to 13.49%,26.09% to 151.95%,5.35% to 107.65%,16.93% to 153.74,0.57% to 6.36%,and 24.12% to 27.13% in the transformation technology.The bulk density of soil decreased by 1.12% to 11.96%,while the soil temperature,humidity,and p H showed no consistent change.The interaction between the elevation gradient and the low-efficiency forest transformation technology of bamboos had significant effects on soil temperature,field water capacity,soil p H,soil organic matter,alkali-hydrolyzable nitrogen,available phosphorus and available potassium(P < 0.05),but no significant effects on soil bulk density,soil porosity and humidity(P > 0.05).(2)With the increase of altitude,the average DIAMETER of DBH decreased gradually,the average plant height,standing density,total number of shoots,total number of retreated shoots,total number of upper forest first increased and then decreased,while the total weight of each plant,the yield of each stem,the yield of each plant and the yield of each leaf decreased to different degrees.The transformation technology of low-efficiency bamboo forest significantly increased the average DBH,average plant height,standing bamboo density,total number of shoots,total number of retreated shoots,total number of upper forests,total weight of single bamboo,yield of single bamboo stem,yield of single plant and yield of single bamboo leaf(P < 0.05).Gain range is between 17.78% ～ 51.72%,20.09% ～ 30.17%,10.33% ～ 31.33%,22.50% ～ 41.44% and-6.17% ～ 14.75%,83.17% ～ 95.98% and 61.71% ～ 136.07%,85.22% ～ 137.00% and 32.36% ～ 124.41%,19.62% ～ 147.99%.The interaction between elevation gradient and low-efficiency forest transformation technology of bambusa edulis had significant influence on total number of bamboo shoots,average total weight of bambusa edulis per plant,total number of returned bamboo shoots and total number of upper forest(P < 0.05),but the influence of average yield of bamboo shoots per plant,average yield of bamboo stalks per plant and average yield of bamboo leaves per plant was not significant(P > 0.05).(3)The net income of bamboos in The white bamboo forest decreased with the elevation increasing,with the decrease range ranging from 4.45% to 21.06%.The implementation of low-efficiency forest transformation technology for White bamboo effectively improved the economic benefits of bamboo,with an increase range of 112%～162.1%,among which the transformation effect of 850 at 750 m above sea level was the best.With the increase of altitude,the survival ability of the population changed from I age to IV age.The technology of low-efficiency forest transformation made the population age structure change from declining type to growing type.(4)The results of correlation between growth and yield of Bambusa edulis and soil factors showed that,the white clip bamboo diameter at breast height and plant height,SOM,soil bulk density,porosity and field capacity was significantly/extremely significant positive correlation,plant height and vertical bamboo density,alkaline hydrolysis n,available p was significantly/extremely significant positive correlation,white bamboo yield and diameter at breast height,plant height,SOM,alkali solution nitrogen,available phosphorus and available potassium,porosity and field capacity was significantly/extremely significant positive correlation. |
