Study On Seed-base Method For Afforestation In Saline Land In Hebei And Rocky Mountainous Area In Beijing

In order to improve the low seed-germination rate,the low seedling survival rate and the low initial growth rate in vegetation recovery in poor sites,a technology called "Seed-bases afforestation technology",which can partially improve site conditions for plant growth,was adopted in the afforesting experiment in seashore saline land in Hebei and rocky mountain area of BeijingIn seashore saline land in Hebei,afforestation measurements such as sowing seeds in seed-bases to breed seedlings,building stair-fields,digging open drains,constructing isolate layers,transplanting seedling with soil column etc.were adopted afforetation activities for evaluating "Seed-bases afforestation technology".The study results showed that the seed-bases had a certain impact on reducing salt movemnment in soil.Vermiculite and pearlite had a better effect than the peat in the rate of emergence,and the seed-base that was made by carrying soil,peat,vermiculite and pearlite in the volume ratio of 5:1:2:2 had the highest rate of emergence.The rate of seedlings emergence in seed-bases was mainly different with tree species in 2008.The bond had a remarkable influence on the seedlings emergence of seed-bases,while the seaweed fertilizer didn't have an influence.The survival condition of seed-bases seedlings are observed continuously in the vegetative season from June to September,and a comprehensive investigation to the seed-bases seedlings was conducted on October 7th.The seedlings of the Chinese scholartree,the white wax,the tree of heaven and the locust tree had a high survival rate and a substantial growth rate.The other 4 tree species had low survival rate,indicating the "Seed-bases afforestation technology" were suitable for the Chinese scholartree,the white wax,the tree of heaven and the locust tree in seashore saline land.Because the carrying soil seed-bases could prevent transplanting seedlings from the harmful effects of salt.The carrying soil seed-bases influence internal soil water and salt movement.Generally,when the soil salinity content of stair-fields was at a moderate or a low level,the plant in the carrying soil seed-bases could get a higher growth rate.When the soil salinity content of stair-fields was at a high level,the plant carrying soil seed-bases would have difficulties to survive.The survival rate was negatively correlated with the soil salt content in stair-fields.Through observing the dynamic situation of moisture and salinity contents of stair-fields,general patterns of moisture and salinity contents in the stair-fields were found.Precipitation and evaporation had a substantial influence on the condition of the stair-fields.The precipitation was low and evaporation was high in April,May and October,meanwhile,the soil moisture content were relatively low and fluctuated.The soil salinity content was high,and its fluctuation was remarkable.The precipitation was abundant in July and August.The soil moisture content reached the upper limit level in the year and the soil salinity content decreased to a certain level.Desalination happened significantly.The difference of the moisture and salinity condition of different stair-field styles was remarkable. The saline level of the stair-fields descending sequence in 2007 was:Stair-field with a layer in the form of a shape of two stripes from south to north＞stair-field with plastic film and a layer in the shape of two stripes from south to north＞stair-field without layer and stair-field of the entire shop type＞stair-field with a layer in the shape of two stripes from south to north＞one strip from east to west.The saline level of the stair-fields descending sequence in 2008 was:stair-field with a layer in the shape of two stripes from south to north＞stair-field without layer＞stair-field of entire shop type＞stair-field with plastic film and a layer in the shape of two stripes from south to north＞stair-field with a layer in the shape of two stripes from south to north＞one strip from east to west.Concerning the insulating material of layer:the slag was better than the waste from buliding site.However,this kind of effectiveness was not as effective as that of the form of insulating layers.The examination of the seed-bases breeding afforestation method in Beijing's low elevation lithical mountainous area was conducted.The experiment of 9 tree species in the different seed-bases was conducted.The status of sapling under the same site condition was investigated.The growth status of different tree species under the different site condtions was tested with single factor variance analysis method to determine the influence of different site condition to the tree species.Thus the most suitable afforestation tree species and its afforestation method were found in this area.The results showed:The of survival rate of 9 tree species under seed-base with random formula was as following sequence: Oriental arbor-vitae＞silver piece maple tree＞locust tree＞lacebark pine＞torch tree＞white wax＞Chinese sumac＞Chinese pine＞Chinese juniper.Especially with the NO.1-15 formula,the survival rates of oriental arbor-vitae,silver piece maple tree,locust tree,lacebark pine and torch were significantly higher than these of white wax,Chinese sumac,Chinese pine and Chinese juniper (P＜0.05).This draws to the conclusion that the seed-based technology afforestation are suitable for the oriental arbor-vitae,silver piece maple tree,locust tree,lacebark pine and torch tree in the infertile earth from rocky mountain area Beijing,and not suitable for the white wax,the Chinese sumac,the Chinese pine,the Chinese juniper.Except Chinese juniper,seedling survival rates of the other 8 tree species such as oriental arbor-vitae,silver piece maple tree,locust tree were significantly correlated..In general,the survival rate in seed-bases was negatively correlated with the applying amount of chemical fertilizer.The Experiment designed 5 kind of chemical fertilizer quantity treatments,the percentage of survival seedling of oriental arbor-vitae in seed-bases decreased with the increasing application of chemical fertilizer.The survival rates of silver piece maple tree,locust tree,lacebark pine,torch and white wax in seed-bases showed significant differences among different fertilizer treatments 0,0.75,1.50 g L^-1., When the amount of application of chemical fertilizer was≥2.25 g L^-1,the difference among different treatments were not significant,indicating that the reasonal amount of applying chemical fertilizer for saplings in seed-bases should be lower than 1.5 g L^-1.Through the analysis,the bond did't show any effect to survival rate of seedling in seed-bases.The chemical fertilizer quantity≥2.25 g L^-1 seed-bases seedling survival rate was extremely low,chemical fertilizer had quantity of≤1.50 g L^-1 seed-bases formula for superior seed-bases.Because the chemical fertilizer quantity was under 1.50 g L^-1 levels,the different matrix allocated proportion 3,8,13,16-21st seed-bases tree seed survival rate analysis,16,19, 20 formula tree percentage were high.3,8,13 formula were the next to the best and 17,18,21 formulas were the lowest.Among the three treatments,the seed-bases seedling survival rate with the plastic film cover,the deadwood fallen leaf cover and the plastic bottle cover had a significant difference.The plastic film cover was better than the other two treatments.