| The vegetation was destroyed in different degree and soil was contaminated by lead in road field ecosystem environment had been existed problems for a long time and it brings direct and indirect influences to plant, animal and human-being . Artificial vegetation restoration and heavy metal phytormediation in soil are effective methods to settle this problem. Physiological reaction on tolerance and supper-accumulation to heavy metal of fitted plant is theoretic basement to sustain growth and fulfill heavy metal remediation, how to evaluate quality of restoration by artificial vegetation along with is key problem connected with stability and standing development of expressway area ecosystem. Related studies were conducted form 2001 to 2004 and the main results as below:1. Growth adjustability of surface vegetation with 22 different species (ecotypes) on green slope were compared under general spray seeding condition, the results indicated that Cynodon dactylo, Pasplummotatum, Melilotus suavena, Eragrostis were applicability in soils atSICHUN and same climate type area, Melilotus suavena, Festuca arundinaceaSchreb behaved good character live through winter and summer and reached high integrate grade (over 6. 5 point), Cynodon dactylon reached 7. 0 point and usually be used for pioneer and most plant of man-made restoration vegetation, and it was suitable for mixed seeding, Eragrostis behaved strong drought and leanness-resistant at side slope of slight-weathered rocks which withered 98 days only in 1 year and growth normally, suitable for single seeding and mixed seeding. Plant selected rule of artificial vegetation restoration at border slope at early stage should obey: fine-leaf type mixed with wider-type, gramineous with leguminous, cluster type with creep type, herb with small shrub.2. Technics, cost, vegetation growth status were first studied aboutborder slope vegetation building technique EM3, CE131 and geo-cell slope protect vegetation restoration technique, the results indicated that the technique CElSlplant net was easy to construct with low cost, technique EMS was better than CE131 vegetation net in border slope vegetation restoration speed, canopy degree, underground biomass and live through summer although with high cost. From the view of ecosystem integrate effect, three-dimension vegetation net EMSwas excelled than CE131, geo-cell can provide basement for the growth of slope vegetation.3. After no-lead gasoline was generalized, soil lead accumulated amount was positive correlative to time and car flux in road environment area, vehicle gas was still important lead contaminated source in specified time range; Cinnamomum Camphorapossess lead adsorb ability whenused as road along tree and should be extended. Melilotus suave was abroadwith adaptability in growth, and can produce a great deal of rhizobium that will be benefit to soil fertility and soil structure with strong endurance and adsorption to lead contamination .4. Under 200mg/L-1500mg/L Pb concentration treatment, the net photosynthesis speed (Y) of Melilotus suavena and light intensity (X) was accord with Y=y0+a*x / (b+x) model, under 400ml/llead concentration treatment, the correlation of net photosynthesis speed and light intensity was highest, R2=0.9932 , accord with regress equation Y=-3. 84+12. 25X/(135. 35+X), under this condition, the amount of absorb of C02 in environment was biggest, the degree of root damage was least, outer edge lead can enhance light compensate point of Melilotus suavena, under 200ml/L-1500ml/L lead concentration treatment, the photosynthesis speed changed with time within day was not significantly, exhibited single apices curve and reached top point at 14. 00 pm and then exhibited decreased trend.5. Under 200mg/L-1500mg/L lead concentration, the value of SOB, POD,CAT activity and MDA content were.influenced in Melilotus suavena, all kind of enzyme and MDA increased with lead concentration increased, lead concentration. was positively correlated with SOD vale( Y=2455. 9+75. 2XR2=0. 8523**)...
|
PDF Full Text Request