The Growth Characteristics Of Parthenocissus Tricuspidata And Its Application For High And Cliff Slope Restoration

The climbing plants is an important species of tropical and subtropical forests,and canprovide deep green cover to many objects,rapidly climbing to supports by means of tendrils oradhesive disks for not standing.They are not only main raw material of medicine and food butalso planted widely for landscaping,soil erosion control and revegation.But sometimes,theclimbing plants act as weed to damage trees,shrubs and flower beds for windly growth anddifficultly control.So learning the growth features and uptake nutrients law of the climbing plantsand finding the limiting factor to growth will contribute to have reasonable application of them inenvironment.Parthenocissus tricuspidata (Sieb.et Zucc) is a woody deciduous climbing plant of thefamily Vitaceae that has been widely planted for city green in china and play an important role inthe envinment management.But it is little known about its growth characteristics.This paperrepresented that the change of nutrients trend and distribution with the change of season,the N,P,K uptake characteristic,the effect of support angles,shaping,high temperature,soil moisture ongrowth,as well as revegetation of high and slope ofP.tricuspidata.The results were as follows:1.With the season change,the concentration of the macronutirents N,P,K,Ca,Mg and themicronutrients Fe,Mn,B,Cu,Zn in different plant parts of natural grown P.tricuspidata haddifferent change trends.The nutrient concentration of leaf was higher than stem and leafstalk.Thetissue nutrient concentration of upside part of the plant was less than of middle part and downsidepart.Nutrient elements of different tissue had different concentration order:in leaf,N＞Ca＞K＞Mg＞P＞Fe＞Mn＞B＞Zn＞Cu;in leafstalk,N＞Ca＞K＞Mg＞P＞Fe＞B3＞Mn＞Zn＞Cu;in stem,N＞Ca＞K＞P＞Mg＞Fe＞Mn＞B＞Zn＞Cu.The N and K was the highest retranslocation rate among allnutrient elements in P.tricuspidata,exceeded 75%,and the Mn retranslocation rate was lowerthan other nutrient elements,only 10.6%.2.Plant branches were smaller and shorter in size under lower nitrogen rates than higher rates.High nitrogen rates also significantly promoted early branching of P.tricuspidata seedlings andlowered branching positions on the main stems.Supplying high nitrogen to P.tricuspidatasignificantly increased plant biomass and nitrogen content in root,leaf and stem.Compared tostem and root,leaf had highest biomass,accounting for 50% of plant total biomass.Leaf was alsothe main tissue for nitrogen accumulation,accounting for 60% to 70% of total accumulatednitrogen.3.Increasing phosphorus rates could increase the biomass and main stem length of P.tricuspidata,but high phosphorus rate (＞0.06 g.L^-1) did not influence significantly the growth of P.tricuspidata.There was significant variation of root style and biomass under lower phosphorusrate.The total root length,root surface area,root volume,root tips and forks under 0.03 g.L^-1 Prate treatment was higher than other treatments.With phosphorus rates increasing,the tissuephosphorus concentration and leaf and root nitrogen concentration of P.tricuspidata had an increase trend while the tissue potassium concentration was reduced,but the stem nitrogenconcentration increased first,and then decreased later.Higher phosphorus rates (0.03 g.L^-1)had noobvious effect on nitrogen,phosphorus and potassium concentration of stems,leaves and roots,and indicated that P.tricuspidata could adapt to lower phosphorus availability.Increasedphosphorus rates can increase potassium use efficiency and decrease nitrogen use efficiency,butno obviously influence on phosphorus use efficiency.4.Increased potassium rates can increase the biomass and main stem length ofP.tricuspidata.However,higher potassium did not affect the biomass,but adjust the biomass partition.Leafgrowth constituted the more biomass proportion while the stem biomass was reduced under higherpotassium rates condition.The tissue potassium concentration and potassium content wereincreased with the increasing potassium rate.But when the potassium rate exceeded 0.18 g.L^-1,theincrement of the tissue potassium concentration and potassium content was not significant.It issuggested that P.tricuspidata could adapt to lower potassium availability.Increased potassiumrates significantly increased the leaf nitrogen concentration,and reduced the leaf and rootphosphorus concentration,but not affected the root and stem nitrogen concentration and thestem phosphorus concentration.Higher potassium rates (＞0.18 g.L^-1) did not greatly influencethe tissue nutrient concentration.With the potassium rates increasing,potassium use efficiencydecreased significantly,and nitrogen use efficiency showed a falling trend while phosphorus useefficiency had a rising trend,but not significantly different.5.The supports angles influenced the morphology and growth of P.tricuspidata.Under nosupporting condition,the biomass and main stem length of P.tricuspidata wasincreased.Undervertical angle condition,P.tricuspidata showed strong branch ability to extend growth space.When the support angles increased,the stem length and diameter of P.tricuspidata decreasedwhile the the branch number and total branch length inceased obviously.6.Different shading measures obviously affected growth and biomass distribution of P.tricuspidata.Proper shading measures was good for developing the growth of main stem andbranches,and low shading increased the leaf biomass while high shading leaded to stem biomassincrease.7.Under the high temperatures 40℃stress,the leaf relative water content (RWC),dissoluble protein content was significantly decreased but the cell membrane thermostability(CMS) and MDA were increased.Superoxide dismutase (SOD),catalase (CAT),peroxidase (POD)activities in leaf increased obviously at early stage of high temperature stress,then decreasedrapidly.After high temperatures stress for two days,the Net photosynthetic rate (P_N) was sharplyfalling.8.Biomass in P.tricuspidata was increased with the enhancing of water supply.However,the seedlings grown under higher water supplies invested more biomass in leaf (in terms of leafnumber and leaf area),and root growth constituted the largest proportion of the biomass underlower water supplies.Decreased water supplies significantly reduced the Net photosynthetic rate (P_N),stomatal conductance (gs) and transpiration rate (E).Different water supplies greatlyinfluenced the tissue N concentration than P and K concentration.P.tricuspidata had a low Kconcentration (below 10 g.kg^-1) in all its plant tissues,which may allow the plants to limit itsstomatal opening and reduce its water loss.Water supplies had significantly affected N-useefficiency,but did not affect P and K-use efficiency.9.P.tricuspidata had higher survival and growth rates,and showed well adaptability todisadvantageous growing conditions of rock slope so that it could be used as pioneer plant speciesto revegetation of rock slopes.The compress substrates can impove the biomass and growth rateof P.tricuspidata planting in rock slope.