| The land is scarce in karst rocky desertification areas,and have serious conflicts between ecological restoration and economic development.To restore the ecological environment of rocky desertification areas,taking the eco-economic road is an important path for ecological restoration in rocky desertification areas.By selecting plant species of ecological and economic value,build a plant community to achieve ecological restoration and obtain economic benefits,it is an important way to coordinate ecological and economic development.More studies about studing single ecological and economical plant communities,but there are not many reports that can achieve better ecological and economic functions.In this study,Akebia trifoliate and Passiflora edulis were used as plant materials.By different planting densities of communities,studing the growth and development of plant functional traits and the process of economic yield accumulation.Stoichiometry and cycling characteristics to maintain nutrient balance,and water storage and soil conservation functions,and assessing eco-economic effects,to explore ways to maintain the stability of plant communities.Fuly play to its ecological functions,also have a plant community cultivation mechanism of economic benefits.This study results can provide theoretical basis for the restoration of ecological environment and the development of local economy in karst rocky desertification areas.In this study,we use the 185 plants/mu(row spacing0.8m×1.5m),296 plants/mu(row spacing1.5m×1.5m),556 plants/mu(row spacing2.4m×1.5m)three planting densities of Akebia trifoliateand.the 1361 plants/mu(row spacing0.7m×0.7m),463 plants/mu(row spacing1.2m×1.2m),261 plants/mu(row spacing1.6m×1.6m),167plants/mu(row spacing2.0m×2.0m),116plants/mu(row spacing2.4m×2.4m)five planting densities of Passiflora edulis which are medicinal and edible homologous plants were used as research objects in the karst region of Guizhou.We combine the field investigations and indoor experiments to study the economic functional traits,nutrient cycling characteristics of N,P,K and soil water retention function of the different planting densities Akebia trifoliate and Passiflora edulis.In order to find out ecological stoichiometry,nutrient cycling capacity,nutrient reabsorption and utilization,soil water holding capacity,and good economic produce and so on,to find out the planting density that not only satisfy the needs of local economic development but also plays an important ecological role.The results are as follows:1.Plant functional traits and density associated with economic functions.The density effects of fruit functional traits of Akebia trifoliate and Passiflora edulis are:the leaf length,leaf width,ground diameter,and plant height of Akebia trifoliate are 185 plants/mu>556 plants/mu>296plants/mu.the biomass of communityes are 5.14?9.58 t/hm~2,the biomass of root,tems,leaf are0.83?2.38t/hm~2,1.95?4.23 t/hm~2,1.20?1.90 t/hm~2,perform are 556 plants/mu>185 plants/mu>296 plants/mu,but the fruit biomass(0.51?0.85 t/hm~2)is most higher in lower density(185 plants/mu).The leaf length,leaf width,ground diameter,and plant height of Passiflora edulis are 116 plants/mu>167 plants/mu>261 plants/mu>463plants/mu>1361 plants/mu,the biomass of communityes are 0.68?2.16 t/hm~2,the root,stem,leaf,fruit biomass respectly are 0.01?0.04 t/hm~2,0.15?0.45 t/hm~2,0.22?0.62t/hm~2,0.29?0.10 t/hm~2,perform are:1361plants/mu>463 plants/mu>261 plants/mu>167 plants/mu>116 plants/mu,and increase with increasing density.2.Ecological stoichiometry of built plant communities.The element content of C,N,P are vital to plants,and the ratio have important indicating function.The ecological stoichiometry and element content of C,N,P of fresh leaves,fallen leaves and soil of Akebia trifoliate and Passiflora edulis are as follows:The ranges C,N,and P contents of fresh leaves of Akebia trifoliate in three densities were:635.0?690.1g/kg,47.81?53.66 g/kg,2.27?2.66g/kg,the ranges C,N,and P contents of fallen leaves are:590.50?592.25g/kg,28.90?35.21g/kg,1.07?1.896g/kg,the ranges C,N,and P contents of soil are:11.18?12.46g/kg,1.74?2.2 g/kg,0.39?0.43g/kg.The ranges of C,N,and P contents of fresh leaves of Passiflore edulis in five densities were:515.71?571.61 g/kg,41.52?48.21 g/kg,4.37?5.92g/kg,the ranges of C,N,and P contents of fallen leaves are:40.3.43?483.28g/kg,19.49?30.76g/kg,3.87?4.54g/kg,the ranges of C,N,and P contents of soil are:32.62?37.45g/kg 1.94?2.33 g/kg,0.80?0.92g/kg.The C,N,P,K contents of the organs and soil of Akebia trifoliate and Passiflora edulis have some differences among densities(P<0.05,the same as below),but the difference regularity is not significant,the element content in the soil layer is 0-15cm>15-30cm>30-45cm>45-60cm.The N/P,C/N,C/P of fresh leave of Akebia trifoliate are 17.20?23.99,12.12?16.83,263.89?284.84,the N/P are higher than 16 of Akebia trifoliate,indicating that its growth is limited by P.The N/P,C/N,C/P of fresh leave of Passiflora edulis are 7.99?9.77,10.98?13.25,102.80?115.61,the N/P values are less than 14 of Passiflora edulis,indicating that its growth is limited by N.The contents of C,N,P and K in plant organs,fallen leaves and soil of two plant communities in different densities have some significant(P<0.05),but have no obvious pattern.3.Nutrient accumulation and cycling characteristics of built plant communitiesThe total elements accumulation of Akebia trifoliate in three density 556 plants/mu,185 plants/mu,296plants/mu specifically are 355.62 kg/hm~2,191.81 kg/hm~2,206.22 kg/hm~2,the accumulation of N,P,and K respectively are 159.21?289.97 kg/hm~2,9.41?289.97 kg/hm~2,23.19?41.88 kg/hm~2.The total elements accumulation of Passiflora edulis in five density 1361 plants/mu,463 plants/mu,261 plants/mu,167 plants/mu,116 plants/mu specifically are 79.54kg/hm~2,54.36kg/hm~2,45.90kg/hm~2,36.10kg/hm~2,30.87kg/hm~2,the accumulation of N,P,and K respectively are 18.14?47.58 kg/hm~2,3.43?10.96 kg/hm~2,9.3?21.0 kg/hm~2.In total,the N accumulation is higher than Pand K of the two plants.The elements accumulation of two plants perform a same trend that is decreasing with increasing density.The element(N,P,K)circulation coefficient of Akebia trifoliata is 0.28?0.48,the utilization coefficient is 0.52?0.76.The circulation coefficient of 296 plants/mu is highest(0.48),have strong nutrient circulation ability,the utilization coefficient is higher(0.52).The element(N,P,K)circulation coefficient of Passiflora edulis is 0.28?0.53,the utilization coefficient is 0.47?0.72.The circulation coefficient of 116 plants/mu is highest(0.53),have strong nutrient circulation ability,the utilization coefficient is lowest(0.47),inefficient utilization of nutrients is high(0.72).4.Water-holding function of built plant communities.The soil effective water storage capacity of Akebia trifoliate is 263.16?271.3 t/hm~2,maximum storage capacity is743.83?871.33 t/hm~2,The average ranges of soil initial permeability,average permeability,stable permeability,and total permeability are 3.34?4.97 mm/min,2.21?3.28 mm/min,2.66?2.78 mm/min,79.45?111.86 mm/min,and the all perform a trend is 556 plants/mu>185 plants/mu>296 plants/mu,there are some significant differences in densities(P<0.05,the same as).The soil effective water storage capacity of Passiflora edulis is 184.25?205.98t/hm~2,maximum storage capacity is 542.02?644.91 t/hm~2.the average ranges of soil initial permeability,average permeability,stable permeability,and total permeability are1.45?2.09mm/min,3.61?5.73mm/min,0.53?0.813mm/min,44.25?71.47mm/min,the soil water storage function and permeability are better in low density or high density,the difference regularity is not significant among other densities.Compare the two species,soil water retention of Akebia trifoliate is better than Passiflora edulis.5.Economic effects of built plant communitiesThe leaves,stems,roots,and fruits of the two medicinal and edible homologous plants can be used as medicine,and the fruit can be used as edible fruit,but currently,the fruit is dominated in market,therefore,we take fruit yield as an economic effect analysis,the price based on 2019 market price.The fruit yield and profit of Akebia trifoliate are 185 plants/mu>296 plants/mu>556plants/mu,the product of density(plants/mu)is highest(3835.40 kg/hm~2),the profit also is highest(34525.02 yuan/year).The fruit yield and profit of Passiflora edulis are 1361 plants/mu>463 plants/mu>261 plants/mu>167 plants/mu>116 plants/mu,the product(6294.14 kg/hm~2)and profit(31568.75 yuan/year)of density(1361 plants/mu)are highest.6.Evaluation of the ecological and economic effects of bult plant communities.We take different planting densitiest of Akebia trifoliate and Passiflora edulis communities as objects,establish an eco-economic assessment index system based on eco-stoichiometry,nutrient cycling characteristics,soil water retention function,and plant functional traits and fruit yield related to economic benefits,through AHP method to comprehensive evaluation and analysis,the result as follows:the evaluation score of 556 plants/mu,296 plants/mu,185plants/mu of Akebia trifoliate are 0.51,0.38,0.47,under high-density(556 plants/mu)is highest,so it's ecological and economic benefits higher,the density(185 plants/mu)is second.The evaluation score of 1361 plants/mu,463 plants/mu,261plants/mu,167plants/mu,116plants/mu of Passiflora edulis are 0.47,0.44,0.32,0.21,0.17,0.16,under high-density(1361 plants/mu)is highest,so the ecological restoration and economic development are better. |
PDF Full Text Request