Study On Restoration Of Near-nature Vegetation Landscape Of Bare Slope In Pearl River Delta

lucid waters and lush mountains are invaluable assets.Slope is an important part of the lush Mountains,Re-greening of ecological vegetation is an important measure to improve environmental quality,“Green of the year,two years of yellow” is a common problem in the current resurrection of the slope.On the basis of reviewing the related research trends of near-natural vegetation restoration technology at home and abroad,this paper puts forward the strategy of combining engineering slope protection with vegetation slope protection,Apply the scientific combination of native forest and shrubs to create a near-natural slope vegetation landscape.in order to provide a basis for promoting the research and development of near-natural vegetation landscape restoration.By analyzing the construction technology of three excellent cases and taking Dashuiniugang and Dafushan compound green slope in Shunde District of Foshan City as the research object,the community sample method is adopted to investigate and study the vegetation restoration and soil fertility change of compound green slope compared with 2012.The main results are as follows:(1)Through the analysis of three typical slope vegetation landscape restoration cases of Daliang poultry hill-climbing slope,Taiping landslide and Changning Town Shanhu Stone Farm in Boluo County,Shunde District,Foshan City,a set of construction techniques for different slope vegetation landscape restoration are summarized.The main slope types and construction techniques are cliff mountain body:installing wedge-shaped concrete slab,filling improved matrix planting;steep slope:using lattice beam to protect slope,filling clay at the base of lattice beam;slope surface:wedge-shaped groove,wedge-shaped groove in row distribution,local reinforced column,horizontal reinforcement,filling soil leveling at the side of lattice beam;gentle slope: first cleaning surface loose stone,covering soil planting,digging pits,Tree-irrigation-tree planting;Platform: digging and filling,planting trees 3-5M near the wall,planting vines hanging on the edge,or setting drainage ditches.After laying geotextiles in the ditches,the earth is pressed 10-20 cm.(2)By investigating the plant species and community structure of Dashuiniugang and Dafushan slopes in Shunde in 2018(which have been repaired for 8 years),andcomparing the results with those in 2012(which have been repaired for 2 years),the results show that the plant species of Dashuiniugang rock slopes have been reduced from 96 to 66 species,among which there are about 16 families and 20 genera and 21 species of trees.The dominant species are: Acacia confusa?Heteropanax fragrans?Elaeocarpus rugouus etc.shrubs are about 19 families,25 genera,28 species,dominant species are Maesa japonica,Excoecaria cochinchinensis,Schefflera octophylla,herbs are about 14 families,15 genera,15 species,dominant species are:Nephrolepis auriculata ?Hedychium coronarium,Neyraudia reynaudiana and so on.The plant species of Dafushan green slope increased from 33 species to 36 species,including about 5 families,5 genera and 6 species of trees.The dominant species were Eucalyptus exserta,Lagerstroemia indica,Litsea glutinosa etc.about 15 families,21 genera and 21 species of shrubs.The dominant species of shrubs were Salix myrtillacea,Camellia japonica,Tephrosia candida etc.There were 6 families,8 genera and 8 species of herbs,and the dominant species of herbs were Blechnum orientale,Neyraudia reynaudiana,Dicranopteris dichotoma and so on.At the same time,some plants which had not been planted in the original project appeared on the green slope of the two mountains,and the old species gradually disappeared,and new species occupied their niche.This phenomenon accords with the law of natural succession.(3)Based on the comparative analysis of the investigation results of two slopes,Dashuiniugang and Dafushan in Shunde,the plant species and community structure suitable for the near-natural vegetation landscape restoration of slopes in South China are summarized.Including: a.Previous pioneer plants: trees such as Dalbergia odorifera,Acacia confusa,Ficus tinctoria,Acacia podalyriifolia and so on;shrubs such as Tephrosia candida,Excoecaria cochinchinensis,Salix myrtillacea,Schefflera arboricola,Pittosporum tobira,Melastoma candidum etc.;herbs such as Hymenocallis littoralis,Vetiveria zizanioides,Melinis minutiflora,Neyraudia reynaudiana,Nephrolepis auriculata,Pennisetum purpureum etc.B.Later dominant species: Acacia confusa,Heteropanax fragrans,Elaeocarpus rugouus,Cinnamomum bodinieri,Eucalyptus exserta,Ilex rotunda,Dalbergia odorifera and so on;shrubs Maesa japonica,Excoecaria cochinchinensis,Schefflera octophylla,Syzygium jambos,Tibouchina seecandra and so on;herbs tuber,Nephrolepis auriculata,Hedychium coronarium,Neyraudia reynaudiana,Blechnum orientale,Taeniophyllum glandulosum etc.C.The main community structures are Acacia confusa +Maesa japonica+Blechnum orientale,Heteropanax fragrans+Excoecaria cochinchinensis+Nephrolepis auriculata,Elaeocarpus rugouus+Tephrosia candida+Cyclosorus interruptus,Ilex rotunda Thunb+Vitex negundo+Taeniophyllum glandulosum,Dalbergia odorifera+Tephrosia candida+Neyraudia reynaudiana,Eucalyptus exserta+Rhodomyrtus tomentosa+Hedychium coronarium,Eucalyptus exserta+Camellia sp+Dicranopteris dichotoma,Eucalyptus exserta+Tibouchina seecandra+Ageratum conyzoides,Lagerstroemia indica+Rhus chinensis+Blechnum orientale,Litsea glnosa+Tephrosia candida+Dicranopteris dichotoma,Manilkara zapota+Mallotus apelta+Lycopodium japonicum,Rhus chinensis+Miscanthus,Acacia confusa+ Hedychium coronarium,Dalbergia odorifera+ Neyraudia reynaudiana,Heteropanax fragrans + Psilopeganum sinense,Cinnamomum bodinieri + Tibouchina seecandra,Bambusa multiplex+ Neyraudia reynaudiana,Camellia oleifera + Bidens pilosa,Salix myrtillacea+Cyclosorus interruptus,TCamellia japonica + Diaphasiastrum veitchii etc.(4)The higher the leaf area index of vegetation canopy is,the more organic matter is enriched,and the higher the soil fertility index is.Through the detection of canopy leaf area index and soil quality index,it was found that the higher the canopy leaf area index of vegetation was,along with the continuous decline of slope height;the canopy leaf area index was positively correlated with soil fertility.(5)By comparing the soil quality of Dashuiniugang Green Slope with that of undamaged slope and that of 2012,the results show that the soil quality of Dashuiniugang Green Slope is only slightly lower than that of undamaged slope,and even the content of available potassium is reversed.This phenomenon shows that the selected plants for slope greening play a very good role in soil restoration.The proportion of deciduous and evergreen plants is very suitable.The application of leguminous plants is also reasonable,and the potassium-rich ability of the applied plants as a whole is very strong.It is concluded that soil remediation has positive effects on plants.Trees include Acacia confusa,Heteropanax fragrans,Elaeocarpus rugouus,Litsea glutinosa,Dalbergia odorifera and so on;shrubs include Schefflera octophylla,Bridelia tomentosa,Excoecaria cochinchinensis,Maesa japonica,Rhodomyrtus tomentosa,Salix myrtillacea,Neyraudia reynaudiana and so on;herbs include Nephrolepis auriculata,Cyclosorus interruptus,Hedychium coronarium,Dicranopteris dichotoma,Bidens pilosa etc.(6)Based on the construction technology,plant species and community structure of vegetation landscape restoration of bare slope in Pearl River Delta region,the slope greening planning and design of Hengmen Mountain in Zhongshan City were carried out.Planning content includes: current situation analysis,plant selection,construction technology,overall planning,zoning layout,with a view to restoring the near-natural vegetation landscape of the project site.