Study On Soil Improvement Of Typical Coastal Protective Forest Of Three Coast Types In Liaoning Province

The study selected 19 forest types of three coast types in Liaoning Province as study objects.Surveying general condition of every stand forests and measuring soil physical and chemical properties,litter and herbs diversity under the forest.Based on these,this paper analyzed and compared with soil improvement of different coastal protective forests in Liaoning province.In order to give full play to soil improvement of coastal protection forest,provide support for scientific construction and maintenance management of 3 coast types in Liaoning Province,and improve the construction of coastal protection forest.The results were described as follows:(1)Pinus tabuliformis pure forest,Pinus tabuliformis-Robinia pseudoacacia mixed forest,Populus spp.pure forest,nearly mature forest of Robinia pseudoacacia,middle aged forest of Robinia pseudoacacia and young forest of Robinia pseudoacacia could reduce the Soil bulk density,capillary porosity,total porosity and pH value,and increase soil volumetric water content,total N and available P in sandy coast.The effect of Robinia pseudoacacia pure forest on soil improvement was best,which increased soil volumetric water content of 62.9%,and increased total N of 28.5%,and increased available P of 314.4%,and reduced pH value of 36.1%.The litter storage of Populus spp.pure forest was 13.50t/hm2,which was the largest,and young forest of Robinia pseudoacacia was 8.76t/hm2,which was the smallest.The percent of undecomposed litter storage and half-decomposed litter storage in different forest types were different,but the percent of undecomposed litter storage was smaller than the percent of half-decomposed litter storage in every forest type.Different forest types had different herb diversity,and the effect of Pinus tabuliformis-Robinia pseudoacacia mixed forest was best.The richness index was significantly negatively correlated with capillary porosity and total porosity,and Simpson diversity index and Pielou evenness index were significantly negatively correlated with pH value.(2)The Platycladus orientalis pure forest,Robinia pseudoacacia pure forest,Quercus liaotungensis pure forest and Quercus liaotungensis-Pinus densiflora mixed forest could increase soil total N,available P and organic matter in rocky coast.The order of four forest types'capacity of improve soil nutrient was:Robinia pseudoacacia pure forests>Quercus liaotungensis-Pinus densiflora mixed forest>Platycladus orientalis pure forest>Quercus liaotungensis pure forest.The total N,available P,organic matter of Robinia pseudoacacia pure forest were 4.23g·kg-1,4.22mg·kg-1,56.76g·kg-1 respectively.The litter storage capacity of Quercus liaotungensis-Pinus densiflora mixed forest was 25.53t/hm,which was the largest.The maximum water capacity,effective retain capacity of the Quercus liaotungensis pure forest were 23.94,62.38,51.77t/hm2 respectively,which has the best water-holding capacity.(3)In muddy coastal protective forests,Fraxinuschinensis pure forest,Robinia pseudoacacia pure forest,nearly mature forest of Ulmus pumila pure forest,Populus popularis pure forest,Populus simonii×P.euphhratica-Robinia pseudoacacia mixed forest,young forest of Ulmus pumila pure forest,P.×liaoningensis pure forest,Populus simonii×P.euphratica-Amorpha fruticose mixed forest and Populus simonii×P.euphratica pure forestcould improve soil physical and chemical properties in 0?40cm layer,and the improvement of 0?20cm layer were better than 20?40cm layer,and the greater the forest age,the more obvious improvement effect.In terms of litter water-holding capacity,the Populus simonii ×P.euphratica-Amorpha fruticose mixed forest was the best,which maximum water capacity,effective retain capacity were 11.58t/hm2 and 9.07t/hm2.On the whole,the soil improvement of Fraxinus chinensis pure forest,Ulmus pumila pure forest,Populus simonii ×P.euphratica-Amorpha fruticosa mixed forest and Populus simonii×P.euphratica-Robinia pseudoacacia mixed forest were the best.(4)The compared and analyzed of three coast types' protective forests shows,in terms of soil nutrient,litter storageand water-holding capacity,the rocky coast was the best,the sandy coast was better,and the muddy coast was the worst.