Effects On Dalbergia Odorifera Growth And Soil Physicochemical Properties At Different Mixing Models In Qipo Forest Farm

Dalbergia odorifera belongs to the family Dalbergia odorifera,a rare and endangered national grade II protected plant,and a rare species of redwood.Previous studies have found that Dalber-gia odorifera has slow growth,low yield,and poor dryness.Therefore,the study was divided into four different forests:Dalbergia odorifera + Incense mixed forest,Dalbergia odorifera + teak Imixed forest,Dalbergia odorifera + Citron mixed forest,Dalbergia odorifera pure forest.The effect of afforestation model on the growth of Dalbergia odorifera and soil physicochemical properties is expected to provide the basic data for the management and management of Dalbergia odorifera plantation.The main findings are as follows:(1)The average tree height of Dalbergia odorifera was the largest in the mixed forest of Dalbergia odorifera and teak,and the average tree height of the three mixed forests was different from that of Dalbergia odorifera forest;the trunk straight height of three mixed forests was extremely high.Significantly higher than Dalbergia odorifera pure forest,indicating that the establishment of mixed forest is conducive to improving the straightness of Dalbergia odorifera.In a word,the mixture of Dalbergia odorifera and teak can better promote the growth and development of DBH height.(2)The highest peak value was found at the height level of the fourth(1.5 m-2 m)of Dalbergia odorifera pure forest.The heights of the mixed forest of Dalbergia odorifera and teak were highest in the ?(3.5 m?4 m),followed by the ?(2.5 m?3.0 m)and the ?(3.0 m-3.5 m).The mixed forest of Dalbergia odorifera and teak showed a peak at the 4th(3 cm to 3.5 cm)diameter level,and the second highest peak was Dalbergia odorifera forest at the lower second(2 cm to 2.5 cm)diameter..In general,under the afforestation model in which Dalbergia odorifera and teak are intermingled,the diameter and height of Dalbergia odorifera are distributed at a higher level,while in the pure forest afforestation model,the height of D,The growth of DBH was relatively insufficient.While,The mixed afforestation of Dalbergia odorifera + Citron and the mixture of Dalbergia odorifera + Incense resides in the former two.(3)The mixed forest of Dalbergia odorifera and teak can significantly increase the contents of ammonia nitrogen,total phosphorus,available phosphorus,total potassium and available potassium in soil.The mixed forest of Dalbergia odorifera and Incense can increase soil total to a certain extent.Nitrogen content,relatively speaking,Dalbergia odorifera pure forest is slightly insufficient to improve the soil fertility.The mixed forest of Dalbergia odorifera and teak can significantly increase soil acid phosphatase activity and soil invertase activity.Dalbergia odorifera pure forest can improve the activity of soil catalase,while the mixed forest of Dalbergia odorifera and Citron can Increase soil urease activity.(4)Four kinds of afforestation pattern differences of soil physical property,Dalbergia odorifera and teak(JY)hold water is best,the mixed Dalbergia odorifera and Incense(JC)times,and is superior to the Dalbergia odorifera and Citron(JX),Dalbergia odorifera and Citron(JX)mixed with soil water is better than that of Dalbergia odorifera pure forest(J).Bulk density from small to large order:Dalbergia odorifera and t,eak(JY)<Dalbergia odorifera and Incense(JC)<Dalbergia odorifera and Citron(JX)<Dalbergia odorifeyra pure forest(J),total porosity by to small order greatly for:Dalbergia odorifera and teak(JY)>Dalbergia odorifera pure forest(J)>Dalbergia odorifera and Citron(JX)>Dalbergia odorifera and Incense(JC).(5)According to the PCA analysis method,the PC1 and PC2 accumulation ratios of the two principal components reach 88.41%,and the contribution rate of the first principal component is as high as 59.36%.There is a close positive correlation with the tree height,available potassium,and acid phosphatase.Relationship,this variable can explain the changes in the height of Dalbergia sinensis and the accumulation of soil nutrients.The contribution rate of the second principal component is 29.05%,which is closely related to the minimum water holding capacity of the original variable.This variable can reflect the overall situation of soil physical properties.(6)The DBH growth was positively correlated with tree height and ammonia nitrogen(P<0.05).The tree height was also significantly positively correlated with the soil ammonia nitrogen,acid phosphatase and sucrase,indicating soil ammonia Nitrogen is an important environmental factor for the growth of Dalbergia odorifera.Soil acid phosphatase and soil sucrase have a significant positive correlation with soil ammonia nitrogen,indicating that acid phosphatase and sucrase are an Indirect important environmental factors for the growth of Dalbergia odorifera.