Effects Of Different Vegetation Restoration Model On Soil Biological Activities In The Carya Cathayensis Stands

This paper described the pure planting forest of Carya cathayensis Sarg that had apparent degraded characteristics from the view of revegetation,then examined the soil microbial diversity by measuring the amount of soil microbes(bacteria,fungi,actinomucetes)and soil microbial major physiological group(nitrogen fixing bacteria)and the activities of six soil enzymes(catalase,amylase,amylase,cellulose,urease,proteinase and invertase)and soil microbial diversity at six typical vegetations along different recovery mode i.e.Amorpha fruticosa Linn*Trrifolium repens,Amorpha fruticosa Linn*Vicia gigantea Bge,Amorpha fruticosa Linn*Scilla scilloides,Amorpha fruticosa Linn*Trrifolium repens L Amorpha fruticosa Linn*Ophiopogon japonicas,respectively,in the south part of the Anhui province(30°24?102?N,119°19?30?E at 298~314 m above mean sea level),China.Which is a long*term field experiment was initiated in 2006.The main results were as follows:1.The soil enzyme activity which decreases with the increase of soil layer,was varies in different recovery mode.There was a obvious spatial distribution characteristic in soil enzyme activities.The soil enzyme activity changed seasonally.From March to September,and it increased gradually until July then reduced little by little.The activity of soil enzyme in September was higher than that in May,and the soil enzyme activity in March was the lowest.In A*O,A*V and A*T patterns,the increase of soil enzyme activity was significantly higher than that of CK patterns.However,the increase amplitude of soil enzyme activity was relatively small in A*S and A*P patterns.In different plant ages,soil enzyme activity of each model was quite different.And there is an interactive process between soil enzyme activity and the recovery of vegetation.In addition,the change of soil enzyme activity is a very slow process,and information has certain correlation with vegetation degradation.2.In different recovery mode,the soil bacteria dominated in the study area,followed by actinomycetes,aerobic nitrogen*fixing bacteria and fungi.The microbial populations had a significant variation in different recovery mode.In same pattern,on the spatial distribution,the soil microbial quantity declined with the increase of soil depth,and at the seasonal level,it showed as following change: fruit enlargement period(July)> fruit mature period(September)> pollinate flowering period(May)> germinate period(March).But they were all significantly higher than that of CK,and the A*O mode had obvious advantages,followed by A*T mode.In different forest age,soil microbial quantity indifferent recovery mode has obvious change.Soil fungi,actinomycetes quantity increased with the increase of plant time,and soil bacteria,aerobic nitrogen*fixing bacteria quantity decreased with the increase of plant time.Soil enzyme activity and soil nutrients have significantly positive correlation.3.There is a magnificant difference of the genetic diversity and community richness of Bacteria in different recovery mode.The results show that different recovery mode soil bacterial community richness and diversity index is significantly higher than natural management mode.The soil bacterial community under different recovery mode richness and diversity index is significantly higher than natural management mode.Through the analysis it is concluded that: Six kinds of patterns are grouped into three broad categories,A * P,A * V,A * S model bound for a category,A * T,A *O model bound for a category,and CK separately into another category.A * T,A * O mode has obvious group advantages.On soil microbial bacteria community similarity analysis results show that: Soil microbial similarity coefficient between different recovery mode is different,Similarities between A*P and A*S model of up to 85.3%,the similarity between the CK and the other five kinds of recovery mode are low,the lowest 45.8%.From what has been discussed above: A*T,A*O model soil microbial quantity is more,high abundance,and CK soil microbial quantity minimum,lowest abundance.Diversity indexes of soil bacteria communitie was positively correlated with soil enzyme activity and soil microbial quantity.According to these results,in the pure planting forest of Carya cathayensis plantation with obvious degraded characteristics.Amorpha fruticosa was suggested to restore vegetation planting in shrub layer and Ophiopogon japonicus,Vicia gigantean and Paspalum natatupure can be selected as ground cover,of which Ophiopogon japonicus was the first choice.The mode of planting Trifolium repens and Scilla scilloides as ground cover had a common effect on ecological recovery.