Dynamics Of Glamycin In Different Periods Of Logging Disturbance In Xiaoxing'an Mountains

Glomalin-related soil protein is a kind of stable glycoprotein produced by arbuscular mycorrhizal fungi in the soil,which plays a very important role in forest soil ecosystem and is of great significance for soil restoration after deforestation.Glomalin-related soil protein can not only improve soil fertility,but also play an important role in the stability of soil carbon pool,and its viscosity can greatly improve the stability of soil aggregates,which is one of the important indicators for evaluating and indicating soil quality.Xiaoxing 'an Mountain is the core area of broad-leaved Korean pine forest in China.After being artificially cut down,it has become a secondary forest with different degrees of damage.GRSP content,soil physical and chemical properties and soil structure in the forest soil are inevitably changed due to changes in forest structure.The purpose of this study was to explore the GRSP dynamics in the soil after the original broad-leaved Korean pine forest was cut down and restored to secondary forests in different periods,and to reveal the quality status of soil restoration through the influence of GRSP on soil organic matter content and soil stability.Selection of original broad-leaved Korean pine forest in different periods after cutting disturbance to restore 20 years,32 years,47 years,61 years of secondary forest and undisturbed original broad-leaved Korean pine forest as the research object.The 0-10 cm,10-20 cm,20-30 cm soil was taken to determine the basic physical and chemical properties of soil,GRSP and soil aggregate stability.The results showed that :(1)The ecological environment of the broad-leaved Korean pine forest was seriously damaged in the early clear cutting stage,and the easily extractable glomalin(EE-GRSP)and total glomalin(T-GRSP)in the soil were significantly reduced.However,in the subsequent 20 – 32 years of recovery,T-GRSP rapidly accumulated,and gradually increased with the increase of recovery years.There was no significant difference in the EE-GRSP content between 20 and 47 years of recovery(p > 0.05).The EE-GRSP and T-GRSP decreased significantly with increasing depth in each restoration year,and at 61 years of restoration the EE-GRSP and T-GRSP layers were not different from the original forest.(2)Similar to GRSP,soil organic matter(SOM),total carbon(TC)and total nitrogen(TN)also showed a gradual increase trend with the increase of recovery years after logging,and gradually decreased with the increase of soil depth.And EE-GRSP and TGRSP were significantly correlated with SOM,TC and TN,and TC had an effect on the change of GRSP content in all soils from 0-30 cm,and TN had an effect on T-GRSP concentration in the top soil.The carbon sink function is weaker in the 20-32 years of secondary forests recovered by cutting,and the contribution of EE-TRSP and T-GRSP to SOM is higher.GRSP is very important for the enhancement of soil carbon sink capacity and soil resilience at this stage.In addition,although the EE-GRSP and T-GRSP contents were significantly lower in deep soils than in the surface layer,they contributed 1.2-2.1and 1.3-2.3 times more to soil organic carbon and nutrients than in the surface layer.(3)With the increase of restoration years,in the 0-30 cm soil layer,the proportion of0.053-0.25 mm microaggregates in the secondary forest and primary forest of 61 years was significantly lower than that in the restoration forest of 20-47 years,and the lowest was in the primary forest.The soil aggregates of < 1 mm gradually decreased with the increase of restoration years,especially in the 0-20 cm soil layer.With the deepening of soil in the vertical direction,the content of soil aggregates with 2-8 mm particle size decreased significantly,and the linear relationship between GRSP and MWD was significant.The results showed that the EE-GRSP and T-GRSP contents of the original broadleaved Korean pine forest decreased significantly after cutting interference,and then increased with the increase of restoration years.After 61 years of restoration,the GRSP content returned to the level before cutting.GRSP promotes the formation of SOM and water-stable macroaggregates in soils,especially when in deep soils,GRSP has a significant effect on carbon and nutrient sequestration and nutrient accumulation,and the production of GRSP at the early stage of recovery is crucial for soil organic matter.