Effects Of Short-term Enclosure On Vegetation Characteristics And Soil Respiration Of Seriphidium Transiliense Desert

In this paper,we studied the effects of short-term enclosures on the community characteristics,plant diversity and soil respiration rate of desert grassland in Seriphidium transiliense.The results can provide a theoretical basis for the ecological restoration and reconstruction of desert grassland and the rational utilization of grassland resources.The main results are as follows:(1)Compared with the grazing area,the important value of S.transiliense in the enclosed area in May was significantly increased by 15.8%(P<0.05),and in July it increased by 30.3%,but the difference was not significant(P>0.05),the important value of S.transiliense in the enclosed area in September was significantly increased by 9.2%(P<0.05).In May,the change trends of important values of Ixiolirion tataricum and Astragalus sp.were basically the same,which were all increased by 150% compared with the grazing area,the important value of Piptatherum songaricum increased by 100% in the enclosed area in July and the important value of Petrosimonia sibirica in the grazing area in September was 100% higher than that in the enclosed area(P<0.05).(2)Compared with grazing areas,the height,coverage and biomass of enclosed communities increased significantly in May,July and September(P<0.05),while the community density decreased significantly in May and July(P<0.05),in September the community density was slightly lower than the grazing area,but the difference was not significant(P>0.05).(3)Compared with the grazing area,the changes of the Simpson index and Shannon-Wiener index in the enclosing area showed a downward trend in May,July and September,among which the Simpson index in the enclosing area decreased significantly in May(P<0.05).In May and September,the Pielou index in the enclosing area showed a downward trend,compared with the grazing area,the Pielou index in the enclosing area decreased significantly in May(P<0.05).The Margalef index in the enclosing area was lower than in the grazing area in July and September,and the Margalef index in the enclosing area in September was significantly lower lower than in the grazing area(P<0.05).(4)The daily rate of soil respiration was ranked from September to July and May,and its highest value appeared at 13:00,and the lowest value appeared at 7:00 am.In July and September the soil respiration rate showed increased first and subsequently decreased,the highest soil respiration rate occurred at 16:00 and the lowest value appeared at 4:00 am and at 1:00.The seasonal variation of soil respiration rate in the study area was ranked from September to July and May,the soil respiration rate of the enclosed area was less than that of the grazing area,and the soil respiration rate in the enclosing area was significantly lower than that in the grazing area in July(P<0.05).The results of the study show that grazing is conducive to improving the soil respiration rate.(5)In May,the maximum value of soil temperature appeared in the study area at 13:00,and the minimum temperature appeared at 7:00 in the morning;in July and September,the highest soil temperature value appeared at 16:00,with the lowest values at 4:00 am and at 1:00,the soil temperature in the enclosed area was lower than in the grazing area.The soil water content in the 0?10 cm oil layer of enclosing and grazing areas was ranked from September to July and May,while the soil moisture content was from May to September in the 10?20 cm soil layer,and the lowest in July.