| Plateau zokor(Myospalax baileyi)is one of unique subterranean species in the Qinghai-Tibet Plateau in China,M.baileyi belongs to Myospalax in Myospalacinae in Spalacidae in Rodentia.Because the zokor plays the very important role in the alpine meadow ecosystem,it is one of the research focus in current studying of rangeland ecology.The plateau zokor has the unique animal behavior that it makes mounds on the ground.Mounds cover the vegetation of grassland result in the decline of grassland productivity and soil erosion,however,little is known about the mound e mit greenhouse gas,like CO2 and CH4,into the air because mound is kind of secondary bare land.The zokor dig the tunnel and push the soil of tunnel into ground as mounds,there is few reports on the releation between greenhouse gas emitted from mounds and the gas inside the tunnels.Therefore,it is very important to know the situation that greenhouse gases emission on the mounds and its releation between the mound and the tunnel made by the plate au zokor.The paper selected the plateau zokor inhabiting in the alpine meadows located in Zhuaxixiulong Township in Tianzhu Autonomous County in Gansu Province in the eastern Q ilian Mountain region and conducted the studying items,including(1)study the seasonal changes of carbon dioxide and methane in the mounds with different years through closed chamber method;(2)used oil Gas Monitor in situ for 12 months and measured gas content of oxygen,carbon dioxide and methane in the active tunnel of the zokor;(3)study the effect of the active tunnel of the zokor on soil moisture and nutrition;(4)study the causes that induce the zokor seal the burrow through experiment in laboratory and in field.The main results obtained as follow:1.In the same month,the ra nk of emissions of carbon dioxide and methane on the mounds was new mound > secondary new mound>old mound? grassland without mounds.The rank of total microorganisms of mounds was new mound < secondary new mound < old mound?grassland without mounds.The amount of fungi had no significant changes in different months on mounds and grassland without mounds.O n the same mound,the emissions of carbon dioxide and methane and the amount of microorganisms showed a decreasing tendency,which was June > September> March?January,the amount of fungi had no seasonal changes in mounds and grassland without mounds.Both the month and the different mounds significantly affected the emissions of carbon dioxide and methane in mound and grassland without mounds(P<0.05),however,there was not influence by the interaction between months and mounds.The emissions of carbon dioxide and methane on mounds had very significantly positive correlation with total microorganisms in mound and the content of carbon dioxide and methane inside the active tunnel(P<0.01).Moreover,The correlation coefficient between the content of carbon dioxide and methane in active tunnel and the emissions of carbon dioxide and methane on mound was higher.The emissions of carbon dioxide and methane in grassland without mounds had positive correlation with total microorganisms in grassland without mounds and the content of carbon dioxide and methane in soil without tunnels.The correlation coefficient between total microorganisms and the emissions of carbon dioxide and methane in grassland without mounds was higher.2.The content of oxygen inside the active tunnel was less than that of inactive tunnel,no tunnel soil and air aboveground every month except October and November(P<0.05),the content of carbon dioxide inside active tunnel was greater than that of inactive tunnel,no tunnel soil and air aboveground every month except July and August,the methane content inside active tunnel was greater than that of air aboveground every month,however,there was not significant difference in methane content compare to the inactive tunnel and the soi without tunnel.The lowest value of oxygen and highest value of carbon dioxide inside the active tunnel was appeared in May and September,these values in the inactive tunnel,the soi without tunnel and air aboveground were appeared from June to August,the lowest and highest value of methane inside active tunnel,inactive tunnel,the soi without tunnel and air aboveground was appeared in January,December,May and September,respectively.The results showed that significant differences existed for months,treatments and the interaction between months and treatments(P<0.05).3.Burrowing activity of plateau zokor had no significant impact on available phosphorus and potassium(P>0.05),however,the zokor's behavior significantly increased soil bulk density,organic matter,total nitrogen,and available nitrogen inside zokor's tunnel(P<0.05),and significantly reduced soil moisture and available nitrogen in soil at 0~10 cm depth(P<0.05),which resulted in changes on vertical direction of the soil nutrient inside zokor's tunnel.4.The rank of burrow-sealing frequency of the plateau zokor in laboratory under 5 factors showed oxygen(52.63%)>light(34.58%)>temperature(20.24%)>air flow(6.48%)> sound(0%).Except light,the burrow-sealing frequency induced by oxygen was significantly higher than other factors(P<0.05).Used oxygen,light and temperature to induce the zokor sealing burrow in field,the burrow-sealing frequency of the plateau zokor in during activity time was 44.44%,11.11% and 0%,respectively in cold season,and 61.11%,38.89%,and 27.78% in warm season.During the activity time of the plateau zokor,oxygen induced burrow-sealing frequency was significantly higher than other factors(P<0.05),there was no significant differences among other factors during non-activity time(P<0.05).Sex has not obvious influences on the frequency and time of burrow-sealing in laborator,there was no significant differences in burrow-sealing time of the plateau zokor among each treatment. |
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