| The daily behavior of plateau pika can be divided into four types including feeding,warning,playing and staying in the cave.By using field observation,the relationships between four vegetation traits?including height,coverage,biomass,and community structure?and daily behavior patterns of plateau pika were investigated.The results indicated that:1.The vegetation height had a significant impact on the behavior pattern of the pika.As the increases of height,the staying time and warning time in the cave increased significantly,while the feeding time and playing time decreased successively.When the vegetation height exceeded27.3 cm,the staying time in the cave rosed sharply,and the difference between the sample plot with the height of 32.7 cm was extremely significant?P<0.01?.The warning time was significantly different at 23.2 cm?P<0.05?,and it did not increase significantly with the increase of vegetation height.When the vegetation height was 23.3cm,the playing time was significantly reduced.The feeding time decreased with the increase of vegetation height.When the vegetation height was 32.7cm,the difference between it and the adjacent sample plot was extremely significant?P<0.01?.2.The change of vegetation coverage had a significant effect on staying time in the cave,feeding and playing time of the pika,while had no effects on the warning time.In the four coverage gradients of 68.7%to 95.3%,the staying time in the cave increased significantly with the increase of vegetation coverage,and the differences between adjacent sample plots reached a significant or extremely significant level.The playing time decreased markedly with the increase of vegetation coverage.The difference of playing time between three asmple plots[from 68.7%???to 83.4%???],and between adjacent sample plot??/?,?/??was all significant?P<0.05?.Feeding time in four plots under coverage of 95.3%???declined significantly,among with,the value corresponding to the coverage of 68.7%and 76.5%,83.4%and 95.3%differed at the level of P<0.05,while the value corresponding to the coverage of 68.7%and 95.3%differed at the level of?P<0.01?.There was no significant correlation between warning time and coverage in different plots.3.All behaviors of the plateau pika had a significant responsed to the changes of aboveground biomass.Among them,the warning and feeding time decreased with the increase of biomass,the staying time in the cave,however,increased with the increase of biomass.When the biomass exceeded 340.0 g?m-2???,the warning time declined significantly as the increase of biomass,the values differed at the level of P<0.05 between the plots,and differed at the level of P<0.01 between the plot?and?,?and?.Feeding time decreased linearly with the increase of biomass,the value corresponding to four biomass gradient of 269.2 g?m-2???to 434.0 g?m-2???were differed at the level of P<0.01.In contrast,the staying time in the cave and the feeding time increased significantly with the increase of biomass,the value corresponding to four biomass gradient of 269.2 g?m-2???to 434.0 g?m-2???were also differed at the level of P<0.01.The biomass had no significant effects on playing time.4.The proportion of grass biomass in vegetation communities had significant effects on feeding time and staying time in the cave.Within the scope of 18%to 22%,the feeding time reduced significantly with the increase of grass?P<0.01?.The staying time in the cave,however,showed a different changes.It increased observably with the increase of grass proportion in the range of 18%—22%.Likewise,the playing time increased slowly with the increase of grass prportion.The warning time,however,decreased slowly with the increase of grass prportion.5.Vegetation height,coverage and above-ground biomass were all negatively correlated with feeding behavior?R2>0.9059,P<0.01?.There was a significant positive correlation between vegetation height and warning time?R2=0.88,P<0.01?.Vegetation coverage was positively correlated with warning time?R2=0.667,P<0.01?.There was a negative correlation between above-ground biomass and grass proportion and alerting time?R2>0.7674,P<0.01?.Vegetation height,coverage and abovementie biomass were positively correlated with hole-retention time?R2>0.9046,P<0.01?.There was a significant negative correlation between vegetation height,coverage and play time?R2>0.9222,P<0.01?.Above ground biomass was positively correlated with play time?R2=0.8955,P<0.01?.Grass proportion was positively correlated with play time?R2=0.7881,P<0.01?.6.There existed a critical point from quantitative changes to qualitative changes between vegetation characters and behavior response of plateau pikas.Exceeding this critical point,the response of plateau pika to vegetation environment may change differently.The smaller the ratio of feeding time and staying in holes is,the greater the stress force of vegetation environment,and vice versa.The effects of vegetation height on pika habitat were greater than that of vegetation coverage,biomass and grass proportion. |
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