a

b

c

1.2CP

1.6CP

2.3CP

3.6CP

N alone

2.39

0.60

0.89

2014

34

32

29

25

N alone

2.43

0.52

0.95

(Site-Seasons)

60

52

45

37

2014_PCR

13.13

10.41

7.81

5.40

(Site-Seasons)_PCR

5.79

4.86

3.65

2.43