Table 1 Linear regression models showing functional trait variations in Parthenium hysterophorus across an elevational gradient

Leaf area (mm²)

(Intercept)

2843.62

187.68

15.15

< 0.001

0.12

0.12

Elevation

−0.65

0.14

−4.51

< 0.001

Leaf dry weight (mg)

(Intercept)

155.29

11.5

13.49

< 0.001

0.13

0.12

Elevation

−0.04

0.01

−4.64

< 0.001

Specific leaf area (mm² mg⁻¹)

(Intercept)

40.3

2.6

15.50

< 0.001

0.37

0.36

Elevation

0.0

0.0

8.85

< 0.001

Leaf mass per area (mg mm⁻²)

(Intercept)

0.0

0.01

0.28

0.78

0.37

0.36

Elevation

0.0

0.0

−8.66

< 0.001

Leaf dry-matter content (mg g⁻¹)

(Intercept)

165.0

28.8

5.72

< 0.001

0.20

0.19

Elevation

0.0

0.0

−4.19

< 0.001

Leaf thickness (mm)

(Intercept)

0.08

0.03

2.69

< 0.001

0.11

0.10

Elevation

0.0

0.0

−4.19

< 0.001

Photosynthetic efficiency (F_v/F_m)

(Intercept)

0.71

0.02

45.13

< 0.001

0.09

0.09

Elevation

−0.0

0.0

−3.86

< 0.001

Chlorophyll a (µg mg⁻¹)

(Intercept)

−4.97

1.89

−2.64

< 0.01

0.44

0.43

Elevation

0.0

0.0

−5.76

< 0.001

Chlorophyll b (µg mg⁻¹)

(Intercept)

0.7

0.09

8.38

< 0.001

0.06

0.06

Elevation

0.0

0.0

−3.15

< 0.001

Total chlorophyll content (µg mg⁻¹)

(Intercept)

−4.76

2.17

−2.19

0.03

0.40

0.39

Elevation

0.0

0.0

−5.52

< 0.001

Total carotenoid content (µg mg⁻¹)

(Intercept)

−1.37

0.5

−2.76

< 0.01

0.48

0.48

Elevation

0.0

0.0

−8.15

< 0.001

Leaf water content (mg)

(Intercept)

0.4

0.04

10.27

< 0.002

0.04

0.03

Elevation

0.0

0.0

−2.40

0.02

Leaf nitrogen content (mg g⁻¹)

(Intercept)

3.62

0.03

113.27

< 0.001

0.81

0.81

Elevation

0.0

0.0

−25.25

< 0.001

Leaf phosphorus content (mg g⁻¹)

(Intercept)

44.56

0.47

95.47

< 0.001

0.87

0.87

Elevation

−0.01

0.0

−31.4

< 0.001