Table 2 Parameters from the best Cox proportional hazard model of Amazon tree mortality.

From: Tree mode of death and mortality risk factors across Amazon forests

  

D

D2

Rel. growth

Max D

Mean growth

WD

WDA

All Amazonia

Coef (SE)

−28 (3)

26 (2)

−0.08 (0.01)

−0.002 (0.0001)

0.2 (0.005)

−0.7 (0.06)

−1 × 10−4 (1 × 10−4)

(n = 116,431; d = 21,272)

χ2

101

216

233

1190

2126

141

2

Northern Amazonia

Coef (SE)

−2.5 (3)

8.6 (2.4)

−0.02 (0.02)

−0.001 (0.0002)

0.2 (0.02)

−0.5 (0.2)

−2 × 10−4 (3 × 10−4)

(n = 17,585; d = 2307)

χ2

0.6

13

1

64

188

9

0.3

East-Central Amazonia

Coef (SE)

8 (3)

10 (2)

−0.2 (0.01)

−0.003 (0.0001)

0.3 (0.01)

−0.8 (0.1)

−9 × 10−4 (2 × 10−4)

(n = 39,281; d = 6077)

χ2

8

21

289

500

668

45

23

Western Amazonia

Coef (SE)

−32 (2)

20 (1.4)

−0.05 (0.01)

−0.002 (0.0001)

0.22 (0.006)

−0.52 (0.08)

−1 × 10−5 (1 × 10−4)

(n = 45,432; d = 10,603)

χ2

166

199

54

511

1154

41

0

Southern Amazonia

Coef (SE)

−18 (4)

16 (3)

−0.08 (0.01)

−0.002 (0.0002)

0.2 (0.01)

−0.9 (0.2)

1 × 10−3 (3 × 10−4)

(n = 14,133; d = 2285)

χ2

26

25

31

145

205

21

16

  1. Coefficients and standard errors, in brackets, and χ2 for each risk factor shown for the model using data from the whole Amazon (All Amazon) and for models describing tree mortality in each of the four Amazon geological regions. Risk factors include characteristics from the trees: size, represented by tree diameter (D) and relative stem diameter growth rates (rel. growth); and species traits: maximum stem diameter size (max D), mean stem diameter growth rate (mean growth), wood density (WD) and drought tolerance represented as water-deficit affiliation33 (WDA). In bold are the coefficients that significantly differ from zero considering α = 0.05. Number of trees included in the analysis (n) and number of dead trees (d) are shown for each region.
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