Ecological Archives M078-003-A2

Lorena Gómez-Aparicio and Charles D. Canham. 2008. Neighborhood models of the effects of invasive tree species on ecosystem processes. Ecological Monographs 78:69–86.

Appendix B. Parameter estimates and two-unit support intervals (in brackets) for the most likely models for the 18 soil properties in Acer platanoides sites. The “maximum impact” is also given, and represents the predicted maximum increase/decrease over the site mean (a) caused by the presence of Acer platanoides trees in a 25-m radius neighborhood.

Parameter

a [Site 1]

a [Site 2]

a [Site 3]

α

β

γ

b

c

Maximum impact

Bulk density
(g/cm3)

0.76
[0.72–0.81]

0.85
[0.80–0.89]

0.84
[0.79–0.88]

           

Litter depth
(mm)

16.24
[14.21–18.43]

16.79
[14.69–18.89]

17.32
[15.16–19.40]

           

Forest floor depth
(mm)

2.36
[-3.32 to 6.97]

2.97
[-0.25 to 6.65]

-17.55
[-21.68 to -13.42]

1

2.45
[2.27–2.66]

0.003
[0.002–0.004]

2.07
[1.29–3.55]

16.07
[14.71–17.44]

-17.17

pH

4.09
[3.99–4.19]

4.38
[4.27–4.49]

3.98
[3.88–4.08]

1

1.00
[1.00–1.06]

0.14
[0.12–0.16]

0.78
[0.73–0.81]

 

0.91

Exchangeable Ca
(mg/g)

25.41
[14.12–35.32]

44.79
[35.45–54.56]

30.08
[21.21–41.23]

2

1.00
[1.00–1.04]

0.18
[0.17–0.20]

-271.21
[-298.32 to -257.30]

26.10
[24.67–28.06]

200.77

Exchangeable Mg
(mg/g)

3.87
[3.09–4.85]

4.53
[3.49–5.12]

5.06
[4.10–5.72]

2

1.00
[1.00–1.19]

0.90
[0.87–0.92]

-47.55
[-55.28 to -40.27]

24.53
[19.28–29.29]

8.9

Exchangeable K
(mg/g)

5.13
[4.41–5.89]

2.88
[2.71–3.07]

4.01
[3.82–4.22]

1

1.23
[1.13–1.39]

0.18
[0.15–0.24]

-13.94
[-17.78 to -10.27]

4.86
[3.99–5.13]

6.55

Mass C
(kg/m2)

6.47
[6.21–6.73]

4.68
[4.41–4.92]

6.46
[6.21–6.75]

           

Mass N
(g/m2)

382.82
[359.85–405.79]

284.01
[261.29–306.73]

354.74
[331.68–377.79]

           

C:N

13.36
[12.76–13.96]

13.41
[12.81–14.02]

14.06
[13.42–14.69]

           

NH4+
(µg/g)

2.65
[2.15–3.15]

1.82
[1.33–2.31]

1.47
[0.98–1.97]

           

NO3-
(µg/g)

0.47
[0.11–0.85]

0.53
[0.15–0.88]

1.62
[1.24–1.98]

1

1.79
[1.68–1.92]

0.22
[0.18–0.25]

6.76
[5.57–7.95]

 

2.9

Microbial biomass C
(µg C/g)

826.53
[719.08–933.97]

554.83
[449.61–663.03]

703.50
[597.98–812.54]

           

Microbial biomass N
(µg N/g)

76.34
[64.51–87.79]

57.64
[46.40–69.45]

66.81
[55.12–78.16]

           

Respiration
(µg C·g-1·d-1)

17.23
[15.25–19.21]

15.85
[13.95–17.83]

15.57
[13.54–17.52]

           

Net N mineralization
(µg N·g-1·d-1)

1.01
[0.84–1.19]

0.77
[0.60–0.95]

1.20
[1.03–1.39]

2

2.99
[2.77–3.00]

0.0004
[0.0003–0.0006]

4.41
[4.28–4.52]

 

1.02

Net nitrification
(µg N·g-1·d-1)

0.77
[0.69–0.83]

0.47
[0.41–0.55]

1.02
[0.84–1.19]

2

3.00
[2.89–3.00]

0.0003
[0.0002–0.0006]

4.79
[4.44–4.86]

 

1.45

Ca mineralization
(µg Ca·g-1·d-1)

0.004
[0.002–0.006]

0.018
[0.014–0.022]

0.009
[0.005–0.013]

2

2.99
[2.70–3.00]

0.06
[0.04–0.09]

-70.56
[-64.89 to -76.98]

15.64
[13.48–17.92]

0.06

   Notes: Maximum impact occurred at Site 1 for exchangeable K; at Site 2 for pH, exchangeable Ca, NO3-, net N mineralization, net nitrification, and Ca mineralization; and at Site 3 for exchangeable Mg and forest floor depth.



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