Ecological Archives E088-139-A2

Jonathan D. Bakker and Margaret M. Moore. 2007. Controls on vegetation structure in southwestern ponderosa pine forests, 1941 and 2004. Ecology 88:2305–2319.

Appendix B. Tables summarizing the canopy cover and tree density inside and outside livestock exclosures at five sites in northern Arizona in 1941 and 2004.

TABLE B1. Canopy cover (%; mean ± SD; min-max) inside and outside livestock exclosures at five sites in northern Arizona in 1941 and 2004. Mature trees and regeneration were measured separately in 1941 but not in 2004. P values are from Wilcoxon tests for differences between grazing treatments; values ≤ 0.05 are in bold. Mean values across sites are in Table 2.

 

Grazing treatment

BF

BS

FP

RT

RL

1941 Mature trees

         
 

In

14±21; 0-80

8±15; 0-63

7±15; 0-58

23±24; 0-82

27±30; 0-100

 

Out

8±22; 0-97

22±24; 0-100

7±15; 0-59

16±26; 0-85

27±28; 0-80

 

P

0.004

<0.001

0.607

0.169

0.957

1941 Regeneration

         
 

In

11±16; 0-58

9±9; 0-32

8±11; 0-54

26±23; 0-79

8±8; 0-32

 

Out

3±6; 0-30

3±5; 0-19

3±7; 0-31

36±27; 0-79

2±6; 0-25

 

P

<0.001

0.002

<0.001

0.250

<0.001

1941 Total

         
 

In

25±23; 0-80

17±16; 0-63

15±17; 0-70

50±24; 5-86

35±31; 0-100

 

Out

12±22; 0-97

25±24; 0-100

11±16; 0-70

52±27; 0-100

29±28; 0-80

 

P

<0.001

0.159

0.013

0.808

0.295

2004 Total

         
 

In

48±28; 0-96

55±21; 14-96

46±30; 0-98

64±23; 24-96

74±16; 25-100

 

Out

33±28; 0-96

54±22; 6-100

23±27; 0-100

60±24; 30-96

39±26; 0-84

 

P

0.001

0.978

<0.001

0.888

<0.001

Site codes: BF = Big Fill; BS = Black Springs; FP = Fry Park; RT = Reese Tank; RL = Rogers Lake.

Received silvicultural treatments within the last 20 years; see Table 1 in text for more details of land-use history.

 

TABLE B2. Density (t/ha; mean ± SD; min-max) inside and outside livestock exclosures at five sites in northern Arizona in 1941 and 2004. Mature trees and regeneration were measured separately in 1941 but not in 2004. P values are from Wilcoxon tests for differences between grazing treatments; values ≤ 0.05 are in bold. Mean values across sites are in Table 2.

 

Grazing treatment

BF

BS

FP

RT

RL

1941 Mature trees

 

In

134±277; 0-1076

53±203; 0-1076

40±142; 0-538

322±441; 0-1614

457±813; 0-3229

 

Out

33±156; 0-1076

107±277; 0-1076

40±166; 0-1076

349±636; 0-2690

161±327; 0-1614

 

P

0.002

0.296

0.776

0.806

0.178

1941 Regeneration

 

In

3498±4784; 0-21,527

1399±1205; 0-4843

760±1160; 0-5381

7938±10,901; 0-44,670

4937±5134; 0-22,066

 

Out

659±1155; 0-5381

1560±1441; 0-5381

396±778; 0-4305

17,841±9706; 538-39,826

322±569; 0-2152

 

P

<0.001

0.811

0.005

<0.001

<0.001

1941 Total

 

In

3632±4870; 0-22,066

1453±1255; 0-4843

800±1177; 0-5381

8261±10,768; 538-44,670

5395±5321; 0-22,066

 

Out

692±1155; 0-5381

1668±1393; 0-5381

437±785; 0-4305

18,191±9716; 1614-40,364

484±619; 0-2690

 

P

<0.001

0.569

0.010

<0.001

<0.001

2004 Total

 

In

1614±1837; 0-6996

450±530; 0-2152

726±1035; 0-5920

762±583; 0-1614

2273±1686; 0-6458

 

Out

598±1055; 0-5381

448±755; 0-3767

200±379; 0-1614

269±450; 0-1076

255±455; 0-1614

 

P

<0.001

0.509

<0.001

0.095

<0.001

Site codes: BF = Big Fill; BS = Black Springs; FP = Fry Park; RT = Reese Tank; RL = Rogers Lake.

Received silvicultural treatments within the last 20 years; see Table 1 in text for more details of land-use history.



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