OP1

          
                View at site 1                                         Typical crust at site 1

Oregon Pipe Cactus, Arizona, USA.  32° 11.935' N latitude, 112° 54.389' W longitude.  Date of sampling:  29 June 2000.

Vascular plants at the site:  Larrea tridentata, bursage, Range ratany, Mesquite.

Mean lichen crust thickness:
Mean algal crust thickness:

Cover summary:

Type Cover        % Cover
Shrubs                     
Annuals                   
Perennial grasses    
Perennial forbs       
Algal crust             
Bryophytes              
Lichens                   
Bare Soil                   
Rock                          
Gravel                       
Litter                         
Cactus                       
            

Chlorophyll a (ng/g):  3903.9
N fixation rate (mmol/n2/m2/hr):  186.48
Soil texture class:

OP2

 
                        View at site 2                                                      Typical crust at site 2

Oregon Pipe Cactus, Arizona, USA.  32° 11.109' N latitude, 112° 56.251' W longitude.  Date of sampling:  29 June 2000.

Vascular plants at the site:  Mesquite, Enselia farinosa, Larrea tridentata, Squaro, Chain fruit cholla.

Mean lichen crust thickness:
Mean algal crust thickness:

Cover summary:

Type Cover        % Cover
Shrubs                     
Annuals                   
Perennial grasses    
Perennial forbs       
Algal crust             
Bryophytes              
Lichens                   
Bare Soil                   
Rock                          
Gravel                       
Litter                         
Cactus                       
            

Chlorophyll a (ng/g):  4169.9
N fixation rate (mmol/n2/m2/hr):  734.42
Soil texture class:

OP3

Oregon Pipe Cactus, Arizona, USA.  31° 53.280' N latitude, 112° 48.401' W longitude.  Date of sampling:  29 June 2000.

Dominant vascular plants at the site:  Encelia farinosa

Other vascular plants:  Christmas cactus, Larrea tridentata, Saquaro sp. , Chain fruit cholla, velvet mesquite, Brittlebrush.

Mean lichen crust thickness:
Mean algal crust thickness:

Cover summary:

Type Cover        % Cover
Shrubs                     
Annuals                   
Perennial grasses    
Perennial forbs       
Algal crust             
Bryophytes              
Lichens                   
Bare Soil                   
Rock                          
Gravel                       
Litter                         
Cactus                       
            

Chlorophyll a (ng/g):  218.81
N fixation rate (mmol/n2/m2/hr):  20.38
Soil texture class:

OP4

Oregon Pipe Cactus, Arizona, USA.  31° 53.826' N latitude, 112° 52.369' W longitude.  Date of sampling:  30 June 2000.

Vascular plants at the site:  Larrea tridentata, Encelia farinosa, Saquaro sp., Ironwood, Velvet mesquite, Condalia globosa, Palo Verde, Chain fruit chlolla.

Mean lichen crust thickness:
Mean algal crust thickness:

Cover summary:

Type Cover        % Cover
Shrubs                     
Annuals                   
Perennial grasses    
Perennial forbs       
Algal crust             
Bryophytes              
Lichens                   
Bare Soil                   
Rock                          
Gravel                       
Litter                         
Cactus                       
            

Chlorophyll a (ng/g):  942.14
N fixation rate (mmol/n2/m2/hr):  30.80
Soil texture class: