Table 2 — Standing crop biomass (g/m 2 dry weight) of species occurring in unfertilized and fertilized plots in years 1 and 3 



Species 



Year 1 



No fertilizer 



Fertilizer 



Year 3 



No fertilizer 



Fertilizer 



Introduced grasses 



Intermediate wheatgrass 



{Agropyron intermedium) 

 Meadow foxtail 



(Alopecurus pratensis) 

 Smooth brome 



(Bromus inermis) 

 Orchardgrass 



(Dactylis glomerata) 

 Timothy 



(Phleum pratense) 



Native species 



Grasses 

 Slender wheatgrass 



(Agropyron trachycaulum) 

 Tufted wheatgrass 



(Deschampsia cespitosa) 

 Muttongrass 



(Poa fendleriana) 

 Spike trisetum 



( Trisetum spicatum) 



Forbs 

 Western yarrow 



(Achillea millefolium) 

 Antennaria 



(Antennaria spp.) 

 Silky phacelia 

 (Phacelia sericea) 



Shrubs 

 Saskatoon serviceberry 



(Amelanchier alnifolia) 

 Mountain big sagebrush 



(Artemisia tridentata vaseyana) 



M.68 ± 0.327 (3) 2 



.06 ± .002 (5) 



1.19 ± .058 (7) 



.92 ± .080 (8) 



.16 ± .010 (4) 



3.97 ± 0.475 (6) 

 .07 ± .007 (4) 

 2.53 ± .100(6) 

 3.22 ± .182(8) 

 .70 ± .036 (5) 



.04 ± .004 (5) 

 .18 ± .011 (4) 



.14 ± .009 (9) 



.01 ± .000 (1) 



.20 ± .000 (1) 



.11 ± .009 (2) 

 .55 ± .060 (4) 



.92 ± .077 (9) 



.15 ± .000(1) 



2.18 ± 0.134 (7) 



1.33 ± .117 (6) 



3.18 ± .179 (8) 



2.65 ± .249 (9) 



.78 ± .052 (8) 



2.00 ± .170 (8) 



.70 ± .070 (8) 



.22 ± .021 (3) 



2.65 ± .023 (7) 



.07 ± .002 (2) 



.14 ± .004 (4) 



.24 ± .000 (1) 



2.81 ± 0.196 (7) 



1.10 ± .078 (6) 



1.80 ± .051 (7) 



2.42 ± .202 (9) 



1.06 ± .050 (8) 



1.99 ± .109 (9) 



.62 ± .049 (6) 



.45 ± .043 (7) 



.21 ± .009 (6) 

 .24 ± .000 (1) 



Woods rose 



.03 



+ 



.005 



(2) 



.03 ± .005 (2) 



.32 ± 



.026 



(4) 



.06 



± 



.000 



(1) 



(Rosa woodsii) 



























Colonizer species 



























Winter bentgrass 













.27 ± 



.021 



(3) 



.51 



+ 



.111 



(3) 



(Agrostis scabra) 



























Idaho fescue 



.01 



+ 



.00 



(1) 



















(Festuca idahoensis) 



























Poa 











.21 ± .000 (1) 

















(Poa spp.) 



























Alkali sandspurry 



5.61 



+ 



.427 



(9) 



30.23 ± 2.103 (9) 



.40 ± 



.041 



(7) 



.46 



+ 



.026 



(9) 



(Spergularia diandra) 



























Spreading groundsmoke 



.21 . 



+ 



.020 



0) 



.20 ± .017(7) 



.11 ± 



.017 



(7) 



.26 



+ 



.027 



(7) 



(Gayophytum diffusum) 



























Prostrate knotwood 



.28 



+ 



.024 



(9) 



1 .38 ± .093 (9) 



.11 ± 



.013 



(3) 



.23 



+ 



.042 



(4) 



(Polygonum aviculare) 

























Draba 











.18 ± .031(2) 



.08 ± 



.005 



(3) 



.06 



+ 



.000 



(1) 



(Draba spp.) 



























Common fireweed 













.02 ± 



.002 



(2) 



.08 



+ 



.016 



(3) 



(Epilobium angustifolium) 

























Aster 













.24 ± 



.000 



(1) 











(Aster spp.) 



























Common dandelion 













.06 ± 



.000 



(1) 











( Taraxacum officinale) 

























Lodgepole pine 













.12 ± 



.016 



(4) 



.06 



+ 



.000 



(3) 



(Pinus contorta) 



'Values are mean ± S.E. 

 'Number of observations. 



5 



