Species Composition Results - June 20, 1998

Plot comparisons: Each of the five plots consists of a 1m² plot in a Buffalo grass patch and a 1m² plot in a nearby knapweed-invaded area. All flowering or otherwise identifiable species were listed by Latin and common name, and all non-flowering or otherwise unidentifiable species were also noted.

Plot 1:

Buffalo grass patch:

1. Buffalo-Grass Buchloe dactyloides
2. Western wheatgrass Agropyron smithii
3. Japanese brome Bromus japonicus
4. Alyssum Alyssum minus
5. Cheat-grass Bromus tectorum
6. Woolly plantain Plantago patagonica
7. June-grass Koeleria macrantha
8. Fleabane Erigeron divergens
9. Vetch Vicia americana
10. Knapweed Centaurea diffusa
11. Bindweed Convolvulus arvensis
12. Unknown - 1 (looks like Rabbitbrush Chrysothamnus nauseosus)

Knapweed patch:

1. Diffuse knapweed Centaurea diffusa
2. Buffalo-Grass Buchloe dactyloides
3. Western wheatgrass Agropyron smithii
4. Japanese brome Bromus japonicus
5. Alyssum Alyssum minus
6. Woolly plantain Plantago patagonica
7. Kentucky bluegrass Poa pratensis
8. Bindweed Convolvulus arvensis
9. Fleabane Erigeron divergens
10. Unknown - 1 (looks like Rabbitbrush Chrysothamnus nauseosus)

Plot 2:

Buffalo grass patch:

1. Buffalo-Grass Buchloe dactyloides
2. Wheat Triticum aestivum
3. Japanese brome Bromus japonicus
4. Alyssum Alyssum minus
5. Cheat-grass Bromus tectorum
6. Woolly plantain Plantago patagonica

Knapweed patch:

1. Diffuse knapweed Centaurea diffusa
2. Buffalo-Grass Buchloe dactyloides
3. Western wheatgrass Agropyron smithii
4. Japanese brome Bromus japonicus
5. Alyssum Alyssum minus
6. Canada bluegrass Poa compressa
7. Bindweed Convolvulus arvensis
8. Fleabane Erigeron divergens
9. Wild Alfalfa Psoralea tenuiflora
10. Vetch Vicia americana
11. Unknown - 1 (looks like Rabbitbrush Chrysothamnus nauseosus)

Plot 3:

Buffalo grass patch:

1. Buffalo-Grass Buchloe dactyloides
2. Bindweed Convolvulus arvensis
3. Japanese brome Bromus japonicus
4. Alyssum Alyssum minus
5. Cheat-grass Bromus tectorum
6. Woolly plantain Plantago patagonica
7. Diffuse knapweed Centaurea diffusa
8. Wild Alfalfa Psoralea tenuiflora
9. Vetch Vicia americana
10. Fleabane Erigeron divergens
11. Unknowns - 2

Knapweed patch:

1. Diffuse knapweed Centaurea diffusa
2. Buffalo-Grass Buchloe dactyloides
3. Western wheatgrass Agropyron smithii
4. Japanese brome Bromus japonicus
5. Alyssum Alyssum minus
6. Bindweed Convolvulus arvensis
7. Vetch Vicia americana
8. Wild Alfalfa Psoralea tenuiflora
9. Unknown - 1

Plot 4:

Buffalo grass patch:

1. Buffalo-Grass Buchloe dactyloides
2. Bindweed Convolvulus arvensis
3. Japanese brome Bromus japonicus
4. Alyssum Alyssum minus
5. Woolly plantain Plantago patagonica
6. Fleabane Erigeron divergens

Knapweed patch:

1. Diffuse knapweed Centaurea diffusa
2. Buffalo-Grass Buchloe dactyloides
3. Western wheatgrass Agropyron smithii
4. Alyssum Alyssum minus
5. Kentucky bluegrass Poa pratensis
6. Bindweed Convolvulus arvensis
7. June-grass Koeleria macrantha
8. Vetch Vicia americana
9. Wild Alfalfa Psoralea tenuiflora
10. Unknown (looks like Rabbitbrush Chrysothamnus nauseosus)
11. Unknown (nonflowering, but will probably be a composite)

Plot 5:

Buffalo grass patch:

1. Buffalo-Grass Buchloe dactyloides
2. Western wheatgrass Agropyron smithii
3. Bindweed Convolvulus arvensis
4. Japanese brome Bromus japonicus
5. Alyssum Alyssum minus
6. Woolly plantain Plantago patagonica
7. Diffuse knapweed Centaurea diffusa
8. Vetch Vicia americana
9. Fleabane Erigeron divergens
10. Wild Alfalfa Psoralea tenuiflora
11. Unknown - 1 (looks like Rabbitbrush Chrysothamnus nauseosus)

Knapweed patch:

1. Diffuse knapweed Centaurea diffusa
2. Buffalo-Grass Buchloe dactyloides
3. Western wheatgrass Agropyron smithii
4. Alyssum Alyssum minus
5. Bindweed Convolvulus arvensis
6. Fleabane Erigeron divergens
7. Vetch Vicia americana
8. Wild Alfalfa Psoralea tenuiflora
9. Kentucky bluegrass Poa pratensis
10. Unknown - 1 (looks like Rabbitbrush Chrysothamnus nauseosus)

Questions:

Is there more diversity in the Buffalo grass patch or the knapweed patch? While the least diverse patch is a Buffalo grass patch, there doesn't seem to be as very much difference in diversity between Buffalo grass patches and knapweed patches.

What is the difference between the species in the Buffalo grass patch and the species in the knapweed patch? No real differences were seen this year.

What is the difference in appearance between the two types of patches? The Buffalo grass patches are noticeably different from the knapweed patches; the Buffalo grass creates a complete ground cover and the plants overall are shorter. The knapweed and bindweed in the Buffalo grass patches are very noticeably shorter and this will results in smaller seed production later in the season. The knapweed patches are more sparsely vegetated and the plants are taller. The bare ground visible in the knapweed patches indicates higher possibility of erosion in knapweed-covered ground. This also increases the likelihood of future knapweed seedlings to establish, as knapweed seedlings prefer bare ground to patches with other plants that may compete with them for light. The difference in the plots indicates heavier competition in the patches containing a solid ground cover of Buffalo grass -- this is probably competition for water as the soil beneath the Buffalo grass must be well populated with Buffalo grass roots. This competition may be what enables Buffalo grass to largely exclude knapweed. The competitiveness of Buffalo grass may well exclude or affect other species as well.