The Role of Native Annual Forbs in the Restoration of Invaded Rangelands
Erin Goergen, Elizabeth Leger, Tara Forbis University of Nevada, Reno USDA ARS Reno, NV Restoration of degraded communities is costly and difficult. Restoration of degraded communities is costly and difficult.
• Weather • Seeding method • Seeds • Species mixes Natural Succession
Late seral Disturbance Annuals Early seral perennials perennials & shrubs Seed Mix 1 Seed Mix 3 • Artemisia tridentata • Elymus lanceolatus • Artemisia tridentata • Leymus cinereus • Purshia tridentata • Poa secunda • Achnatherum hymenoides • Pseudoroegneria spicata • Agropyron crestatum • Achillea millefolium • Elymus lanceolatus • Leymus cinereus Seed Mix 2 • Pascopyrum smithii • Artemisia tridentata • Poa secunda • Achnatherum hymenoides • Pseudoroegneria spicata • Elymus lanceolatus • Achillea millefolium • Poa secunda • Medicago sativa • Pseudoroegneria spicata Can we improve restoration success by more closely following natural successional patterns?
Late seral Disturbance Annuals Early seral perennials perennials & shrubs Native annual forbs may be valuable restoration species for multiple reasons
1. Adapted to post-disturbance environmental conditions. 2. Likely to be phenologically similar to and competitive with Bromus tectorum. 3. Contribute to plant diversity and habitat in rangelands. Native annuals can be abundant! Annuals increase after disturbance!
• Native annual forbs have relatively low abundance in climax sagebrush communities.
• Underdown Canyon, Austin NV – 1 year after fire, native annual forbs increased by 70% – Cover stayed high even 3 years post-fire Annuals are good competitors!
Cryptantha pterocarya
25 – 85% reduced!
Collinsia parviflora 25 – 35% reduced! There is overlap in phenology
Fall Winter Spring Summer Fall Bromus tectorum Annual forbs
Forbis (2010) Plant Species Biology 25:221-230 _ B. tectorum Native perennial grasses Native annual forbs _ _
_ B. tectorum Native perennial grasses Native annual forbs _ _ + _ B. tectorum Native perennial grasses
Can seeding native annual forbs improve establishment of the short-lived, native perennial grass Elymus multisetus? Questions
1. What is the effect of individual annuals, on Elymus multisetus and Bromus tectorum? 2.When grown in mixtures, what effect do annual forbs have on Elymus multisetus and Bromus tectorum? Field Experiment • Target E. multisetus and B. tectorum – grown alone, with single annual forb species, B. tectorum, or forb + B. tectorum. • 5 Native forbs chosen:
Amsinckia tesellata Descurinia pinnata AMTE DEPI
Amsinckia intermedia Mentzelia veatchiana Blepharipappus AMIN MEVE scaber BLSC Experimental Design
Target: Elymus multisetus or Bromus tectorum
Competitors: none, annual forb, B. tectorum, or both Seeds were sown around a target plant at typical field densities Questions
1.What is the effect of individual annuals, on target Elymus multisetus and Bromus tectorum? 1. ELMU grows best with BLSC, DEPI, and MEVE
A
) g 1 AB 70% 75%
83% 0.5 aboveground aboveground ( biomass B
94%
multesitus 99% 97% E. E.
0 AMTE AMIN BRTE MEVE DEPI BLSC 1. Competitive pressure on BRTE is not equal! 3.5 A 3 AB 38% 2.5 46%
2 59% 1.5
vegetative (g) biomass vegetative BC
1 84% C 88% 0.5 B. tectorum B. 97% 0 AMTE BRTE AMIN MEVE DEPI BLSC Questions
2. When grown in mixtures, what effect do annual forbs have on Elymus multisetus and Bromus tectorum? MEVE and BRTE AM and BRTE 2. When with BRTE, ELMU is larger when 0.5 MEVE is also present.
) 71% g 0.4
0.3
0.2 27% aboveground aboveground biomass ( BRTE 60% 0.1 multesitus 79% E. 95%
0 BRTE+AMTE BRTE+AMIN BRTE+DEPI BRTE+BLSC BRTE+MEVE 2. BRTE is most impacted when grown with AMTE and AMIN. 1 A 90%
AB
0.5
6% 7% vegetative (g) biomass vegetative BC 51%
B. tectorum B. C 88% 0 BRTE+AMTE BRTE+AMIN BRTE+DEPI BRTE+MEVE BRTE+BLSC Field summary
• A. tesselata and A. intermedia show promise as a good competitors against B. tectorum.
• M. veatchiana has the potential to facilitate establishment of E. multisetus. Next steps
• Multiple years!
• We need to learn more about our native annual forbs! – Germination strategies – Dormancy issues – Competitive abilities Questions?