Appendix 3‐1
Comparative characteristics of a native tallgrass prairie, a conventional corn–soybean farm, and an oak–hickory forest.
| Characteristic | Native tallgrass prairie | Conventional farm | Oak–hickory forest |
|---|---|---|---|
| Physiography | central lowlands of level to undulating terrain | central lowlands of level to undulating terrain | central lowlands and Ozark Plateaus |
| Climate | eastern Kansas | east‐central Nebraska | north‐central Missouri |
| Mean annual temperature,°C | 12.8 | 10.0 | 12.2 |
| Mean January temperature,°C | −2.3 | −6.2 | −2.5 |
| Mean July temperature,°C | 26.7 | 25.0 | 25.5 |
| Avg. frost‐free period, d | 190 | 167 | 194 |
| Mean annual precipitation, mm | 800 | 695 | 1015 |
| Quarterly precipitation, % of annual(Jan.–Mar./Apr.–June/July–Sept./Oct.–Dec.) | 12/38/32/18 | 12/40/33/15 | 18/32/27/23 |
| Annual precipitation variability, yr(1961–1990) | |||
| <75% of avg. | 4 | 5 | 3 |
| >125% of avg. | 4 | 7 | 2 |
| Hydrology | |||
| Actual evapotranspiration, mm | 760 | 649 | 747 |
| Potential evapotranspiration, mm | 780 | 704 | 842 |
| Percolation and runoff, mm | 40 | 46 | 268 |
| Soil | |||
| Predominant soil order | Mollisol | Mollisol | Alfisol |
| Suborder | Udoll | Ustoll | Udalf |
| Total SOM, g m−2 (0–100 cm) | 31,600 | 19,640 | 7,027–13,403 |
| Soil N (0–100 cm) | |||
| Inorganic N, g N m−2 | 4.5 | 4.6–11.0 | 3.2–6.1 |
| Organic N, g N m−2 | 1,550–1,580 | 982 | 410–782 |
| Community composition & structure | |||
| Physiognomy | grasses dominant with a 0.5–3.3‐m closed canopy | maize or soybean monocultures with uniform closed canopies (2.5–3 m maize; 0.7–1 m soybean) | broadleaf deciduous forest in which 50% or more of the trees are oak or hickory with a 5.5–8.3‐m (avg. 6.3) |
| Dominant floristic type | perennial grasses | annual grass (maize) or annual broadleaf (soybean) | perennial broadleaf trees |
| Species richness (250 ha) | 200–300 vascular plant species | dominance by two crop species | ~94 vascular plant species |
| Species evenness | >50 % of aboveground biomass in 3–4 species | >90 % of aboveground biomass in 2 species | >90% of aboveground biomass in 3–4 species |
| Avg. annual max. aboveground biomass (includes litter), g m−2 | 650–1,075 | 870 (live only) | 10,934 |
| Avg. annual max. belowground biomass, g m−2 | 1,869–1,985 | 160 | 2,592 |
| Belowground OM (includes living and SOM), % of total OM | >98 | 96 | 47–59 |
| Leaf area index, m2 m−2 | 4 | 4–4.5 | 2.5–4.5 |
| Root depth distribution | 90% of root biomass in top 50 cm | >90% of root biomass in top 75 cm | >50% in upper 30 cm |
| Energy flow | |||
| Solar radiation, growing‐season PAR, kJ m−2 | 2227 × 103 | 1772 × 103 |
2017 × 103
|