|Brauer, David - Dave|
Submitted to: National Convention of the Society of American Foresters
Publication Type: Abstract only
Publication Acceptance Date: 4/4/2002
Publication Date: 9/1/2002
Citation: Ares, A., Reid, W., Brauer, D.K. 2002. Production and economics of silvopastoral systems with native pecan. National Convention of the Society of American Foresters. pp. 341-343. Interpretive Summary:
Technical Abstract: Silvopastoral systems with native pecan (Carya illinoinensis) are considered an example of sustainable and profitable agroforestry systems in southern and central regions of the United States. A study in southeastern Kansas examined nut, timber and forage production in managed mature pecan systems. During 1981-2000, nut production varied between 50 to 1600 kg/ha yr in stands ranging in density between 35 and 79 trees/ha. Pecan trees had a typical pattern of bearing more nuts every other year. Stem diameter growth followed a linear trend but nut production did not increase over time despite the increase in tree diameter and stand basal area, suggesting that nut production reached a relative equilibrium. Nonlinear seemingly unrelated regression was used to generate functions to predict timber yields based on trunk dimensions. Livestock grazed the understory dominated initially by tall fescue (Festuca arundinacea) which was replaced by a variety of grasses in late season. Protein content varied between 7.7 and 12.6% in spring and between 7.3 and 12.6% in fall. Forage production measured under several solar radiation regimes (25 to 83 % of transmitted light) along three transects decreased with decreasing radiation (P < 0.01). Nut, timber and understory production data were input to the Agroforestry Estate Model to generate economic simulations for different prize and management scenarios.