Competitive interactions between Cynodon dactylon and Acacia smallii seedlings at different nutrient levels

• Published in: The American midland naturalist Vol. 121; no. 2; pp. 265 - 272
• Main Authors: Cohn, E.J. (University of Texas, San Antonio), Van Auken, O.W, Bush, J.K
• Format: Journal Article
• Language: English
• Published: Notre Dame, IN University of Notre Dame 01-04-1989; University of Notre-Dame; American Midland Naturalist
• Subjects: ACACIA; Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; BIOLOGICAL COMPETITION; COMPETENCIA BIOLOGICA; COMPETITION BIOLOGIQUE; CRECIMIENTO; CROISSANCE; CROP YIELD; CYNODON DACTYLON; DISPONIBILIDAD DE NUTRIENTES; ELEMENT NUTRITIF DISPONIBLE; ESTABLECIMIENTO DE PLANTACIONES; ETABLISSEMENT DE LA PLANTE; FERTILIDAD DEL SUELO; FERTILITE DU SOL; Flowers & plants; Fundamental and applied biological sciences. Psychology; Grasses; GROWTH; Herbaceous plants; Legumes; NUTRIENT AVAILABILITY; Nutrient nutrient interactions; PLANT ESTABLISHMENT; PLANT INTERACTION; PLANT POPULATION; Plants; PLANTULAS; PLANTULE; POBLACION VEGETAL; POPULATION VEGETALE; Prairie soils; RENDEMENT DES CULTURES; RENDIMIENTO DE CULTIVOS; SEEDLINGS; SOIL FERTILITY; Soil nitrogen; Soil nutrients; Soil resources; Soils; Synecology; Terrestrial ecosystems; TEXAS; Competition; Productivity; Monocotyledones; Nutrition; United States; Growth; Soil fertility; North America; Monoculture; Cynodon dactylon; Mixed cropping; Leguminosae; Gramineae; Dicotyledones; Texas; America; Angiospermae; Wild plant; Spermatophyta; Fodder crop; Small tree; Greenhouse study; Species succession
• ISSN: 0003-0031; 1938-4238
• DOI: 10.2307/2426030

The interaction between Acacia smallii Isley (huisache) and Cynodon dactylon (L.) Pers. (bermuda grass) was examined in a greenhouse replacement experiment with two levels of soil nutrients. No significant negative effects of one species on the other were found in nonsupplemented native soil. Relative yield of C. dactylon was 30-50% higher in mixtures, whereas relative yield of A. smallii was 10-20% lower in the same mixtures. In supplemented native soil, A. smallii growth was reduced 70-90% when grown in mixtures with C. dactylon, compared to growth in monoculture. Cynodon dactylon growth was 1.5-2.4 times greater in mixtures than in monoculture. Added nutrients increased the growth of C. dactylon in mixtures and monoculture. However, addition of nutrients did not affect the growth of A. smallii in monoculture and actually decreased its growth in mixtures. Concentration of soil nutrients and proportion in mixture are important in determining growth of A. smallii and C. dactylon. We suggest that C. dactylon reduced the level of a soil resource below a level required for growth of A. smallii. In nutrient poor soils, C. dactylon would probably not have a negative influence on the establishment or growth of A. smallii. In more fertile soils, C. dactylon would reduce the growth of A. smallii seedlings, suggesting that gaps in vegetation are required for establishment and growth of A. smallii seedlings.