Effects of changing the supply of nitrogen and phosphorus on growth and interactions between Eucalyptus globulus and Acacia mearnsii in a pot trial

• Published in: Plant and soil Vol. 280; no. 1-2; pp. 267 - 277
• Main Authors: Forrester, D.I, Cowie, A.L, Bauhus, J, Wood, J.T, Forrester, R.I
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer 01.01.2006
• Subjects: Aboveground biomass; Acacia mearnsii; Agronomy. Soil science and plant productions; Animal and plant ecology; Animal, plant and microbial ecology; Artificial regeneration. Forest nurseries. Planting; Autoecology; Belowground biomass; Biological and medical sciences; biomass; Biomass production; continuous cropping; Demecology; Eucalyptus globulus; fertilizer application; Fertilizers; Forest soils; Forestry; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; intercropping; Nitrogen; nitrogen fertilizers; nutrient use efficiency; phosphorus; Phosphorus fertilizers; plant nutrition; Plants; Plants and fungi; pot culture; Soil interactions; soil nutrients; Soil resources; soil water content; Soil-plant relationships. Soil fertility; Soil-plant relationships. Soil fertility. Fertilization. Amendments; Sowing and planting; Growth; Soil fertility; Eucalyptus globulus; mixed-species; Supply; Environmental factor; competition; Inorganic element; Dicotyledones; Mixity; Angiospermae; Myrtaceae; Interspecific competition; Hardwood forest tree; Soil science; Species; Influence factor; Non metal; Facilitation; Nutrition; Interaction; Forest tree; Phosphorus; Ecology; Acacia mearnsii; Woody plant; Change; Nitrogen; Experimental study; Pot experimentation; Group VA element; Edaphic factor; Pot growing; Leguminosae; Artificial forest stand; Limiting factor; Site factors; Forestry; Spermatophyta; Soil plant relation; Mixed forest stand
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-005-3228-x

Significant increases in aboveground biomass production have been observed in mixed plantations of Eucalyptus globulus and Acacia mearnsii when compared to monocultures. However, this positive growth response may be enhanced or lost with changes in resource availability. Therefore this study examined the effect of the commonly limiting resources soil N, P and moisture on the growth of E. globulus and A. mearnsii mixtures in a pot trial. Pots containing two E. globulus plants, two A. mearnsii plants or one of each species were treated with high and low levels of N and P fertiliser. After 50 weeks, E. globulus plants grew more aboveground biomass in mixtures than monocultures. A. mearnsii were larger in mixtures only at low N, where both species were similar in size and the combined aboveground biomass of both species in mixture was greater than that of monocultures. At high N and both high and low levels of P fertiliser E. globulus appeared to dominate and suppress A. mearnsii. In these treatments, the faster growth of E. globulus in mixture did not compensate the reduced growth of A. mearnsii, so mixtures were less productive than (or not significantly different from) E. globulus monocultures. The greater competitiveness of E. globulus in these situations may have resulted from its higher N and P use efficiency and greater growth response to N and P fertilisers compared to A. mearnsii. This trial indicates that the complex interactions between species in mixtures, and thus the success of mixed plantations, can be strongly influenced by site factors such as the availability of N and P.