马尾松苗遭遇不同养分斑块的觅养行为和生长响应

设置了N、P和全养分斑块等3种异质养分环境的盆栽试验,并以同质养分环境的盆栽试验为对照,研究马尾松苗觅取N、P斑块养分的行为差异。结果表明:马尾松苗在遭遇富P和全养分斑块时将明显有利其苗的生长和干物质积累,而在遭遇富N斑块时马尾松苗生长反应则不敏感。马尾松苗在觅取斑块P素时根系形态可塑性和生理可塑性发挥了重要的作用,遭遇富P素斑块时马尾松苗根系大量增生,表现出较大的根系广布性、较高的觅养精确性和反应敏感度,根系N、P吸收效率也明显提高;马尾松苗在N斑块的异质养分环境中的根系广布性小、觅养精确性和反应敏感度

Foraging Behaviors and Growth Responses of Pinus massoniana Seedlings in the Heterogeneous Nutrient Environment with Different Nutrient Patches

A pot experiment consisting of three different heterogenerous nutrient environments was designed, with homogeneous nutrient environment as control, to study the differences of foraging behavior of Pinus massoniana to N and P nutrient patches. The results showed that P. massoniana exhibited greater seedling growth, more biomass accumulation in P and whole nutrient heterogeneous environment, while it responsed unsensitively to nutrient heterogeneous environment. The root physiological and morphological plasticity played important roles when P. massoniana absorbed nutrient in P patch with poor mobility. Moreover, in P patch, root growth exhibited some characteristics, such as root proliferation, greater root scale, higher precision and sensitivity, improvement of root N and P absorption efficiency. However, its root scale, precision and sensitivity were lower in N patch, while root did not need to proliferate to acquire N with rich mobility, and N and P absorption efficiency were also low, which could illuminate that root physiological and morphological plasticity had no obvious effects on acquiring nutrients in N-enriched patch. The foraging behavior of P. massoniana in whole nutrient patch was similar with in P heterogeneous nutrient environment.