Research On Adaptability And Foraging Behavior Of Different Afforestation Species To Soil Nutrient Heterogeneity

It was investigated to detect the differences in adaptability and foraging behavior to heterogeneous nutrient environment among different species of Cunninghamia lanceolata lamb Pinus massoniana, Schima superba and Liriodendron Chinese, and effects of light condition, competition and nutrient patch on the foraging behavior . The results as following:The study of differences in adaptability to heterogeneous nutrient environment among families indicated that significant differences among three families were found for the adaptability to heterogeneous nutrient environment and in response to soil patches. The family of"Jinpin 45"responsed sensitively to heterogeneous nutrient environment as it exhibited greater plant height, higher biomass accumulation and more developed root in heterogeneous environment than in homogeneous environment. In comparison,"Long15"and"Jing 398"grew better in homogeneous environment. Although the responses of the three families were different, root proliferated mainly in poor patch. Pinus massoniana referenced had higher sensitivity, larger scale and higher sensitivity. The family of Jin-ping 45 responsed sensitively and showed high root physiological plasticity to heterogeneous environment, but these of families of Long 15 and Jing 398 were low and average in heterogeneous environment.The study on relationship of foraging behavior and light condition showed that under full light, the plant height and biomass of both P. massoniana and S. superba was enhanced in heterogenous nutrient environment, with the root biomass increased by 99.5% and 66.7% compared with that in homogenous environment, whereas L. chinese exhibited singnificant growth benefits in homogenous environment. The root scale, root forage precision and sensitivity of S. superba were markedly reduced under shading, which in turn decreased its growth benefit in heterogenous nutrient environment. The influence of shading on P. massoniana was weaker than that of S. superba, and still presented some growth benefit due to its root proliferation and enhanced nutrient absorption in nutrient rich patch. There was slight influence of shading on the root forage precision and sensitivity of L. chinese, with no growth response pattern change to heterogenous nutient environment occurred.The result of effect of competition showed that two species responsed sensitively to nutrient heterogeneity. Compared with that in homogenerous nutrient envionment, the seedlings in heterogeneous nutrient environment were of higher plant height, greater dry matter accumulation and more effective nutrient absorption with increase of root proliferation in the nutrient-rich patches. It was found that S. superba in mixed-planted with P. massoniana grew better than that in single- and pure-planted treatments and exhibited enhancement of root morphological and physioigical plasticity in foraging patchy nutrient. P. massoniana in mixed-planted with S. superba also exhibited higher plant height not only because of little change of root scale, sensitivity and precision but also increase of nutrient absorption efficiency. However, the co-species competition obviously reduced root scale, sensitivity and root N, P content of two species, resulted in significant decrease in seedling height and dry matter accumulation. And S. superba was affected more markedly by co-species competition than P. massoniana in heterogeneous environment.The result of foraging behavior to different nutrient patches showed that significant differences were found in response to three nutrient patches. In P nutrient patch treatment, P. massoniana exhibited greater plant height and more developed root in heterogeneous environment than in homogeneous environment, while it responsed unsensitively to N nutrient patch. P. massoniana grew better in heterogeneous environment than in homogeneous environment for the enhancement of physiological and morphological plasticity in foraging. It proliferated unsignificantly in rich patch in N nutrient treatment, having lower precision and sensitivity. As observed in the experiments, lower dry matter acculmlation in heterogeneous nutrient environment of P nutrient patch treatment was found, it was inferred that fertilizer provided local and single can not meet the need of plants and counteracted growth.