[Effects of habitat change on nutrient contents in Quercus variabilis seedlings]

Quercus variabilis seedlings were collected from the habitats at different latitudes, and transplanted on the same experimental sites installed in the central part and southern and northern boundaries of China, where Q. variabilis has a natural distribution, aimed to study the effects of habitat change on the nutrient contents in the seedlings in their vigorous growth period. With habitat change, the various organs nitrogen (N) content and the stem phosphorous (P) content of the transplanted seedlings changed significantly, but the organs potassium (K) content and the leaf- and root P content had less change. In the experimental sites, the organ N content of the transplanted seedlings had significant positive correlation with the latitudes where the seedlings grew, the stem- and root P contents decreased with the increasing latitude, while the leaf N:P ratio had less change. The organ N and P contents of the transplanted seedlings growing in northern boundary decreased significantly, and the effect of the latitudes was more obvious. The leaf N:P ratio of all the seedlings transplanted from different altitudes increased to different degrees. It was concluded that the nutrient contents in different organs of Q. variabilis seedlings varied with latitude, and the seedlings had different responses to habitat change.