Dynamics Of Soil Nutrient Pools, Nutrient Use Strategies Of Dominant Trees In The Typical And Degraded Evergreen Broad-leaved Forests

Evergreen broad-leaved forest (EBLF), covering a lot of area in China, is the zonal vegetation type in subtropical area. However, under long-term human disturbances, this forest is shifting to include much more degraded area dominated by secondary forests, shrub, grassland and plantation. Unfortunately, plant-soil interaction and forest nutrient dynamics remain poorly qualified, despite the growing view that these processes might be extremely important in helping us understand changes of biogeochemical cycle at regional scale in the context of the global change (particular in the change of land use), and shedding light on the conservation and restoration of EBLF.To understand the impacts of the degradation of EBLF on soil carbon and nutrient pools, and nutrient use strategies of dominant tree species, we first quantified soil nutrient pools and net nitrogen mineralization and nitrification in these forests. Then we related soil nutrient dynamics with the characteristics of litterfalls. Third, we described nutrient limitation with emphasizing N:P, nutrient use efficiency, and resources response efficiency in different types of degraded EBLF. Finally, we discussed different nutrient use strategies of dominant tree species under the pressure of limited nutrient availability in the typical and degraded EBLF.This study was done in Tiantong National Forest Park (29°52'N, 121°39'E, 200 m a.s.l), Zhejiang province, eastern China. Although all vegetation is secondary in character, the mature forests can be thought as the climax monsoon EBLF partly because forest area around a Buddhist temple in the centre of the park is believed to have been protected from complete clearance. The EBLF outside of this area represents a range of all degraded forest types. In this study, we chose mature EBLF as the reference climax forest, and secondary forest, shrub, grassland and plantation to represent different degradation types. After examining the plant-soil interactions and nutrient dynamics, we obtained the following results and conclusions. 1. Degradation of EBLF decreased soil carbon and nutrient pools...