Transportation Traits Of N And P In Chao Lake P-Rich Basin And The Cons Equent High-Risk Identification

Chaohu is one of the most important lakes that have been seriously contaminated and has been attracted a lot of attention as one area to manage. Particularly, this area is featured by soil profiles that rich in phosphorus (P), which character is liable to cause eutrophic problems. Additionally, areas near the lake suffered from sustaining mining which has been uncovering the P-rich rock formation, making weathering processes more easily to occur. The consequence result of eutrophy will definitely occur to the water as influenced by the above mentioned factors. This study focused on areas near the lake with bare rock formations, studied the plant-soil processes of P-rich places in the upstream of a little river. We tried to provide support for the P contamination control in Chao Lake area by case study in this place. The main findings are as following:1) The low mountainous district in Chao Lake area is featured by typical vegetation types and the vegetation are now during their successional process. The soil nutrients accumulation is substantial but due to the short sustaining time of the dominant species and the fierce competition between plants species, little improvements on the soil quality are observed. However, it will still be effective to plant herbaceous plant in improving soil quality and soil nutrients accumulation.2) Across all the sample places, Ex-P and Ca-P are both extremely low in top20cm soil layers. The activity P is high in shrub lands while the inertial P concentration is high in community structure sable grasslands and Masson pine forest lands. For three mine tailing bare lands investigated in this research, all kinds of P are very low while however the ratio of Fe-P、 Al-P in soil total P is high in comparison with other lands managements.3) Mine tailing bare lands are all high in soil run off flux, while it is very low in shrub lands and grasslands. The dissolved soil nutrients and particle nutrients in mine tailing bare lands are the lowest while however, in a whole year scale, the total nitrogen and P run off fluxes are the highest across all the sample managements.4) The occurrences of soil fluent are highest in shrub lands and grasslands, and the lowest in top20cm soil in mine tailing bare lands. Nitrogen contents in soil fluent are highest in mine tailing lands and lowest in artificial forest lands. For P concentration in soil fluent, it is highest in deserted farmlands and lowest in mine tailing lands. Particularly, the nitrogen run off mainly exists as dissolved nitrate. Moreover, P in soil is lost mainly as organic dissolved pattern and decreased as soil depth increased in this study.5) The soil P loss intensity expressed as highest in the midstream, second high in downstream and lowest in top hill areas. The highest and lowest areas are classified as transformation/construction land, high cover degree forest lands, respectively. Despite the fact that low fluent produced in dry farm land, it ranked at the second in all the nine land managements investigated in this study due to its high nutrient concentration in soil fluent.