Effects Of Mowing On The Relationship Between Biodiversity And Productivity And On The Soil Properties In Songnen Plain

Mowing is one of the most important utilization modes of Aneurolepidium. Study of mowing on vegetation and soil characteristics is great significant to grassland management and sustainable utilization. This study takes at the Leymus chinensis meadow of Songnen Plain. Set artificial exclusion and mowing treatmens in Changling County of Jilin Province, then take comparative study between mowing and fencing. Every year, 20 replicate plots (1m×1m) were got within each treatment, in July. Survey the community characteristics, and then note the number of species, height and cover of the plant on each quadrat. In August, bring the soil for measuring the total nitrogen, total phosphorus, total potassium, available nitrogen, available phosphorus, available potassium, organic matter, pH, and conductivity. Measure species diversity through the two indicators: number of species (S), Simpson index (D).Take the aboveground biomass as the primary productivity indicator, and respectively take single factor variance analysis in the indicates for two years of enclosed plots and mowing plots, take the correlation analysis between number of species, Simpson index and aboveground biomass.The results show that: (1) Compared with the exclosure field, communities species diversity, biomass, density, cover and plant height, even the composition of species in communities had a certain impact by mowing. And the community's biomass, biodiversity were declined. (2) Mowing improved the relationship of biodiversity and productivity. Longer the cutting of years, the relationship of species diversity and aboveground biomass is more linear trend parallel to the X-axis. The correlation between the relationship has been weekend by mowing. (3) Some soil fertilities and pH were changed by mowing. But lots of them were not haven a significant change. After mowing, there was an increase in soil organic matter, but not have a significant change. And the content of soil available nitrogen, available phosphorus and available potassium were all had a change by mowing, but there was no uniform law in our experiment. Effects of mowing on soil total nitrogen, total phosphorus and total potassium content were not significant.Overall, mowing once a year on Leymus chinensis meadow of Songnen Plain has a series of impact on aboveground vegetation and soil chemical properties, but enclosure nasdaqterm and climatic factors also have a great impact on result. The aboveground biomass and cover on the above two years have the opposite trend occurred, it may be related to extremely arid climate in the summer of 2009.