Effect Of Warming On Rice - Wheat Rotation Ecosystem

Now, global climate change is one of the focus issues, the academic and social pay more attention to the climate change.The feedback mechanisms between the terrestrial ecosystem and the climate change is the hot spot in Ecology, with great scientific significance. Currently, from the research level, to stuty the impact of climate change on crop growth, mainly from the temperature, precipitation, CO2concentration and the extreme weather events. Temperature is one of the most important ecological factors, Therefore, the temperature change will cause significant impact ecosystems,and the warming experiment under the natural conditions came into being. Warming experiment is now a very important method to study the feedback between climate warming and terrestrial ecosystem. The experimental results can provide key prediction and verification parameters estimation for middle or long term dynamic model of terrestrial ecosystem structure and function. At present, a large number of warming experiments conducted to investigate the species and biodiversity changes of various ecosystems,home and abroad.Most of the warming experiments are operated at high latitude natural ecosystem such as tundra, temperate meadow and forest. There are few warming experimental results about climate warming effects on tropical or subtropical ecosystem, especially agro-ecosystem.What’s more, During the warming experiments, it is hard to separate the warming effect from drought stress effect since no effective measurement to manipulate the water table. At Qingpu district of Shanghai, based on measurements of Water Resources Ministry Agricultural Water Irrigation Technology Station, we develop warming experiment on Rice-Wheat rotation paddy field ecosystem using infrared heater arrays, and maintain the water table no difference between warming and control plots, we surveyed the warming effects on the aro-ecosystem from the crops growth, Biomass,prodution and water requirement,etc. According to the results analysis, we predict that under the scenario of climate warming without changing the current Agriculture management, the filed ecosystem responses to food production, climate regulation, water resources pressure and food Security. Two consecutive years experimental observation and study in the field, a rice-wheat rotation ecosystem, we got the first-hand data in biomass and production changes, to fill the lack of experimental data limitations.The main results are as follows:(1) Under the experimental warming, the aboveground biomass of rice and winter wheat have changed from different degrees. The aboveground biomass of rice in the warming plot were811.76±20.88g/m2&515.95±17.69g/m2,respectively;But in the control,its were848.66±50.75g/m2&638.94±6.38g/m2. Experimental warming reduced the rice aboveground biomass by3.47%&19.53%. Experimental warming improved the wheat aboveground biomass by6.55%&5.71%.(2) Experimental warming reduced the rice production by5.84%&22.57%,in2008～2009. Experimental warming improve the wheat production by55.19%&5.00%,with no significant difference,Indicating that biomass and yield relevant.(3)Warming accelerated the growth of the rice root. Under the warming condition,the below-ground biomass was55.83g/m2,compared to the controls,51.36g/m2.Warming Increased the below-ground biomass by8.69%,with no significant difference(P=0.080)(4) Experimental warming have an impact on the allocation of the above-ground biomass.2008-2009,The rice leaf weight took accounted for11.43%&12.35%of the total above plant weight in the treatment plot,but took accounted for10.40%&10.50%in the controls.The wheat changed a lot.(5) Experimental warming increased the crops water requirement.2008-2009,compared the warming treatments to controls,the rice water requirement increased by27.03%&10.47%,only took concern of the irrigated water;the wheat water requirement increased by12.37%&13.93%.