题目

 It was 1963, in Paris. While walking through the fruit and vegetable market Alice Waters was struck by the display of brilliant colors, the music of farmers selling their produce, and in the middle of a great city. She felt directly connected to the land. Chez Panisse, a Berkeley restaurant, which was founded upon Waters' ecological philosophy, has been named The Best Restaurant in America by both the James Beard Foundation and by Gourmet magazine, many times in the past. Only the food grown in accordance with the principles of sustainable (可持续发展的) agriculture was used in t下图是我县万亩林场的一个人工农业生态系统模式图，它利用鸭旺盛的杂食性，吃掉稻田里的杂草和害虫，用水稻养猪、养鸭，水稻的秸秆可以培育蘑菇、生产沼气，猪鸭粪、沼渣肥田。请据图分析回答：（1）该人工农业生态系统的最基本、最关键的生物成分是________________，生态系统能量流动的起点是___________________________。（2）该生态系统中杂草属于______________，蘑菇属于________________。（3）鸭在该生态系统中属于第________________营养级。在水稻养猪这条食物链中，如果猪的体重增加15克，则至少需要消耗水稻___________克。（4）写出该生态系统中的鸭营养级最高的食物链________________________。（5）碳在无机环境和生物之间是以__________的形式循环的, 该生态系中自我调节能力较弱的原因是__________________。（6）我县万亩林场的人工农业生态系统模式，就能量流动来讲最大的好处是___________。