题干

某地大力发展农家乐,构建旅游与生态并举的生态农业.池塘养鱼垂钓,水稻长势喜人,农民正忙着进行除草、治虫、施肥等生产活动.根据生态学的原理,分析回答下列问题:

(1)从生态系统的成分看,池塘中的藻类属于该生态系统中的____ ,它们在群落垂直方向上的分布具有分层现象,这种现象与不同水域深度的____ 有密切相关.

(2)从能量流动的角度分析,农民除草、治虫的目的是____ .

(3)从物质循环的角度分析,稻田生态系统中要不断施加氮肥,主要原因是____ .

(4)假定某种群当年数量是一年前种群数量的λ倍,图1为λ值随时间的变化曲线.图2为该系统能量流动示意图[单位:J/(m2•d)],请分析回答:

图l中该种群数量在ad段的增长曲线呈____ 型,e点种群数量比d点____ .图2中由草食动物流入分解者的能量除包含其尸体残骸中的能量外,还包含____ 中的能量.该生态系统中第二、三营养级间的能量传递效率是____ .

(5)随着规模扩大,游客增多,有些废弃物和垃圾扔进池塘,但并未引起生态系统的破坏,原因是____

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同类题1

    "Tammy! Come here, please! Mother needs your help in the kitchen." Her father called out to her.
    Tammy was in her room, getting ready to do her homework. "Yes, Daddy!" she replied. "I'll be right there."
    She hurried out of her bedroom and down the hallway. She was only nine years old. Her elder sister, Ella, had just moved away to go to a performing arts high school in another city. Her brother, Harry, was in middle school and always got home late. With Ella leaving home, Tammy was expected to do a lot more than she had ever done before, especially now, because her mother was ill.
    Her father was in the kitchen. "Tammy, I know you usually do your homework right now, but with things being different, we all have to change a little bit. I'll help you and Harry with your homework later on, OK?"
    Her father had an apron(围裙) on over his clothes, and he looked kind of funny. He was doing the dishes and he always splashed(溅出) water all over when he did that. After helping her father with the dishes, Tammy helped set the table.
    After supper, her father helped her and Harry with their homework, and then they played a board game so that their mother could lie down for a while.
    The next morning, Tammy got up early on her own because she wanted to help her mother with breakfast. She made orange juice and even put bread in the toaster and got out the butter so that her mother could sleep for a few more minutes.
    When her mother got up half an hour later, she was very surprised and moved to see the breakfast on the dining table. She gave Tammy a big hug.
    "Thank you, Tammy. You really are mother's little helper now, aren't you?"