模拟酸雨对水生植物生长的影响毕业论文_生态学毕业论文

模拟酸雨对水生植物生长的影响毕业论文

2021-04-27更新

摘 要

本试验以氮磷吸收能力较强的水生植物石菖蒲和三白草为研究对象,探讨模拟酸雨与富营养化复合胁迫对水生植物根系活力的影响。试验材料被分为三组,分别培养在三个不同的营养水平下,并对其进行四次酸雨处理,最后测定试验材料的根系活力。结果表明:(1)石菖蒲的根系活力值不随酸雨处理次数的增加而降低。三白草的根系活力值随酸雨次数和酸度的增加呈下降趋势。(2)石菖蒲的根系活力不受随酸雨次数的增加的影响,后次酸雨后各处理石菖蒲的根系活力值基本高于前次酸雨处理后的根系活力值,在酸雨高发区和酸雨控制区的水域,适宜选择种植石菖蒲。三白草受酸性降雨次数、酸度的影响较大,在酸雨区进行生态修复时,不适宜选择根系活力易受影响的三白草。(3)随着富营养化水平提高,超富营养水平处理下石菖蒲的根系活力低于中富营养水平,有时还低于中营养水平,石菖蒲生长量小,长势缓慢,表明在超富营养化区域,不适宜种植石菖蒲。中富营养水平下,三白草的根系活力值有明显的下降趋势;超富营养水平中,三白草的根系活力值与中营养水平比较无明显的下降趋势。表明在水体富营养化趋势加剧的情况下,三白草由于个体生长量大,生长快,适宜在富营养化水体中种植,进行生态修复。

关键词:酸雨;富营养化;水生植物;根系活力

Effects of Acid Rain and Eutrophication Combined Stress

on Root Activity of Acquatic Plants

ABSTRACT

Two aquatic plants, Acorus gramineus and Saururus chinensis are selected as experimental materials with higher N、P uptake abilities. The experiment is to research effects of acid rain and eutrophication combined stress on root activity of acquatic plants. Experimental materials are divided into three groups and grown respectively under three different levels of nutrition. Then, spout acid rain on experimental materials for four times. Finally, measure the root activity of experimental materials. Main results are described as follows: (1) Root activity of A. gramineus was not reduced with increasing frequency of acid rain. Root activity of S. chinensis was reduced with increasing frequency and intensity of acid rain. (2) The frequency of acid rain have no effect on the root activity of A. gramineus. The root activity of A. gramineus after the latter acid rain is higher than that after the former one. As a result, A. gramineus is fit to be planted in the water area where acid rain happens frequently. The root activity of S. chinensis is easy to be affected by the frequency and intensity of acid rain. While carrying out ecological restoration in acid rain area, S. chinensis is not suitable to be planted. (3) With the increasing of the level of eutrophication, the root activity of A. gramineus at the level of hyper eutropher is lower than that at the level of middle eutropher, sometimes is even lower than that at the level of mesotropher. A. gramineus grows slowly at the level of hyper eutropher so it is not suitable to be planted in the hyper eutropher area. At the level of mesotropher, the root activity of S. chinensis decreases obviously, while, at the level of hyper eutropher, the root activity does not tend to decrease in comparison with that at the level of mesotropher. The result shows that: when the level of eutrophication become serious, the mass growth of S. chinensis is still large and fit to be planted in the eutrophic water area.

Key words:acid rain; eutrophication; acquatic plants; root activity

目 录

1文献综述 – 1 –

1.1 酸雨的概念及形成 – 1 –

1.2 我国酸雨的现状 – 2 –

1.2.1 我国酸雨的类型 – 2 –

1.2.2 我国酸雨的空间分布 – 2 –

1.3 酸雨的危害 – 3 –

1.4 模拟酸雨对水生植物生长影响及研究进程 – 4 –

1.4.1 酸雨对水环境的影响 – 4 –

1.4.2 酸雨对水生植物生长的影响 – 4 –

2 试验材料及方法 – 6 –

3 结果及分析 – 7 –

3.1酸雨对石菖蒲根系活力的影响 – 7 –

3.2 酸雨对三白草根系活力的影响 – 10 –

4 结论 – 14 –

5 致谢 – 15 –

6 参考文献 – 16 –

1文献综述

1.1 酸雨的概念及形成

酸沉降是指天然和人为产生的酸性物质进入大气,经扩散、迁移和化学转化而最终到达地表的过程。干沉降指气溶胶及其他酸性物质通过重力直接沉降到地表或者是随着下降气流到达地表而被树木或建筑物阻留的现象;酸性物质由于雨水的冲洗和清除而降落到地面的则称为湿沉降,又称酸雨(Acid rain,AR),通常是指pH 值低于5.6 的酸性降水,包括雪、雾、雹等其它形式的大气降水[1]

酸雨的形成条件极其复杂,受到多方面的影响,化学性质和物理性质都是影响酸雨的主要因素,酸雨的形成离不开两大物质,有机酸和无机酸。但是绝大部分的含量都有硝酸和硫酸的组分[2]。工业生产和民用生产是排出二氧化硫的主要地区。汽车排放的尾气中含有氮氧化合物,燃烧的石油经过云内雨逐渐形成水汽,水汽的凝结主要是附在硝酸根和硫酸根等凝结核中,这样不仅可以进行液相反应还可以形成硝酸雨滴和硫酸雨滴,酸雨在整个云下冲涮洗礼之后,逐渐下降,并且不断的吸附空气中的尘粒然后合并成云雨,最后形成酸雨。酸雨的气体和其他含酸的气体会直接形成较大的雨滴。最后形成硫酸型的雨水。通常,大气中含有二氧化碳,降水溶解在二氧化碳时,可能会形成较弱的硫酸型降雨,因此,正常的雨水斗含有酸雨的成分,可以是微酸性,PH 值在5~6 之间。其中1986 年6 月的国际环境会议上,第一次将PH值定为小于5.6 的酸雨。酸雨中的酸绝大部分是硝酸(可占25%~30%) 和硫酸(可占65%~ 70%)。酸雨的形成过程, 可用以下两种类型的化学反应来表示:

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