【作者】 袁桂香；

【导师】 葛大兵； 吴爱平； 储昭升；

【作者基本信息】 湖南农业大学 ， 生态学， 2010， 硕士

【摘要】 本研究根据洱海目前挺水植被的状况,选择了四种典型的挺水植物(水葱(Scirpus validus)、菖蒲(Acorus calamus)、香蒲(Typha orientalis)、茭草(Zizania caduciflora)),研究水位梯度下这四种挺水植物的生存策略,通过相关指标的测定,找出挺水植物随水位变化的一般规律。按水位梯度采集了大量的野外挺水植物测定其相关的生长指标,总结野外自然条件下,挺水植物生长随水位变化的规律。将两种条件下生长的挺水植物随水位变化的规律进行了对比,发现两者的规律具有一致性。总结了四种挺水植物随水位变化的规律如下：(1)水位从Ocm到100cm,水位的增加对水葱的生长有显著的抑制作用,表现为：随着水位的增加,水葱的根茎长度、分蘖数和生物量均显著减少；7月份水葱各水位梯度根状茎长度分别为31.33cm、19.50cm、7.63cm、3.58cm；7月份水葱各水位梯度的分蘖数分别为15.25株、12.75株、9.25株、2.25株；7月份水葱在四个水位梯度下的平均总生物量(干重)分别为23.28 g、15.87 g、10.95g、0.67 g。水葱为了在深水中获得生存,将大部分的能量投资于地上部分的生长,地上部分的高度和地上部分与地下部分的比值都随着水位的增加而增大；另外随着水深的增加,水葱叶的直径增加,干湿比减少,这可能是水葱在深水区为了增强气体交换而产生了大量的通气组织的缘故。(2)随着水深的增加对菖蒲生长产生的抑制作用强度逐渐增强。根长度和根状茎的长度都随着水深的增加而减小,如7月份菖蒲在四个水位梯度下的根长度分别为43.60 cm、37.56 cm、30.10 cm、18.06 cm；菖蒲的高度和地上部分与地下部分的比值都随着水深的增加而增大,如7月份菖蒲在四个水位梯度下生物量分配比值分别为1.46、1.67、2.96、4.12,这是菖蒲为适应不利环境而积极调整能量分配策略的结果；受水分条件的影响,叶绿素的含量在30cm水深处含量较大。(3)对香蒲生长最为有利的水深不是在Ocm,而是35cm水深左右。在35cm水深处,香蒲根状茎的长度和生物量都要显著的高于其他三个水位梯度。在35cm水位处四个月香蒲根状茎长度分别为17.84 cm、52.06 cm、54.64 cm、73.20 cm,生物量分别为20.74 g、37.30 g、38.83 g、66.42 g；在Ocm水位处四个月香蒲生物量分别为22.09 g、32.98 g、16.29g、38.93 g。分蘖数与Ocm水位处香蒲总体分蘖数没有显著差异；香蒲的高度和地上部分与地下部分干重的比值都随着水位的增加而增大；随着水位的增加,香蒲叶基部的最大直径和最小直径的平均值都有增加的趋势,但这种趋势并不显著。(4)Ocm到30cm左右的水深处均适宜茭草的生长,水位过深会对茭草的生长产生强烈的抑制作用,甚至导致茭草死亡；综合分析根茎长度、分蘖数和生物量这三个指标,本研究认为茭草生长的最佳水深为30cm左右；7、8、9月份30cm水位处茭草生物量分别为26.99g、72.94 g、113.34 g,7、8、9月份Ocm水位处茭草生物量分别为17.47 g、42.62 g、70.38 g；茭草的高度和地上部分与地下部分的比值均随着水位的增高而增大；随着水位的增加和淹水时间的延长,由于茭草基部叶片的脱落,茭草的横断面会逐渐由椭圆形状向圆形转变。(5)综合分析,菖蒲耐淹时间最长,但由于根状茎长度短、分蘖慢,扩散繁殖慢；香蒲、水葱、茭草根状茎生长快,能够在短时间内扩散到大范围的区域；香蒲最适水深为35cm左右；茭草、水葱、菖蒲的适宜水深为Ocm至30cm左右,水位过深不利于其生长。更多还原

【Abstract】 Based on the present emergent macrophytes in Erhai lake, four typical emergent macrophytes(Scirpus validus、Acorus calamus、Typha orientalis、Zizania caduciflora) were selected, and the relationship between emergent macrophytes and different gradient water level was studied, by measuring some relative index finding the rules of emergent macrophytes responsive to water gradient levels. We also collected some field emergent macrophytes and measured the relative index to find the rule of the field emergent macrophytes responsive to water gradient levels. Then we compared the rules in this two growth condition to seem the uniformity. The rules of the four emergent macrophytes responsive to water gradient levels are as following:As the water level from Ocm to 100cm, inhibiting effect on S. validus are gradually increased. The rhizome, tiller number and biomass are significantly decreased due to the increasing water level. In deep water, S. validus put the large proportion biomass to the above ground and less to the below ground, thus, the biomass proportion of above ground to below ground (BPAGBG) are increased compared to sallow water. In addition, the diameters of leaves are bigger in deep water than in sallow water, and the ratio of dry weight and fresh weight of leaves are decreased as the increasing water level, which may because S. validus developed much aeration tissue to enhance the exchange of gases.The inhibiting effect on the growth of the A. calamus increased as the increasing water level. To adapt to the adverse condition A. calamus adjust its strategy of energy allocation, decreasing the length of roots and rhizomes and increasing the BPAGBG in deep water. Effected by the water, the largest content of chlorophyll of A. calamus was in 30cm water depth.The most advantageous water level to the growth of T. orientalis was not in Ocm water depth, but 35cm water depth, under which water depth T. orientalis has the longest length of rhizome and the largest biomass, and the length and biomass are significantly big than the other three water level (0cm、70cm、120cm). However, the tiller number of the Ocm and 35cm water level were not significant. As the increasing water depth, the BPAGBG also increased as S. validus and A. calamus. The mean largest and least diameter of the T. orientalis increased as the water depth increasing.The suitable depth for the growth of Z. caduciflora is from 0cm to 30cm, and the too deep water level would inhibit the growth severely or would lead to death. Based on the length of the rhizome, tiller number and biomass, the best depth of water for growth is 30cm. The height and BPAGBG of Z. caduciflora increased as the increasing water depth. The transverse section of Z. caduciflora changed from ellipse to round probably due to the leaves falling off as the increasing water depth and the time extending.Comprehensive analysis of the four emergent macrophytes, A. calamus has the longest living time in drowned condition, but its rhizome length is shorter, till number less and reproducing and spreading slower than the other three emergent macrophytes. The rhizome of S. validus, T. orientalis and Z. caduciflora extending very fast, they can reach large areas in very short time. The best suitable depth for T. orientali growth is about 35cm water depth, and the suitable depth for S. validus, A. calamus, Z. caduciflora is from 0cm to 30cm water depth.更多还原