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不同盐分条件对骆驼刺幼苗定居过程的影响研究
赵生龙
学位类型硕士
导师曾凡江
2016
学位授予单位中国科学院大学
学位授予地点北京
学位专业水土保持与荒漠化防治
关键词骆驼刺 盐分条件 种子出苗 生理指标 分株生长
摘要塔克拉玛干沙漠南缘是环境条件异常严酷的区域,这里风沙肆虐、高温干旱、盐碱严重。由于人为不合理地利用和破坏,使绿洲近外围的自然植被遭受严重破坏,导致土壤盐碱化问题日益突出。疏叶骆驼刺(Alhagi sparsifolia Shap. )(以下简称骆驼刺)作为塔克拉玛干沙漠南缘的优势植物种,不仅适应性强,分布广,而且在防风固沙,改善环境等方面具有非常重要的生态效益。因此,揭示骆驼刺植物的盐分适应规律,加快绿洲外围植被修复刻不容缓。本研究依托位于塔南地区的策勒研究站的生态学实验平台,展开不同浓度盐分条件对骆驼刺不同生长阶段影响的控制实验,对骆驼刺出苗(持续两个月)后在持续盐分条件下的幼苗生长、形态特征、生物量分配、根系生长特性和分株生长状况进行研究,以期进一步揭示盐分条件下骆驼刺幼苗的定居过程和更新规律,为该区域的人工骆驼刺植被修复提供依据。研究结果包括以下几个方面: (1)在种子出苗方面:骆驼刺种子的出苗率、出苗指数随着盐浓度增大先增大后减小,并在200 mmol/L盐浓度条件下达到最大,并且不同盐分条件延迟了骆驼刺种子出苗。进一步研究表明种子出苗的耐盐适宜范围为0~200 mmol/L。 (2)在幼苗生长方面:①骆驼刺幼苗株高和冠幅均随盐浓度的逐渐增大而减小。总生物量在处理30天时,中低浓度(<200 mmol/L)条件下差异不显著,但在处理65天时差异显著,高浓度(400 mmol/L)盐分条件显著抑制了其生长(p<0.05)。骆驼刺幼苗净光合速率随盐浓度增大呈降低趋势,瞬时水分利用效率在浓度达到400 mmol/L时显著增大。处理30天的骆驼刺幼苗叶绿素a、b与总叶绿素含量在高浓度(400 mmol/L)条件下显著降低,中低浓度(<200 mmol/L)条件下无明显差异。处理65天时,其叶绿素a、b、总叶绿素和类胡萝卜素含量均较处理30天时显著降低,且随盐浓度的增大逐渐降低。处理30天的骆驼刺幼苗比叶面积和叶片干物质含量均随着盐浓度增大呈降低趋势,处理65天时,其比叶面积随盐浓度增大呈增大趋势,叶片干物质含量则随盐浓度增大显著降低。骆驼刺幼苗N含量在中低浓度盐分条件下差异不显著,高浓度条件下显著降低,P含量随盐浓度增大先减小后增大,表明高浓度盐分条件不仅影响其生物量的积累,对其光合、色素含量、N、P含量均有影响。②处理30天的骆驼刺根系生物量在中低浓度(<200 mmol/L)盐分条件下较对照有所减少,高浓度条件下显著减少;其根冠比在不同盐分条件下无差异。处理65天的骆驼刺幼苗根系生物量随盐浓度增大先增大后减小;其根冠比随盐浓度增大先增大后减小。说明增大根冠比是骆驼刺适应盐环境一种有效的策略,而在高浓度条件下其根系生物量与根冠比显著减小,表明骆驼刺生长受到了抑制。 (3)在生物量分配方面:处理30天时,骆驼刺幼苗茎比重和根比重在高浓度(400 mmol/L)条件下较对照有所减小,而叶比重则随盐浓度增大而增大;处理65天时,茎比重在中低浓度(<200 mmol/L)条件下无显著性差异,高浓度条件下较对照有所增加;叶比重则是先减小后增大;根比重在中低浓度(<200 mmol/L)条件下有所增大,高浓度下明显减小。并且处理65天的骆驼刺幼苗较处理30天的幼苗茎和叶比重有减小趋势,而根比重逐渐增大。说明盐处理早期(处理30天),骆驼刺把更多的生物量分配到地上部分来竞争光照资源,而在处理65天后,骆驼刺把更多的生物量分配到根系部分来适应盐环境。 (4)在盐离子分布方面:在不同浓度的盐分条件下,Na+在骆驼刺幼苗不同器官的含量分布为:茎>叶>根,K+则为茎、叶>根;其 K+/Na+在根中随盐浓度的增大先增大后减小,茎中随盐浓度的增大逐渐减小,叶片中则是整体呈减小趋势。说明无论是低盐还是高盐条件均抑制了各器官对K+的吸收,并且地上部分(茎、叶)的抑制作用大于地下部分(根系)。 (5)在分株形成方面:骆驼刺属于克隆植物,通过产生分株来竞争光照、水分和养分等资源来适应恶劣的环境。在较好的水分条件下,一年生的骆驼刺能够产生较多的分株,很好的进行无性繁殖。本研究中仅对照条件下(50 mmol/L)形成了分株,表明低浓度盐分条件(0~50 mmol/L)有利于骆驼刺分株的形成。
其他摘要In the southern fringe of Taklamakan desert, with raging sandstorm, high temperature and drought, salinity serious, so it is a region of harsh environmental conditions area. And because of the human unreasonably use and destruction, it brings oasis periphery of serious damage to the natural vegetation, which results in soil salinization problems have become increasingly prominent. Alhagi sparsifolia Shap. is one of the dominant plant species in the southern edge of the Taklimakan Desert. With strong adaptability and widely distributed, it has a very important ecological benefits in sand-fixing, inhibiting grassland degradation and improving the surrounding environment. Therefore, it is necessary to reveal the adaptation rules for salt of A. sparsifolia, and it is also urgent to accelerate the peripheral oasis vegetation restoration. The study relies on the ecology experimental research platform of Cele Desert Research Station which is located in the southern edge of the Tarim Basin. And it expands the control experiment that is the effect of different concentrations of salt on A. sparsifolia at different growth stages. It also researches the seedlings growth, morphological characteristics, biomass allocation and root growth characteristics as well as the growth of ramets of A. sparsifolia under continuous salt conditions. To further reveal the A. sparsifolia seedlings settlement process and update rule under the condition of salinity, and provide the basis for artificial A. sparsifolia vegetation restoration in the region. Our main results were identified as follows: (1) The aspect of seed emergence: As the salt concentration increases, the A. sparsifolia seed germination rate, seedling index first increases and then decreases. It also reaches the maximum at 200 mmol/L salt condition, and different salt conditions delays A. sparsifolia seed emergence. Further indicates A. sparsifolia seed emergence salt suitably ranges from 0~200 mmol/L. (2) The aspect of seedlings growth: ① The A. sparsifolia height and width decreases with increasing salt concentration, total biomass in the treatment for 30 days is no difference in low concentration (<200 mmol/L), in the treatment for 65 days obviously decreases in high concentration (400 mmol/L). The A. sparsifolia net photosynthetic rate decreases with increasing salinity concentration, water use efficiency significantly increases in the concentration of 400 mmol/L. In the treatment for 30 days its chlorophyll a, b and total chlorophyll content reduces in the 400 mmol/L concentration, and it is no significant difference between the low concentration (<200 mmol/L) conditions. Comparing with 30 days treatment, the A. sparsifolia for 65 days treatment its chlorophyll a, b, total chlorophyll content and carotenoid content are lower, and they are all gradually decreases with increasing salt concentration. The A. sparsifolia seedlings that deal with 30 days specific leaf area and leaf dry matter content decreases with increasing salt concentration. When dealing with 65 days, its specific leaf area increases with increasing salt concentration, but leaf dry matter content obviously decreases. The A. sparsifolia seedlings nitrogen content is no significant difference in low concentration (<200 mmol/L), but decreases in the concentration of 400 mmol/L, and phosphorus content first reduces and then increases with increasing salt concentration. It shows that high concentration of salt conditions affects not only the accumulation of biomass but also photosynthetic, pigment content, nitrogen and phosphorus content of A. sparsifolia seedlings. ② The A. sparsifolia root biomass that deal with 30 days in low concentration (<200 mmol/L) less than control, high concentration condition significantly reduces, and its root-shoot ratio is no significant difference between different salt conditions. The A. sparsifolia root biomass that deal with 65 days first increases and then decreases with increasing of salt concentration, and its root-shoot ratio also shows similar discipline. It indicates that is an effective strategy to adaptation to salt environment of A. sparsifolia through increasing the root-shoot ratio, its root biomass and root-shoot ratio significantly decreases under high concentration also reflects A. sparsifolia growth is inhibited. (3) The aspect of biomass allocation: The A. sparsifolia proportion of stem and root weight that dealing with 30 days in high concentration (400 mmol/L) less than control, with increasing of salt concentration its leaf proportion gradually increases. The A. sparsifolia stem proportion that dealing with 65 days is no difference between (<200 mmol/L) salt conditions, high concentration condition significantly increases, its leaf proportion first decreases and then increases with increasing of salt concentration, root proportion increases under low concentration (<200 mmol/L), and decreases in high concentration. The A. sparsifolia that dealing with 65 days compares with dealing with 30 days stem and leaf weight proportion decreases, but root weight proportion increases. It shows that the A. sparsifolia in salt treatment early (for 30 days) allocates more biomass to shoot resources to compete for light, and in the 65 days after treatment, it allocates more biomass to root to adapt to salt environment. (4) The aspect of ion distribution: At different concentrations of salt conditions, Na+ contents distribution in different organs of A. sparsifolia seedlings substantially: stem> leaf > root. And K+ in different organs of A. sparsifolia seedlings substantially: stem and leaf > root. With increasing salt concentration, its K+/Na+ in roots first increase and then decrease, in stems decrease all the time, in leaves the overall decreasing trend. The phenomenon illustrates that either low salt concentrations or high salt conditions inhibits the absorption of K+ in different organs of A. sparsifolia seedlings, and aerial parts (stems and leaves) inhibition greater than belowground (root). (5) The aspect of ramets formation: The A. sparsifolia is clone plant, and it competes light, water and nutrient resources to adapt to the evil environment by producing ramets. Under good moisture conditions, annual A. sparsifolia can produce more ramets for good asexual reproduction. In the present study, only the control condition (50 mmol/L) to form ramets, which indicates that the low concentration salt conditions (0~50 mmol/L ) is in favor of the formation of A. sparsifolia ramets.
学科领域水土保持与荒漠化防治
语种中文
文献类型学位论文
条目标识符http://ir.xjlas.org/handle/365004/14693
专题研究系统_荒漠环境研究室
作者单位中科院新疆生态与地理研究所
推荐引用方式
GB/T 7714
赵生龙. 不同盐分条件对骆驼刺幼苗定居过程的影响研究[D]. 北京. 中国科学院大学,2016.
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