塔里木沙漠公路防护林植物幼苗根系分布特征对灌溉量的响应
文献类型：学位论文
| 作者 | 单立山 |
| 学位类别 | 硕士 |
| 答辩日期 | 2007 |
| 授予单位 | 中国科学院．新疆生态与地理研究所 |
| 导师 | 张希明，新疆生态与地理研究所 |
| 关键词 | 塔里木沙漠公路 梭梭 多枝柽柳 根系 根表面积 根冠比 根系消弱系数Tarim Desert highway Haloxylon ammodendron Tamarix ramosissima root system root surface area root-shoot ratio root extinction coefficient |
| 其他题名 | Response of root distribution of speice seedling of Tarim desert highway protection forest to irrigation amount |
| 中文摘要 | 水分是影响植物生存和生长发育的主要限制因子，其变化对植物水分平衡和地上、地下部分的形态建成具有重要影响。在塔克拉玛干沙漠腹地，通过分层分段挖掘法对不同灌溉量条件下(35kg/株?次、24.5kg/株?次、14kg/株?次)梭梭(Haloxylon ammodendron)和多枝柽柳 (Tamarix ramosissima)幼苗根系分布特征进行了研究。获得以下主要研究结果： ①、 在不同灌溉量条件下，梭梭和多枝柽柳幼苗根系生物量随土壤深度的增加而逐渐减少，但随着灌溉量的减少，最深层次根系生物量有增加的趋势，各灌溉量地下垂直各层生物量与土壤垂直深度呈显著的负对数关系。在滴灌条件下， 0～60cm的土层中两灌木幼苗根系生物量累计百分比达85%以上，根系趋于浅层化。 ②、在滴灌条件下梭梭和多枝柽柳幼苗根系以水平根为主，水平根系发达，最大水平根长为垂直主根长的2倍左右。 ③、相同灌溉量条件下，梭梭幼苗根长、根表面积、根体积垂直分布趋势相似，均为单峰型曲线；但不同灌溉量条件下，其根长、根表面积、根体积的峰值出现在不同深层，灌水量减少其峰值出现的位置越深。多枝柽柳根长和根表面积两参数在垂直方向的变化趋势随灌溉量的不同而有所不同，灌溉量为35kg/株?次、24.5kg/株?次的两处理，根长和根表面积随深度的增加呈指数递减，而灌溉量为14kg/株?次的处理，根长与根表面积为单峰型曲线。 ④、不同灌溉量条件下，梭梭幼苗所在样地的土壤含水量均随土壤深度的增加呈单峰型曲线。各灌溉量梭梭幼苗吸收根生物量的垂直分布与土壤含水量的垂直变化趋势基本一致，但灌溉量不同，吸收根生物量峰值在土壤中出现的深度不同，随着灌溉量的减少，吸收根集中分布层有向深层发展的趋势。 ⑤、梭梭幼苗垂直根深与株高之比随着灌溉量的减少有增加的趋势，表明植物在轻度水分胁迫条件下，只有通过根系下扎或增加分支来扩大自己的资源空间，以满足植物对水分的需求，保持植物体内水分平衡适应干旱环境条件。 ⑥、各月不同灌溉量条件下多枝柽柳、梭梭幼苗根冠比随灌溉量的减少呈增加的趋势，即随灌溉量的减少，其光合产物倾向于向地下部分转移，增强根系竞争能力，最大限度地保持自身的水分平衡。在生长季节，不同灌溉量条件下，两种灌木根冠比最大值均出现在11月，且多枝柽柳幼苗各月不同处理的根冠比均大于1，而梭梭幼苗则均小于1。As a primary limiting factor affecting survival and growth of plants, moisture has important effects on above- and below-ground morphological characteristics. We studied root distribution characteristics in the Tarim Desert Highway Protection Forest to provide suggestions for water management. We excavated soil to study root distribution in Haloxylon ammodendron and Tamarix ramosissima seedlings grown with different amounts of irrigation (35, 24.5 and 14 kg?ind.Plant-1?once-1) in the Taklimakan Desert. Major results as following: ① With the soil depth increased, roots biomasses of T.ramosissima seedling and H.ammodendron seedling gradually decreased in different irrigation amount. But with less irrigation, the distribution of root biomass shifted to greater depth. Underground biomass had a significantly negative logarithmic relationship with soil depth under different irrigation amounts. In the 0～60cm soil layer, the percent of roots biomasses of two shrubs seedling reach to 85% under dropping irrigation in hinterland of Taklimakan desert, the seedling tend to be shallowlly rooted. ② Maximum horizontal spread of T.ramosissima seedling and H.ammodendron seedling roots was twice that of vertical root spread, and horizontal distribution of root biomass was consistent under all irrigation amounts. ③ Root length, root surface area and root volume of H. ammodendron seedling have a similar variety trend under the same irrigation amount. They all revealed a single peak curve, but under different irrigation amount, the peak values of root length, root surface area and root volume appear in the difference of soil layers. The less the irrigation amount was, the deeper the distributions of peak value were. The vertical chang of root length and root surface area of T. ramosissima seedling is different under irrigation with different volume. The root length and root surface are decreased in an exponential way with increasing soil depth under irrigation with volumes of 35.0 kg?ind.Plant-1?once-1 and 24.5 kg?ind.Plant-1?once-1, and the curves of root length and root surface area under irrigation with volume of 14.0 kg?ind.Plant-1?once-1 are unimodal. ④ Under different irrigation amount, the soil moisture of H. ammodendron seedling sample is single peak curve with increasing of soil depth. The tendency of vertical distribution of H. ammodendron seedling absorptive roots biomass was nearly consistent with the vertical changes of soil moisture. But the peak values of absorptive roots biomass in different irrigation amount appeared in different soil layers. With irrigation amount decreased, distribution of absorptive roots concentrated in deeper soil layer. ⑤ Under dripping irrigation in hinterland of Taklimakan desert, the proportion of vertical roots depth and individual plant height of H. ammodendron seedlings were increased with irrigation amount decreased. It indicated under light water stress, the plants enlarge their nutrition space by tracing into the lower layer and increasing their embranchment for satisfying the water demand, keeping interior water balance, thereby adapt drought environment. ⑥ The root-shoot ratio of T.ramosissima seedlings and H.ammodendron seedling in Tarim desert highway protection forest have an increased trend with decreasing irrigation amount under different irrigation amount in each month. In the period of their growth, the maximums of the root-shoot ratio appear in November with different irrigation amount. The root-shoot ratio＞1 of T.ramosissima seedling under different treatment in every month , but the root-shoot ratio＜1 of H.ammodendron seedling. |
| 学科主题 | 植物生理学 |
| 语种 | 中文 |
| 公开日期 | 2010-11-12 |
| 页码 | 共53页 |
| 源URL | [http://ir.xjlas.org/handle/365004/7910]  |
| 专题 | 新疆生态与地理研究所_中国科学院新疆生态与地理研究所(2010年以前数据) |
| 推荐引用方式 GB/T 7714 | 单立山. 塔里木沙漠公路防护林植物幼苗根系分布特征对灌溉量的响应[D]. 中国科学院．新疆生态与地理研究所. 2007. |
入库方式： OAI收割
来源：新疆生态与地理研究所
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