盐碱胁迫条件下羊草的生态化学计量内稳性研究

发布时间：2018-03-14 11:09

本文选题：内稳性　切入点：生态化学计量　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：吉林西部的松嫩草地曾以水草丰美而闻名,优势种羊草草质肥美、生长旺盛,是当地畜牧业发展的有力支撑。然而,目前该区的突出表现是:草地盐碱化严重、生产力下降、优质牧草逐渐被劣质牧草和其他植物替代、生态平衡逆向发展,对当地畜牧业的发展和生态系统的稳定造成不可弥补的危害,严重限制了该地区经济、社会、生态的全面发展。因此,草地植被的恢复、优势物种的保护以及土壤盐碱化的改善等工作亟待进行。本文以吉林西部草原优势物种羊草(Leymus chinense)为研究对象,采用氮、磷添加与盐碱胁迫相交叉的沙培实验,对羊草进行为期55天的培养,并分别测定植物地上及地下生物量的氮、磷含量。利用生态化学计量学的相关理论,以植物内稳性为突破点,研究羊草地上、地下部分的氮、磷含量以及氮磷比与相对应基质中的氮、磷浓度以及氮磷比之间的关系。同时借助内稳性模型,对植物的内稳性进行计算和比较,分析在不同碱性环境中,羊草地上、地下部分的内稳性特征。研究结果表明:(1)浓度为2~16mmol/L的N添加会促进植物对P的吸收,而P添加对于植物对N的吸收没有明显促进作用。(2)高浓度的N、P添加(N24mmol/L、P4.8mmol/L),以及pH9.1的强碱性环境均不利于羊草对营养元素的吸收。(3)羊草在pH8.4的弱碱性环境以及8N24mmol/L的氮浓度下可以对地上、地下的营养元素进行合理分配。(4)在不同盐碱条件下,羊草地上部分N、P元素及其比值的内稳性普遍高于地下部分。(5)在不同盐碱条件下,羊草地上部分HNHP,而地下部分HPHN,说明羊草地上部分的生长主要取决于N,而地下部分主要受P影响。(6)在pH=7-9.8环境下,羊草地上部分的内稳性指数范围为4.45-12.93;而地下部分HN和HN:P(+N)在pH9.1时不再符合内稳性模型。说明羊草长期受高强度盐碱胁迫,根系内稳性比地上部分反应更敏感。
[Abstract]:The Songnen grassland in the west of Jilin Province was once famous for its abundance and beauty of water grass. It is a strong support for the development of local animal husbandry. However, at present, the prominent performance of this area is that the grassland salinization is serious and the productivity is declining. The high quality forage was gradually replaced by inferior forage and other plants, and the ecological balance developed inversely, which caused irreparable harm to the development of the local animal husbandry and the stability of the ecosystem, and severely restricted the economy and society of the region. Therefore, the restoration of grassland vegetation, the protection of dominant species and the improvement of soil salinization are urgently needed. The cultivation of Leymus chinensis was carried out for 55 days, and the nitrogen and phosphorus contents of aboveground and underground biomass of plants were determined by the sand culture experiment of phosphorus addition and saline-alkali stress. The relevant theory of ecochemometrics was used. Taking plant internal stability as the breakthrough point, the relationship between nitrogen, phosphorus content and the ratio of nitrogen and phosphorus in the underground part of sheep grassland and the nitrogen, phosphorus concentration and nitrogen / phosphorus ratio in the corresponding substrate was studied. At the same time, the internal stability model was used to study the relationship between nitrogen, phosphorus and nitrogen / phosphorus ratio. The internal stability of plants was calculated and compared, and the characteristics of internal stability in sheep grasslands in different alkaline environments were analyzed. The results showed that the addition of N at the concentration of 2o 16 mmol / L promoted the uptake of P by plants. But P addition has no significant effect on N uptake by plants. (2) the high concentration of NNP + N 24 mmol / L (P 4. 8 mmol / L) and the strong alkaline environment of pH9.1 are not conducive to the absorption of nutrient elements by Leymus chinensis in the weak alkaline environment of pH8.4 and the nitrogen concentration of 8 N 24 mmol / L of Leymus chinensis in the weak alkaline environment. The degree can be opposite to the ground, Under different saline-alkali conditions, the internal stability of some NP-elements and their ratios in sheep grassland was generally higher than that in underground part. 5) under different saline-alkali conditions, the internal stability of NNP and its ratio in sheep grassland was higher than that in underground part. The growth of the aboveground part of Leymus chinensis was mainly dependent on N, while the underground part was mainly affected by P in pH=7-9.8 environment. The range of internal stability index of sheep grassland was 4.45-12.93, but HN and HN: P (N) in the underground part were not consistent with the internal stability model during pH9.1. The results showed that the internal stability of root system was more sensitive than that of the aboveground part under high salinity and alkali stress for a long time.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S543.9

【相似文献】