Dissertation > Excellent graduate degree dissertation topics show

Response of δ13C Values of Wetland Ecosystem Plants to Soil Salinity in Yellow River Delta

Author: WangWenWen
Tutor: LiuXianZhao
School: Lu Tung University
Course: Physical Geography
Keywords: δ13C value of plants soil salinity C3plants C4plants Yellow River Deltawetland
CLC: X173
Type: Master's thesis
Year: 2012
Downloads: 78
Quote: 0
Read: Download Dissertation

Abstract


Stable carbon isotope composition (δ13C) is a comprehensive actions of environment andbiological factors and the δ13C information in plants can reveals eco-physiologicalcharacteristics of plants. So analysis of δ13C composition feature can reveal the change ofexternal environment factors. Soil salinity content is high in salty land and coastal wetlandand salinity is an important factor which influences δ13C of plants. Discussing the relationshipbetween soil salinity and δ13C of plants and judging plant δ13C whether can as an indicator ofplant salt-tolerant to study plant salt resistance, the improvement of salty land and protectionand recovery of the ecological environment in coastal wetland has important significance intheory and practice. Based on the hot spot of protection and restoration of the Yellow Riverdelta wetland ecological system and weak domestic study on the relationship between soilsalinity and δ13C value of plants, in order to study deeply about the change rule andmechanism of δ13C value of plants with salinity, In this paper, the composition feature, spatialdifferentiation and influencing factors of C3and C4plants δ13C value of the Yellow Riverdelta wetland ecological system were discussed, the response of plant δ13C value to varianceof salinity was analyzed, and the mechanism of plant δ13C value to variance of salinity wasseeked from plant nitrogen content and soil conditions.The main conclusions were drawn asfollows:1. The value range of C3plants δ13C from-31.97‰to-22.16‰and within acquiredproduction, the average value was-28.73‰and more slightly negative than the researchresults of the pioneers, which have some connection with difference on temperature andmoisture in different study areas.While the value intervals of C4plants δ13C were-18.2‰-12‰and average value was-14.46‰, which were more slightly negative than acquiredresult and may have to do with soil environment and the amount of plant species. C3plantsδ13C value showed a weak negative correlation with elevation in the Yellow River deltawetland study area,but no significant correlation with longitude and latitude. However, C4plants δ13C value showed no significant correlation with three geographic variables （altitude,longitude and latitude）.So the spatial disparity of plants δ13C value on the whole in studyarea.The relativity of soil salinity and δ13C value achieveed a significant level,but the soilwater, pH and organic matter contents had no significant effect on plants δ13C value. Therefore, soil salinity is main environment factor of distribution and variation of plants δ13C value in Yellow River delta wetland.2. A significant positive relationship was found between δ13C value in C3plants andsalinity on the whole, but salinity coefficient was different from the previous results and rangeof study area and plant life form are probably main reason. The changing trend of δ13C valuewith salinity of individual species in two sampling belts were variant.There were significantpositive correlation between δ13C in four C3plants species and soil salinity in the secondsampling belt, while the δ13C values of Suaeda glauca and Phragmites australis only showedpositive correlation with salinity and Artemisia capillaris and Artemisia kanashiroi were notresponsive to salinity in the first sampling belt,Which have some connection with salinitydifference, different salt-tolerance of plant, hereditary factor and influence of microhabitatsbetween different sampling belts. For C4plants, there were no significant correlation betweenδ13C values and salinity, and the δ13C values depend on the values of ci/caand φ. Soenvironmental influences to δ13C in C4plants more complex than C3.3. No significant correlationship was found between leaf N content and salinity on thewhole, and leaf N content of Suaeda glauca only showed positive correlation with salinity insingle species. The leaf N content showed no significant correlation with δ13C values, thereason might be plant have minor N use efficiency in photosynthesis. The δ13C values ofSuaeda glauca of the second sampling belt only decreased with leaf N content increased insingle species and soil salinity had no influence on the relationship between δ13C values andleaf N content. The effect of soil salinity on δ13C value of C3plants was mainly by osmosisand affecting changes in stomatal conductance and photosynthetic rate of plant photosynthesis.For C4plants, further study is needed to determine the φ value to have a reasonableexplanation for the mechanism of soil salinity affecting δ13C value.

Related Dissertations

  1. Study on Salt Transfer Laws of Cotton with Drip Irrigation under Plastic Mulch and Growth Index of Cotton in Responses to Salinity,S562
  2. The Studies of Agricultural Soils Comprehensive Evaluation and Improved Utilization of Honggu District of Lanzhou City,S158
  3. Self-adaptability to Main Ecological Factors of Oligostachyum Lubricum,S795
  4. The Relationship between Soil Physical-Chemical Characteristics and Quality of Coastal Plain,S158
  5. The Analysis of the Soil Physical and Chemical Properties in New Reclamation Area in Yili Valley, Xinjiang,S158
  6. Dynamic Changes of Soil Salinization and Sustainable Development Strategy of Oasis in Qitai,S156.4
  7. The Application of Aged Refuse on Saline-Alkali Soil for Greening,S156.4
  8. Research on Subsurface Drip Irrigation (SDI) Technology of Alfalfa,S274
  9. Study on Characteristics of Soil Moisture and Salinity in Dunhuang Oasis,S714
  10. Studies on Photosynthetic Physiology and Ecological Adaptability of Hibiscus Hamabo,S685.99
  11. The Genetic Variation of Achnatherum Splendens Populations and Ecological Adaptation to Soil Salinity,Q948
  12. Effects of Soil Salinity Rate on Morphological Characteristics of Phragmites Australis, and Its Potential Applications in Constructed Wetlands,S564.2
  13. Coupled Soil Moisture, Temperature and Salinity Dynamics in Salined Land during Seasonal Freezing-thawing Period,S156.4
  14. Soil Physical, Chemical and Biological Properties of Saline-Alkali Paddy Field "Surface Dilution",S156.4
  15. Study on the Dynamic Changes of Soil Salinity in Ili River Irregated Area,S153.6
  16. Study on Sea-ice Water Secure Irrigation Utilization Index in Cotton Field,S562
  17. Study on Selection of Sensitive Demonstractive Plants to Saline Soil and the Plant Instruction Salinity Technology Research,S156.4
  18. Study on Soil Salinity Characteristics and Its Salt-driven Actuation Factors in Yutian Oasis,S153
  19. The Research for Spatial Distribution Rules of the Soil Salt of Typical Area in Yutian Oasis,S156.4
  20. Study on Natural Vegetation and Soil Salt of Typical Area in Yutian Oasis,S153
  21. Sulphate saline soil mechanics parameters and ground bearing calculation method,U416.1

CLC: > Environmental science, safety science > The basic theory for the Environment and Science > Environmental Biology > Environmental botany
© 2012 www.DissertationTopic.Net  Mobile