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https://ptsldigital.ukm.my/jspui/handle/123456789/519716| Title: | Growth responses of mangrove plant rhizophora apiculata to elevated carbon dioxide with different temperature, water regime, and salinity conditions |
| Authors: | Abd Ali Baseem Malik (P76866) |
| Supervisor: | Wan Juliana Wan Ahmad, Assoc. Prof. Dr. |
| Keywords: | Mangrove conservation Mangrove ecology Universiti Kebangsaan Malaysia -- Dissertations Dissertations, Academic -- Malaysia |
| Issue Date: | 11-Aug-2021 |
| Description: | Climate change is one of the most critical issues that had a significant impact on mangrove ecosystems. The increasing emissions of carbon dioxide (CO2) coupled with the rise of temperature have had many adverse and harmful effects on mangrove ecosystem, and this has led to the alteration of other inter-related environmental factors within its ecosystem. Mangrove plants have shown an ability to tolerate and adapt well to extreme habitat conditions. Hence, the principal motivation for this study was to elucidate the mechanisms of mangrove trees to survive and acclimatise in unfavourable growth conditions. The aim of this study was to investigate the effects of elevated carbon dioxide concentration, air temperature, water regime and salinity, and the interactions of these factors, on the growth performance of Rhizophora apiculata. The study was conducted in controlled plant growth chambers for three months. The R. apiculata seedlings were treated with CO2 concentration at 650 ppm and 450 ppm, air temperature at 38°C, 28°C and 21°C, with 3.0 litres and 0.5 litres and, the salinity concentration at 28 ppt and 3 ppt were watered every two days. The control was at ambient CO2 concentration, i.e. 450±20 ppm under average temperature at 28°C. The growth performances of R. apiculata were examined through morpho-physiological and biochemical parameters. Minitab 18 software was used to analyse the effects of the four factors on the seedling growth, whereas the Design of Experiment (DoE) program was used to find the interactions between the four factors. The results showed different seedling growth responses for each factor which indicated high acclimatisation properties of R. apiculata. The most significant effect on R. apiculata growth was at the highest air temperature of 38°C, where the majority of the samples died at the end of the experiment. All morpho-physiological parameters showed negative responses to the rising levels of CO2 and temperature. The interaction model (DoE) of the climate change factors showed a great harmonization between the MGP values and the experimental values, which were 0.98 and CoV of 15.69%. The effect of interaction between climatic factors were demonstrated through the increased growth of R. apiculata according to the growth development stages at the temperature of 38°C compared to 21°C. The growth of R. apiculata at the temperature of 38°C and CO2 at 450 ppm was higher than the elevated CO2 at 650 ppm. Also R. apiculata's growth, gradually rises at the temperatures of 38°C and 21°C when the water level increases, meanwhile R. apiculata's growth gradually reduced at the temperatures of 38°C and 21�C when the salinity concentration was high, but the biggest effect for water regime and salinity factors was when the temperature at 38°C. Photosynthesis, chlorophyll, protein, and Rubisco activity also displayed a clear negative response to extreme climatic conditions at temperature 38°C especially in biochemical reactions. The results of this study clearly showed that the decline in normal metabolic function was the first observed response. The decline was related to the rising temperature at 38°C and elevated carbon dioxide concentration and these two factors might influence the distribution and survival of mangrove plants in its natural environment. Further evidence supporting this fact was represented by the good competitive ability of most R. apiculata saplings under low salinity and high level of water conditions. Additional physical and climatic factors interfere as interaction factors that determine the increase or decrease of R. apiculata growth.,Ph.D |
| Pages: | 189 |
| Call Number: | QH541.5.M27A233 2021 tesis |
| Publisher: | UKM, Bangi |
| Appears in Collections: | Faculty of Science and Technology / Fakulti Sains dan Teknologi |
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| File | Description | Size | Format | |
|---|---|---|---|---|
| Growth responses of mangrove plant rhizophora apiculata to elevated carbon dioxide .pdf Restricted Access | 738.78 kB | Adobe PDF |  View/Open |
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