Water relations of Alhagi sparsifolia Shap. at the transition zone between oases and sandy desert were studied in the southern fringe of Taklamakan Desert. Results showed that A. sparsifolia maintained the positive tu...Water relations of Alhagi sparsifolia Shap. at the transition zone between oases and sandy desert were studied in the southern fringe of Taklamakan Desert. Results showed that A. sparsifolia maintained the positive turgor during the summer. The steady high predawn water potential (psi(P)) indicated A. sparsifolia had sufficient hydration and water supply in growing season. In July, water deficit caused by drought stress had no effect on the transpiration of A. sparsifolia. Therefore, drought stress is not a main factor affecting the survival of plants. The physiological adaptation to drought of A. sparsifolia was shown mainly at the leaf level by significant difference (DeltaII) and relative water content (RWC) between the osmotic pressure at full turgor and at turgor loss, by occurring of osmotic adjustment, by high percentage of dry mass-related water content ( WCsat), by RWC at turgor loss point ( RWCp) in stable level and low RWC of the saturated symplast (RWCsym). However, the morphological features of transpiring surface reduction and deep root system seem to be the main way for the plant to adapt to the extreme drought environment. Result also suggests that one time of irregular irrigation in summer will not be helpful to recover water status of A. sparsifolia in location where the water table is very low.展开更多
中国生态系统研究网络(Chinese Ecosystem Research Network,CERN)植物物候观测数据集是CERN生态站植物物候观测数据综合集成的产物,包含21个生态站2003~2015年660余个物种的物候观测记录。因木本植物和草本植物观测的物候期不同,本数...中国生态系统研究网络(Chinese Ecosystem Research Network,CERN)植物物候观测数据集是CERN生态站植物物候观测数据综合集成的产物,包含21个生态站2003~2015年660余个物种的物候观测记录。因木本植物和草本植物观测的物候期不同,本数据集被分为木本子集和草本子集。木本子集主要记录了芽开放期、展叶期、开花始期、开花盛期、果实或者种子成熟期、叶秋季变色期和落叶期等物候信息。草本子集则记录了萌动期、开花期、果实或种子成熟期、种子散布期和黄枯期等物候信息。另外,本数据集还包含生态站代码、年份、样地代码、样地名称、样地类别、植物种名、拉丁名等信息。本数据集可以为环境变化、碳循环、植物对环境变化的响应等方面的研究提供数据支持。展开更多
Water relation characteristics of the desert legume Alhagi sparsifolia were investigated during the vegetation period from April to September 1999 in the foreland of Qira oasis at the southern fringe of the Taklamakan...Water relation characteristics of the desert legume Alhagi sparsifolia were investigated during the vegetation period from April to September 1999 in the foreland of Qira oasis at the southern fringe of the Taklamakan Desert, Xinjiang Uygur Autonomous Region of China. The sea- sonal variation of predawn water potentials and of diurnal water potential indicated that Alhagi plants were well water supplied over the entire vegetation period. Decreasing values in the sum- mer months were probably attributed to increasing temperatures and irradiation and therefore a higher evapotranspirative demand. Data from pressure-volume analysis confirmed that Alhagi plants were not drought stressed and xylem sap flow measurements indicated that Alhagi plants used large amounts of water during the summer months. Flood irrigation had no influence on water relations in Alhagi probably because Alhagi plants produced only few fine roots in the upper soil layers. The data indicate that Alhagi sparsifolia is a drought-avoiding species that utilizes ground water by a deep roots system, which is the key characteristic to adjust the hyper-arid environment. Because growth and survival of Alhagi depends on ground water supply, it is important that varia- tions of ground water depth are kept to a minimum. The study will provide a theoretical basis for the restoration and management of natural vegetation around oasis in arid regions.展开更多
文摘Water relations of Alhagi sparsifolia Shap. at the transition zone between oases and sandy desert were studied in the southern fringe of Taklamakan Desert. Results showed that A. sparsifolia maintained the positive turgor during the summer. The steady high predawn water potential (psi(P)) indicated A. sparsifolia had sufficient hydration and water supply in growing season. In July, water deficit caused by drought stress had no effect on the transpiration of A. sparsifolia. Therefore, drought stress is not a main factor affecting the survival of plants. The physiological adaptation to drought of A. sparsifolia was shown mainly at the leaf level by significant difference (DeltaII) and relative water content (RWC) between the osmotic pressure at full turgor and at turgor loss, by occurring of osmotic adjustment, by high percentage of dry mass-related water content ( WCsat), by RWC at turgor loss point ( RWCp) in stable level and low RWC of the saturated symplast (RWCsym). However, the morphological features of transpiring surface reduction and deep root system seem to be the main way for the plant to adapt to the extreme drought environment. Result also suggests that one time of irregular irrigation in summer will not be helpful to recover water status of A. sparsifolia in location where the water table is very low.
文摘中国生态系统研究网络(Chinese Ecosystem Research Network,CERN)植物物候观测数据集是CERN生态站植物物候观测数据综合集成的产物,包含21个生态站2003~2015年660余个物种的物候观测记录。因木本植物和草本植物观测的物候期不同,本数据集被分为木本子集和草本子集。木本子集主要记录了芽开放期、展叶期、开花始期、开花盛期、果实或者种子成熟期、叶秋季变色期和落叶期等物候信息。草本子集则记录了萌动期、开花期、果实或种子成熟期、种子散布期和黄枯期等物候信息。另外,本数据集还包含生态站代码、年份、样地代码、样地名称、样地类别、植物种名、拉丁名等信息。本数据集可以为环境变化、碳循环、植物对环境变化的响应等方面的研究提供数据支持。
文摘Water relation characteristics of the desert legume Alhagi sparsifolia were investigated during the vegetation period from April to September 1999 in the foreland of Qira oasis at the southern fringe of the Taklamakan Desert, Xinjiang Uygur Autonomous Region of China. The sea- sonal variation of predawn water potentials and of diurnal water potential indicated that Alhagi plants were well water supplied over the entire vegetation period. Decreasing values in the sum- mer months were probably attributed to increasing temperatures and irradiation and therefore a higher evapotranspirative demand. Data from pressure-volume analysis confirmed that Alhagi plants were not drought stressed and xylem sap flow measurements indicated that Alhagi plants used large amounts of water during the summer months. Flood irrigation had no influence on water relations in Alhagi probably because Alhagi plants produced only few fine roots in the upper soil layers. The data indicate that Alhagi sparsifolia is a drought-avoiding species that utilizes ground water by a deep roots system, which is the key characteristic to adjust the hyper-arid environment. Because growth and survival of Alhagi depends on ground water supply, it is important that varia- tions of ground water depth are kept to a minimum. The study will provide a theoretical basis for the restoration and management of natural vegetation around oasis in arid regions.
