[Objective] The aim was to choose appropriate floating plant in the wetland in the north China.[Method] Pistia stratiotes L.,Eichhornia crassipes,and Hydrocharis dubia（Bl.） Backer were planted in the aquatic biologi...[Objective] The aim was to choose appropriate floating plant in the wetland in the north China.[Method] Pistia stratiotes L.,Eichhornia crassipes,and Hydrocharis dubia（Bl.） Backer were planted in the aquatic biological pool of constructed subsurface flow wetland system in the reservoir.Through filed investigation,the growth of the three kinds of plants was studied and their adaptability to the northern climate was concluded.[Result] Judging from the growth speed and state of the three kinds of floating plants,the biological characteristic of Pistia stratiotes L.can perfectly adapt the environment in the pool in the reservoir,followed by the Eichhornia crassipes.The growth state of the Hydrocharis dubia（Bl.） Backer was the worst one and it can not adapt to the north environment.[Conclusion] It provided references for the choice of artificial floating plant in the north area.展开更多
Continuing climate changes are strongly associated with status of water, threatening the majority of ecosystems, including the grass ecosystem. The climate changes primarily affect the botanical composition of grassla...Continuing climate changes are strongly associated with status of water, threatening the majority of ecosystems, including the grass ecosystem. The climate changes primarily affect the botanical composition of grassland that is subsequently determined by production of above-ground phytomass which is used like feed for the ruminants. In our field experiment we assessed the impact of climate changes on grass ecosystem during the long-term period （23 years）. We obtained a picture of the preceding development of botanical composition in this stand, due to the assumption that expected climate changes are going to disturb the botanical composition of grassland especially in the grass biome. From the obtained results follows the significant change in botanical composition in grass-herbaceous vegetation with the low share of legumes. It is not possible to confirm strict relation between precipitation during vegetation season and the share of individual botanical group. Analysis of long-term development of the botanical composition of monitored grassland influenced by different pratotechnical interventions demonstrated the significant flexibility this plant community in the times of changing climatic conditions.展开更多
To apply carbon isotope composition （δ13C） analyses of C4 plants to the quantitative reconstruction of paleoclimate, the functional mechanism linking plant δ13C （δ13Cp） to the environment, which is based on the...To apply carbon isotope composition （δ13C） analyses of C4 plants to the quantitative reconstruction of paleoclimate, the functional mechanism linking plant δ13C （δ13Cp） to the environment, which is based on the plants＇ physiological characteristics and morphological adaptability, must be thoroughly understood. Foxtail millet （Setaria italic） and common millet （Panicum miliaceum）, as C4 plants, are representative crops of the rain-fed agriculture present in northern China. Fossil millets are ideal for paleoclimatic studies because of the ease of acquisition and identification to the species level. Modem seeds of foxtail and common millet collected from different habitats of the Chinese Loess Plateau, and their carbon isotope compositions, were an- alyzed and correlated with environmental factors, such as latitude, altitude, temperature, precipitation, water availability, and relative humidity. The results showed that the δ13C of foxtail millet had a significantly negative correlation with latitude （R=-0.46）, which may indicate the influence of light. The effect of light on the δ13C of foxtail millet accounted for only 21% of variability, while other climatic factors did not exert significant influences. Thus, the δ13C of foxtail millet was not suitable for extracting climatic information. The δ13C of common millet was significantly and positively correlated with precipitation during the growing period （R=0.75）, explaining 56% of variability. The functional mechanisms analyzed, using the plants＇ physiological characteristics and morphological adaptability, indicated that common millet can adapt to environmental changes because of stomatal sensitivity and some non-stomatal factors. Therefore, the 813C of common millet can record precipitation during growth and is a promising factor for paleoclimatic reconstruction.展开更多
基金Supported by National Water Special Project"River Water Environment Comprehensive Management Technology Study and Comprehensive demonstration"(2008ZX07209-002-002)China Institute of Water Resources and Hydropower Research Open Fund(IWHRKF201013)~~
文摘[Objective] The aim was to choose appropriate floating plant in the wetland in the north China.[Method] Pistia stratiotes L.,Eichhornia crassipes,and Hydrocharis dubia（Bl.） Backer were planted in the aquatic biological pool of constructed subsurface flow wetland system in the reservoir.Through filed investigation,the growth of the three kinds of plants was studied and their adaptability to the northern climate was concluded.[Result] Judging from the growth speed and state of the three kinds of floating plants,the biological characteristic of Pistia stratiotes L.can perfectly adapt the environment in the pool in the reservoir,followed by the Eichhornia crassipes.The growth state of the Hydrocharis dubia（Bl.） Backer was the worst one and it can not adapt to the north environment.[Conclusion] It provided references for the choice of artificial floating plant in the north area.
文摘Continuing climate changes are strongly associated with status of water, threatening the majority of ecosystems, including the grass ecosystem. The climate changes primarily affect the botanical composition of grassland that is subsequently determined by production of above-ground phytomass which is used like feed for the ruminants. In our field experiment we assessed the impact of climate changes on grass ecosystem during the long-term period （23 years）. We obtained a picture of the preceding development of botanical composition in this stand, due to the assumption that expected climate changes are going to disturb the botanical composition of grassland especially in the grass biome. From the obtained results follows the significant change in botanical composition in grass-herbaceous vegetation with the low share of legumes. It is not possible to confirm strict relation between precipitation during vegetation season and the share of individual botanical group. Analysis of long-term development of the botanical composition of monitored grassland influenced by different pratotechnical interventions demonstrated the significant flexibility this plant community in the times of changing climatic conditions.
基金supported by the National Natural Science Foundation of China(Grant Nos.41301042&41172161)the National Basic Research Program of China(Grant No.2015CB953803)
文摘To apply carbon isotope composition （δ13C） analyses of C4 plants to the quantitative reconstruction of paleoclimate, the functional mechanism linking plant δ13C （δ13Cp） to the environment, which is based on the plants＇ physiological characteristics and morphological adaptability, must be thoroughly understood. Foxtail millet （Setaria italic） and common millet （Panicum miliaceum）, as C4 plants, are representative crops of the rain-fed agriculture present in northern China. Fossil millets are ideal for paleoclimatic studies because of the ease of acquisition and identification to the species level. Modem seeds of foxtail and common millet collected from different habitats of the Chinese Loess Plateau, and their carbon isotope compositions, were an- alyzed and correlated with environmental factors, such as latitude, altitude, temperature, precipitation, water availability, and relative humidity. The results showed that the δ13C of foxtail millet had a significantly negative correlation with latitude （R=-0.46）, which may indicate the influence of light. The effect of light on the δ13C of foxtail millet accounted for only 21% of variability, while other climatic factors did not exert significant influences. Thus, the δ13C of foxtail millet was not suitable for extracting climatic information. The δ13C of common millet was significantly and positively correlated with precipitation during the growing period （R=0.75）, explaining 56% of variability. The functional mechanisms analyzed, using the plants＇ physiological characteristics and morphological adaptability, indicated that common millet can adapt to environmental changes because of stomatal sensitivity and some non-stomatal factors. Therefore, the 813C of common millet can record precipitation during growth and is a promising factor for paleoclimatic reconstruction.
