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C_4 plant species and geographical distribution in relation to climate in the desert vegetation of China 被引量:1
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作者 PeiXi Su TingTing Xie ZiJuan Zhou 《Research in Cold and Arid Regions》 2011年第5期381-391,共11页
Water use efficiency of Ca plants is higher than that of C3 plants, and CAM (Crassulaceae Acid Metabolism) plants have the highest water use efficiency. In the desert regions of China, CAM plants are scarce, and C4 ... Water use efficiency of Ca plants is higher than that of C3 plants, and CAM (Crassulaceae Acid Metabolism) plants have the highest water use efficiency. In the desert regions of China, CAM plants are scarce, and C4 plants, especiaUy C4 woody plants, have an important position and role in the desert ecosystem. There are 45 species of Ca woody plants in the desert regions of China, including semi-woody plants, accounting for 6% of the total desert plant species in China, and most of them are concentrated in the families of Chenopodiaceae and Polygonaceae, which are 19 species and 26 species, respectively. The number of C4 herbaceous plants is 107 species, including 48 monocot species and 59 dicot species. C4 woody plants mainly inhabit the northwestem arid desert regions of China west of the Helan Mountains. The drought-resistance and drought-tolerance of Ca herbaceous plants are worse than C4 woody plants, and C4 herbaceous plants mainly inhabit areas with shallow groundwater depth and better water conditions in the desert regions, and are widely distributed along the margins of oases. The abundance of C4 woody plants is closely correlated with drought, but the abundance of C4 herbaceous plants increases with wet conditions. 展开更多
关键词 desert plant Ca photosynthesis woody plant geographical distribution
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Comparison of anatomical structure and photosynthetic characteristics between the two photosynthetic organs of the desert plant Hedysarum scoparium 被引量:1
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作者 QiaoDi Yan PeiXi Su Song Gao 《Research in Cold and Arid Regions》 2010年第3期241-249,共9页
The desert plant Hedysarum scoparium uses leaflets and rachises as its photosynthetic organs. The abundance of leaflets was lower under unfavorable environmental conditions and higher with improved water conditions. T... The desert plant Hedysarum scoparium uses leaflets and rachises as its photosynthetic organs. The abundance of leaflets was lower under unfavorable environmental conditions and higher with improved water conditions. To examine the characteristics associated with the adaptation of H. scoparium to its environment, we selected plants with both compound leaves and rachis without leaflets to study the anatomical structures and gas exchange characteristics of the two organs. The results show that the water storage tissues in rachises were more developed compared with the leaflets. The diurnal courses of the net photosynthetic rate for the rachis and the leaflet were both in a bimodal pattern. Meanwhile, both two peak values of the rachis were significantly higher than those of the leaflet. The daily average transpiration rate was significantly higher in the rachis than in the leaflet in order to lower the temperature of the rachises. It was concluded that under desert drought conditions, the leaflets of H. scoparium were partially or completely degraded to reduce the transpiration area as an adaptive response to water deficit, and only the rachises were retained as photosynthetic organ. The rachises were found to be better suited to a desert habitat than the leaflets. 展开更多
关键词 anatomical structure desert plant Hedysarum scoparium photosynthesis photosynthetic organ
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Effect of spatial scale and topography on spatial heterogeneity of soil seed banks under grazing disturbance in a sandy grassland of Horqin Sand Land, Northern China 被引量:9
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作者 XiaoAn ZUO ShaoKun WANG +3 位作者 XueYong ZHAO WenJin LI Johannes KNOPS Amy KOCHSlEK 《Journal of Arid Land》 SCIE 2012年第2期151-160,共10页
Soil seed banks play an important role in the distribution and composition of plant communities in semiarid grassland ecosystems. However, information on how spatial scale influences the spatial heterogeneity of soil ... Soil seed banks play an important role in the distribution and composition of plant communities in semiarid grassland ecosystems. However, information on how spatial scale influences the spatial heterogeneity of soil seed banks in a grassland under grazing disturbance is still lacking. Based on field sampling and greenhouse germination, we measured the species composition and seed density of soil seed banks at different spatial scales (30 mx30 m, 30 mx60 m and 30 mx90 m) along a topographical gradient in a sandy grassland in Horqin Sand Land, Northern China. By applying geostatistical methods, we examined how spatial scale and topography affected the spatial distribution of soil seed banks in the study area. Our results showed that the total number of species in soil seed banks, as well as the number of dominant annuals, increased with the increase of spatial scales. Seed density in soil seed banks decreased with the increase of spatial scales due to an increase in the slopes and relative heights of the sampling points. Geostatistical analysis showed that the relative structural variance (C/(C0+C)) of seed density and species richness were over 65% for all spatial scales, indicating that these variables had an ob- vious spatial autocorrelation and the spatial structured variance accounted for the largest proportion of the total sample variance. Spatial autocorrelation of seed density in soil seed banks increased with the increase of measured scales, while that of species richness showed a reverse trend. These results suggest that the total number of spe- cies in soil seed banks is spatial scale dependent and lower topography may accommodate more seeds. Spatial distribution of seed density in soil seed banks is also scale dependent due to topographic variation. Grassland management, therefore, needs to consider local grazing disturbance regime, spatial scale and topography. 展开更多
关键词 sandy grassland grazing disturbance topographic variation seed density species richness scale dependence Inner Mongolia
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Effects of drought stress on antioxidant enzyme,photosynthetic pigment and flavonoid pathway in two desert shrubs 被引量:5
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作者 YuBing Liu MeiLing Liu Bo Cao 《Research in Cold and Arid Regions》 2011年第4期332-338,共7页
Antioxidant enzyme activity, photosynthetic pigment content, and free malondialdehyde (MDA), as well as flavonoid content and the key enzyme activity in the flavonoid pathway were determined in two desert shrubs, Ca... Antioxidant enzyme activity, photosynthetic pigment content, and free malondialdehyde (MDA), as well as flavonoid content and the key enzyme activity in the flavonoid pathway were determined in two desert shrubs, Caryopteris mongolica Bunge and Reaumuria soongorica (Pall.) Maxim. under drought stress. The free MDA content was enhanced during the experimental period, which may be an indicator of oxidative stress. Superoxide dismutase (SOD), peroxidase (POD), and ascorbate peroxidase (APX) activities in C. mongholica showed a significant increase during the experiment, but catalase (CAT) activity was slightly decreased. On the other hand, POD and APX activities showed a significant increase and SOD and CAT activity data had no significant changes in R. soongorica. APX, SOD, and CAT activities were higher in R. soongorica than in C. mongholica, but MDA content was lower, indicating that the lower values of MDA were attributed to higher activities of antioxidant enzyme in R. soongorica. Chlorophyll content decreased significantly in the two shrubs during the experiment, which indicated that there was a photoprotection mechanism through reducing light absorbance by decreasing pigments content. Caretonoids content increased in C. mongholica and decreased in R. soongorica. The ratio of Chla/Chlb decreased significantly but caretonoids/Chl revealed a significant increase in the two shrubs, which could be explained as no decrease of peripheral light-harvesting complexes and a higher tolerance to drought. Total flavonoid content and the activities of phenylalanine ammonialyase (PAL) and chalcone isomerase (CHI) showed different changes between C. mongholica and R. soongorica after treatment. These values decreased in R. soongorica and increased in C. mongholica except for PAL activity. However, anthocyanin content increased in the two shrubs, indicating that there was a different regulation response in the ftavonoid pathway in the two shrubs under drought stress, and anthocyanin should be an important antioxidant both in the shrubs. Our results demonstrated the different responses of antioxidant defense and drought tolerance ability between the two shrubs. 展开更多
关键词 antioxidant enzyme photosynthetic pigment flavonoid Caryopteris mongolica Bunge Reaumuria soongorica (Pall.) Maxim.
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Evidence of functional and structural changes in the microbial community beneath a succulent invasive plant in coastal dunes
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作者 Pablo Souza-Alonso Yaiza Lechuga-Lago +1 位作者 Alejandra Guisande-Collazo Luís González 《Journal of Plant Ecology》 SCIE CSCD 2022年第6期1154-1167,共14页
Coastal dunes represent priority habitats for conservation due to the provision of valuable ecosystem services such as land protection,water supply or biodiversity conservation.Soil microbial communities are of crucia... Coastal dunes represent priority habitats for conservation due to the provision of valuable ecosystem services such as land protection,water supply or biodiversity conservation.Soil microbial communities are of crucial importance to maintain plant diversity due to harsh environmental conditions,water limitation and nutrient scarcity.Invasive alien plants represent a major threat to ecosystem conservation.Here,we explored different impacts of Carpobrotus edulis,a succulent plant invading coastal areas worldwide,on the function and structure of bacterial communities.Sand represents a challenging substrate due to low organic matter content and limited microbial activity.We optimized bacterial extraction for functional evaluation before assessing ecosystem impacts produced by C.edulis.We compared 12 extracting procedures combining different soil storage,sample amount and extracting solutions on the functional activity of sand communities through the community-level physiological profile.We further explored the function(using Biolog Ecoplates)and structure[using polymerase chain reaction–denaturing gradient gel electrophoresis(PCR-DGGE)]of bacterial communities from dunes invaded by C.edulis.Saline solution consistently increased bacterial cells detected by cytometry(P≤0.001).Principal component analysis suggested a limited temporal framework(0–24 h)in which community function can be explored without significant alterations in C substrate consumption.Changes under C.edulis invasion exhibited a different pattern of C substrate utilization comparing native and non-native zones(interspecific),but also between native zones(intraspecific),suggesting that functional impacts are site-dependent.Complementary,results obtained from PCR-DGGE indicated that the bacterial community structure of native dunes significantly differed from dunes invaded by C.edulis. 展开更多
关键词 invasive alien plants(IAPs) Carpobrotus edulis coastal dune ecosystems sand communities sample storage community function bacterial structure
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基于不同养分策略的亚热带常绿与落叶树种的共存机制 被引量:1
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作者 Xiaoping Chen Xingui Le +3 位作者 Karl JNiklas Dandan Hu Quanlin Zhong Dongliang Cheng 《Journal of Plant Ecology》 SCIE CSCD 2023年第4期25-35,共11页
常绿和落叶树种共存于中国东南部的亚热带森林中。为探究常绿和落叶树种应对亚热带磷限制所采用的碳获取策略,我们选取阳际峰常绿阔叶林中75种共存的木本植物,包括44种常绿树种和31种落叶树种,测定了其叶片的光合和呼吸速率,以及与碳(C... 常绿和落叶树种共存于中国东南部的亚热带森林中。为探究常绿和落叶树种应对亚热带磷限制所采用的碳获取策略,我们选取阳际峰常绿阔叶林中75种共存的木本植物,包括44种常绿树种和31种落叶树种,测定了其叶片的光合和呼吸速率,以及与碳(C)、氮(N)和磷(P)利用效率和再吸收效率的相关性状。落叶树种的光合氮利用效率(PNUE)、单位氮和磷的呼吸速率(R_(d,N)和R_(d,P))均显著高于常绿树种,但光合磷利用效率(PPUE)在二者之间无显著差异。对于任意给定的叶片P,常绿树种的碳利用效率(CUE)高于落叶树种。此外,落叶和常绿植物的氮再吸收效率(NRE)、磷再吸收效率(PRE)和N:P均无显著差异。这些结果表明,常绿树种维持高CUE使其在P限制的亚热带森林中成为优势树种。这些结果对其他生物群落中落叶和常绿物种的养分策略比较具有重要意义,也为未来的气候变化下的亚热带森林的群落动态建模提供了新见解。 展开更多
关键词 光合养分利用效率 碳利用效率 氮吸收效率 磷吸收效率 物种共存
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