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Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[ Objectives] By measuring the root growth characteristics, photosynthetic characteristics, nitrogen content, biomass and yield of japonica and indica rice under elevated CO2 concentration, this study aimed to clarify the effect of elevated CO2 concentration on rice physiological characteristics and growth, and the relationship between rice root characteristics and photosynthetic down-regulation. [ Methods] Using open top air chamber platform, CO2 was set at current atmospheric CO2 level( CK) and 200 µmol·mol-1 above CK(T). Two rice varieties,' Wuyunjing 30' and' Yangdao 6' were selected to measure the photosynthetic characteristics, root growth, above-ground biomass and yield. [ Results] The degree of the response of root morphological parameters of ' Yangdao 6' to CO2 concentration was more pronounced compared with' Wuyunjing 30' . Under high CO2 concentration, 'Yangdao 6' increased root length and root surface area by 21.8% and 15.1 %, respectively, while' Wuyunjing 30' increased by 7.3% and 11.1 %, respectively. 'Wuyunjing 30' root morphological parameters did not increase significantly in the late growing season.' Yangdao 6' had photosynthetic down-regulation earlier in the growing season, while' Wuyunjing 30' had that in the late growing season. The root length and root surface area of' Wuyunjing 30' had significant correlations with photosynthetic parameters, hut no such correlation was found for 'Yangdao 6' . Elevated CO2 increased the dry matter weight of' Yangdao 6' . Under CK and T treatments, the dry matter weight of root of' Yangdao 6' were higher than those of' Wuyunjing 30' . The yield of the two rice varieties was significantly different under different CO2 concentration levels, and the rice yield increased significantly at elevated CO2 concentrations. [ Conclusions] Elevated CO2 increased the above-ground and root biomass and yield, and the effects differed between the two rice varieties. Under high CO2 treatment, both the maximum carboxylation efficiency ( Vemax ) and root nitrogen content of rice decreased, while the total root length and root surface area of rice showed an increasing trend. The root length and root surface area of' Wuyunjing 30' had a positive effect on changes in photosynthetic indicators. [ABSTRACT FROM AUTHOR]

Copyright of Acta Prataculturae Sinica is the property of Acta Prataculturae Sinica Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Obejective To study the root surface area of maxillary first molar by micro-CT and MeVisLab software. Methods Nineteen extracted Chinese maxillary first molars were randomly collected and scanned by micro-CT. An application framework of MeVisLab 2.6.1 software package was used for image segmentation and reconstruction. Root surface area， surface areas apical to the buccal， mesial and distal furcation layer were calculated，respectively. SPSS software was used for statistical analysis. Results Root surface area of the maxillary first molars was（449.25±66.02）mm2,surface areas apical to the buccal， mesial and distal furcation layer were （292.75±57.94） mm2， （299.77±59.09） mm2, （288.49±56.22） mm2, respectively （ ＞0.05） . Conclusion Micro-CT scans and MeVisLab software are useful tools for root surface area assessment. [ABSTRACT FROM AUTHOR]

A controlled glasshouse experiment was conducted to explore the effects of heterogeneous Cd stress on root growth of Vicia faba and Sonchus asper. The root length, root surface area and root volume were examined. The results showed that the root length, root surface area and root volume of Vicia faba was greater increase in no Cd patches than in the Cd stress patches. The root length, root surface area and root volume of Sonchus asper was greater increase in Cd stress patches than in no Cd patches. When the root diameter of Vicia faba was 0~0.5 mm and the soil depth was 15~20 cm, the root length, root surface area and root volume in no Cd patches were 4.63, 3.14 times and 2.39 times that in the Cd stress patches; Root diameter for 0.5~1 mm and greater than 1 mm, soil depth of 30~35 cm, root length in no Cd patches were 1.69 times and 5.04 times that in the Cd stress patches, root surface area in no Cd patches were 1.78 times and 5.05 times that in the Cd stress patches, root volume in no Cd patches were 1.85 times and 33 times that in the Cd stress patches. When the root diameter of Sonchus asper was 0~0.5mm and the soil depth was 0~5 cm, the root length, root surface area and root volume in the Cd stress patches were 1.66, 1.36 times and 1.57 times that in no Cd patches; Root diameter for 0.5~1 mm , soil depth of 35~40 cm, the root length, root surface area and root volume in the Cd stress patches were 2.86, 2.16 times and 2.81 times that in no Cd patches; Root diameter for greater than 1 mm, soil depth of 15~20 cm, the root length, root surface area and root volume in the Cd stress patches were 26.94, 52.26 times and 139.33 times that in no Cd patches. The root growth of Vicia faba was alleviated, and the root growth of Sonchus asper was promoted under Cd stress. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Understanding on distribution of above-and below-ground biomass and the effects of degradation on root/ shoot ratio and root area is crucial to predict the degraded processes in the alpine meadow. First, In Naqu Ecological and Environmental Observation and Research Station of Kobresia Fence (2009 enclosed) select native vegetationplace randomly selected Kobresia pygmaea, K. humilis, Stipa purpurea, Potentilla bifurca and Carex moorcroftii five species, degradation choice (compared with native vegetation) of Potentilla bifurca and Carex moorcroftii, then drying to constant weight and using a scanner to scan the surface area of roots. Finally, the use of different species and different levels of sampling two-way ANOVA to test the effects of above-and below-ground biomass, according to species and degraded state, the use of two-way ANOVA to test effects on aboveground biomass, and the use of the species, sampling levels and degraded state three-way ANOVA to examine the influence of biomass, root and shoot ratio and root surface area on Potentilla bifurca and Carex moorcroftii. Our results showed that belowground biomass of Kobresia pygmaea, K. humilis and Stipa purpurea mainly concentrated in the 0--10 cm soil layer which was about 70% of total belowground biomass of 0--30 cm, and belowground of 0--30 cm was about 96% of the total above-and below-ground biomass. Belowground biomass of 0--10 cm for Potenttilla bifurca and Carex moorcroftii was about 50% of the total belowground biomass of 0--30 cm. Belowground biomass of 0--30 cm for Potenttilla bifurca and Carex moorcroftii was about 57% and 85% of total above-and below-ground biomass respectively. As main plant species for the degraded alpine meadow, we found that degradation decreased aboveground biomass, belowground biomass, its root/shoot ratio and root surface area for Potenttilla bifurca; and it increased aboveground biomass but reduced root/shoot ratio for C. moorcroftii, whereas there was no significant effect on its belowground biomass and root surface area. [ABSTRACT FROM AUTHOR]

By using soil core method, the biomass, surface area, and length density of roots ⩽2 mm and 2-5 mm in diameter in a 50-year-old Populus cathayana plantation on the northern slope of Qinling Mountains were determined during growth season. Among the roots <5 mm in diameter, those ⩽2 mm and 2-5 mm in diameter accounted for 77.8% and 22.2% of the total root biomass, respectively. The surface area and length density of the roots ⩽2 mm in diameter accounted for more than 97% of the total, and those of the roots 2-5 mm in diameter only occupied less than 3%. The biomass, surface area, and root length density of roots ⩽2 mm in diameter decreased with soil depth, while those of the roots 2-5 mm in diameter were the least in 20-30 cm soil layer. The biomass, surface area, and length density of roots ⩽2 mm in diameter were significantly correlated with soil organic matter and available nitrogen, but no significant correlations were found for the roots 2-5 mm in diameter. [ABSTRACT FROM AUTHOR]

To explore root architecture and its effects on soil reinforcement of main tree species in typical black soil region, we measured root spatial distribution characteristics, root fractal characte-ristics, and geometric morphological characteristics of Amygdalus triloba , Caragana microphylla , Betula platyphylla , Acer negundo , Picea koraiensis , Pinus sylvestris var . mongolica , using whole root excavation method and WinRHIZO Pro LA2004 root analysis system. All the examined species are distributed widely in typical black soil region. The vertical uprooting force was determined by in-situ uprooting tests. The results showed that inclined roots were dominant in A. triloba , horizontal roots were dominant in C. microphylla , B. platyphylla , A. negundo and P. koraiensis , and the horizontal and vertical distribution of roots were commensurable in P. sylvestris var . mongolica . Except for the total root surface area of B. platyphylla and the total root length of P. koraiensis , the total root length and root surface area of shrub species were significantly greater than those of arbor species, while deciduous broad-leaved trees were significantly larger than coniferous evergreen trees. The total root volume of B. platyphylla was significantly larger than that of C. microphylla , A. negundo , P. koraiensis and P. sylvestris var . mongolica . The root fractal dimension and abundance of A. triloba , C. microphylla , B. platyphylla were significantly higher than those of P. koraiensis and P. sylvestris var . mongolica . The average maximum uprooting force of A. triloba , C. microphylla , and A. negundo was significantly higher than that of B. platyphylla , P. koraiensis , and P. sylvestris var . mongolica . Due to the role of total root length, total root surface area and the number of inclined roots, root system of A. triloba , C. microphylla and A. negundo showed strong soil reinforcement capacity. A. triloba , C. microphylla and A. negundo could be used as the option-preferred tree species when constructing soil and water conservation vegetation in typical black soil region.

To clarify the morphological characteristics of soil preferential flow and the effect of plant roots on its formation, plants from the typical vegetation types of an artificial woodland (Leucaena acacia) and a dry watershed grassland (Heteropogon contortus) of Yuanmou County, Jinsha River were selected as the experimental objects. Based on the staining and tracing method combined with Photoshop CS5 and the Image-Pro Plus 6.0 image processing technology, we analyzed the morphological and distribution characteristics of soil preferential flow under the two planting types and examined the effects of plant roots. We found significant difference in soil preferential flow dyeing area between the woodland and grassland species, and the overall variation trend of the forestland dyeing area ratio decreased with increasing soil depth. The dyeing area of the grassland decreased monotonously with the increases of soil depth. The occurrence degree of soil preferential flow in forest was higher than that of grassland. Root systemaffected the formation of soil preferential flow. At the root diameter ranges of 0≤d≤5 mm and d>10 mm, root length density of the woodland showed a monotonous decreasing trend with increasing soil depth, while in the root diameter range of 5 mm5 mm. The overall change trend of soil preferential flow dyeing area of two vegetation types in the study area decreased with increasing soil depth. Plant root system was closely related to the formation of soil preferential flow. Fine roots could promote while coarse roots may retard the formation of preferential flows.

A field experiment was conducted to explore the mechanism of cultivation measures in affecting crop yield by investigating root distribution in spring wheat-pea rotation based on a long-term conservation tillage practices in a farming region of Gansu. The results showed that with the develo-pment of growth period, the total root length, root surface area of spring wheat and pea showed a consistent trend of increase after initial decrease and reached the maximum at flowering stage. Higher root distribution was found in the 0-10 cm soil layer at seedling and 10-30 cm soil layer at flowering and maturity stages in spring wheat, while in the field pea, higher root distribution was found in the 0-10 cm soil layer at seedling and maturity, and in the 10-30 cm soil layer at flowering stages. No tillage with straw mulching and plastic mulching increased the root length and root surface area. Compared with conventional tillage in spring wheat and field pea, root length increased by 35.9% to 92.6%, and root surface area increased by 43.2% to 162.4%, respectively. No tillage with straw mulching and plastic mulching optimized spring wheat and pea root system distribution, compared with conventional tillage, increased spring wheat and field pea root length and root surface area ratio at 0-10 cm depths at the seedling stage, the root distribution at deeper depths increased significantly at flowering and maturity stages, and no tillage with straw mulching increased root length and root surface area ratio by 3.3% and 9.7% respectively, in 30-80 cm soil layer at the flowering stage. The total root length, root surface area and yield had significantly positive correlation for spring wheat in each growth period, and the total root length and pea yield also had significant positive correlation. No tillage with straw mulching and plastic mulching boosted yield of spring wheat and pea by 23.4%-38.7% compared with the conventional tillage, and the water use efficiency was increased by 13.7%-28.5%. It was concluded that no-till farming and straw mulching (plastic) could increase crop root length and root surface area, optimize the spatial distribution of roots in the soil, enhance crop root layer absorption ability, so as to improve crop yield and water utilization.