移植BTEC的成功之路

文章分析了我校BTEC模式的优点，介绍了移植BTEC模式的经验，及移植后取得的成绩。

Plant drought tolerance trait is the key parameter in improving the modeling of terrestrial transpiration in arid and semi-arid regions

The prediction of precipitation depends on accurate modeling of terrestrial transpiration.In recent decades,the trait-based plant hydraulic stress scheme has been developed in land surface models,in order to better predict the hydraulic constraint on terrestrial transpiration.However,the role that each plant functional trait plays in the modeling of transpiration remains unknown.The importance of different plant functional traits for modeled transpiration needs to be addressed.Here,the Morris sensitivity analysis method was implemented in the Common Land Model with the plant hydraulic stress scheme(CoLM-P_(50)HS).Traits related to drought tolerance(P_(50);),stomata,and photosynthesis were screened as the most critical from all 17 plant traits.Among 12 FLUXNET sites,the importance of P_(50);,measured by normalized sensitivity scores,increased towards lower precipitation,whereas the importance of stomatal traits and photosynthetic traits decreased towards drier climate conditions.P_(50);was more important than stomatal traits and photosynthetic traits in arid or semi-arid sites,which implies that hydraulic safety strategies are more crucial than plant growth strategies when plants frequently experience drought.Large variation in drought tolerance traits further proved the coexistence of multiple plant strategies of hydraulic safety.Ignoring the variation in drought tolerance traits may potentially bias the modeling of transpiration.More measurements of drought tolerance traits are therefore necessary to help better represent the diversity of plant hydraulic functions.

Vegetation Traits and Soil Properties in Response to Utilization Patterns of Grassland in Hulun Buir City, Inner Mongolia, China

Numerous studies have focused on vegetation traits and soil properties in grassland, few of which concerned about effects of human utilization patterns on grassland yet. Thus, this study hypothesized that human disturbance(e.g., grazing, mowing and fencing) triggered significant variation of biomass partitioning and carbon reallocation. Besides, there existed some differences of species diversity and soil fertility. To address these hypotheses of grassland with diverse utilization patterns in Hulun Buir City, Inner Mongolia, China, we sampled in situ about aboveground biomass(AGB) and belowground biomass(BGB) to evaluate their biomass allocation. Species diversity and soil properties were also investigated. Subsequently, we discussed the relationship of species diversity with environmental conditions, using data collected from 23 sites during the ecological project period of Returning Grazing Lands to Grasslands(RGLG) program. The results were as follows: 1) both AGB and BGB were lower on grazing regime than those on fencing and mowing, but the ratio of root-to-shoot(R/S) was higher on grazing regime than the other two utilization patterns; 2) neither of evenness and Simpson Index was different significantly among all grassland utilization patterns in desert, typical, and meadow grassland at 0.05. In meadow grassland, species richness of fencing pattern was significantly higher than that of grazing pattern(p < 0.05); 3) both of soil organic carbon content and soil available phosphorous content were increased significantly on fencing pattern than grazing pattern(p < 0.05) in desert grassland, and mowing patterns increased the soil nutrients(soil organic carbon, soil total phosphorous, soil available phosphorous, and soil total nitrogen) significantly compared with grazing patterns(p < 0.05) in typical grassland. However, there were no significant differences among utilization patterns in meadow grassland. In conclusion, both of AGB and BGB were increased significantly by fencing. Moreover, species diversity and soil nutrients can be promoted via mowing and fencing. This study suggested that implementation of Ecological Project played a positive role in sustainable grassland utilization of Hulun Buir City and a strong positive influence on the entire temperate grassland.

Dry Matter Partitioning, Nodulation and Seed Traits of Medium and Late Maturing Soybean Varieties as Affected by Planting Pattern and Plant Density

An experiment was conducted on Fluvisols of Awassa for two consecutive years （2005-2006） to determine effects of planting pattern and plant density on dry matter accumulation, nodulation, protein and oil content in early and late maturing soybean varieties. Results indicated that Awassa-95 variety produced significantly higher （P 〈 0.05） number of nodules/plant （NDN）, nodule dry matter （NDM） and leaf dry matter （LDM at R2 （mid flowering） stage of soybean growth than that of variety Belessa-95）. Similarly, variety Awassa-95 （45%） produced significantly higher protein content than variety Belessa-95 （40%）. However, variety Belessa-95 accumulated significantly higher （P 〈 0.01） dry matter in straw, grain and total biomass at R7 （physiological maturity） stage of soybean growth than variety Awassa-95. Similarly, oil content of variety Belessa-95 （18.1%） was significantly （P 〈 0.05） higher than that of variety Awassa-95 （15.9%）. Equidistant rows produced significantly higher （P 〈 0.05） NDM than either rectangular or paired rows. Moreover, soybean plants grown in both rectangular and equidistant rows produced significantly higher （P 〈 0.01） straw dry matter than those grown in paired rows; but, grain dry matter/plant （GDM） was significantly higher （P 〈 0.01） paired and rectangular rows compared to equidistant rows. Plant density also affected the per plant GDM production as it was significantly higher （P 〈 0.01） in 20 and 30 plants/m2 than higher plant densities （40 and 50 plants/m2）. However, dry matter and yield components had strong negative association with protein content. In fact, strong positive correlation （R 〉 0.600） occurred between grain yield and its components with dry matter components at R2 （stem dry matter （SDM）, leaf dry matter （LDM） and stem ＋ nodule ＋ leaf dry matter together known as TDM） and straw dry matter at R7 in both varieties. This study depicted that soybean plants that produce higher dry matter components at R2 would probably produce more straw dry matter, greater grain yield components and higher grain yield dry matter at later stages.

Shifting towards a Mediterranean Diet in the US： How Far Do We Have to Go, What Are the Potential Health Benefits and Can We Get There？

In the public dialogue surrounding the development of the 2015 dietary guidelines for Americans, public health and environmental advocates converged around a simple theme of shifting towards a more plant-forward Mediterranean-style diet. A robust body of literature documenting the health benefits of this eating pattern provides compelling reasons to change our dietary habits in ways that also benefit our environment, but we also need to have the right foods available and affordable to support this modest shift. This commentary discusses the gaps in current US dietary intakes compared to recommendations for meat and protein versus plant-based foods and the potential health benefits of shifting towards a more plant-based diet, focusing on the complex role of Mediterranean crops, such as tree nuts and olive oils, needed to support this shift.

Exotic plant species with longer seed bank longevity and lower seed dry mass are more likely to be invasive in China

Globalization of social and economic activities has led to the large-scale redistribution of plant species.It is still unclear how the traits aid the successful invasion of alien species.Here,we downloaded global plant trait data from the TRY-Plant Trait Database and classified alien species in China into four groups:high,medium,need attention and harmless according to their distribution and degree of harm to local plant communities based on existed studies.The relationship between plant functional traits and invasion level was clarified,and we established a prediction model based on plant functional traits and taxonomy.The results showed that species with smaller seeds,smaller individuals,lower special leaf area and longer seed bank longevity(SL)are more likely to be an invasive species after introduction to foreign ecosystems.In summary,exotic species with longer SL and lower seed dry mass are more likely to be invasive in China.We also trained two predictive models to check if we can predict a species’invasion.Combining the two models together,statistically,we could predict if a species is invasive from its traits and taxonomy with a 91.84%accuracy.This model could help local governments,managers and stakeholders to evaluate shall we introduce some plant species in China.

Soil Salinity Changes in the Jordan Valley Potentially Threaten Sustainable Irrigated Agriculture

The integrated effect of irrigation and agricultural practices on soil salinity in the Jordan Valley （JV）, where over 60% of Jordan＇s agricultural produce is grown, was investigated in this study during 2009-2010. Due to the differences in agricultural operations, cropping patterns, irrigation management, and weather conditions, 206 top- and sub-soil samples were taken every 1 to 3 km from representative farms along a north-south （N-S） transect with 1 to 2 km lateral extents. Soil electrical conductivity of saturated extract （ECse）, Ca, Mg, K, Na, CI, and Na adsorption ratio （SAR） were determined in saturated paste extracts. Results indicated that about 63% of soils in the JV are indeed saline, out of which almost 46% are moderately to strongly saline. Along the N-S transect of the JV, ECse increased from 4.5 to 14.1 dS m-1 in top-soil samples. Similar increase was observed for the sub-soil samples. The major chemical components of soil salinity; i.e., Ca, Mg, and C1, also showed a similar increase along the N-S transect of the valley. Moreover, compared to previous field sampling, results showed that changes in soil salinity in the JV were dramatic. In addition, it was found that C1 imposed an existing and potential threat to sensitive crops in 60% of the soils in the JV, where C1 concentrations were greater than 710 mg L-1. Under the prevalent arid Mediterranean conditions, improving the management of .irrigation water, crops, and nutrient inputs and increasing water and fertilizer use efficiencies should be indispensable to conserve and sustain the already fragile agricultural soils in the JV.

Performance analysis of a solar-aided power generation(SAPG) plant using specific consumption theory

In contrast to a traditional coal-fired power generation plant where steam extracted from a turbine is used to preheat the feedwater in all preheating stages, a solar-aided power generation(SAPG) plant uses solar heat to replace a part or all of the extracted steam in one or more preheating stages. The performance of an SAPG plant with different replacements is investigated in this study by using specific consumption theory(SCT). Fuel-specific and cost-specific consumption models for SAPG plants are built based on the SCT. A typical 330 MW coal-fired power plant is used as the study case. The performance of the SAPG plant in terms of specific consumption, with steam obtained from the first through the eighth(except for the fourth) stages of extraction replaced by solar heat, is compared with that of the reference coal-fired power plant. The fuel-specific consumption of the SAPG plant is determined to be lower than that of the reference coal-fired power plant. The fuel-specific consumption accrual distribution in SAPG plants is used to assess the effect of each individual replacement. Effective strategies to reduce the specific costs of the SAPG and coal-fired power plants are proposed based on the results of this study.

Study on Distribution Pattern of Plant Diversity of Forest Vegetation in Luofu Mountain,Guangdong

Through sample plot survey and statistic analysis,this paper adopts ecological method to study the characteristics of plant diversity of forest vegetation in Luofu Mountain,Guangdong.The results show that there is a great plant diversity of forest vegetation in Luofu Mountain owing to the ascendancy of aqueous and thermal condition in subtropical zone.The total number of species in 4 500 m2 sample plot(s)are 170 with 3 870 individual plants in total;Dahl species richness index(D)is 44.932;Simpson diversity index(L,D)is 0.022,0.022;Simpson(1982)diversity index(D)is 3.806;Pielou evenness index(E)is 0.984 and Hulbert evenness index(E)is 0.815;Shannon-wiener diversity index(information index H')is 4.188;Asymmetry index(r)is 0.185.These indexes show that a better habitat will bring about plant diversity of forest vegetation,and the diversity of zonal vegetation shows that the higher latitude is,the less species of vegetation can be found.Besides,vertical change of plant diversity of forest vegetation in Luofu Mountain is obvious.Its species richness index and plant diversity index show that monsoon evergreen broad-leaved forest is the tallest,mountain evergreen broad-leaved forest follows as the second and conifer-broad-leaved mixed forest is the shortest.The Wilson β-diversity index,which is obtained by comparison between forest vegetation below 300 m and forest vegetation between 600-900 m,is 0.621.Calculated from comparison between forest vegetation in 600-1 100 m and forest vegetation in 900-1 100 m,the Wilson β-diversity index is 0.727;by comparing forest vegetation below 300 m with forest vegetation in 900-1 100 m,the Wilson β-diversity index is 1.877.This shows that the plant diversity of forest vegetation is affected by the change in gradient of elevation.