不同生草类型对冬枣园土壤理化性状和品质的影响

为探讨不同生草类型对冬枣园土壤含水量、容重、土壤速效养分和冬枣品质的影响,该研究以山东沾化冬枣为试验材料,以当地清耕处理为对照,设置自然生草、生鼠茅草、生三叶草和生蛇床草处理,开展不同生草类型对冬枣园土壤理化性状和品质的影响研究。结果表明,生草类型显著影响冬枣园0~40 cm土层土壤物理性状、土层土壤有机质含量、碱解氮含量、速效磷含量、速效钾含量、全氮含量和冬枣品质;不同生草类型均可显著提升土层土壤含水量,降低土壤容重,提升土壤有机质含量和果实品质,但会降低土壤碱解氮含量、速效磷含量、速效钾含量和全氮含量,其中生三叶草处理冬枣园土壤理化性状的改善和冬枣品质提升效果较佳。因此山东省滨州市沾化区冬枣种植区可种植三叶草代替清耕,同时在生草时应适当增加肥料施用量。

旱薄山地枣园不同覆草类型对土壤及产量的影响

本文通过每年应用杂草、玉米秸杆、紫花苜蓿覆盖、翻压旱薄山地枣园,试验研究了不同覆草类型对土壤水分、有机质含量、一等果率和产量的影响。其结果表明,不同覆草类型地面覆盖、翻压旱薄山地枣园,均有逐年增产的趋势。一等果率增加了23.3%,产量增加了64.2%,产值增加在97%以上,效益显著。其中覆盖材料以紫花苜蓿优于杂草,杂草优于玉米秸秆,因杂草成本低,取材容易,是最佳覆盖材料。

吉林省西部半干旱区打草场现状调查研究

针对吉林省西部7个县市的打草场进行了20个点、60个样方的取样调查,完成了地上植被的种类、株高、鲜草产量及地下生物量的调查,并对其治理对策进行了探讨。

黄河三角洲贝壳堤灌草群落的土壤颗粒分形特征

为揭示黄河三角洲贝壳堤典型灌草群落的土壤颗粒分形特征及其影响因素,以滩脊地带酸枣蒙古蒿、杠柳砂引草和蒙古蒿芦苇3种灌草群落为研究对象,并以裸地作为对照,采用激光衍射分析技术,测算不同灌草群落的土壤颗粒粒径分布、单重和多重分形特征。结果表明:灌草群落的贝壳砂呈现非均匀分布的特性,具有明显的异质性。贝壳砂单重分形维数D在1.411~2.490之间,数值从大到小依次为酸枣蒙古蒿、杠柳砂引草、蒙古蒿芦苇和裸地,同一灌草群落与裸地不同土层之间的贝壳砂单重分形维数差异显著(P<0.05),0~10 cm土层均小于10~20 cm。不同灌草群落不同土层之间容量维数D0、信息维数D1、关联维数D2、D1/D0、D0-D1差异显著(P<0.05)。容量维数D0与贝壳砂黏粒、粉粒、极细砂粒的体积分数呈显著正相关(P<0.05),可作为表征贝壳砂粒径分布的指示性参数。贝壳砂生境增加灌草群落的数量有利于提高贝壳砂细粒物质的含量,植被改良土壤粒径组成效果显著。

枣园林下不同草本植物生境中粘虫板对绿盲蝽的诱集效果

为探究枣园不同生草类型生境中粘虫板对绿盲蝽的诱集效果,于2018年6月下旬至10月上旬在3种不同生草类型的样地中使用4种颜色粘虫板诱集绿盲蝽。结果表明,荠菜+三叶草带粘虫板的全年诱集虫量显著低于荠菜+灰绿藜带,但显著高于空白对照带(F=64.01,P<0.000 1),且蓝色粘虫板中的荠菜+灰绿藜带显著大于荠菜+三叶草带(F=35.60,P<0.000 1);荠菜+三叶草带与对照带的诱集虫量6月、10月最多,7月、8月最少,而荠菜+灰绿藜带的诱集虫量8月份最多。枣园人工生草显著的加剧了绿盲蝽的聚集,以荠菜+灰绿藜为代表的杂草为绿盲蝽提供了良好的栖息环境。研究结果明确了生草的类型对绿盲蝽聚集的影响,为实际生产中枣园绿盲蝽的综合防治提供了科学依据。

太行山草被水土保持功能的研究

为了对太行山区草被类型的水土保持功能有个具体估价，通过人工降雨测定截留量，观察草被对降雨的截持和传导过程，调查枯落物量、土壤、根系等方法，对降雨从落到草丛至渗入土壤中的各个环节，分别进行了研究。结果表明，盖度７０％以上，以黄背草、白羊草为主的草被类型，当降雨达２０ｍｍ时，截留量已达饱和状态，总截留量为４．５６ｍｍ；雨滴经层层草叶的传导，到达地面时的动能近于０；枯落物量平均４．４５ｔ／ｈｍ２，可吸收降水０．８２７ｍｍ；０～５ｃｍ、５～１０ｃｍ、１０～１５ｃｍ土壤层的根系密度分别为３１、３３、２８条／１００ｃｍ２；非毛管孔隙度为３．２２％，渗透速度为４．０７ｍｍ／ｍｉｎ。草被的水保功能主要在于能消减雨滴动能，增加地面枯落物量，增强土壤的渗透力和抗蚀力。

不同牧草品种在草甸草原生长的适应性评价

补播和混播是恢复退化草地的重要措施,但是不同区域适宜的牧草物种和混播类型并不相同,利用2020-2021年进行的不同牧草品种补播和混播试验研究了不同牧草品种在单播和混播条件下牧草的农艺性状,以筛选出最适宜的牧草品种和最佳的混播类型,为退化草地的生态恢复提供科学依据。结果表明:垂穗披碱草、扁穗冰草和小花碱茅表现出优异的农艺性状,草产量较高具有较强的区域适应性;垂穗披碱草+小花碱茅+黄花苜蓿的混播组合和草地早熟禾+新麦草+黄花苜蓿的混播组合可以显著提高草产量,是退化草地恢复的最佳混播类型;单播和混播条件下影响草产量的因素不同,单播条件下高度对草产量影响较大,混播条件下覆盖度对草产量影响较大。研究结果可以为草甸草原补播改良品种选择提供理论依据。

Investigation of Types and Hazard of Weeds in Coffea arabica Orchads in Nujiang River Basin

[Objective] Through the investigation of weeds in Coffea arabica orchads in NuJiang River basin, this study aimed to provide scientific guidance for the weed control and improving the ecological and economic benefits of the plantation of Cof- fea arabica. [Method] The types of weeds and the characteristics of weed occur- rence in Coffea arabica orchads in Nujiang River basin were investigated from July to August in 2012. [Result] The results showed that there were 69 types of weeds belonging to 21 families in Coffea arabica orchads. The predominant harmful types were shown as follows： Commelina nudiflora L. ＋ Leptochloa chinensis, Cyperus ro- tundus L. ＋ Bidens pilosa L. ＋ Eleusine indica, Imperata cylindrical ＋ Ageratum conyzoides L. ＋ Eupatorium odoratum L., Ageratum conyzoides L. ＋ Digitaria san- guinalis （L.） Scop. The preponderant weeds consisted mainly of 10 species, namely, Cyperus rotundus L., Commelina nudiflora L., Leptochloa chinensis, Digitaria san- guinalis （L.） Scop, Imperata cylindrical, Bidens pilosa L., Ageratum conyzoides L, E- upatorium odoratum L., Eleusine indica and Chenopodium serotinum L. [Conclusion] The result from this study is of great significance for the plantation of Coffea arabica in Nujiang River basin, as well as the control of weeds.

Herbal compound 861 regulates mRNA expression of collagen synthesis- and degradation-related genes in human hepatic stellate cells

AIM： To identify the role of herbal compound 861 （Cpd 861） in the regulation of mRNA expression of collagen synthesis- and degradation-related genes in human hepatic stellate cells （HSCs）. METHODS： mRNA levels of collagen types I and III, matrix metalloproteinase 1 （MMP-1）, matrix metalloproteinase 2 （MMP-2）, membrane type-1 matrix metalloproteinase （MT1-MMP）, tissue inhibitor of metalloproteinase 1 （TIMP-1）, and transforming growth factor β1 （TGF-β1） in cultured-activated HSCs treated with Cpd 861 or interferon-γ, （IFN-γ,） were determined by real-time PCR. RESULTS： Both Cpd 861 and IFN-γ reduced the mRNA levels of collagen type Ⅲ, MMP-2 and TGF-β1. Moreover, Cpd 861 significantly enhanced the MMP-1 mRNA levels while down-regulated the TIMP-1 mRNA expression, increasing the ratio of MMP-1 to TIMP-1 to （6.3 ＋ 0.3）- fold compared to the control group. CONCLUSION： The anti-fibrosis function of Cpd 861 may be mediated by both decreased interstitial collagen sythesis by inhibiting the transcription of collagen type Ⅲ and TGF-β1 and increased degradation of these collagens by up-regulating MMP-1 and down-regulating TIMP-1 mRNA levels.

NC code generation for laser assisted turn-mill of various type of clovers and square section members

Laser assisted turning （LAT） is one of the advanced machining technologies, which uses laser power to heat the surface of a workpiece before the material is removed. It has several advantages of low manufacturing costs, high productivity and high qualities to machine difficult-to-cut materials such as silicon nitride, muUite, zirconia and Ni. A large part of studies on LAT have been focused on a round bar. With increasing demands for high quality products and high performance engineering system, the researches on LAT for clover and square section members are necessary. But, these workpieces are impossible to be machined on conventional CNC lathe and to generate NC code with current CAM softwares. As a basic research for combining LAT with a tilting index table type 5-axis machining center, i.e. laser assisted turn-mill, a new method is suggested to generate NC code that can process various types of clover and square section members through development of C＋＋ program.

Management Options and Soil Types Differentially Affect Weeds in Maize Fields of Kakamega, Western Kenya

Maize production in Kenya is constrained by weed infestation and nutrient deficiencies. Field studies were conducted during the 2008/2009 cropping seasons to investigate weeds in maize fields on three dominant soil types in Western Kenya. Weeds were inventoried and their composition was compared using Jaccard＇s index. The economic importance of weed species （potential to reduce yields and the difficulty to control them by manual weeding） was assessed through participatory surveys. Finally, field trials assessed the effects of management options （farmer＇s practice, clean weeding, green manure, zero-tillage ＋ cover crop and zero-tillage） on weed biomass and species composition. Across the three soil types, 55 weed species in 21 families were identified. Soil types influenced species composition as confirmed by Jaccard＇s similarity indices of 0.50, 0.58 and 0.62 for Nitisol vs. Acrisol, Ferralsol vs. Acrisol and Nitisol vs. Ferralsol, respectively. The economically important weeds were Commelina benghalensis, Cynodon nlemfuensis, Bidens pilosa, Galinsoga parviflora and Leonotis nepetifolia. Management options significantly （P 〈 0.05） reduced weed biomass, irrespective of soil type and seasons. Maize biomass response was highest （7-16 Mg ha1） in zero-tillage and zero-tillage ＋ cover crop and lowest （2-8 Mg ha1） in farmer＇s practice. Significantly negative relationships （P 〈 0.01, r2 = 0.37 - 0.51） were established between leaf area index of maize and weed biomass across the soils. Zero-tillage combined with the use of a cover crop had the lowest weed biomass （〈 30% of the farmer practice） and thus appears to be a promising strategy combining soil fertility improvement with weed suppression in smallholder maize farming systems of Western Kenya.

Interspecific Variation of Micromorphology of Glandular Trichomes between two Salvia Species in South Albania

Micromorphology of glandular hairs on the leaves of Salvia officinalis L. and Salvia triloba L. was investigated by light microscopy. We noticed similiarity and variation between the two species regarding morphology of glandular trichomes. Two main types of glandular trichomes were identified on both species： peltate and capitate. Peltate trichomes consisted of a basal cell, one stalk cell and a large multisecretory head in S. officinalis L. In S. triloba L. peltate trichomes posses a basal cell, a short unicellular stalk, and a large secretory head with 8 secretory cells. In Salvia officinalis L., four types of capitate trichomes have been distinguished. Five types of capitate trichomes have been found in Salvia triloba L. The fifth type of capitate trichome, called digitiform trichome was found in S. triloba L. This determined interspecific diversity between the two Salvia species.

A method for retrieving soil moisture from GNSS-R by using experiment data

Soil moisture is a key parameter in agricultural irrigation. The L band（1.58GHz） on board global position system （GPS） satellite is well suited for monitoring the change of soil moisture. In order to investigate the potential of retrieving soil moisture using the L-band GPS bistatic radar, this paper analyzed a retrieval method by using field experiment data. In order to investigate the relation- ship between the soil moisture （ corresponding roughly to the 0 - 5cm top soil layer） and the signal- to-noise ratio （PT-S-R） to the direct GPS signal-to-noise ratio （Pd_sNR）, an experiment was conducted in Hulunber grassland of China in 2009 and 2011. Six field sites in the soil moisture experiment were utilized to analyze the relationship between soil moisture and the ratio of Pr-SNR to Pd-SN~ and the square of correlation coefficient was about 0.9 when the surface type was known and the elevation angle of the satellite ranged from 65 to 85 degrees approximately. The analysis shows that ratio of Pr-SNR to Pd-SNR can be used to monitor the soil moisture, because the ratio of Pr-SVR to Pd-SNR maxi- mized the elimination of the influence of different signals from different GPS satellites. The estimation accuracy could be improved if we make full use of the empirical knowledge on elevation angles of GPS satellites and ground roughness of different surface types.

Responses of aboveground biomass of alpine grasslands to climate changes on the Qinghai-Tibet Plateau

Aboveground biomass in grasslands of the Qinghai-Tibet Plateau has displayed an overall increasing trend during 2003–2016, which is profoundly influenced by climate change. However, the responses of different biomes show large discrepancies, in both size and magnitude. By applying partial least squares regression, we calculated the correlation between peak aboveground biomass and mean monthly temperature and monthly total precipitation in the preceding 12 months for three different grassland types(alpine steppe, alpine meadow, and temperate steppe) on the central and eastern Qinghai-Tibet Plateau. The results showed that mean temperature in most preceding months was positively correlated with peak aboveground biomass of alpine meadow and alpine steppe, while mean temperature in the preceding October and February to June was significantly negatively correlated with peak aboveground biomass of temperate steppe. Precipitation in all months had a promoting effect on biomass of alpine meadow, but its correlations with biomass of alpine steppe and temperate steppe were inconsistent. It is worth noting that, in a warmer, wetter climate, peak aboveground biomass of alpine meadow would increase more than that of alpine steppe, while that of temperate steppe would decrease significantly, providing support for the hypothesis of conservative growth strategies by vegetation in stressed ecosystems.

Driving Mechanism of Gross Primary Production Changes and Implications for Grassland Management on the Tibetan Plateau

The contribution of climatic change and anthropogenic activities to vegetation productivity are not fully understood.In this study,we determined potential climate-driven gross primary production(GPPp)using a process-based terrestrial ecosystem model,and actual gross primary production(GPPa)using MODIS Approach in alpine grasslands on the Tibetan Plateau from 2000 to 2015.The GPPa was influenced by both climatic change and anthropogenic activities.Gross primary production caused by anthropogenic activities(GPPh)was calculated as the difference between GPPp and GPPa.Approximately 75.63%and 24.37%of the area percentages of GPPa showed increasing and decreasing trends,respectively.Climatic change and anthropogenic activities were dominant factors responsible for approximately 42.90%and 32.72%of the increasing area percentage of GPPa,respectively.In contrast,climatic change and anthropogenic activities were responsible for approximately 16.88%and 7.49%of the decreasing area percentages of GPPa,respectively.The absolute values of the change trends of GPPp and GPPh of meadows were greater than those of steppes.The GPPp change values were greater than those of GPPh at all elevations,whereas both GPPp and GPPh showed decreasing trends when elevations were greater than or equal to 5000 m,4600 m and 4800 m in meadows,steppes and all grasslands,respectively.Climatic change had stronger effects on the GPPa changes when elevations were lower than 5000 m,4600 m and 4800 m in meadows,steppes and all grasslands,respectively.In contrast,anthropogenic activities had stronger effects on the GPPa changes when elevations were greater than or equal to 5000 m,4600 m and 4800 m in meadows,steppes and all grasslands,respectively.Therefore,the causes of actual gross primary production changes varied with elevations,regions and grassland types,and grassland classification management should be considered on the Tibetan Plateau.

Factors contributing to amphibian road mortality in a wetland

To understand road characteristics and landscape features associated with high road mortality of amphibians in Zoige Wetland National Nature Reserve, we surveyed road mortality along four major roads after rainfall in May and September 2007. Road mortality of three species, Rana kukunoris, Nanorana pleskei and Bufo minshanicus, was surveyed across 225 transects （115 in May and 110 in September）. Transects were 100 m long and repeated every two kilometers along the four major roads. We used model averaging to assess factors that might determine amphibian road mortality. We recorded an average of 24.6 amphibian road mortalities per kilometer in May and 19.2 in September. Among road characteristics, road width was positively associated with road morality for R. kukunori and B. minshanicus. Traffic volume also increased the road mortality of B. minshanicus in September. Of the landscape features measured, area proportions of three types of grassland （wet, mesic and dry） within 1 km of the roads, particularly that of wet grassland, significantly increased road mortality for R. kukunori and total mortality across all three species. To most effectively reduce road mortality of amphibians in the Zoige wetlands, we suggest better road design such as avoiding wet grasslands, minimizing road width, underground passes and traffic control measures. The implementation of pub- lic transit in the area would reduce traffic volume, and hence mortality

Relative pollen productivities of typical steppe species in northern China and their potential in past vegetation reconstruction

The Relative Pollen Productivities(RPPs)of common steppe species are estimated using Extended R-value(ERV)model based on pollen analysis and vegetation survey of 30 surface soil samples from typical steppe area of northern China.Artemisia,Chenopodiaceae,Poaceae,Cyperaceae,and Asteraceae are the dominant pollen types in pollen assemblages,reflecting the typical steppe communities well.The five dominant pollen types and six common types(Thalictrum,Iridaceae,Potentilla,Ephedra,Brassicaceae,and Ulmus)have strong wind transport abilities;the estimated Relevant Source Area of Pollen(RSAP)is ca.1000 m when the sediment basin radius is set at 0.5 m.Ulmus,Artemisia,Brassicaceae,Chenopodiaceae,and Thalictrum have relative high RPPs;Poaceae,Cyperaceae,Potentilla,and Ephedra pollen have moderate RPPs;Asteraceae and Iridaceae have low RPPs.The reliability test of RPPs revealed that most of the RPPs are reliable in past vegetation reconstruction.However,the RPPs of Asteraceae and Iridaceae are obviously underestimated,and those of Poaceae,Chenopodiaceae,and Ephedra are either slightly underestimated or slightly overestimated,suggesting that those RPPs should be considered with caution.These RPPs were applied to estimating plant abundances for two fossil pollen spectra(from the Lake Bayanchagan and Lake Haoluku)covering the Holocene in typical steppe area,using the"Regional Estimates of Vegetation Abundance from Large Sites"(REVEALS)model.The RPPs-based vegetation reconstruction revealed that meadow-steppe dominated by Poaceae,Cyperaceae,and Artemisia plants flourished in this area before 6500–5600 cal yr BP,and then was replaced by present typical steppe.

Woody plant encroachment may decrease plant carbon storage in grasslands under future drier conditions

Aims Woody plants are widely distributed in various grassland types along the altitudinal/climatic gradients in Xinjiang,China.Considering previously reported change in carbon(C)storage following woody plant encroachment in grasslands and the mediating effect of climate on this change,we predicted that a positive effect of woody plants on plant C storage in semiarid grasslands may revert to a negative effect in arid grasslands.We first investigated the spatial variation of aboveground C(AGC)and belowground C(BGC)storage among grassland types and then tested our prediction.Methods We measured the living AGC storage,litter C(LC)and BGC storage of plants in two physiognomic types,wooded grasslands(aboveground biomass of woody plants at least 50%)and pure grasslands without woody plants in six grassland types representing a gradient form semiarid to arid conditions across Xinjiang.Important Findings Living AGC,LC,BGC and total plant C storage increased from desert to mountain meadows.These increases could also be explained by increasing mean annual precipitation(MAP)or decreasing mean annual temperature(MAT),suggesting that grassland types indeed represented an aridity gradient.Woody plants had an effect on the plant C storage both in size and in distribution relative to pure grasslands.The direction and strength of the effect of woody plants varied with grassland types due to the mediating effect of the climate,with wetter conditions promoting a positive effect of woody plants.Woody plants increased vegetation-level AGC through their high AGC relative to herbaceous plants.However,more negative effects of woody plants on herbaceous plants with increasing aridity led to a weaker increase in the living AGC in arid desert,steppe desert and desert steppe than in the less arid other grassland types.Under greater aridity(lower MAP and higher MAT),woody plants allocated less biomass to roots and had lower BGC and had a more negative impact on herbaceous plant production,thereby reducing vegetation-level BGC in the desert,steppe desert and desert steppe.In sum,this resulted in a negative effect of woody plants on total plant C storage in the most arid grasslands in Xinjiang.As a consequence,we predict that woody plant encroachment may decrease rather than increase C storage in grasslands under future drier conditions.

Estimates of Soil Organic Carbon Stocks in Zhejiang Province of China Based on 1:50000 Soil Database Using the PKB Method

Soil organic carbon(SOC) is an important component of farming systems and global carbon cycle. Accurately estimating SOC stock is of great importance for assessing soil productivity and modeling global climate change. A newly built 1:50 000 soil database of Zhejiang Province containing 2 154 geo-referenced soil profiles and a pedological professional knowledge-based(PKB) method were used to estimate SOC stock up to a depth of 100 cm for the Province. The spatial patterns of SOC stocks stratified by soil types,watershed(buffer analysis), topographical factors, and land use types were identified. Results showed that the soils in Zhejiang covered an area of 100 740 km2 with a total SOC stock of 831.49 × 106 t and a mean SOC density of 8.25 kg m-2, excluding water and urban areas. In terms of soil types, red soils had the highest SOC stock(259.10 × 106t), whereas mountain meadow soils contained the lowest(0.15 × 106t). In terms of SOC densities, the lowest value(5.11 kg m-2) was found in skel soils, whereas the highest value(45.30 kg m-2) was observed in mountain meadow soils. Yellow soils, as a dominant soil group, determined the SOC densities of different buffer zones in Qiantang River watershed because of their large area percentage and wide variation of SOC density values.The area percentages of various soil groups significantly varied with increasing elevation or slope when overlaid with digital elevation model data, thus influencing the SOC densities. The highest SOC density was observed under grassland, whereas the lowest SOC density was identified under unutilized land. The map of SOC density(0–100 cm depth) and the spatial patterns of SOC stocks in the Province would be helpful for relevant agencies and communities in Zhejiang Province, China.

Compost Effect on Diuron Retention and Transport in Structured Vineyard Soils

Diuron is frequently detected in surface- and groundwater under the vineyards, where organic amendments are often used, in Burgundy of France. Undisturbed column experiments were conducted to study the influence of three composted organic amendments on diuron leaching through columns of two vineyard soils from Vosne-Roman′ee(VR, calcareous Cambisol) and Beaujolais(Bj, sandy Leptosol), France. Bromide(used as non-reactive tracer) and diuron breakthrough curves(BTCs) were analyzed using convectivedispersive equation(CDE), two-region(mobile-immobile, MIM) and two-site models. No influence of the composts was observed on the bromide recovery rates. The CDE model described well the bromide BTCs for all columns of the Bj soil and seven of the VR soil, suggesting a homogeneous water flow. However, for five VR soil columns, the MIM model fitted better, suggesting a partition of the water flow(15%–50% of matrix flow). The texture, the coarse material content and the tillage of the VR soil could explain this heterogeneity. However, for all columns, diuron leaching was greater through the Bj soil(46%–68%) than the VR soil(28%–39%). The compost addition resulted in a contrasting effect on diuron leaching: no difference or a decrease was observed for the VR soil, probably due to an increase of adsorption sites, whereas no difference or an increase was observed for the Bj soil possibly because of interactions and/or competition of diuron with the compost water-extractable organic matter which could facilitate its transport. All the diuron BTCs were best described using the two-site model, suggesting a large proportion of time-dependent sorption sites(30%–50%). The soil type and the nature of the amendments had contrasting influences on diuron transport. Composts with a high water-soluble fraction must be avoided in sandy soils to reduce the risk of groundwater contamination.