Elevational patterns of warming effects on plant community and topsoil properties: focus on subalpine meadows ecosystem

Climate warming profoundly affects plant biodiversity, community productivity, and soil properties in alpine and subalpine grassland ecosystems. However, these effects are poorly understood across elevational gradients in subalpine meadow ecosystems. To reveal the elevational patterns of warming effects on plant biodiversity, community structure, productivity, and soil properties, we conducted a warming experiment using open-top chambers from August 2019 to August 2022 at high(2764 m a. s. l.), medium(2631 m a. s. l.), and low(2544 m a. s. l.) elevational gradients on a subalpine meadow slope of Mount Wutai, Northern China. Our results showed that three years of warming significantly increased topsoil temperature but significantly decreased topsoil moisture at all elevations(P<0.05), and the percentage of increasing temperature and decreasing moisture both gradually raised with elevation lifting. Warming-induced decreasing proportions of soil organic carbon(SOC, by 19.24%), and total nitrogen(TN, by 24.56%) were the greatest at high elevational gradients. Experimental warming did not affect topsoil C: N, p H, NO_(3)^(-)-N, or NH_(4)^(+)-N at the three elevational gradients. Warming significantly increased species richness(P<0.01) and Shannon-Weiner index(P<0.05) at low elevational gradients but significantly decreased belowground biomass(P<0.05) at a depth of 0–10 cm at three elevational gradients. Warming caused significant increases in the aboveground biomass in the three elevational plots. Warming significantly increased the aboveground biomass of graminoids in medium(by 92.47%) and low(by 98.25%) elevational gradients, that of sedges in high(by 72.44%) and medium(by 57.16%) elevational plots, and that of forbs in high(by 75.88%), medium(by 34.38%), and low(by 74.95%) elevational plots. Species richness had significant linear correlations with SOC, TN, and C: N(P<0.05), but significant nonlinear responses to soil temperature and soil moisture in the warmed treatment(P<0.05). The warmed aboveground biomass had a significant nonlinear response to soil temperature and significant linear responses to soil moisture(P<0.05). This study provided evidence that altitude is a factor in sensitivity to climate warming, and these different parameters(e.g., plant species richness, Shannon-Weiner index, soil temperature, soil moisture, SOC, and TN) can be used to measure this sensitivity.

Effects of planting patterns on yield, quality, and defoliation in machine-harvested cotton

The aim of this study was to elucidate the effects of different machine-harvested cotton-planting patterns on defoliation,yield,and fiber quality in cotton and to provide support for improving the quality of machine-harvested cotton.In the 2015 and 2016 growing seasons,the Xinluzao 45(XLZ45)and Xinluzao 62(XLZ62)cultivars,which are primarily cultivated in northern Xinjiang,were used as study materials.Conventional wide-narrow row(WNR),wide and ultra-narrow row(UNR),wide-row spacing with high density(HWR),and wide-row spacing with low density(LWR)planting patterns were used to assess the effects of planting patterns on defoliation,yield,and fiber quality.Compared with WNR,the seed cotton yields were significantly decreased by 2.06–5.48%for UNR and by 2.50–6.99%for LWR,respectively.The main cause of reduced yield was a reduction in bolls per unit area.The variation in HWR yield was–1.07–1.07%with reduced bolls per unit area and increased boll weight,thus demonstrating stable production.In terms of fiber quality indicators,the planting patterns only showed significant effects on the micronaire value,with wide-row spacing patterns showing an increase in the micronaire values.The defoliation and boll-opening results showed that the number of leaves and dried leaves in HWR was the lowest among the four planting patterns.Prior to the application of defoliating agent and before machine-harvesting,the numbers of leaves per individual plant in HWR were decreased by 14.45 and 25.00%on average,respectively,compared with WNR,while the number of leaves per unit area was decreased by 27.44 and 36.21%on average,respectively.The rates of boll-opening and defoliation in HWR were the highest.Specifically,the boll-opening rate before defoliation and machine-harvesting in HWR was 44.54 and 5.94%higher on average than in WNR,while the defoliation rate prior to machine-harvesting was 3.45%higher on average than in WNR.The numbers of ineffective defoliated leaves and leaf trash in HWR were the lowest,decreased by 33.40 and 32.43%,respectively,compared with WNR.In conclusion,the HWR planting pattern is associated with a high and stable yield,does not affect fiber quality,promotes early maturation,and can effectively decrease the amount of leaf trash in machine-picked seed cotton,and thus its use is able to improve the quality of machine-harvested cotton.

The unimodal latitudinal pattern of K,Ca and Mg concentration and its potential drivers in forest foliage in eastern China

Potassium(K),calcium(Ca),and magnesium(Mg)are essential elements with important physiological functions in plants.Previous studies showed that leaf K,Ca,and Mg concentrations generally increase with increasing latitudes.However,recent meta-analyses suggested the possibility of a unimodal pattern in the concentrations of these elements along latitudinal gradients.The authenticity of this unimodal latitudinal pattern,however,requires validation through large-scale field experimental data,and exploration of the underlying mechanisms if the pattern is confirmed.Here,we collected leaves of common species of woody plants from 19 montane forests in the north-south transect of eastern China,including 322 species from 160 genera,67 families;and then determined leaf K,Ca,and Mg concentrations to explore their latitudinal patterns and driving mechanisms.Our results support unimodal latitudinal patterns for all three elements in woody plants across eastern China,with peak values at latitude 36.5±1.0°N.The shift of plant-functional-type compositions from evergreen broadleaves to deciduous broadleaves and to conifers along this latitudinal span was the key factor contributing to these patterns.Climatic factors,mainly temperature,and to a lesser extent solar radiation and precipitation,were the main environmental drivers.These factors,by altering the composition of plant communities and regulating plant physiological activities,influence the latitudinal patterns of plant nutrient concentrations.Our findings also suggest that high leaf K,Ca,and Mg concentrations may represent an adaptive strategy for plants to withstand water stress,which might be used to predict plant nutrient responses to climate changes at large scales,and broaden the understanding of biogeochemical cycling of K,Ca,and Mg.

Leaf Photosynthetic Characteristics of High-Yield Soybean[Glycine max(L.)Merr.]Under Different Planting Densities,Different Fertilization Rates,and Single/Mixed Planting Patterns

Understanding the photosynthetic characteristics of high-yield soybean[Glycine max(L.)Merr]cultivar(HYC)would aid research aiming at investigating the soybean high yield formation mechanism and optimization of cultivation system.To assess the photosynthesis of HYC,a pot experiment was conducted to quantify the differences in photosynthetic characteristics between HYC and common-yield soybean cultivar(CC)under different planting densities,fertilization rates,and single/mixed planting patterns.The leaf greenness(Lg),net photosynthetic rate(Ph),stomatal conductance(St)and transpiration rate(Tr)were significantly higher in HYC than CC mainly in seed-filling stages.HYC was more tolerant to dense and mixed planting because the decreases of Ph and St under high planting density and those of Ph,St,and Tr under mixed planting were lower in HYC than CC.The Lg and Ph in HYC were more superior to those in CC at high fertilization rate.Thus,the HYC has a superior performance in photosynthetic characteristics under the varied cultivation practices,which may contribute to the greater seed yield in HYC than CC.

Improving Soil Fertility with Different Planting Patterns in Rocky Desertification Areas

[Objectives]This study was conducted to investigate the effect of different planting patterns on soil improvement in rocky desertification areas.[Methods]The one-way ANOVA analysis method was used to statistically analyze the soil physical and chemical properties,enzyme activity,microbial quantity,CEC,ECEC,and aggregate content distribution with different planting patterns.[Results]The walnut+sesame+mung bean planting pattern showed the highest soil available phosphorus,available potassium,porosity,non-capillary porosity,and contents of free living nitrogen-fixing bacteria,organophosphate-dissolving bacteria,bacteria,fungi and actinomycetes,at 63.2 mg/kg,178.8 mg/kg,22.85%,6.89%,10.0×10^6 bacteria/g,18.0×10^6 bacteria/g,21.0×10^5 CFU/g,5.7×10^3 CFU/g and 7.9×10^5 CFU/g,respectively,and it reduced soil bulk density(the same as treatment F and treatment E)compared with other planting patterns.The walnut+American chicory+sweet potato planting pattern had the highest alkali-hydrolyzale nitrogen,organic matter,CEC,ECEC,water-air ratio and moisture content,which were 227.9 mg/kg,46.30 g/kg,36.38 cmol/kg,24.00 cmol/kg,8.13,and 32.89%,respectively,and it reduced soil bulk density,increased capillary porosity,acid phosphatase,and contents of bacteria and actinomycetes compared with single cropping of walnut.[Conclusions]Interplanting crops under walnut forests is an effective measure to improve the ecological environment of rocky desertification farmland.

Landscape pattern and its effect on ecosystem functions in Seoul Metropolitan area:Urban ecology on distribution of the naturalized plant species

During land transformation process in the human history, naturalized plants were introduced to several land use patterns by the different ways of plant itself. Including some naturalized plants that had been contribute to land restoration, many naturalized plants have been invaded to original habitat or landscape for native plants. Once the plants were colonized, they extend their area and population size. Urban developed areas often give an important role of source habitat for naturalized plants and expanding their population size. In recent, this situation is appearing as one of environmental problems about the urban landscape management controlling the naturalized plants that invaded in the developed area and conserving the native vegetation. This paper is focusing on relationships between distribution of habitat of naturalized plants and landscape patch in urban area in Seoul. Gangdong-Gu, one of the administrative areas in Seoul was selected for this study. We examined the recent land use change using LANDSAT TM data and spreading of the representative naturalized plants (Robinia pseudoacacia and Eupatorium rugosum) by Seoul Biotope Mapping Project and field survey in 1999. As a result, these two species were often occurred in the same habitat and distributed in forest edge disturbed by man. Their distribution patterns were related to landscape indices (patch size and shape) in the forest edge.

Effects of rainfall patterns on annual plants in Horqin Sandy Land, Inner Mongolia of China

Growth of annual plants in arid environments depends largely on rainfall pulses. An increased understanding of the effects of different rainfall patterns on plant growth is critical to predicting the potential responses of plants to the changes in rainfall regimes, such as rainfall intensity and duration, and length of dry intervals. In this study, we investigated the effects of different rainfall patterns（e.g. small rainfall event with high frequency and large rainfall event with low frequency） on biomass, growth characteristics and vertical distribution of root biomass of annual plants in Horqin Sandy Land, Inner Mongolia of China during the growing season（from May to August） of 2014. Our results showed that the rainfall patterns, independent of total rainfall amount, exerted strong effects on biomass, characteristics of plant growth and vertical distribution of root biomass. Under a constant amount of total rainfall, the aboveground biomass（AGB）, belowground biomass（BGB）, plant cover, plant height, and plant individual and species number increased with an increase in rainfall intensity. Changes in rainfall patterns also altered the percentage contribution of species biomass to the total AGB, and the percentage of BGB at different soil layers to the total BGB. Consequently, our results indicated that increased rainfall intensity in future may increase biomass significantly, and also affect the growth characteristics of annual plants.

Distribution patterns and industry planning of commonly used traditional Chinese medicinal plants in China

Medicinal plants are the primary material basis for disease prevention and treatment in traditional Chinese medicine(TCM).The conservation and sustainable utilization of these medicinal plants is critical for the development of the TCM industry.However,wild medicinal plant resources have sharply declined in recent decades.To ameliorate the shortage of medicinal plant resources,it is essential to explore the development potential of the TCM industry in different geographical regions.For this purpose,we examined the spatial distribution of commonly used medicinal plants in China,the number of Chinese medicinal material markets,and the number of TCM decoction piece enterprises.Specifically,multispecies superimposition analysis and Thiessen polygons were used to reveal the optimal range for planting bulk medicinal plants and the ideal regions for building Chinese medicinal material markets,respectively.Furthermore,we quantitatively analyzed mismatches between the spatial distribution of commonly used medicinal plant richness,Chinese medicinal material markets,and TCM decoction piece enterprises.We found that the areas suitable for growing commonly used medicinal plants in China were mainly distributed in Hengduan Mountain,Nanling Mountain,Wuling Mountain,and Daba Mountain areas.The Thiessen polygon network based on Chinese medicinal material market localities showed there are currently fewer markets in southwestern,northwestern,and northeastern China than in central and southern China.TCM decoction piece enterprises are concentrated in a few provinces,such as Hebei and Jiangxi.We found that the distribution of commonly used medicinal plants,Chinese medicinal material markets and TCM decoction piece enterprises are mismatched in Henan,Shaanxi,Hunan,Hubei,Zhejiang,Fujian,Chongqing,and Xizang.We recommend strengthening development of the TCM industry in Henan,Hunan,Zhejiang,Shaanxi,Hubei,Chongqing,Fujian,and Xizang;building more Chinese medicinal material markets in southwestern,northwestern,and northeastern China;and establishing medicinal plant nurseries in resource-rich provinces to better protect and domesticate local medicinal plants.

An Analysis of the Correlation between the Changes in Sa-tellite DNA Methylation Patterns and Plant Cell Responses to the Stress

The differences in satellite DNA methylation pattern of corn seedlings with various spontaneous chromosome aberration yields and changes in methylation pattern of these DNA sequences under different exposure modes of acute UV-C and chronic gamma-irradiations have been investigated. The obtained experimental data and the conducted correlation analysis demonstrated the significant correlation between the satellite DNA methylation pattern varieties and chromosome aberration yields under various stress exposure modes. The role of satellite DNA methylation pattern variability and its changing in key responses to stress such as mobile elements’ activation, cell’s passage of checkpoints, and homological repair was discussed.

Vertical patterns in plant diversity and their relations with environmental factors on the southern slope of the Tianshan Mountains(middle section)in Xinjiang(China)

The investigation of distribution patterns of species diversity is significant for successful biodiversity conservation. The spatial patterns of vegetation and different life-forms species diversity along an elevation gradient in the middle section of the southern slope of the Tianshan Mountains in Xinjiang, China were explored, using the detrended canonical correspondence analysis(DCCA) and the generalized additive model(GAM) methods based on a field survey of 53 sampling plots. In this work 158 species of seed plants were recorded, including 141 herbaceous, 14 shrub, and 2 tree species, in which the woody plants are very limited. 53 sampling plots were classified into 9 major plant communities. The results indicate that the herb communities were the most sensitive to changes in elevation gradient. The diversity indices of the community as a whole presented bimodal patterns. The peak values for the species diversities were found in the transition region between mountain steppe desert and mountain desert steppe(2,200–2,300m), and in the alpine grassland region(2,900–3,100m), while maximum species diversities were in the areas of intermediate environmental gradient. The main environmental factors on the distribution patterns in plant diversity were the elevation, soil water, total nitrogen, available nitrogen, organic matter, and total salt. The response tendency of the four diversity indices for the whole community to the soil environment was the same as that of the herb layers.

Geographic patterns of taxonomic and phylogenetic β-diversity of aquatic angiosperms in China

China covers a vast territory harbouring a large number of aquatic plants.Although there are many studies on the β-diversity of total,herbaceous or woody plants in China and elsewhere,few studies have focused on aquatic plants.Here,we analyse a comprehensive data set of 889 aquatic angiosperm species in China,and explore the geographic patterns and climatic correlates of total taxonomic and phylogeneticβ-diversity as well as their turnover and nestedness components.Our results show that geographic patterns of taxonomic and phylogenetic β-diversity are highly congruent for aquatic angiosperms,and taxonomic β-diversity is consistently higher than phylogenetic β-diversity.The ratio between the nestedness component and total β-diversity is high in northwestern China and low in southeastern China.The geographic patterns of taxonomic and phylogenetic β-diversity of aquatic angiosperms in China are obviously affected by geographic and climatic distances,respectively.In conclusion,the geographic patterns of taxonomic and phylogenetic β-diversity of aquatic angiosperms are consistent across China.Climatic and geographic distances jointly affect the geographic patterns of β-diversity of aquatic angiosperms.Overall,our work provides insight into understanding the large-scale patterns of aquatic angiosperm β-diversity,and is a critical addition to previous studies on the macroecological patterns of terrestrial organisms.

Planting Adaptability of Brassica napobrassica cv. Huaxi Under Economic Fruit Forest

The growth speed,fresh grass yield,nutritional components,soil nutrient variation and economic benefit of Brassica napobrassica cv. Huaxi under different planting patterns( drilling,hole sowing and seedling transplanting) were analyzed by a test of interplanting B. napobrassica cv. Huaxi under economic fruit forest,to solve the contradiction between food and feed during rapid development of ecological animal husbandry and improve land utilization rate. The comprehensive performance of B. napobrassica cv. Huaxi was good under the three planting patterns,and the comprehensive performance of B. napobrassica cv. Huaxi under the seedling transplanting pattern was the best among the three planting patterns. The fresh grass yield and net profit of B. napobrassica cv. Huaxi under the seedling transplanting pattern can reach 125 580. 0 kg/hm^2 and 16 674. 0 Yuan/hm^2,respectively. Interplanting B. napobrassica cv. Huaxi under economic fruit forest can improve soil physical and chemical properties,increase soil nutrients and inhibit weed growth.

Effects of Planting Methods on Levels of Common Pesticides and Heavy Metals in Dendrobium officinale

The levels of common pesticides and heavy metals in Dendrobium officinale grown from 2012 to 2014 were measured, and three planting methods were used in 2014. The quality of plant husbandry improved during the study period. Thirteen types of pesticides were detected in D. officinale grown in 2014 and antimicrobials, including carbendazim, difenoconazole and azoxystrobin, were evident in 61.53% of plants. These three pesticides constituted 72.33% of all the antimicrobials detected. Planting methods affected the levels of pesticides and heavy metals. Trellising in plastic sheds was optimal, being associated with the lowest amounts of both pesticides and heavy metals. Both cadmium（Cd） and lead（Pb） levels were high in treed plants, whereas Cr, As and Cu levels were the highest in potted plants.

Construction of Spatial Pattern of Garden Plant Landscape in Urban Waterfront

The spatial pattern of urban waterfront landscape is an important factor affecting the quality of urban culture and improving the recognition of the city.As the core material of urban landscape design,garden plants play a very important role in the construction of spatial pattern of urban waterfront landscape.The spatial pattern of garden plant landscape can be divided into three types:two-dimensional,vertical and special.The two-dimensional spatial pattern focuses on the construction of"meaning and form".The vertical spatial pattern focuses on the construction of"image".The special spatial pattern of garden plants focuses on the construction of"artistic conception".The three types are used to create a spatial pattern of urban waterfront landscape with rich spatial and temporal changes and artistic connotation.

Species composition and influencing factors of understory woody species in Robinia pseudoacacia plantations on the Loess Plateau

Black locust(Robinia pseudoacacia L.)plantations have contributed significantly to soil and water conservation and ecological reconstruction on China’s Loess Plateau.Understanding the impact of stand and environment on species composition of understory woody plants will improve the stability of existing black locust plantations.Ten stands were selected in second-generation black locust plantations in tableland and gully areas of the Loess Plateau.The number of understory tree species in the tablelands was significantly lower than in the gully stands.Regenerated black locust(19.76%)and Rubus corchorifolius L.f.(64.85%)were the most abundant understory tree and shrub species,respectively,in the tableland stands;Broussonetia papyrifera(L.)L’Hér.ex Vent.(6.77%)and Acanthopanax senticosus(Rupr.Maxim.)Harms.(37.22%)were most abundant in the gully stands.Species richness(S),Shannon diversity(H),and evenness index(J)of the understory plants were significantly lower in the tableland stands than in the gully stands.More diverse understory species and community structures occurred in the gully stands.Differences in species diversity among landform positions may be attributed to differences in soil moisture.In addition,77.57%of the variation in understory species composition was explained,among which shrub and herb coverage,stand age,leaf area index,slope and total soil phosphorus in the 10-20 cm layer were the main factors.Soil organic carbon and total potassium significantly impacted S,H and J.Considering the environmental conditions and the biological characteristics of the plants investigated,R.corchorifolius should be given priority in the development of tableland stands,while B.papyrifera and Celtis sinensis Pers.should form mixed forests with black locust in gully stands.This management could promote biodiversity and stability of the existing black locust plantations but also optimize regional landscape patterns.

Impacts of Rice Field Winter Planting on Soil Organic Carbon and Carbon Management Index

To tackle with the problem of prevailing farmland abandonment in winter,5 treatments includes Chinese milk vetch-double cropping rice(CRR),rape-double cropping rice(RRR),garlic-double cropping rice(GRR),winter crop multiple cropping rotation(ROT),winter fallow control(WRR)were set up.By measuring soil total organic carbon,active organic carbon and its components and calculating the soil carbon pool management index in 0~15 cm and 15~30 cm soil layers in the early and late rice ripening stage.The effects of different winter planting patterns on the changes of soil organic carbon and carbon pool management index were discussed.In order to provide theoretical basis for the optimization and adjustment of winter planting pattern of double cropping rice field in the middle reaches of Yangtze River.The results showed that soil total organic carbon,active organic carbon and its components in different winter cropping patterns were increased,and ROT and CRR treatments were more beneficial to the accumulation of soil total organic carbon,active organic carbon and its components as well as the improvement of soil carbon pool management index,which should be preferred in the adjustment of cropping patterns.

江苏水稻种植方式碳足迹和经济效益综合评价

系统分析水稻不同种植方式碳足迹及经济效益对水稻生产碳减排和发展低碳农业具有重要意义,目前在省级尺度上关于不同水稻种植方式碳足迹和经济效益综合评价的研究尚少见报道。基于江苏水稻农情调查数据,利用生命周期评价方法定量分析江苏水稻不同种植方式碳足迹及经济效益。结果表明,2016-2020年不同水稻种植方式单位面积碳足迹为11.28~14.39t·hm^(-2),单位产量碳足迹为1.30~1.52kg·kg^(-1),单位产值碳排放为0.49~0.58kg·yuan^(-1),单位面积碳足迹、单位产量碳足迹和单位产值碳足迹从大到小依次为抛秧水稻或手插水稻、机插水稻、直播水稻。机插水稻和手插水稻生产单位面积碳足迹随年份的增加呈下降趋势。机插水稻、手插水稻和直播水稻单位产量碳足迹随年份的变化呈下降趋势。不同水稻生产种植方式碳足迹中占比最大的是稻田甲烷排放,其次为氮肥施用导致的碳足迹、稻田氧化亚氮排放和灌溉用电导致的碳足迹。氮肥和灌溉用电是影响不同水稻种植方式碳足迹差异的主要驱动因素。不同水稻种植方式总收益为2.51×10^(3)~2.75×10^(3)yuan·hm^(-2),资源投入成本为1.88×10^(3)~1.99×10^(3)yuan·hm^(-2),碳排放成本为0.20×10^(3)~0.25×10^(3)yuan·hm^(-2),考虑碳排放的净收益(NI-CO_(2))为0.39×10^(3)~0.64×10^(3) yuan·hm^(-2)。机插水稻NI-CO_(2)低于其他三种水稻种植方式,这与机插水稻较高的总收益和较低的资源投入成本和较低的碳排放成本有关。综上所述,仅考虑碳排放,直播水稻是最为低碳的水稻种植方式,综合碳排放和经济效益,机插水稻优于手插、直播和抛秧水稻。