Table of Content

10 December 2023, Volume 42 Issue 12

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The responses of Moringa oleifera to combined Cd-Pb-Cu-Zn stresses and their enrichment characteristics in the dry-hot valley of Yunnan. 

DUAN Xiaoqing, ZHAO Guang, ZHANG Yangjian, MU Yu, YANG Wangxin, JIN Jie, HAN Xueqin, LIAO Chengfei

2023, 42(12):  2817-2827.  doi:10.13292/j.1000-4890.202312.019

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Heavy metal pollution caused by the unreasonable exploitation of mineral resources becomes serious in China. Phytoremediation is an effective way to dispose heavy metal pollution. This study aimed to screen a remediation plant that can suffer from heavy metal stress from tailings. Moringa oleifera is a widely introduced species in the dry-heat valley of Yunnan. We conducted a pot experiment with different levels of combined Cd-Pb-Zn-Cu stresses to explore the responses of leaf photosynthesis, growth characteristics, and biomass allocation and thus to reveal the adaptation mechanism and the enrichment characteristics of M. oleifera to combined heavy metal stresses. The results showed that combined heavy metal stresses significantly affected leaf blade photosynthetic capacity, plant growth, and biomass distribution of M. oleifera. Low heavy metal stress enhanced photosynthetic capacity, while high concentration inhibited it. The growth parameters such as plant height, ground diameter, root length, and root diameter of M. oleifera were all negatively affected, with such inhibitory effects being gradually strengthened with increasing stress. M. oleifera  allocated more biomass into belowground as the stress increased. During the remediation process, M. oleifera allocated more heavy metals to belowground biomass. In addition, among the four different heavy metals, M. oleifera showed better tolerance to Cu²⁺ and Zn²⁺, and had high enrichment in Cd²⁺ and Zn²⁺. In conclusion, M. oleifera has good tolerance to mild stress of heavy metals, and could be used as a remediation plant species in areas with mild pollution of combined heavy metals.





The resorption and accumulation of abiotic heavy metal elements in leaves from four types of forests in mid-subtropical China.

PENG Qingqing, ZHANG Yaoyi, ZHANG Huiling, PENG Yan, NI Xiangyin, WU Fuzhong

2023, 42(12):  2828-2835.  doi:10.13292/j.1000-4890.202312.005

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The accumulation of abiotic heavy metal elements may adversely affect plant growth. However, whether forest leaves resorb these heavy metals during senescence is not fully understood. We analyzed the changes of chromium (Cr), cadmium (Cd), and plumbum (Pb) contents in mature and senescent leaves during the growing season (from April to October) to elucidate resorption or accumulation efficiency of heavy metals in four types of mid-subtropical forests. The results showed obvious leaf resorption of Cr, Cd and Pb in four types of forests, although the resorption efficiency significantly varied across forest types, elements, and sampling months. The Castanopsis carlesii natural forest displayed Cr resorption in April and from July to October with the highest resorption rate of 67.8% in April, and Cd resorption in April and June, but Pb resorption only in October, while the elements showed accumulation in senescent leaves in other months. In contrast, the C. carlesii secondary forest displayed Cr resorption in April (the highest resorption rate of 62.5%), May, and October; it also showed Cd and Pb resorption in April and October, but the elements exhibited accumulation in senescent leaves in other months. Cr was accumulated in senescent leaves throughout the growing season in C. carlesii plantation, although Cd was resorbed in August and September, and Pb was resorbed in April, from July to August and October. Moreover, Cunning hamia lanceolata plantation showed Cr resorption in April and October, and Pb resorption in October, but Cd was accumulated in senescent leaves throughout the growing season. The resorptions of Cr and Cd were significantly higher in natural and secondary forests than those in plantations, while Pb showed an opposite pattern. In addition, the dynamics of Cr and Pb in mature and senescent leaves were significantly positively correlated with precipitation and negatively with temperature in four types of forests, whereas the changes of Cd were negatively correlated with the Cr and Pb. These results indicated that the natural and secondary forests are more efficient in avoiding Pb toxicity than plantations, which provides a new insight for forest establishment and sustainable management.





Effects of foliar application of water-soluble chitosan and silicon fertilizers on cadmium uptake of two winter rapeseed cultivars.

JIAO Yuzi, XIA Cunyan, HE Mengke, HU Jian, ZHENG Guodi, YANG Junxing, GUO Junmei, MENG Xiaofei

2023, 42(12):  2835-2843.  doi:10.13292/j.1000-4890.202312.016

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To explore the effects of silicon fertilizer (Si) and water-soluble chitosan (WSC) on the cadmium (Cd) content of rapeseed, a field experiment was set up in a cropland with a slight-moderate level of Cd pollution, around a typical operating smelter in Jiyuan City, Henan Province. We examined the effects of Si and WSC foliar fertilizations on biomass, Cd content, and bioconcentration coefficient of two large-scale planting cultivars of winter rapeseed (Brassica napus), Qinyou No. 1 (QY₁) and Sanyuehuang (SYH). The results showed that, compared with the control, spraying Si or WSC could reduce the Cd uptake by the grains and husks of the two tested rapeseeds. After foliar spraying of Si and WSC, the Cd content in QY₁ grains decreased by 8.80%-44.01% and 15.01%-37.77%, respectively; the Cd content in SYH grains decreased by 20.94%-32.42% and 14.33%-28.65%, respectively. The Cd contents of grains and husks of rapeseed reached the lowest level after spraying Si twice, and second lowest was the treatment with spraying WSC once. Compared with SYH, QY₁ had a higher biomass and lower Cd enrichment capacity after foliar fertilizations. Therefore, QY₁ is more suitable for the safe production in slightly to moderately Cd-contaminated soil. In conclusion, the low-Cd-accumulating rapeseed cultivar combined with agronomic measures of spraying foliar fertilizer can preliminarily realize the safe utilization of slightly or moderately Cd-contaminated soils surrounding the smelter.





The content, speciation, spatial distribution, and risk assessment of arsenic in the surface sediments of Bohai Sea.

LIU Sijia, SHI Mingyi, MA Xu, WANG Shaofeng, WU Xing, WANG Xin, ZENG Xiangfeng, JIA Yongfeng

2023, 42(12):  2844-2852.  doi:10.13292/j.1000-4890.202312.003

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In this study, we measured the content, speciation, and distribution of arsenic in the surface sediments with samples collected from 37 sites in Bohai Sea, China. The ecological risks associated with the sedimentary arsenic were evaluated, and the impacts of aquatic and sedimentary physicochemical parameters on the distribution of arsenic in sediments were explored. The results showed that the total arsenic concentrations in the surface sediments of the Bohai Sea ranged from 9.77 to 20.60 mg·kg^-1, with an average concentration of 13.33 mg·kg^-1. There were significant differences in total arsenic content of the sediments among different sea areas. Generally, the concentration of total arsenic in the surface sediments decreased from the nearshore areas to the middle of the Bohai Sea. Total arsenic burdens in the western areas of the Bohai Sea were usually higher than that from the eastern areas. The highest total arsenic concentrations in the sediments were recorded in Bohai Bay and Laizhou Bay. The results of sequential extractions showed that volatile sulfides, carbonates or amorphous iron and manganese oxides associated arsenic were the main forms of the arsenic in the surface sediments. The arsenic in the sediments of the Bohai Sea had low to moderate ecological risks. Total arsenic content in the surface sediments was significantly correlated with temperature, P concentration, pH, dissolved oxygen content of the overlying seawater, and iron content and organic matter content in the sediments.





Assessment of the ecological risk of heavy metal pollution in groundwater of typical lead-zinc mine and influenced area in Inner Mongolia.

ZHANG Zixiang, MA Long, LIU Tingxi, SUN Guohua, LI Yao, BAO Yufeng

2023, 42(12):  2853-2863.  doi:10.13292/j.1000-4890.202312.002

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Heavy metals have the characteristics of high toxicity, easy accumulation, and refractory degradation, which pose a potential threat to the ecological environment. The established ecological environment risk assessment index system of heavy metals in groundwater considers relatively limited external factors, and the rationality of the assessment results needs to be improved. In this study, based on the contents and spatial distributions of eight heavy metals in groundwater in typical lead-zinc mines and surrounding areas in Inner Mongolia, single factor and fuzzy mathematics were used to evaluate the environmental quality of heavy metals. The results showed that the Ni content in groundwater generally exceeded the standard, while Pb, Mn, Zn, As, Se and Cd exceeded the standard to varying degrees, and Cu did not exceed the standard. Spatially, the groundwater was generally at grades IV-V, and locally at grades I-II. The distribution of heavy metals was affected by human activities, as well as by natural factors such as soil minerals and hydrodynamic characteristics. The results of the potential ecological risk assessment showed that the single potential ecological risk index for As, Se, and Cd was between mild and strong levels, while fluctuated greatly for Cd, moderate for Mn, and mild for the rest. The comprehensive potential ecological risk of multiple elements was moderate or severe, with slight risk locally. The ecological environment risk assessment of heavy metal pollution in groundwater was carried out by the analytic hierarchy process, and the results showed that the ecoenvironmental risks in the study area was between low and high levels, decreasing spatially from northwest to southeast, and the areas with medium or high risk levels accounting for 31.3% of the study area, which was located near the mining activity area and tailings. Our results were reasonable and comprehensive, reflecting the actual eco-environment risk. The evaluation results can provide reference for local environmental pollution control, while the evaluation index system can provide support for ecological environment assessment in similar areas.





Remediation effect of MICP cementation on heavy metal contaminated tailings soil in an arid area.

CHANG Daoqin, SONG Naiping, YUE Jianmin, MENG Chen

2023, 42(12):  2864-2873.  doi:10.13292/j.1000-4890.202312.017

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The objective of this study was to clarify the optimal cementing rounds of microbially induced carbonate precipitation (MICP) technique in the remediation of heavy metal contaminated soil in northwest China. As with strong evaporation and high wind erosion in northwest China, we selected a copper and silver mine in Zhongwei City of Ningxia Hui Autonomous Region as the research area to examine the effects of bacterial dose and spraying frequency of Lysinibacillus fusiformis on inducing calcium carbonate precipitation. We used the cementing solution made by spindle-type L. fusiformis solution (OD₆₀₀=2.02), urea, and calcium chloride (cemented 1 to 6 times, respectively, denoted as T1 to T6, 140 mL for each time), to explore the effects of different cementation rounds on heavy metal content, occurrence valence, and physicochemical properties of the tailings soil in the study area. The crystal types of calcium carbonate in the tailings soil under different cementation rounds were analyzed by XRD. The results showed that there were no significant differences in Cr, As, and Hg contents in the T4-T6 tailings soil (P>0.05). At T6, the conductivity, ammonium ions, and precipitation of calcium carbonate were the largest (6271.67 μS·cm^-1, 15.45%, and 0.09 μg·g^-1, respectively), and pH was the lowest. At T4, Cu was negatively correlated with reducible Cr, As, and oxidizable Hg (P<0.01), while Cr was positively correlated with reducible Cu and weak acid-extractable Hg (P<0.05). The pH of the tailings soil and the total amount of heavy metals affected the occurrence forms of heavy metals. In summary, our results indicated that the MICP technique with four cementation rounds performed better, providing a theoretical basis for effectively repairing soil pollution by MICP technique in arid areas.





Research progress on bioremediation of polycyclic aromatic hydrocarbons and heavy metals co-contaminated soil.

LI Jingming, TONG Menghan, GUO Shuhai, LI Fengmei

2023, 42(12):  2874-2884.  doi:10.13292/j.1000-4890.202312.010

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Polycyclic aromatic hydrocarbons (PAHs) and heavy metals are representatives of soil organic and inorganic pollutants. They can easily cause combined contamination of soil because of the wide spread pollution sources and long-term existence in the soil. Complex interactions occur when PAHs and heavy metals coexist, which makes soil remediation more difficult than single contamination. Bioremediation has the advantages of low cost, no secondary pollution, which is suitable for remediation of large-area contaminated soil. It is a promising technology for the remediation of soil co-contaminated by PAHs and heavy metals. This paper describes the distribution characteristics of combined pollution and interaction of PAHs and heavy metals in soil, summarizes the mechanism and research progress of bioremediation technology for soil co-contaminated by PAHs and heavy metals, and puts forward the prospect for the development of bioremediation technology.





Nonadditive effects of mixed decomposition of coniferous and broad-leaved species litter on the release of phenolics.

ZHANG Xiaoxi, LIU Kaixuan, CHE Wenrong, HU Jiawei, LI Jiangwen, TIAN Shuang

2023, 42(12):  2885-2894.  doi:10.13292/j.1000-4890.202312.013

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Litter-derived phenolics are one of the main media affecting the surrounding environment of trees. The effects of mixed decomposition induced non-additive effects on litter phenolics release remain unclear. To investigate how coniferous and broad-leaved species litter affects the release of phenolics from each other during the mixed decomposition, we created nine combinations of 1∶1 (w/w) coniferous and broad-leaved mixed litters, with coniferous species litters of Picea asperata (Pa), Larix principis-upprechtii (Lp), and Pinus armandii (Par), and broad-leaved species litters of Acer tsinglingens (At), Betula albosinensis (Ba), and Catalpa fargesii (Cf) from Qinling Mountains. Litter mixtures with litterbag were incubated under dark indoor condition at 20-25 ℃ and constant humidity for six months. The results showed that: (1) Pa+At combination and Lp+At combination firstly had antagonistic overall effect on water-soluble phenols release of litter mixture, and turned to synergistic effect at the late stage (P<0.05). Specifically, the mutual effects between coniferous and broad-leaved litter on water-soluble phenols release also exhibited a similar pattern to their combinations. The other seven litter combinations had antagonistic overall effect on water-soluble phenols release of litter mixture (P<0.05). For the mixtures of Pa+Ba, Pa+Cf, Lp+Cf, and Lp+Ba, the water-soluble phenols release of coniferous litter was firstly inhibited and then accelerated (P<0.05) or unchanged in the late stage. The release was significantly inhibited in the mixtures of Par+Ba, Par+Cf, and Par+At (P<0.05). Generally, the water-soluble phenols release of broad-leaved litters was significantly inhibited in the aforementioned seven mixtures (P<0.05). (2) All combinations had overall antagonistic effects on condensed tannins release of litter mixtures (P<0.05). In litter mixtures of Lp+At and Lp+Ba, the condensed tannins release of coniferous litter tended to be accelerated, while an opposite pattern was observed for the broad-leaved litters (P<0.05). In other mixtures, coniferous and broad-leaved litters tended to significantly inhibit condensed tannins release of each other (P<0.05).





Effect of dry-wet cycles on quantity and characteristic of common tree litter-derived dissolved organic carbon in subtropical plantations.

YANG Na, WANG Simin, YU Lelin, MAO Rong

2023, 42(12):  2895-2902.  doi:10.13292/j.1000-4890.202312.023

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In subtropical plantations, plant litters often experience repeated dry-wet cycles. To explore the influence of dry-wet cycles on litter-derived dissolved organic carbon (DOC), we conducted a 40-day laboratory incubation experiment with leaf litters from six deciduous broad-leaved tree species, four evergreen broad-leaved tree species, and two evergreen coniferous tree species from typical subtropical plantations of China. There were three treatments: dry (maintaining mass ratio of litter∶water below 20∶1), wet (maintaining mass ratio of litter∶water at 1∶1), and dry-wet (drying for four days and rewetting for four days, with a total of five cycles). To assess the effects of dry-wet cycles on DOC quantity and characteristics, we investigated the variations of leaf litter-derived DOC amount and spectral characteristics (specific ultraviolet absorbance at 254, 284, and 350 nm), and litter mass loss. The results showed that litter mass loss was greater in the wet and dry-wet treatments than in the dry treatment, and that leaf litter mass loss under dry-wet treatment was comparable to that under wet treatment. For both deciduous and evergreen broad-leaved species, litter-derived total DOC production in the dry-wet treatment was higher than that in the dry treatment, but was lower than that in the wet treatment. However, litter of evergreen coniferous trees had lower total DOC production in the dry-wet treatment than in the dry and wet treatments. Litter-derived DOC had higher specific ultraviolet absorbance at 254, 284, and 350 nm in the wet and dry-wet treatments than in the dry treatment, indicating a greater aromatic degree of DOC. These findings suggest that repeated dry-wet cycles are an important factor controlling the quantity and quality of litter-derived DOC in subtropical plantations.





Composition and distribution characteristics of vascular plants in Beijing.

HU Lile, MA Junli, ZHAO Jinman, LIU Changfeng, ZHAO Jingwen, YAN Boqian

2023, 42(12):  2903-2910. 

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Understanding the composition and distribution of wild vascular plants in Beijing is the basic work for regional biodiversity protection. Based on the survey data of “Arctic Flower Biological Survey App”, combined with literature, flora and other related data, we statistically analyzed species composition and distribution of vascular plants in Beijing. There were 2714 vascular plant species in Beijing, belonging to 1024 genera and 178 families, including 80 species from 18 genera and 8 families of Lycopodium and Pteridophytes, 52 species from 18 genera and 8 families of gymnosperms, and 2582 species from 976 genera and 153 families of angiosperms. The top four families were Asteraceae (299 species), Poaceae (214 species), Leguminosae (133 species), and Rosaceae (132 species). The top four genera were Carex (45 species), Artemisia (29 species), Allium (24 species), and Cyperus (21 species). The three regions with the largest species number were Haidian (1585 species), Yanqing (1526 species), and Mentougou (1311 species). The three regions with the least species number were Chaoyang (220 species), Tongzhou (209 species), and Shijingshan (181 species). In total, 134 species of national and municipal key protected plants were recorded in Beijing, belonging to 59 families and 103 genera. Among them, national and municipal protected plants were 44 and 102 species, respectively. There were 4 families containing more than 4 species, including Orchidaceae (35 species), 5 Liliaceae (5 species), Pinaceae (5 species), and Rutaceae (5 species). In total, 2 genera involve more than 4 species, which consists of 6 species of Cymbidium and 5 species of Neottia. Three regions had more than 60% of the total species of key protected plants, with 90 species in Mentougou, 86 species in Yanqing, and 80 species in Miyun. In conclusion, vascular plant species were abundant in Beijing area. The dominant families were Compositae, Gramineae, Leguminosae, and Rosaceae, and the dominant genera were Carex, Artemisia, Allium, and Cyperus. The most vascular plant species were found in Haidian, Yanqing, Mentougou, and Miyun, while the most protected plant species were found in Mentougou.





Population age structure and quantitative dynamics of Clematis acerifolia, a rare and endangered species endemic to Taihang Mountains.

HUANG Chunxiao, LIU Quanru, DU Yuxuan, HU Yu, HE Yi

2023, 42(12):  2911-2917.  doi:10.13292/j.1000-4890.202312.020

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Clematis acerifolia is an endangered national key protected wild plant species in China (Class II), which is distributed only on the limestone cliffs in northern Taihang Mountains. Based on field investigation, the shoot age data of 458 individuals were obtained from 11 sites. Ages of the individuals were estimated based on the number of bud scale scars on the longest shoot. Accordingly, the age structure and dynamics of the populations were quantitatively analyzed. The results showed that: (1) The population age structure was a typical pyramid pattern, with few young individuals at age class 1; (2) The population declined between age class 1-2 and 6-7, but had the ability to renew and maintain; (3) The population survival curve was N_x=259e^-0.4x, which was close to Deevey Ⅱ. The first peak of mortality rate (q_x) and disappearance rate (K_x) curve emerged at the age class 5. After that q_x remained stable and K_x rose rapidly; (4) The greatest increase or decrease of survival rate and cumulative mortality rate happened to the first six age classes, and such changes tended to be gentle after age class 7. The first peak of risk function λ_(ti) curve appeared in the age class 6. The death density f_(ti) was generally low, with the maximum value at the age class 3; (5) The prediction analysis of time sequence model suggested an increase in the number of middle-aged and old-aged individuals after the time of age class 2, 5, and 8. The population showed a high elimination rate in young age class, stable in middle age class, and depressed in old age class. The age structure was relatively stable at present, but with early signs of depression that lack of young age class individuals was the main cause limiting the population growth of Clematis acerifolia.





Resource status and population characteristics of the relict mangrove species Nypa fruticans Wurmb. in China.

ZHANG Mengwen, ZHONG Cairong, LYU Xiaobo, FANG Zanshan, CHENG Cheng

2023, 42(12):  2918-2925.  doi:10.13292/j.1000-4890.202312.018

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Nypa fruticans Wurmb. is a true mangrove species in family Arecaceae. As a key protected species in China, it is only distributed in Hainan Island. N. fruticans is a relict species with important scientific value in tropical flora, paleontology, marine geoarchaeology, and paleobotany. To understand the endangered status and protection strategy of N. fruticans, we investigated resource status, community characteristics, population structure, and distribution pattern of N. fruticans. The results showed that: (1) There were six natural populations of N. fruticans, with 9319 individuals covering a total area of 3.96 hm², which distributed in Wild Pineapple Island and Daoxue Village in Dongzhai Port of Haikou, Yuyang Park and Touyuan Village in Wenchang City, Wenchang Village in Qionghai, and Riyue Bay in Wanning. (2) There were 28 mangrove species in the community, and the dominant species were N. fruticans+Bruguiera sexangula+Parmentiera cerifera, and N. fruticans+B. sexangula. (3) The populations in Haikou, Qionghai, and Wanning were declining, while that in Wenchang was increasing. All populations exhibited clumped distributions. (4) Extreme climate change, excessive deforestation and exploitation, and limited reproduction of individuals were the three main reasons leading to the endangered N. fruticans populations. We call for scientific research and technology input to solve the problem of provenance, strengthen habitat restoration and in situ conservation, and optimize ex situ conservation and field return strategies to expand the population.





Community characteristics of Carpinus turczaninowii and the soil environmental interpretation on Dalu Island in the northern Yellow Sea.

LI Hongfei, ZHANG Hua, FU Jie, WANG Junfu, YU Limin

2023, 42(12):  2926-2935.  doi:10.13292/j.1000-4890.202312.021

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To explore the community characteristics of Carpinus turczaninowii and their relationships with soil environmental factors on Dalu Island in the northern Yellow Sea, we carried out plot survey with nine C. turczaninowii communities on Dalu Island. We analyzed community characteristics by flora composition, species importance value, species diversity, and diameter structure, and determined the soil influencing factors by using twoway indicator species analysis (TWINSPAN) and redundancy analysis (RDA). The results showed that: (1) A total of 110 vascular plant species belonging to 46 families and 84 genera were recorded in the C. turczaninowii communities, including 107 species in 82 genera of 44 families of seed plants and 3 species in 2 families of 2 genera of ferns. Most of the seed flora composition had temperate distribution properties. The dominant species in the tree, shrub, and herb layers were C. turczaninowii, Zanthoxylum schinifolium, and Carex callitrichos var. nana, with importance values of 52.84%, 34.49%, and 21.54%, respectively. Species composition of tree layer was relatively poor, while species of shrub and herb layers were more abundant. The community did not reach the climax stage of succession. The diameter size structure of C. turczaninowii populations reflected that the community was composed of growing population. (2) The cluster analysis classified the C. turczaninowii  communities into four types of clusters. The ordination analysis results verified the rationality of the aforementioned cluster analysis results, and showed that soil thickness, soil total phosphorus content, and pH were the main factors affecting species distribution in C. turczaninowii communities.





Effects of environmental factors on root vessel anatomical traits of Astragalus herbs.

DONG Yanjun, LI Zongshan, CHEN Ying, GAO Guangyao, WANG Cong, WANG Xiaochun

2023, 42(12):  2936-2943.  doi:10.13292/j.1000-4890.202312.012

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Hydraulic anatomical structure plays an important role in the adaptation of plants in arid and semiarid areas. In this study, we used paraffin section method to obtain the anatomical traits of root vessels of four Astragalus herb species (Astragalus adsurgens, Astragalus membranaceus, Astragalus galactites, and Astragalus melilotoides) in arid and semiarid regions of China. Pearson correlation was used to analyze the responses of vessel anatomical features to environmental factors (temperature and precipitation). The results showed that there was great variability in the vessel anatomical traits (vessel number, vessel fraction, mean vessel area, mean hydraulic conductivity, and hydraulic diameter) of Astragalus herbs. With the increases of precipitation and temperature, the vessel number of Astragalus herbs significantly decreased, while the traits related to hydraulic conductivity (hydraulic diameter, mean vessel area and mean hydraulic conductivity) significantly increased, which suggested that Astragalus  herbs from areas with low precipitation and temperature have higher hydraulic safety (more and smaller vessel), while those from areas with high precipitation and temperature have higher hydraulic efficiency (fewer and larger vessel). The correlation coefficients between root anatomical traits and temperature were higher than those with precipitation, which suggested that temperature may be the main climatic factor limiting the anatomical structures of Astragalus herbs in arid and semiarid areas of China.





Effects of clover living mulches on weed, predatory arthropod, and crop yield in maize and soybean production.

LYU Long, ZHANG Dengkui, WANG Qi, ZHANG Xiaojuan, ZHAO Wucheng, WANG Xiaoyun, Erastus MakMensah, CUI Xunzhen, ZHOU Xujiao, ZHAO Xiaole

2023, 42(12):  2944-2952.  doi:10.13292/j.1000-4890.202312.008

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To find the suitable planting mode of clover living mulches in semiarid regions in China, a field experiment was conducted in a completely random design. We explored the effects of clover living mulches on soil moisture, weed density and biomass, predatory arthropod density, and fodder and crop yield with no mulches as a control in maize and soybean production systems. Compared to no mulches in maize production, soil water storage, weed density and biomass under clover living mulches decreased by 6.6%-10.0%, 2.6%-65.6%, and 26.8%-89.2%, respectively, while the predatory arthropod density, maize fodder yield, and crop yield under clover living mulches increased by 22.2%-100.0%, 11.1%, and 5.7%, respectively. Compared to no mulches in soybean production, soil water storage, weed density and biomass, and soybean grain yield under clover living mulches decreased by 6.9%-21.9%, 36.2%-65.2%, 29.9%-62.4%, and 0.8%, respectively, while the predatory arthropod density and soybean fodder yield under clover living mulches increased by 25.0%-250.0%, and 259.0%, respectively. Clover living mulches significantly reduced soil water storage, weed density and biomass, and increased predatory arthropod density in maize and soybean production systems. However, clover living mulches did not affect fodder yield and grain yield of maize and soybean. The competition between clover and soybean was higher than that between clover and maize under clover living mulches. Therefore, clover living mulches were beneficial to maintaining cropland ecosystem diversity and crop yield in maize and soybean production. The clover living mulches in maize production can be used as an effective cultivation technology for sustainable agricultural production in semiarid regions in China.





Alleviating effect of exogenous melatonin on soybean seedlings under soda saline-alkali stress.

ZHONG Xingjie, ZHANG Mingcong, HAN Aiping, QIN Bin, DING Zhepeng, ZHANG Yuxian

2023, 42(12):  2953-2960.  doi:10.13292/j.1000-4890.202312.015

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Spraying melatonin is one of the effective ways to alleviate the damage of soybean under stress. Clarifying the regulation effect of spraying melatonin on the growth of soybean seedlings under soda saline-alkali stress can provide theoretical basis and technical support for alleviating soda saline-alkali stress of soybean seedlings. Using a sand culture experiment method, we set up four treatments, including conventional treatment + spraying water (CK), conventional + spraying melatonin treatment (CKM), soda saline-alkali stress treatment + spraying water (S), soda saline-alkali stress + spraying melatonin treatment (SM). The response of different physiological indices in seedling stage of soybean cultivar Henong 71 to soda saline-alkali stress was investigated. The results showed that compared with conventional treatments (CK and CKM), the growth of soybean seedlings under soda saline-alkali stress (S and SM) was inhibited. Compared with S treatment, SM treatment significantly increased the initial fluorescence (F₀) and maximum fluorescence yield (F_m) of PSII reaction center, increased the non-photochemical quenching coefficient (NPQ), enhanced the excess light energy dissipation of crop photosynthetic mechanism, improved the photoprotection ability of PSII reaction center, and significantly increased net photosynthetic rate (P_n). The activity of antioxidant enzymes (SOD, POD, and APX) and scavenging ability of ROS in leaves, and the contents of sugars and soluble proteins in roots and stems were significantly increased. The MDA production rate in leaves and roots was significantly decreased. Root dry matter accumulation, total surface area, total volume and average root diameter were significantly increased. The intracellular hormone levels in leaves were maintained, and the contents of IAA, CTK, ETH and MT in leaves were increased by 15.9%, 31.9%, 8.7%, and 55% (P<0.05), respectively. In conclusion, spraying melatonin can alleviate the adverse effects of salinealkali stress on the physiological indices of soybean seedlings and improve their saline-alkali tolerance.





Soil microbial communities of methanogens and methanotrophs in the rice-fish coculture ecosystem.

2023, 42(12):  2961-2971.  doi:10.13292/j.1000-4890.202312.001

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The effects of rice-fish coculture on soil methane (CH₄) emission have been well documented, but it remains unclear whether rice-fish coculture affects methanogens and methanotrophs. To examine the effects of rice-fish coculture on soil methanogens and methanotrophs, we conducted a field experiment in the site of the Globally Important Agricultural Heritage Systems (GIAHS)―Qingtian rice-fish system. There were three treatments, including rice monoculture (RM), rice-fish coculture without feed (RFN), and rice-fish coculture with feed (RFF). The yields of rice and fish, the contents of soil organic carbon (SOC), soil total nitrogen (TN) and soil total phosphorus (TP), and the communities of methanogens and methanotrophs were examined. The results showed that rice yield and the increments of SOC and TN in the treatment RFF were significantly higher than those in treatments RM and RFN. Quantitative PCR (qPCR) analysis showed that the abundances of methanogen and methanotroph in both RFN and RFF were significantly higher than those in RM, while RFF had significantly higher methanotroph abundance than RFN. The Illumina Miseq analyses showed that both RFN and RFF affected the community structure of methanogen, but did not affect the methanotroph. For the different metabolic types of methanogens, RFN and RFF had higher abundance of Hydrogenotrophic than RM, and RFF had higher abundance of Aceticlastic than RFN. For the different metabolic types of methanotrophs, both RFN and RFF did not affect the abundance of Type I compared to RM, but the abundance of Type Ⅱ in RFF was significantly higher than those in RM and RFN. Our results suggest that rice-fish coculture affects the community composition of methanogen and methanotroph, which may be mediated by fish feed input.





Inorganic phosphorus fractions and the influencing factors in saline-alkali soils under different land use types.

JIA Xueying, WANG Peijiang, TIAN Zhijie, YIN Haixing, JIA Wenru

2023, 42(12):  2972-2978.  doi:10.13292/j.1000-4890.202312.027

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We explored the characteristics of inorganic phosphorus fractions and influencing factors in saline-alkali soils in North China, by analyzing soil samples from eight land use types, including pepper field, mildly saline-alkali corn field, heavily saline-alkali corn field, sunflower field, Leymus chinensis grassland, Chloris virgata grassland, Suaeda glauca grassland, and bare land. The results showed that the proportion of Ca_10-P in soil inorganic phosphorus fractions of saline-alkali soil was the highest, and the proportions of other phosphorus fractions were following an order of Ca_8-P>Al-P>O-P>Fe-P>Ca_2-P. The results of redundancy analysis and correlation analysis showed that Ca_2-P and Ca_8-P were significantly negatively correlated with soil pH, electrical conductivity, and sodium adsorption ratio (P<0.05), but significantly positively correlated with available phosphorus, available nitrogen, and available potassium (P<0.05). Soil physicochemical factors explained 36.03% of the variations of inorganic phosphorus fractions. Ca_2-P and Ca_8-P of saline-alkali soil were the key fractions of soil phosphorus, and mainly affected by soil pH, electrical conductivity, and sodium adsorption ratio. According to the differences of phosphorus fractions and physicochemical properties of the eight land use types, pepper and sunflower can be used as the preferred crops for the improvement and utilization of mildly and severely saline-alkali land, respectively. L. chinensis can be used as a grassland species for ecological restoration of saline-alkali land. In addition, soil phosphorus availability in saline-alkali lands can be enhanced by improving soil physicochemical properties such as pH, electrical conductivity, sodium adsorption ratio, and organic matter.





Spatial distribution of selenium in cultivated soil and its influencing factors in Hunan Province.

SHANG Guiduo, ZHOU Weijun, ZHENG Chao, LIU Rui, XU Zhangqian, CUI Haojie, ZHOU Yuzhou, LI Min

2023, 42(12):  2979-2986.  doi:10.13292/j.1000-4890.202312.014

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To rationally utilize selenium-rich soil resources and develop seleniumrich agricultural products, we investigated the spatial distribution characteristics of selenium content and its influencing factors in cultivated soil in Hunan Province. The results showed that the average content of selenium was 0.56 mg·kg^-1, which was 1.93 times the national background value (0.29 mg·kg^-1). The average content of soil selenium in southwest Hunan was the highest and that in northern Hunan was the lowest. The coefficient of variation of selenium content in southwest Hunan was the largest, with high dispersion and uneven distribution. On the contrary, the coefficient of variation of selenium content in southern Hunan was the smallest, with low dispersion and relatively uniform distribution. The area of selenium-rich cultivated land in Hunan was 2.2496 million hm², accounting for 60.7% of the cultivated land area. The area of selenium-rich paddy field was 1.8563 million hm², accounting for 50.1% of the cultivated land area of the province. The area of selenium-enriched dryland was 0.3933 million hm², accounting for 10.6% of the cultivated land area. The sequence of soil selenium content developed from soil-forming parent material was as follows: weathering materials of shale plate > weathering materials of limestone > Q4 red clay > weathering materials of sandstone > weathering materials of granite > alluvial sediments > weathering materials of purple sandstone. The order of selenium content in different types of soil was yellow-brown soil > yellow soil > red soil > limestone soil > paddy soil > alluvial soil> purple soil. When pH <5.0, there was a negative correlation between soil selenium content and pH. When 5.0 < pH < 7.8, there was a positive correlation between soil selenium content and pH. When pH >7.8, there was a negative correlation between soil selenium content and pH. Organic matter was one of the important factors affecting soil selenium content, with a positive correlation between soil selenium content and organic matter content. Soil selenium content was positively correlated with zinc, copper, and manganese contents, and cation exchange capacity (P<0.01). When the altitude was lower than 230 m, soil selenium content increased with increasing altitude. When the altitude was higher than 230 m, soil selenium content decreased with increasing altitude. The area of selenium-rich soil in cultivated land in Hunan Province was large and had noticeable spatial differences. It is necessary to rationally protect and develop the selenium-rich soil resources according to regional differences.





Deposition levels and dynamics of atmospheric nitrogen at Mt. Dongling of Beijing, China.

LIU Meina, CHEN Zhili, SONG Wei, LIU Xueyan

2023, 42(12):  2987-2997.  doi:10.13292/j.1000-4890.202312.004

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Anthropogenic reactive nitrogen emissions in cities affect air quality and lead to acontinuous increase of atmospheric nitrogen input to surrounding terrestrial ecosystems. However, simultaneous observations of atmospheric reactive nitrogen in terrestrial ecosystems, especially dissolved inorganic nitrogen (DIN) and dissolved organic nitrogen (DON), are still lacking, affecting the comprehensive and accurate assessment of the ecological effects of nitrogen deposition. In this study, we weekly observed the concentrations of bulk ammonium nitrogen (NH₄⁺-N), nitrate nitrogen (NO₃^--N) and total dissolved nitrogen (TDN) at Dongling Mountain Forest Ecosystem Orientation Research Station in Beijing from June 2019 to January 2020, calculated the DON concentration and the deposition flux of various forms of nitrogen, and analyzed their intermonthly, dry and wet seasonal differences and the underlying mechanisms. The results showed that the volume-weighted average concentrations of NH₄⁺-N, NO₃^--N, DON, and TDN in atmospheric deposition were 1.45±0.04, 0.70±0.01, 1.81±0.66, and 3.96±0.65 mg N·L^-1, respectively. The annual deposition flux of TDN was 25.00 kg N·hm^-2·a^-1. The annual deposition fluxes NH₄⁺-N, NO₃^--N, DON and their proportions in TDN were 8.76 (35%), 4.38 (18%), and 11.86 (47%), respectively, indicating a high degree of nitrogen pollution at this site. The average values of DIN/DON and NH₄⁺-N/NO₃^--N in atmospheric deposition were 1.1 and 2.0, respectively, indicating that DON was an important form of atmospheric nitrogen input, and NH₄⁺-N was dominant in DIN input. The concentration and percentage in TDN of NO₃^--N decreased with increasing precipitation, indicating that the removal efficiency of NO₃^--N was higher and there was a dilution effect, while the concentration and percentage of NH₄⁺-N and DON had no significant correlation with precipitation. The bulk deposition flux of each form of nitrogen increased with   increasing precipitation, so the average concentration and deposition flux of each form of nitrogen in the wet season (June-August) were generally higher than those in the dry season (September-January), indicating that more precipitation in the future would drive the increase of atmospheric nitrogen input into the forest floor, which is of great significance for plant growth. This study comprehensively reports the bulk deposition fluxes of NH₄⁺-N, NO₃^--N, DON, and TDN in a typical forest of Beijing-Tianjin-Hebei region, clarifies their forms and differences between wet and dry season, and reveals the effects of precipitation on atmospheric nitrogen deposition flux in areas with high nitrogen deposition level. Our results enrich the forest atmospheric nitrogen input data in typical high anthropogenic nitrogen emission areas in China, and provide useful information for evaluating the ecological and environmental effects of anthropogenic nitrogen pollution.





Effects of landscape pattern on water quality under different spatial characteristic scales.

LIN Jiayuan, ZHANG Fan, QIU Liping, LAI Riwen

2023, 42(12):  2998-3007. 

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Exploring the relationship between landscape pattern and water quality at the spatial characteristic scale is of great significance to revealing the impacts of landscape pattern on water pollution migration. In this study, water quality data were collected from 26 monitoring sections in the Minjiang River basin in Fujian Province, which was divided into three spatial scales as sub-watershed, riparian buffer zone, and circular buffer zone. Landscape pattern characteristics were analyzed based on Landsat-8 images. Each spatial characteristic scale was identified to examine the impacts of landscape pattern on water quality under the spatial characteristic scale by means of semivariogram and redundancy analysis. The results showed that: (1) water quality of Minjiang River basin generally met the Level Ⅱ standard. However, there were still polluted waters that exceeded the Level Ⅲ standard, which was mainly caused by aquaculture and livestock breeding. (2) The characteristic scale of riparian zone was in 1000 m buffer zone, while the one of circular zone was in 2000 m. (3) Landscape pattern at sub-watershed had the strongest overall interpretation of water quality, up to 58.4%, followed by riparian buffer zone (45.2%) and circular buffer zone (38.4%). (4) Forest cohesion and urban largest patch index were the main landscape pattern variables affecting water quality. The upstream catchment is the key area for future water resources management. Reducing the discharge of pollution, increasing the advantage and aggregation of forest, and breaking the continuity of extensive built-up areas, could help improve water quality.





Spatial variations of bird community composition and habitat quality evaluation of urban green space at different construction times in Wenyu River Park in Beijing. 

ZHAO Xueqin, WU Lan, WANG Yuyu, CAO Jingxuan, YANG Lijuan, LIU Yonghua, ZHANG Yuting

2023, 42(12):  3008-3018.  doi:10.13292/j.1000-4890.202310.016

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As an important part of urban green space, bird community composition of urban parks is closely related to habitat quality and can serve as a key indicator of urban environment. Beijing Wenyu River Park is the largest ecological space in Beijing City. The construction of the park started in 2019. To provide scientific supports for park management, we monitored the changes of bird diversity during the construction. From September 2020 to August 2021, monthly surveys were carried out at three sites, including Qinghe River Camp Park built in 2010, Chaoyang Demonstration Area of Wenyu River Park built in September 2020, and the planned area at confluence of the Wenyu River and Qinghe River, using transect line methods. On this basis, habitat quality assessment was carried out using remote sensing interpretation and the surveys of food-sourced plant species diversity. A total of 65 bird species from 13 orders and 29 families were recorded, including 4 national second-class protected species. The confluence of the Wenyu River and the Qinghe River recorded highest abundance, number and diversity of protected species of birds among three surveyed sites, with an averaged Shannon index of 2.20±0.30. The habitat quality was at an excellent level. Birds in Chaoyang Demonstration Area of Wenyu River Park had a relatively high number of protected and threatened bird species, with an averaged Shannon index of 1.89±0.28. The habitat quality was at a good level. The richness and abundance of birds in Qinghe River Camp Country Park was the lowest, with an averaged Shannon index of 1.49±0.27. Nevertheless, habitat quality was assessed as excellent. Our results indicated that the confluence of the Wenyu River and the Qinghe River was the most important site in maintaining the bird diversity of Wenyu River Park, which should be protected as a core area by reducing human construction. In the future, the management of Beijing Wenyu River Park should consider the habitat requirement of birds to maintain ecosystem services for supporting a greater urban biodiversity.





Effects of coexistence of dissolved organic matter and nano zinc oxide on performance and clogging of constructed wetlands.

LIU Yuhao, KONG Fanlong, LI Yue, WANG Kang, WANG Wenyue, WANG Xiaoyan, WANG Sen

2023, 42(12):  3019-3029.  doi:10.13292/j.1000-4890.202312.025

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The presence of dissolved organic matter (DOM) affects the stability of zinc oxide nanoparticles (ZnO NPs) in water. By constructing vertical subsurface constructed wetlands, taking humic acid (HA) as a representative substance of DOM, we examined the effects of coexistence of 1 mg·L^-1 ZnO NPs and different concentrations of HA (1, 5, 10, 20 and 30 mg·L^-1) on the treatment performance, clogging and microbial communities of constructed wetlands. The results showed that low HA concentration (≤1 mg·L^-1) could promote the agglomeration of ZnO NPs, while the mediumhigh concentrations (1-25 mg·L^-1) showed opposite effect. The coexistence of ZnO NPs and DOM would reduce the purification effect of constructed wetlands. At the concentration of 1 mg·L^-1  HA, the removal efficiencies of COD, ammonia nitrogen and total nitrogen decreased by 18.07%, 19.94%, and 26.37%, respectively. Under the condition of 1 mg·L^-1 DOM and 1 mg·L^-1 ZnO NPs, the constructed wetland was most seriously blocked, and the permeability coefficient decreased by 67.5% after 60 days. The coexistence of HA and ZnO NPs could affect the secretion of extracellular polymeric substance (EPS). The EPS concentration was as high as 140.30±0.29 mg·g^-1 at 1 mg·L^-1 ZnO NPs and 1 mg·L^-1 HA, while that in the blank group was only 78.67±0.32 mg·g^-1, explaining the clogging of constructed wetlands. In addition, the addition of ZnO NPs and HA reduced the richness and diversity of microbial community and promoted the growth of EPS-secreting bacteria (Thauera). The findings may provide a new explanation for the clogging mechanism of constructed wetlands.





Responses of forest soil methane uptake to global change.

HAN Shihui, LIU Lei, ZHOU Guoyi, LI Lin, FANG Xuechun

2023, 42(12):  3030-3037.  doi:10.13292/j.1000-4890.202312.011

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Forest soils are the main sink of atmospheric methane (CH₄) in the terrestrial ecosystems. Global changes, such as increasing atmospheric CO₂ concentration, warming, changing rainfall regime, and increasing nitrogen (N) deposition, affected soil CH₄ uptake by altering soil physicochemical properties, plant growth, and soil microorganisms. In this study, we conducted a meta-analysis of the impacts of global changes on CH₄ uptake in forest soils. Based on 195 sets of data collected from 155 papers, we found that the rate of CH₄ uptake by forests decreased significantly under elevated CO₂ and N deposition, but increased under drought. There were no significant differences in CH₄ uptake rates at the annual scale in tropical, temperate, and boreal forests. Global warming did not affect CH₄ uptake rates in forest soils. Moreover, the results of seasonal and drought experiments on forest soil CH₄ uptake demonstrated that soil moisture was negatively correlated with CH₄ uptake. The linear model of CH₄ uptake in soil water balance fitted in this study did not reflect the negative correlation between soil water surplus and soil CH₄ uptake. These results indicate that soil water balance model requires more empirical data when it is applied at the global scale. Our results shed light on future experiments related to the impacts of global change on CH₄ uptake in forest soils.





Effects of drought and rewatering on plants and soil microorganisms under climate change: review and perspectives.

CHEN Junfang, WU Xian, YANG Jiarong, LIU Xiaolin, LIU Yu

2023, 42(12):  3038-3049.  doi:10.13292/j.1000-4890.202312.009

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Terrestrial ecosystems provide a variety of ecological services essential to human welfare. Caused by global warming and the alteration in precipitation regime, the frequency and intensity of drought have been remarkably increased, with profound consequences on the structure and function of terrestrial ecosystems. Given the importance of plants and soil microorganisms in biogeochemical cycling and energy flow, an increasing number of studies have been conducted to investigate how drought affects plants and soil microorganisms. However, these studies mainly focused on the drought process, with little attention being paid to the effects of rewatering after drought on plants and soil microorganisms. It has been widely recognized that rewatering after drought not only generates a growth compensation effect on plants, but also facilitates the recovery of terrestrial ecosystems. Therefore, understanding the effects of rewatering on plants and soil microorganisms is important for mitigating drought effects and is becoming a focus of climate change study. In this paper, were reviewed the effects of drought and rewatering on plants and soil microorganisms from the perspectives of plant growth, physiological traits, and soil microorganisms. We identified problems that currently face the field and proposed future study directions. This review would provide a synthetic account for understanding responses of plants and soil microorganisms to drought and rewatering under climate change and for maintaining the structure and function of terrestrial ecosystems and protecting biodiversity.





Methods of “Three-dimensional and Holographic” observation for forest ecosystems centered on “Multi-Tower”.

ZHU Jiaojun, GAO Tian, ZHANG Jinxin, SUN Yirong, SUN Tao, LIU Zhihua, YU Lizhong, LU Deliang, YU Fengyuan, TENG Dexiong, YAN Qiaoling, YANG Kai, SONG Lining, ZHENG Xiao, WANG Xugao, WANG Qingwei, LIANG Yu, LI Huidong, LIU Lifang, XU Shuang, LIU Huaqi, HU Yanyang, LI Xiufen, WANG Zongguo, ZHOU Xinhua

2023, 42(12):  3050-3054.  doi:10.13292/j.1000-4890.202312.024

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The research on forest ecology should develop towards more macroscopic and more microscopic at spatiotemporal scales, which has challenged traditional approaches for ecological observation. With the development of information technology, shifts in the research paradigm are critically needed. Based on  Ker Towers as a Corner-Stone Research Infrastructure Project in Qingyuan Forest CERN, National Observation and Research Station, we propose a framework of “space-air-tower-ground” for integrated observation and research with the tower(s) as the center. The framework includes four components: active/passive satellite-based remote sensing (space), near-ground remote sensing platform by unmanned aerial vehicle with LiDAR and multi/hyperspectral sensors (air), tower group or single tower (tower), and long-term forest plot arrays (ground). Along with information technology such as the Internet of Things, cloud computation and artificial intelligence, data acquisition, transmission, computation, analyzation and display can be achieved to develop an information technology-based “three-dimensional and holographic” observation and research in forest ecology. This framework would promote knowledge innovation in forest ecology, ecosystem ecology, and forest science, and provide insights toward the paradigm shifts in geography, remote sensing science, boundary layer meteorology, and other disciplines.





The optimization of rural sewage treatment mode based on life cycle and multi-criteria decision-making.

CUI Tao, LI Yue, KONG Fanlong, WANG Sen, ZHAO Yan

2023, 42(12):  3055-3065.  doi:10.13292/j.1000-4890.202312.007

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To scientifically and reasonably select rural sewage process, a model coupling life cycle sustainability assessment (LCSA) and multi-criteria decision analysis (MCDA) was constructed. Constructed wetland (CW), sequence batch reactor activated sludge process (SBR), anaerobic-anoxic-oxic process (A₂O), membrane bioreactor (MBR), and bio-contact oxidation (BCO) were chosen as the research objects to make assessment and propose improvement suggestions under the effluent quality standard reaching the first grade A standard of “Urban Sewage Treatment Plant Pollutant Discharge Standard”. The results showed that five systems contributed most of the environmental impacts (over 85%) and economic costs (over 60%) during the operation phase. CW had the best environmental and economic sustainability, which occupied a larger area. MBR had the worst environmental and economic sustainability, with better social sustainability. A₂O required more energy during operation resulting in poor environmental and economic sustainability, while SBR and BCO had the relatively balanced sustainability in the above-mentioned three aspects. The results of MCDA for different stakeholders showed that the MBR, SBR and BCO exhibited their advantages under different preferences, in which the CW had the best sustainability (0.59-0.70). However, CW was no longer the optimal scheme when the subjective weight of occupied land area reached 65%. Based on the evaluation results, users could improve sustainability of wastewater treatment processes and reduce the negative impacts of environmental, economic and social dimensions by optimizing the consumption during operation and flexibly adjusting the discharge standard according to the drainage direction.





Isolation and nitrogen removal capability of a psychrotolerant bacterium, Pseudomonas sp. strain W4.

BAO Hongxu, HU Jiawei, REN Hongpeng, HAN Siqin, ZHANG Ying, WANG Yongxuan, SHI Rongjiu

2023, 42(12):  3066-3072.  doi:10.13292/j.1000-4890.202312.006

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A psychrotolerant bacterium strain W4 was isolated from active sludge and its nitrogen-removal capability at 5, 15, and 25 ℃ was evaluated. Results showed that W4 is affiliated to Pseudomonas, and could grow at 4 to 42 ℃, 0 to 30 g·L^-1 NaCl, and pH 6 to 9. At 5 ℃, strain W4 removed 74.3% of NH₄⁺-N (initial concentration of 76.0 mg·L^-1) within 72 h, corresponding to an average nitrogen-removal rate of 0.78 mg·L^-1·h^-1. Under aerobic conditions, up to 42.4% of nitrate (86.3 mg·L^-1) or 38.2% of nitrite (82.2 mg·L^-1) could be removed by strain W4. At 15 and 25 ℃, the nitrogen-removal efficiency was further improved, as evidenced by that more than 95% of ammonium, 66% of nitrate, and 69% of nitrite were removed. Strain W4 showed the activity of heterotrophic nitrification and aerobic denitrification (HA-ND). No nitrite accumulation was observed during nitrification process. The HA-ND capability by strain W4 justifies the potential in the treatment of inorganic nitrogen pollution under meso to psychrophilic conditions. Our findings help enrich psychrotolerant nitrogen-removing microbial resources, and contribute to the nitrogen pollution treatments through HA-ND process.