Table of Content

10 September 2023, Volume 42 Issue 9

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Effects of rotary tillage and straw incorporation on microbial community of brown soil.

SUI Pengxiang, LIAN Hongli, WANG Zhengyu, JIANG Ying, QI Hua, LUO Yang, ZHENG Jinyu

2023, 42(9):  2049-2060.  doi:10.13292/j.1000-4890.202309.034

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We examined the effects of rotary tillage and straw incorporation approaches on microbial community characteristics of brown soil with a 5-year field experiment in Tieling, Liaoning Province. There were four treatments: (1) whole soil layer rotary tillage without straw incorporation (RT); (2) ridges of rotary tillage without straw incorporation (RR); (3) whole soil layer rotary tillage with straw incorporation (RTS); and (4) ridges of rotary tillage with straw incorporation (RRS). The results showed that compared with no straw incorporation (RT and RR treatments), RTS and RRS treatments significantly increased the relative abundance of Proteobacteria,  Acidobacteria, Chloroflexi, and Ascomycota, and decreased the relative abundance of Actinobacteria, Patescibacteria, Firmicutes, WPS-2, and Basidiomycota. Bacterial and fungal gene copy numbers, Chao1 index and Shannon index under straw incorporation treatments were 130.0%, 15.9%, 14.9% and 185.1%, 31.9%, 28.4% higher than those under no straw incorporation treatments, respectively. Compared with RRS, RTS increased the bacterial and fungal gene copy numbers by 40.9% and 50.1%. Results of the bacterial-fungal co-occurrence network analysis showed that RTS and RRS treatments significantly increased the nodes, links, and average connectivity degree. Moreover, RRS had the highest positive link percentage. Bacterium Ellin 6519 and Knufia were key microorganisms under straw incorporation treatments. There was a significant positive correlation between soil bacterial and fungal gene copy number and community diversity. The structural equation modeling showed that soil organic carbon content and bulk density directly affected bacterial community characteristics, while soil organic carbon content and leucine aminopeptidase activity directly affected fungal community characteristics. The results provide a theoretical basis for analyzing the effects of straw strip incorporation with rotary tillage on microbial community in brown soil.





Characteristics of microbial communities in walnut (Juglans regia L.) rhizosphere during different growth periods.

CHENG Qi, NING Xin, QIAO Minhang, DU Binghai, MA Hailin, SUN Shanshan, LIU Kai, DING Yanqin

2023, 42(9):  2061-2071.  doi:10.13292/j.1000-4890.202309.032

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Plant roots recruit enormous diverse microorganisms from the complex soil environment to construct rhizosphere microbial communities, which is beneficial to plant health. In this study, we collected rhizosphere and non-rhizosphere soil samples during the budding period, flowering period, and fruiting period of walnut. The high-throughput sequencing and the subsequent analysis of differential species and function, and microbial ecological network correlation were performed to characterize rhizosphere microbial communities during different growth periods. Results showed that there was difference in the dominant microorganisms dwelling in the walnut rhizosphere during different growth periods. The relative abundance of Bacillus and unclassified Fungi significantly increased during the budding period; unclassified Chloroplast, Cladosporium, Alternaria and Acaulium significantly increased during the flowering period; unclassified Micrococcaceae, Pseudomonas, Streptomyces, Gibberella and Mortierella significantly increased during the fruiting period. Among them, Bacillus (with a relative abundance of 3.0%), unclassified Chloroplast (4.5%) and Pseudomonas (17.9%) were the dominant beneficial genera in the rhizosphere soil during the budding period, flowering period, and fruiting period, respectively. The structure of rhizosphere microbial communities significantly differed during different growth periods (P<0.05). The results of topological features analysis showed that, compared to the non-rhizosphere soil, the microbial ecological network in the rhizosphere soil showed stronger, more complex, and tighter correlations. The network complexity of bacterial and fungal communities was the highest during fruiting period and budding period, respectively, while the positive correlation was the highest during the budding period and fruiting period, respectively. This study provided a theoretical basis for the collection of soil samples and the screening of beneficial bacteria for walnut growth promotion and biocontrol.





Effects of stand densities on understory vegetation diversity and soil physicochemical properties of Robinia pseudoacacia forest in loess region of western Shanxi Province.

HU Yawei, SHI Zhengle, LIU Chang, XU Qintao, ZHANG Jianjun

2023, 42(9):  2072-2080.  doi:10.13292/j.1000-4890.202309.014

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Understory plant diversity and soil physicochemical properties are key indices reflecting the stability and growth capacity of soil and water conservation forest. We examined the understory plant species diversity and soil physicochemical properties of Robinia pseudoacacia plantations with stand densities of 900, 1075, 1450, 1850, 2325 trsse·hm^-2 in Caijiachuang watershed of western Shanxi loess region, aiming to provide the basis for the highquality development and sustainable management of R. pseudoacacia plantations in the loess region of western Shanxi Province. With the increases of R. pseudoacacia stand density, the average tree height and diameter at breast height (DBH) decreased gradually. The Margalef, Simpson and Shannon indices of shrub layer and herb layer increased firstly and then decreased, with a peak at 1850 plants·hm^-2. Periploca sepium was the dominant species (importance value: 40.01) in shrub layer, and Artemisia gmelinii was the dominant species (importance value: 41.03) in herb layer. The bulk density of 0-60 cm soil layer decreased first and then increased with increasing R. pseudoacacia stand density, with the lowest value at 1850 trees·hm^-2 (1.19 g·cm^-3). Porosity, organic matter content, and total nitrogen content increased first and then decreased with increasing stand density, with the highest values at 1850 trees·hm^-2. The dominance and diversity indices of shrub layer and herb layer were negatively correlated with soil bulk density (P<0.05), while positively correlated with capillary porosity and organic matter content (P<0.01). The evenness index was positively correlated with total porosity and capillary porosity (P<0.05). According to principal component analysis, the comprehensive score of R. pseudoacacia plantations with different stand densities was ranked as follows: 1850 trees·hm^-2 (0.772), 1075 trees·hm^-2 (0.354), 1450 trees·hm^-2 (0.001), 2325 trees·hm^-2 (-0.012), 900 trees·hm^-2 (-1.115). Our results suggested that too high or too low stand densities would not be suitable for the sustainable development of R. pseudoacacia plantations. A stand density of 1850 trees·hm^-2 would be more conducive to the growth of understory vegetation and the accumulation of soil nutrients.





Amounts and spectral characteristics of dissolved organic matter leached from leaf litters among different plant growth forms in subtropical plantations.

DING Yidong, LI Suli, ZHANG Yun, XU Jiawen, WU Panpan, MAO Rong

2023, 42(9):  2081-2090.  doi:10.13292/j.1000-4890.202309.007

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Dissolved organic matter (DOM) leached from plant litter plays an essential role in carbon (C) and nutrient cycling in forest soils. However, the characteristics of leaf litter leachates (i.e., amounts, chemical composition and structure) from different plant growth forms are still unclear, especially lacking of empirical evidence of multiple tree species. In this study, we collected leaf litters of 11 broadleaf tree species, 3 coniferous tree species, and 4 fern species from subtropical plantations in Jiangxi Province. A laboratory leaching experiment was conducted to compare the difference in leaf litterleached DOM parameters among plant growth forms. Furthermore, the correlation between DOM parameters and initial leaf litter properties was analyzed. The results showed that amounts and chemical composition of litter-leached DOM exhibited substantial variations among plant growth forms. Specifically, amounts of dissolved organic carbon (DOC) and total nitrogen (DTN) leached from leaf litter were greatest in broad-leaf trees, but ferns had highest amounts of dissolved total phosphorus (DTP). Compared with coniferous trees, broadleaf trees and ferns had higher SUVA₂₅₄ and SUVA₂₈₀ values but lower S_275-295 and S_R values in litter leachates, indicating higher DOM aromaticity and molecular weight in litter leachates from broadleaf trees. Leaf carbon content, nutrient content, stoichiometric ratios, and physical traits (i.e., specific leaf area, tissue density and water-holding capacity) would well explain the variations in production and aromatic degree of DOM of leaf litter from different plant growth forms. Our results suggest that replanting broadleaf tree under low-efficiency and coniferous plantations would be an effective strategy to improve ecological services, such as soil carbon pool and forest productivity by promoting the amounts and diversity of DOM input to soils.





Characteristics of leaf water absorption and water reverse transport in Cunninghamia lanceolata under drought stress.

CHEN Yu, JIA Jianbo, YAN Chengzheng, HU Yuwen, REN Xinlei, WANG Yifan, WU Xiaohong

2023, 42(9):  2091-2099.  doi:10.13292/j.1000-4890.202309.010

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Uneven spatial and temporal distribution of precipitation pattern induced by global climate change has caused the increasingly serious periodic drought of monsoon climate in subtropical regions. Water uptake of leaves plays important ecological and hydrological roles in alleviating drought stress. In this study, potted Chinese fir (Cunninghamia lanceolata) was sprayed with heavy water (δD) to simulate precipitation. We conducted a continuous monitoring on utilization ratio of water absorption and reverse migration of Chinese fir leaves under four soil moisture levels (naturally abundant, naturally suitable, slightly dry, moderately dry; the corresponding actual soil water content (SWC) was 21%-26%, 16%-21%, 12%-16%, and 8%-12%, respectively) and four durations of leaf wetting (10, 30, 40, and 60 min). The results showed that under drought stress (SWC 8%-16%) and when the duration of leaf wetting was ≥ 30 min, foliar water uptake occurred across all soil moisture treatments, and water absorbed by leaves could be reversely transported to the xylem and soil near roots along the leaf-branch-root water potential gradient, which can improve water status of plants. The proportion of leaf utilization of reversely transported heavy water gradually decreased with the increases of time after the end of simulated precipitation, and reached the maximum value of 10.82% one hour after precipitation. The utilization ratio of reversely transported heavy water by branches and roots firstly increased and then decreased slowly with the increases of time after the precipitation; the utilization ratio reached the maximum value of 8.36% and 0.65% after 2 h and 2-4 h after the precipitation, respectively. These results indicate that the response time of different parts of C. lanceolata is different and that there is a certain lag in the utilization ratio of reversely transported heavy water. Therefore, C. lanceolata can absorb water through leaves and roots, which is of great significance to effectively utilize natural water resources and alleviate drought stress in seasonally dry regions.





Effect of air warming on root biomass of Cunninghamia lanceolata saplings.

LIU Yuanhao, HUANG Jinxue WANG Xiaonan, CHEN Xinyi, PEI Yun, XIONG Decheng, YANG Zhijie

2023, 42(9):  2100-2106.  doi:10.13292/j.1000-4890.202309.011

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To understand the responses of belowground biomass of subtropical Chinese fir plantation to global warming, the allocation of root biomass in different soil layers and diameter classes were examined in an experiment with open-top chamber (OTC) to simulate climate warming. Air warming did not affect total root biomass, fine root biomass, and coarse root biomass. Air warming significantly decreased the proportion of fine root in the 20-50 cm soil layer and that of coarse root in the 0-10 cm soil layer, but significantly increased that of coarse root in the 20-50 cm soil layer. Neither fine root biomass nor coarse root biomass in other soil layers was significantly influenced by air warming. Air warming did not affect fine root and coarse root biomass in all diameter classes. Overall, after air warming, Chinese fir saplings could increase the proportion of coarse root biomass in deep soil to support growth, and maintain fine root biomass in topsoil by reducing the proportion of deep fine root biomass to ensure the uptake of nutrients and water. Air warming affects the allocation of root biomass in different soil layers and diameter classes, as well as belowground carbon allocation, with consequences on carbon cycling.





Litter input effects on soil dissolved organic carbon.

ZHANG Yu, WU Fuzhong, AI Ling, FAN Xuebo, YANG Ying, ZHENG Xiaping, ZHU Jingjing, NI Xiangyin

2023, 42(9):  2107-2112.  doi:10.13292/j.1000-4890.202309.016

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Dissolved organic carbon (DOC) could be leached rapidly from soils and assimilated by soil microorganisms, and thus is one of key components of biogeochemical cycles in terrestrial ecosystems. Litter is an important source of soil DOC, but the types and amounts of surface litter vary greatly in different ecosystems due to the divergent vegetation types and coverage. Moreover, chemical composition of different litter types directly affects DOC release during decomposition. Therefore, assessing the changes in soil DOC concentrations under litter inputs is of great significance for understanding soil biogeochemical processes. We compiled 494 paired observations (with and without litter addition or removal) from 47 literature to evaluate the changes in soil DOC concentrations under double litter addition or removal of different litter types (leaf litter, roots and both leaf litter and roots) across ecosystems (forests and grasslands) over different experimental periods (<1, 1-3, 3-6 and >6 months). The results showed that double litter addition significantly increased soil DOC by 28.9%, while soil DOC concentrations were reduced by 23.1%, 6.6% and 16.9% after removal of leaf litter, roots, or both, respectively. Soil DOC concentrations in grasslands and forests were increased by 28.6% and 28.5% under double litter input, but were decreased by 30.4% and 21.2% after litter removal, respectively. Soil DOC concentration increased rapidly by 29.6% within one month of double litter addition, but this increase was gradually slowed down in the later periods, yet soil DOC concentration was then increased rapidly by 34.0% after six months of manipulation. Similarly, litter removal decreased soil DOC concentration by 65.2% within one month of manipulation, but such effect was gradually slowed down in the later periods. These results suggest that litter is an important source of soil DOC, and that the contribution of leaf litter is approximately 3.5 times higher than roots. Our global synthesis figures out the interactions between litter inputs and soil DOC, which improve our mechanistic understanding of biogeochemistry in terrestrial ecosystems.





Spatial distribution pattern and impact factors of soil saturated hydraulic conductivity in Hevea brasiliensis-Alpinia oxyphylla  agroforestry.

WANG Haofei, WANG Li, ZHU Xiai, LIU Wenjie, JIANG Xiaojin

2023, 42(9):  2113-2120.  doi:10.13292/j.1000-4890.202309.003

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Rubber-based agroforestry in the humid tropical region is a strategy to alleviate land degradation and seasonal drought under rubber monoculture plantations. We analyzed the spatial characteristics of saturated hydraulic conductivity (K_s, a measure of soil water availability) under rubber-Alpinia oxyphylla agroforestry in the humid tropical region of Southwest China. The experiment was conducted in the Xishuangbanna Tropical Botanical Garden by establishing a permanent plot (25 m × 11 m) under a rubber-A. oxyphylla agroforestry. A total of 40 quadrats were established for measuring the K_s, soil bulk density, non-capillary porosity, and field water-holding capacity. The ordinary kriging interpolation, path analysis and geostatistics method were used to analyze K_s spatial distribution pattern, variation characteristics and its controlling factors in rubber-A. oxyphylla agroforestry. The K_s was significantly higher (P<0.01) in A. oxyphylla planting zone than in rubber planting zone, and K_s decreased with the increases of the distance from the A. oxyphylla planting zone. Affected by structural factors, both K_s and field water-holding capacity showed a strong positive spatial autocorrelation (nugget coefficient C₀/(C₀+C)≤25%). K_s was significantly negatively correlated with soil bulk density (-0.613, P<0.01), but positively correlated with non-capillary porosity (0.408, P<0.01) and field water-holding capacity (0.352, P<0.01). Results of the multiple linear regression analysis showed that soil bulk density was the main controlling factor for K_s, indicating that intercropping A. oxyphylla with rubber could reduce bulk density, enhance soil porosity, and thus improve soil water infiltration.





Effects of mulching film residue on soil physical properties and cotton root growth under different irrigation quotas.

CHEN Lijun, LIN Tao, LOU Zhenshuai, TANG Qiuxiang, JIANG Pingan, BAO Zhe, XI Bin, JIN Tuo

2023, 42(9):  2121-2128.  doi:10.13292/j.1000-4890.202309.018

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Plastic film mulching is a major management strategy for agricultural water saving and yield-increasing in arid and semi-arid areas. However, long-term and high-intensity plastic film mulching has caused serious “white pollution” and thus is not sustainable. In this study, we investigated the effects of residual film pollution on soil physical characteristics and cotton root growth under simulated residual film accumulation and drought. We designed a soil column installation with two irrigation amounts \[1950 m³·hm^-2 (50% field water-holding capacity, moderate drought), 3900 m³·hm^-2 (100% field water-holding capacity, full irrigation)\] and four residual film levels (0, 160, 270, and 490 kg·hm^-2). The results showed that soil physical properties were mainly affected by residual film amount. With the increases of residual film amount, soil bulk density increased, while saturated water content, field water-holding capacity, capillary water-holding capacity, and total porosity decreased. The increased residual film amount inhibited the expansion of cotton root, decreased root biomass, root surface area, root volume, root length, and root diameter, as well as the proportion of cotton roots in the 0-20 cm soil layer. Except for field water-holding capacity, all the above mentioned indices showed significant differences when the residual film amount exceeded 270 kg·hm^-2. Under the same amount of residual film, root architecture of the high irrigation quota was better than that of the drought treatment. A comprehensive analysis showed that the increasing range in soil bulk density was 1.88%, while the decrease ranges in saturated water content, capillary water retention, and total porosity were 7.97%, 6.42%, and 9.39%, respectively. Root biomass, root surface area, root volume, and root diameter decreased by 41.34%, 64.10%, 47.27%, and 86.67%, respectively. In conclusion, residual film pollution severely damaged soil structure, inhibits root growth, and led to decreases in soil physical properties, root water and fertilizer absorption capacity. The reduction of such effect may require more water consumption, which will further exacerbate the water shortage crisis. Therefore, the corresponding residual threshold should be strictly controlled below 270 kg·hm^-2. The results provide theoretical support for the risk assessment and control strategy of farmland residual film pollution.





Effects of nine-year low amount biochar return and potassium fertilization on potassium, maize yield and potassium balance in brown soil.

2023, 42(9):  2129-2137.  doi:10.13292/j.1000-4890.202309.026

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Potassium is deficient in most of China’s arable lands. The application of organic amendments, such as biochar, is an effective way to increase soil potassium content. The research on the interactions between long-term and annual low amount of biochar returning and potassium application on brown soil potassium, crop productivity, and soil potassium balance is not sufficient. We carried out a long-term field experiment on maize cropland, which followed a two-factor randomized block design with two factors including biochar (C) and potassium fertilizer (K). There were two levels of biochar addition (0 t·hm^-2 and 2.625 t·hm^-2; denoted as C₀ and C₁, respectively), and two potassium fertilizer levels (0 kg·hm^-2 and 60 kg·hm^-2; denoted as K₀ and K₁, respectively). Biochar and potassium fertilizer had different effects on different forms of potassium across soil layers. In 0-20 cm soil layer, the content of water-soluble potassium, slowly available potassium, available potassium, and total potassium in C₁ treatment was significantly increased by 57.14%, 17.25%, 23.48%, and 8.31% compared with C₀. On the contrary, the content of soil readily available potassium in C₁ treatment was 8.31% lower than that in C₀ treatment. The contents of soil readily available potassium, slowly available potassium, and available potassium in K₁ treatment were 16.61%, 16.42%, and 44.25% higher than those in K₀ treatment, respectively. Compared with C₀K₀ treatment, C₁K₁ significantly increased the contents of water-soluble potassium, slowly available potassium, and available potassium by 72.72%, 77.45%, and 36.19%, respectively. Biochar had a significant effect on soil water-soluble potassium content, which was contrary to that in 0-20 cm soil layer. At K₀ and K₁ levels, soil water-soluble potassium content in C₁ was significantly reduced by 8.65% and 42.57% compared with C₀, respectively. The contents of soil readily available potassium, slowly available potassium, and available potassium in K₁ treatment increased by 13.33%, 10.84%, and 19.63%, respectively, compared with K₀. The content of water-soluble potassium only in K₁ treatment decreased by 40.35% compared with K₀ at C₁ level. Compared with C₀K₀ treatment, soil water-soluble potassium content in C₁K₁ was significantly decreased by 45.51%, while available potassium content was significantly increased by 24.26%. Both biochar and potassium fertilizer could significantly increase dry weight of maize organs and total dry weight, and the potassium absorption of different organs and the whole plant. Both biochar and potassium fertilizer could significantly increase maize yield, with 8.66% higher in C₁ than in C₀, 10.10% higher in K₁ than K₀, and 19.76% higher in C₁K₁ than in C₀K₀. The application of biochar could significantly improve the absorption and utilization rate of potassium fertilizer, resulting in surplus in soil potassium. Our results indicated that the long-term return of low amount of biochar and potassium fertilizer application year by year increased potassium availability in the surface soil, improved the dry matter accumulation and potassium absorption of maize, alleviated the negative potassium balance in the soil, and enhanced maize production. The comprehensive analysis showed that the combined application of biochar and potassium fertilizer is an effective fertilization management mode to improve the effectiveness of soil potassium and increase maize yield.





Effects of reclaimed water irrigation modes on soil environment, microbial community structure, and grape growth in vineyards.

WANG Fang, CHEN Haonan, ZHAO Zhanning, LI Wenhui, NAN Xiongxiong, ZHENG Lanxiang

2023, 42(9):  2138-2147.  doi:10.13292/j.1000-4890.202309.029

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We explored the effects of different irrigation modes with reclaimed water from wine production on soil condition, microbial community structure, and grape growth in vineyards. The optional method of reclaimed water utilization was determined to provide empirical evidence that could assist the recycling of wastewater from wine production at the eastern foot of Helan Mountain, Ningxia, China. We conducted a field experiment with three-year-old grapevines (Vitis vinifera cv. Merlot) and four treatments: clean water irrigation (CI, control), alternate irrigation with fresh clean water and reclaimed water (AI), mixed irrigation with fresh clean water and reclaimed water (1∶1, MI), and reclaimed water irrigation (RI). Soil physicochemical properties, rhizosphere bacterial diversity and community composition, as well as grape yield and quality were measured. Compared with the CI treatment, pH values of 0-80 cm soil layers were not significantly changed under different irrigation modes with reclaimed water. The electrical conductivity of 20-40 and 80-100 cm soil layers markedly increased under the MI treatment by 53.98% and 99.66%, respectively. There were no differences in soil organic carbon content among various irrigation treatments with reclaimed water. However, under the AI treatment, the total nitrogen and phosphorus contents of 0-20 cm soil layer dramatically increased by 38.46% and 39.94%, respectively, and the total phosphorus content of the 40-100 cm soil layers markedly increased by 32.88%-79.63%, compared with the CI treatment. Different irrigation modes had limited effects on soil available nutrients. The genus-level bacterial community composition of rhizosphere soils and its relationships with soil factors distinctly varied under the MI and RI treatments compared with the CI treatment. However, PCoA analysis revealed consistent results under the AI treatment with the CI treatment, and the relationships between soil environmental factors and microbial community composition did not change substantially. The yield components of wine grape and the soluble solid content, titratable acid content, and sugar-acid ratio of fruits had minor differences under various irrigation modes. In the wine-producing area of the eastern foot of Helan Mountain, the alternate irrigation mode with clean water and reclaimed water can convey benefits to regional water use efficiency, soil fertility, and sustainable grape production.





The characteristics of fungal community in the rhizosphere soil of potato infected by late blight in an area with high geological background of heavy metals in Northwest Guizhou.

REN Yi, LIU Hongyan, WU Longhua, WANG Xulian, MEI Xue, JIAN Huailiang, ZHAO Luyue

2023, 42(9):  2148-2155.  doi:10.13292/j.1000-4890.202309.033

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Weining is a typical county with both high geological background and heavy metal pollution in Northwest Guizhou. Potato (Solanum tuberosum) production is one of the important agricultural industries in the county. There is high incidence of potato late blight caused by Phytophthora infestans. Here, we investigated the response of the rhizosphere soil microbial community to the occurrence of potato late blight in the context of high heavy metal geology. The fungal community composition and diversity of rhizosphere soil of potato late blight infected plants and healthy plants of different cultivars were analyzed by Illumina Hiseq high-throughput sequencing technology. The results showed that soil Cd concentration ranged from 1.75 to 2.67 mg·kg^-1, showing a serious contamination. Cr, Ni, and Zn were also slightly contaminated. The incidence of late blight in different potato cultivars was in an order of Weiyu 3 (21%) > Weiyu 5 (13%) > Qingshu 9 (5%). The dominant fungi in the rhizosphere soil of potato plants infected with late blight were Ascomycota and Mortierellomycota at the phylum level and Mortierella and Penicillium at the genus level. There was no difference for αdiversity of fungal community between plants with and without late blight infection for the three cultivars. Among the late blight infected plants, the resistant cultivar Qingshu 9 showed a higher fungal community diversity in the rhizosphere soil, while the sensitive cultivar Weiyu 3 showed a lower fungal community diversity and a higher relative abundance. Results of principal coordinates analysis showed that rhizosphere soil fungal community structure of potato late blight infected plants and healthy plants was significantly separated. The results of redundancy analysis showed that soil Cd content and pH greatly affected fungal community composition of rhizosphere soil. The proportion of dominant fungi phyla and genera in the rhizosphere soil of potatoes infected with late blight was changed under the contamination by heavy metals. There were more pathogenic fungi in the rhizosphere soil of Weiyu 3 potato with low disease resistance, which may have direct or indirect effects on the occurrence of potato late blight.





Application and toxicity determination of sodium lignosulfonate in petroleum contaminated soil washing.

XIAO Mei, GONG Zongqiang, JIA Chunyun, LI Xiaojun, LIU Wan

2023, 42(9):  2156-2167.  doi:10.13292/j.1000-4890.202309.002

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We examined the oil washing capability of sodium lignosulfonate (SL) and the elution efficiency of the combination ability of SL with surfactants such as triton X₁₀₀ (TX₁₀₀) in soil contaminated with high-concentration petroleum. We assessed toxicity of residual pollutants to seed germination and root elongation of six species planted in the eluted soil with water washing twice after surfactant washing. The results showed that SL could desorb petroleum from the oil-contaminated soil. The optimized cleansing conditions of SL were as follows: SL concentration of 2.5 g·L^-1, temperature of 30 ℃, time of 60 min, rotation speed of 200 r·min^-1, and pH of 11. Under such conditions, the maximum oil removal rate was 25.4% and 42.3% for the artificial oil contaminated soil (FP) and in site petroleum contaminated soil (XJ), respectively. Based on the above results, six groups of optimal compound formulation were confirmed through repeated experiments as follows: TX₁₀₀ (0.06%-0.10%), SL (0.20%-0.25%), sodium carbonate (0.37%-0.41%), and sodium silicate (0.36%-0.42%). When solid liquid ratio was 1:15 and total reagent concentration was 10.8 g·L^-1, the efficiency of oil washing was 69.6%-77.9% and 80.3%-89.7% for FP and XJ soils, respectively. Results from the toxicity tests of residual pollutants in the eluted soils for germination and root growth of common crop, vegetable and forage seeds showed no toxic effect in FP-soil, and an inhibitory effect in XJ-soil to some extent, which was 1.0%-2.5% for germination percentage and 3.9%-10.9% of root elongation. Therefore, the compound eluant containing SL is of great significance for the establishment of green, low-cost, and high-efficient cleansing technique for soil contaminated with high-concentration petroleum.





Physiological responses of three hermatypic corals to different calcium ion concentrations.

LIU Yina, WANG Chenying, ZHANG Han, WANG Qifang, ZHENG Xinqing

2023, 42(9):  2168-2175.  doi:10.13292/j.1000-4890.202309.022

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This study aimed to evaluate the effects of Ca²⁺ concentration on physiological response of three hermatypic corals, including Seriatopora caliendrum, Galaxea fascicularis and Montipora digitata. The calcification rate, maximum quantum yield (F_v/F_m), and effective quantum yield (Φ_PSⅡ) were measured at six Ca²⁺ concentrations (180, 250, 320, 390, 460 and 530 mg·L^-1). The results showed that the calcification rate of three corals significantly reduced at low Ca²⁺ concentrations (180 mg·L^-1). With increasing Ca²⁺ concentration, the calcification rates of S. caliendrum and M. digitata displayed inverted parabolic growth and peaked at 320-390 mg·L^-1, while the calcification rate of G. fascicularis increased with increasing Ca²⁺ concentration at low Ca²⁺ concentration (180-320 mg·L^-1) and then did not change afterwards. Fourteen days after treatment initiation, the F_v/F_m and Φ_PSⅡ of S. caliendrum associated zooxanthellae showed a trend of first increasing and then decreasing with increasing Ca²⁺ concentration, probably because the corals suffered from a certain stress at too low or too high Ca²⁺ concentration. G. fascicularis associated zooxanthellae displayed no significant difference in F_v/F_m but a significant increase in Φ_PSⅡ at fourteen days after treatment initiation compared to that at day one of treatment initiation. These results indicate speciesspecific physiological response of corals to different Ca²⁺ concentrations. Therefore, it is necessary to pay attention to and adjust Ca²⁺ concentration in closed circulating aquacultural systems for hermatypic corals to maintain the optimum growth.





The blocking effects of electric barrier with different electrode arrangements and electrical parameters on silver carp.

HUANG Xiaolong, BAI Yanqin, JIANG Wei, LIN Feng, WU Yupu, XIE Lihui, LI Weidong, WANG Huilin, ZHANG Jinyu, SHI Xiaotao

2023, 42(9):  2176-2183.  doi:10.13292/j.1000-4890.202309.021

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We investigated the repellency and safety of electric barrier with different electrode arrangements and electrical parameters on silver carp (average body length of 21.05 cm). Under static water condition, an orthogonal experimental design with four factors and three levels was adopted to study the impacts of electrode arrangement, pulse voltage, pulse frequency, and pulse width on the blocking effect of electric barrier and the number of injured experimental fish. Under the conditions of inlet velocity of 0.3 and 0.5 m·s^-1, the optimal electrode arrangement and electrical parameters were used to repeat the experiment to explore the adaptability of the electric barrier at different velocities. Under the static water condition, the blocking effect of the second condition (electrode arrangement 1 with pulse voltage of 80 V, pulse frequency of 10 Hz and pulse width of 30 ms) was the best, with a blocking rate of 100%. The order of influencing factors with respect to strength was pulse voltage, pulse width, electrode arrangement, and pulse frequency. There was no significant difference in the average blocking rate of the same factor at different levels under static water condition. Further, the optimal electrode arrangement and electrical parameters, which were obtained under static water condition, were adopted. When the inlet velocity was 0.3 m·s^-1, the average blocking rate of electric barrier was the same as that under static water condition. When the inlet velocity was 0.5 m·s^-1, the average blocking rate of the electric barrier decreased to 97.92%, which had no difference with that under static water condition. Electrode arrangement and inlet velocity could significantly affect the average number of injured experimental fish, and the variation of the average number of attempts with inlet velocity was highly similar to that of the average number of injured experimental fish. Our results provide reference for the design optimization and engineering application of electric barrier, further improving its safety and effectiveness.





The niche characteristics of dominant species and community structure of metazooplankton in North Pan River and South Pan River in Guizhou.

ZHANG Jingze, YANG Bo, XIAO Jing, XIA Wei, LI Qiuhua

2023, 42(9):  2184-2192.  doi:10.13292/j.1000-4890.202309.024

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To clarify the niche characteristics of dominant species and community structure of metazooplankton in North Pan River and South Pan River, we collected samples of the metazooplankton in October 2020 (normal period), April 2021 (dry period), and July 2021 (wet period), and evaluated dominance, niche breadth, and niche overlap values. The results showed that a total of 43 species were recorded in North Pan River and South Pan River, including 28 species of rotifers, 3 species of copepods and 12 species of cladophors. Among them, 25 species were common in South Pan River and North Pan River. Keratella cochlearis, Mesocyclops sp., and Nauplius  (larvae) were the dominant species in the three hydrographic periods of South Pan River and North Pan River. The abundance of metazooplankton in South Pan River was 424.58, 1482.08, and 383.10 ind·L^-1 in the wet, normal, and dry periods respectively, and the biomass was 0.397, 0.369, and 0.006 mg·L^-1, respectively. In North Pan River, abundance was 329.33, 553.90, and 117.73 ind·L^-1 in the wet, normal, and dry periods, and biomass was 0.397, 0.369, and 0.006 mg·L^-1, respectively. Dominant species was mainly narrow-niche population (42.86%) in South Pan River, while it was middle-niche population (64.29%) in North Pan River. Niche overlap value and niche breadth changed seasonally due to the changes of environmental factors. The niche breadth of dominant species in South Pan River was significantly different (P<0.01), and the adaptability of dominant species to environment was quite different. There was no difference in niche breadth of dominant species (P>0.05) in North Pan River, and little difference in the ability to adapt to environment among dominant species. The average overlap values of dominant species in the South Pan River and North Pan River were dry period < wet period < normal period (0.328<0.780<0.847 for South Pan River; 0.283<0.508<0.812 for North Pan River). The overlap values between Keratella cochlearis and other dominant species were large. The average overlap value of Keratella cochlearis and other dominant species in South Pan River and North Pan River was 0.68 and 0.56, respectively, being the highest frequency of occurrence of 92.86%, indicating that it had a strong ability to utilize resources. As indicated by community structure and niche characteristics of dominant species of metazooplankton, the competition among dominant species in South Pan River and North Pan River in wet period and normal period was stronger than that in dry period, and the niche of dominant species changed seasonally.





Characterization of butterfly diversity in urban parks in Kunming under multiple landscape dimensions.

HUANG Qiuxia, ZHANG Zhe, MA Hongyan

2023, 42(9):  2193-2203.  doi:10.13292/j.1000-4890.202309.030

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Butterflies are an important part of urban ecosystems and are environmental indicator species. A multidimensional study of butterfly diversity characteristics in urban parks can provide theoretical guidance for maintaining the stability of urban ecosystems. We conducted a one-year field investigation of butterfly diversity and plant species in 20 urban parks in Kunming, China. High-resolution remote sensing was used to visualize and analyze the effects of environmental factors on butterfly diversity in three dimensions: mountain-city-water spatial patterns, park landscape, and landscape micro-habitat. A total of 3562 butterflies belonging to 105 species, 67 genera, and 9 families, as well as 320 plant species belonging to 238 genera and 98 families were recorded. Butterfly diversity was generally higher in parks located near mountains and close to Dianchi Lake than that in other parks. The overall landscape area, the proportion of woodland and grassland areas, the core patch area of woodland, and the degree of woodland and grassland connectivity had a positive effect on butterfly diversity. Butterfly diversity tended to decline as the fragmentation degree of the overall landscape and artificial hardscape and the areal proportion of artificial hardscape increased. The more serious the fragmentation of grassland landscapes, the more uneven the butterfly distribution. The effects of vegetation structure and plant composition on butterfly diversity varied among seasons. Our results help explain butterfly diversity in urban park green space, providing a scientific basis for enhancing butterfly diversity in urban parks of Kunming.





Spatiotemporal variations of habitat quality in protected area of giant panda in Sichuan Province.

HU Lu, FENG Bin, BAI Wenke, DONG Xin, XIAO Qiang, ZHANG Jindong, HUANG Youyou, ZHOU Caiquan

2023, 42(9):  2204-2211.  doi:10.13292/j.1000-4890.202309.009

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We examined land use changes in giant panda protected areas and their impacts on habitat quality for 37 counties (cities/districts) of giant panda habitats in Sichuan Province. Based on the data of land use and habitat threat factors from 2000 to 2020, the changes of habitat quality of giant panda protected areas was analyzed from the perspective of land use change, using land use transfer matrix, land use dynamic degree, landscape pattern index and InVEST model. The results showed that forest land (+1.49%), built-up land (+59.72%), and water area (+27.79%) increased from 2000 to 2020, while grassland (-2.44%) and cultivated land (-2.14%) area decreased. The main change types were the inter-conversion of grassland and forest land and the conversion of cultivated land into built-up land. The spatial variation range of habitat quality and landscape fragmentation in the study area was roughly the same. The habitat quality was lower in the area with higher landscape fragmentation. Spatially, habitat quality decreased from west to east, with the area of improving habitat quality (952.35 km²) being smaller than that of decreasing habitat quality (1562.38 km²). The habitat quality within the giant panda habitats remained stable. The degradation of the overall habitat quality showed an increasing trend, with the mean value of habitat degradation index being increased from 0.018 in 2000 to 0.022 in 2020. Moreover, the spatial distribution patterns of high degree of habitat degradation and low habitat quality were relatively consistent, mainly in the eastern and southern parts of the study area. Our results provide a scientific reference for the conservation and restoration of giant panda habitats.





Effects of wide-ridge rice-fish-chicken co-culture on rice population growth and yield.

MA Weiwei, HUANG Huang, CHEN Can, REN Bo, WANG Ren, YUAN Jiao, ZHANG Yin, OU Linzhi, MA Yunjun, LUO Yucong

2023, 42(9):  2212-2217.  doi:10.13292/j.1000-4890.202309.017

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To clarify the effects of wide-ridge rice-fish-chicken co-culture on the growth and yield of rice, we carried out a field experiment for two consecutive years (2020-2021) with four treatments, including wide-ridge rice-chicken co-culture (RC), wide-ridge rice-fish co-culture (RF), wide-ridge rice-fish-chicken co-culture (RFC) and conventional rice cultivation (CK). The results showed that compared with CK, leaf area index of RC and RFC treatments increased by 46.99% and 46.32% (P<0.05) at grain filling stage, and panicle dry weight increased by 40.85% and 33.39% at maturity stage, respectively. The dry matter accumulation of rice aboveground at the booting to full heading stage under the treatments of RC and RFC increased by 29.83% and 33.71% (P<0.05), respectively. Population growth rates of RFC and RC treatments increased by 80.94% and 75.34% (P<0.05), and photosynthetic potential at the full heading to grain filling stage increased by 34.25% and 39.74% (P<0.05), respectively. The photosynthetic rate of RC and RFC treatments from booting stage to full heading stage increased by 3.05%-14.87% and 6.45%-19.38%, respectively. The rice yield under the treatments of RC, RFC and RF increased by 10.89%, 13.23%, and 11.56% respectively, while the effective panicle number of RC treatment increased by 13.25% (P<0.05). In summary, RC and RFC treatments could improve leaf area index, photosynthetic rate and population growth rate of rice, and increase panicle dry weight of rice, so as to achieve stable yield and yield enhancement.





Distribution of tidal channels in different landscape types in coastal wetlands of the Yellow River estuary.

ZHANG Xin, LI Xue, YU Junbao, LI Yunzhao, GUAN Bo, ZHOU Jie, LING Yue, MA Yuanqing

2023, 42(9):  2218-2226.  doi:10.13292/j.1000-4890.202309.02

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We analyzed the typical landscape types and tidal channel changes of different landscape types in the Yellow River estuary, based on five remote sensing images of Yellow River estuary from 2000 to 2020 and field observation data. The area proportions of bare mudflats, Phragmites australis, and Suaeda salsa decreased, while the landscape fragmentation increased. The area of Spartina alterniflora patches increased by 38.32 km² from 2010 to 2020. The average annual length of tidal channels in different landscape types followed an order of bare mudflats>Spartina alterniflora>Suaeda salsa>Phragmites australis. Average number and density of tidal channels showed as: bare mudflats>Suaeda salsa>Spartina alterniflora>Phragmites australis. From 2000 to 2020, the length of tidal channels in bare mudflats and Suaeda salsa dominated landscape decreased by 15.28 and 14.35 km, respectively, while the length of tidal channels in Spartina alterniflora dominated landscape increased by 86.03 km. The network circuit connectivity, node connectivity, and network connectivity were at a low level. The hydrological connectivity in bare mudflats, Suaeda salsa, and Phragmites australis changed little. There were rapid increases of hydrological connectivity in the Spartina alterniflora dominated landscape from 2015 to 2020.





Effects of mass bleaching events on coral reef ecosystems.

MA Jing, YU Kefu

2023, 42(9):  2227-2240.  doi:10.13292/j.1000-4890.202309.023

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Coral bleaching induced by global warming has greatly affected coral reef ecosystems. In the past three decades, there have been three mass bleaching events with a complex chain-regime shift among coral, macroalgae, and fish communities. Global bleaching events have important effects on coral reef ecosystem. For instance, population structure of coral community could shift to smaller and younger colony groups with dominant taxa changes. The coral-algal phase shifts from coral to macroalgae dominance, with Lobophora and Sargassum as dominants. Fish community declines with a lag in total abundance and richness, with increased abundance of some herbivorous fishes, decreased corallivores generally, but almost no change in cryptobenthic fishes. Coral reefs are predicted for several possible futures. First, coral would migrate to deeper and higher-latitude waters. Second, thermal resistant populations could serve as germplasm reservoirs, such as ‘super coral’ in the northern Red Sea. Third, the thermal adaptability of coral might effectively resist the negative impacts of ocean warming and realize the in-situ ecological restoration of coral community. Research in China has mostly focused on the thermal adaptability of coral and the ecological relationship between coral and its symbiotic zooxanthellae. More attention should be paid to coordinated ecological changes between corals, fish and macroalgae, so as to provide scientific basis for the protection and development of coral reefs.





Research progress on photosynthesis of non-leaf tissues and organs in plants.

ZENG Sijie, ZHU Junjie

2023, 42(9):  2241-2249.  doi:10.13292/j.1000-4890.202309.025

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Photosynthesis is the source of biomass and energy production in the world. In addition to leaves, non-leaf green tissues and organs such as flowers, fruits, stems, and barks also show substantial capacity for photosynthesis. Non-leaf photosynthesis, especially the irreplaceable photosynthetic metabolism under stress conditions, has attracted considerable attention recently. In this paper, we reviewed the stomatal configuration, chloroplast formation, carbon assimilation regulation, and photosynthetic stress resistance of non-leaf photosynthetic tissues and organs. Our analyses are based on the structure and functions of non-leaf green tissues and organs, and would provide fundamental references for developing and improving photosynthetic potential of non-leaf green tissues and organs.





Research progress on the relationship between oxidative stress and bird reproduction.

ZHAO Chaoqun, WAN Dongmei, HAN Yu, WEI Yanhui, WANG Juan

2023, 42(9):  2250-2255.  doi:DOI:10.13292/j.1000-4890.202309.008

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Oxidative stress is an important physiological mechanism mediating life-history trade-offs in birds, which is closely related to bird reproduction. Oxidative stress can affect avian mate choice through modulating the expression of sexual characteristics and sperm quality, mediate the trade-off between reproduction investment and self-maintenance, and predict reproduction success and chick growth. In turn, reproduction investment affects the level of oxidative stress. Most studies focus on behavioral exploration, and few are available for in-depth mechanism studies. It is important to fully understand the regulatory mechanisms of oxidative stress on bird reproductive behaviors and how these mechanisms co-evolve with changing environments. These all require in-depth thinking and exploration.





Pollution characteristics, source-sink relationship and control countermeasures in Shengli Oilfield.

ZHAN Haiyin, ZHOU Qixing

2023, 42(9):  2256-2265.  doi:10.13292/j.1000-4890.202309.035

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While oil exploitation injects impetus into China’s economic development, it leads to many oil-polluted sites. The appearance of these polluted sites restricts the coordinated development of social economy and ecological environment. Taking the Shengli Oilfield in the Yellow River Delta as an example, we proposed that n-alkanes, monocyclic aromatic hydrocarbons, 16 preferentially controlled polycyclic aromatic hydrocarbons, and heavy metals can be used as characteristic pollutants for identifying oil mining site pollution. We found that the distribution of pollutants mainly clustered near oil wells and oil transportation lines. The source-sink relationship of soil pollution in oil extraction sites was explored. Oil leakage during oil exploration, extraction, transportation, storage and processing and the combustion of energy fuels during extraction were the main sources of pollution in oil extraction sites. From the perspectives of source control, pollution control and environmental management, we analyzed and discussed the control measures of environmental pollution in oil mining sites, which include actively promoting clean production, improving the level of pollution site control, and improving the enterprise environmental management system. This study provides a scientific basis for the identification and comprehensive treatment of oil-contaminated sites.





Characteristics of evapotranspiration from Chinese fir plantation in Huitong based on eddy covariance method and a comparison with Penman-Monteith method.#br#

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HU Yuke, ZHAO Zhonghui, XIANG Wenhua

2023, 42(9):  2266-2275.  doi:10.13292/j.1000-4890.202309.013

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The objective of this study was to accurately evaluate the evapotranspiration characteristics of Chinese fir (Cunninghamia lanceolata) plantation and to explore the possibility of estimating the evapotranspiration by Penman-Monteith method (PM). Based on the observation data of meteorological gradient and flux from the National Field Scientific Observation and Research Station of Chinese Fir Plantation Ecosystem in Huitong, Hunan Province from 2016 to 2019, we used the eddy covariance method (EC) to analyze the temporal variation of evapotranspiration (ET) in a Chinese fir plantation, and compared the ET obtained with PM. The results showed that the ET showed single wave diurnal and annual variations. During the day, the maximum ET value appeared at 12:30-13:00, and the minimum value appeared at 0:00-2:30. In the year, the maximum value of ET appeared in July-August, and the minimum value appeared in December-February. The ET increased with increasing net radiation (R_n), air temperature (T_a), and vapor pressure deficit (VPD), while decreased with increasing soil water content (SWC). The main meteorological factors affecting the ET were R_n, T_a, and VPD. The ET obtained by PM and EC were consistent in spring and autumn, but significantly different in summer and winter. The difference of ET obtained by PM and EC showed linear and positive correlations with R_n, T_a, and VPD, but a negative correlation with SWC. The results provided theoretical support for exploring the hydrological process of Chinese fir plantation and the feasibility of estimating its ET by PM.





Differences in measurement methods for quantifying spatial accessibility of park green spaces in Hefei City.

LIU Qinqin, LI Mingshi, WANG Nan, YE Junhong, JIANG Lufan

2023, 42(9):  2276-2285.  doi:10.13292/j.1000-4890.202309.028

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Exploring the allocation fairness and effectiveness of spatial accessibility of urban parks and green spaces is of great significance to urban planning and layout, as well as the livability of urban residents. From the perspective of park green space accessibility, we integrated multiple accessibility assessment models that consider varying travel modes. We used an improved kernel density function based twostep moving search model (KD2SFCA) that combines multilevel reachable time thresholds for different park green space types, followed by comparing its assessment results with those of network analysis method and Gaussian two-step moving search model (Ga2SFCA), to quantify the distribution characteristics of population and settlements and the accessibility characteristics of different park types under different travel modes. We evaluated the accessibility of green space of parks within the ring road of Hefei City bypass. The differentiation characteristics of assessment results and the optimization recommendations for urban planning were proposed. The park green spaces showed a clustering distribution pattern in the southern part of the study area, with a high overlap between park green spaces and the areas with high population density. The Ga2SFCA model and the improved KD2SFCA model gave spatially similar assessment results of parkland accessibility in most areas, but substantial differences existed in few limited areas. The spatial accessibility of parklands in Changfeng district (6.54%, 9.57%) and Luyang district (1.24%, 1.57%) were lowest in terms of the accessible area ratio and population ratio. The accessibility calculation results of the improved KD2SFCA and their spatial distributions were more realistic. This study identifies areas with insufficient park green space resources and provides data support and theoretical reference for the planning and layout of urban public spaces.





Sensitivity analysis and quantitative inversion of multi-source remote sensing to soil salt content in dry and wet seasons in Ningxia.

WANG Yijing, JIA Pingping, CHEN Ruihua, ZHANG Junhua

2023, 42(9):  2286-2295.  doi:10.13292/j.1000-4890.202309.006

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Rapid and accurate inversion of soil salinity in arid areas is the premise to effectively prevent the expansion of salinization. To address sensitivity analysis and quantitative inversion of soil salt content in dry and wet seasons by means of ground hyperspectra and Landsat 8 OLI images, we obtained data of topsoil (0-20 cm) salt content, ground hyperspectra and Landsat 8 OLI image in the dry season (April) and wet season (October) in Pingluo County, Ningxia. Linear and nonlinear functions were used to test the sensitivity of the spectral data and corresponding salinity index. We established the models to estimate soil salt content based on ground hyperspectral and image data using partial least squares regression (PLSR), support vector machine (SVM), and back propagation neural network model (BPNN). The average soil salt content in dry and wet seasons was 6.17 and 4.28 g·kg-1, respectively, indicating serious soil salinization. The sensitive bands and salinity index of ground hyperspectra and image spectra to soil salinity differed among seasons. The resampling band and salinity index of ground hyperspectra showed extremely high sensitivity to soil salinity. The stability and prediction ability of BPNN estimation model of soil salt content were better than those of PLSR and SVM. Hyperspectral-BPNN in dry and wet seasons was the best estimation model, with the prediction accuracy of 0.739 and 0.819, and the relative analytical errors of 1.49 and 1.95, respectively. After calibrated by the resampled measured spectrum model, the estimation accuracy of the image spectra based model increased from 0.685 to 0.844 in the dry season and from 0.654 to 0.788 in the wet season, which effectively enhanced the accuracy in estimating soil salt content at large scale. We successfully made the spatial transformation of soil salt content from small to large scale. The results provided a scientific reference for identification and prevention of soil salinization in Yinbei of Ningxia.





Inversion of soil salinity in Yinchuan Plain based on fractional-order differential spectral index.

CHEN Ruihua, WANG Yijing, ZHANG Junhua, SHANG Tianhao

2023, 42(9):  2296-2304.  doi:10.13292/j.1000-4890.202309.004

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Soil salinization is one of the important factors restricting agricultural production, food security, and sustainable development in arid and semi-arid areas of China. With Yinchuan Plain as the research area, we tried to improve the way for hyperspectral data inversion of soil salinity based on data of hyperspectral reflectance and measured soil salinity. The original reflectance was processed with fractional-order differential transformation. Multiple linear regression (MLR) and support vector machine (SVM) models of soil salinity (with a sample size of 133) were established by using a twodimensional spectral index to screen sensitive parameters. Differential transformation can effectively enhance the response of hyperspectral information to soil salinity, and the integer order differential of first order had the best effect, with a correlation coefficient of 0.486. The effect of fractional-order differential order 0.9 was the best, with a correlation coefficient of 0.461. The combination of characteristic bands screened by fractional-order differential and two-dimensional spectral index had a stronger correlation with soil salinity than that of one-dimensional bands. The accuracy of the SVM model was better than that of the MLR model. The accuracy of the two models with order 1.1 was the best, with the R_p², RMSE and RPD being 0.839, 0.96, and 2.46 for the SVM model, and 0.730, 1.32, and 1.79 for MLR model, respectively. The inverse distance weight method of the SVM interpolation can better predict soil salinity in Yinchuan Plain, providing scientific support for improving the accuracy of hyperspectral inversion of soil salinity and a basis for accurate diagnosis, improvement and utilization of saline-alkali  lands.