作者机构：
The Research Center of Soil and Water Conservation and Ecological Environment, Chinese Academy of Sciences and Ministry of Education, Yangling, China;State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation CAS and MWR, Yangling, China;University of Chinese Academy of Sciences, Beijing, China;[Yan Li; Chunyan Wu] Institute of Environment Resource and Soil Fertilizer, Zhejiang Academy of Agricultural Sciences, Hangzhou, China;[Tianyi Qiu; Haoran He] College of Natural Resources and Environment, Northwest A&F University, Yangling, China
通讯机构：
[Linchuan Fang] T;The Research Center of Soil and Water Conservation and Ecological Environment, Chinese Academy of Sciences and Ministry of Education, Yangling, China<&wdkj&>State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation CAS and MWR, Yangling, China<&wdkj&>CAS Center for Excellence in Quaternary Science and Global Change, Xi’an, China
摘要：
• N fertilizer altered bacterial community compositions by changing soil nutrients. • Bacterial ammonia oxidation became predominated with the increasing N rate. • Excessive N input caused the information of a more complex microbial network. • Intensified microbial competition by excessive N was due to negative link increase. Nitrogen (N) fertilization drives the structure and function of soil microbial communities, which are crucial for regulating soil biogeochemical cycling and maintaining ecosystem stability. Despite the N fertilizer effects on soil microbial composition and diversity have been widely investigated, it is generally overlooked that ecosystem processes are carried out via complex associations among microbiome members. Here, we examined the effects of five N fertilization levels (0, 135, 180, 225, and 360 kg N ha−1) on microbial co-occurrence networks and key functional taxa such as ammonia-oxidizers in paddy soils. The results showed that N addition altered microbial community composition, which were positively related to soil total N and available phosphorus (P) contents. The abundance of ammonia-oxidizing archaea (AOA) significantly decreased after N addition, whereas ammonia-oxidizing bacteria (AOB) increased in N360 treatment. Compared with low-N group (N0 and N135), the high-N group (N225 and N360) shaped more complex microbial webs and thus improved the stability of the microbial community. Partial least squares path modeling further revealed that N fertilizer had a higher effect on microbial network complexity in the high-N group (0.83) than the low-N group (0.49). Although there were more positive links across all microbial networks, the proportion of negative links significantly increased in the high-N network, suggesting that excess N addition aggravated the competition among microbial species. Disentangling these interactions between microbial communities and N fertilization advances our understanding of biogeochemical processes in paddy soils and their effects on nutrient supply to rice production. Our findings highlighted that highly N-enriched paddy soils have more stable microbial networks and can better sustain soil ecological functions to cope with the ongoing environmental changes.
期刊：
Journal of Soils and Sediments,2024年:1-9 ISSN：1439-0108
通讯作者：
Xiufu Shuai
作者机构：
[Xiufu Shuai] Hubei Province Key Lab. for Geographical Process Analysis and Simulation, School of Urban and Environmental Science, Central China Normal Univ, Hubei Province, Wuhan, China
通讯机构：
[Xiufu Shuai] H;Hubei Province Key Lab. for Geographical Process Analysis and Simulation, School of Urban and Environmental Science, Central China Normal Univ, Hubei Province, Wuhan, China
关键词：
Dispersion coefficient;Turbulent flow;Eddy dispersion;Taylor diffusion;Capillary bundle model
摘要：
For a homogeneous soil, the traditional laminar flow and well-known Taylor diffusion mechanism cannot interpret dispersivity (linear relationship between dispersion coefficient and pore-water velocity). The objective of this study was to propose a new mechanism and mathematical model based on fluid mechanics. Due to the roughness of the wall of a soil capillary tube, a new turbulent flow is proposed to be eddies at the wall and laminar flow at the main stream of a soil capillary tube. A new eddy dispersion mechanism is that the behavior of solute in the eddies follows random walks and the solute mixes instantly between the wall and main stream in a tube at the microscale. The new turbulent flow and eddy dispersion occur when the pore-water velocity is greater than a critical value. Transition to the new mechanism from a laminar flow in the tube and molecular diffusion is described by a plateau-linear model. It was tested by published datasets of pore-water velocity and dispersion coefficient in miscible displacement experiments on a loam and a sandy loam. The plateau-linear model fit the published datasets. The estimate of dispersivity was 0.135 cm. The transition of water flow and dispersion process occurred at the critical pore-water velocity 0.216 cm h−1 or Reynolds number of the order of 10−6. Dispersivity in homogeneous soils was interpretated by the turbulent water flow and the eddy dispersion mechanism. It is determined by the structure of rough wall in a soil capillary tube at the miscroscale.
摘要：
Approximately 1 billion people worldwide currently inhabit slum areas. The UN Sustainable Development Goal (SDG 11.1) underscores the imperative of upgrading all slums by 2030 to ensure adequate housing for everyone. Geo-locations of slums help local governments with upgrading slums and alleviating urban poverty. Remote sensing (RS) technology, with its excellent Earth observation capabilities, can play an important role in slum mapping. Deep learning (DL)-based RS information extraction methods have attracted a lot of attention. Currently, DL-based slum mapping studies typically uses three optical bands to adapt to existing models, neglecting essential geo-scientific information, such as spectral and textural characteristics, which are beneficial for slum mapping. Inspired by the geoscience-aware DL paradigm, we propose the Geoscience-Aware Network for slum mapping (GASlumNet), aiming to improve slum mapping accuracies via incorporating the DL model with geoscientific prior knowledge. GASlumNet employs a two-stream architecture, combining ConvNeXt and UNet. One stream concentrates on optical feature representation, while the other emphasizes geo-scientific features. Further, the feature-level and decision-level fusion mechanisms are applied to optimize deep features and enhance model performance. We used Jilin-1 Spectrum 01 and Sentinel-2 images to perform experiments in Mumbai, India. The results demonstrate that GASlumNet achieves higher slum mapping accuracy than the comparison models, with an intersection over union (IoU) of 58.41%. Specifically, GASlumNet improves the IoU by 4.60 similar to 5.97% over the baseline models, i.e., UNet and ConvNeXt-UNet, which exclusively utilize optical bands. Furthermore, GASlumNet enhances the IoU by 10.97% compared to FuseNet, a model that combines optical bands and geo-scientific features. Our method presents a new technical solution to achieve accurate slum mapping, offering potential benefits for regional and global slum mapping and upgrading initiatives.
期刊：
European Journal of Agronomy,2024年155:127104 ISSN：1161-0301
通讯作者：
Jian Zhang
作者机构：
Macro Agriculture Research Institute, College of Resource and Environment, Huazhong Agricultural University, 1 Shizishan Street, Wuhan 430070, China;Key Laboratory of Farmland Conservation in the Middle and Lower Reaches of the Ministry of Agriculture, Wuhan 430070, China;[Chenghai Yang] Aerial Application Technology Research Unit, USDA-Agricultural Research Service, College Station, TX 77845, USA;[Jie Kuai] College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China;[Jing Xie] College of Engineering, Huazhong Agricultural University, Wuhan 430070, China
通讯机构：
[Jian Zhang] M;Macro Agriculture Research Institute, College of Resource and Environment, Huazhong Agricultural University, 1 Shizishan Street, Wuhan 430070, China<&wdkj&>Key Laboratory of Farmland Conservation in the Middle and Lower Reaches of the Ministry of Agriculture, Wuhan 430070, China
摘要：
Crop lodging detrimentally affects crop yield and mechanical harvest efficiency. Traditional remote sensing-based methods primarily focus on the identification and area extraction of lodging using image texture and spectrum. However, the response of image texture and spectrum to lodging is indirect and varies under diverse conditions. Moreover, other important finer details of lodging phenotyping, such as lodging angle and lodging type, have frequently been neglected. In this study, a robust and accurate method was developed for investigating lodging phenotypes in the field. The method was based on the three-dimensional morphological information of rapeseed (Brassica napus L.) canopy reconstructed from unmanned aerial vehicle (UAV) images. In contrast to traditional remote sensing methods that only identify lodging targets and their respective areas, the novel method in this study calculated the total lodging angle (TLA), root lodging angle (RLA), stem lodging angle (SLA = TLA - RLA), and lodging types according to a morphological method and a lodging classification model. Initially, the method employed a geometric model to characterize the stalk shape of lodged rapeseed. After assessing numerous lodging samples from individual rapeseed plants, the circle function was identified as the optimal geometric model. With this optimal function, the canopy height derived from the UAV images was found effective in calculating TLA, RLA, and SLA across 24 rapeseed cultivars in five climatic zones within the Yangtze River Basin (YRB) in China. Results showed that the average root mean square error (RMSE) was 8.3° for TLA and 7.4° for RLA. Subsequently, based on field measured data of SLA and RLA, a decision tree model was constructed to classify lodging types and an accuracy of 95.4% was achieved. Using the classification model and estimated values of RLA and SLA, the spatial distribution information and specific area estimates for different lodging types were obtained. Based on the analysis of these results, the rapeseed cultivars Zhongshuang 11 and Dadi 199 were determined to be the dominant cultivars with lodging resistance in the YRB, even though they did not achieve the mean high yields in multiple climatic zones. However, the lodging-prone cultivars such as Qinyou7 and Qinyou33 fell under the low-yield level in all climatic zones. The robust and cost-effective method proposed in this study for acquiring detailed crop lodging phenotyping data has the potential to enhance mechanized harvesting, accurately estimate the risk of low yield, and assess the lodging status of various crops.
关键词：
biochar;coastal saline soils;polyacrylamide;soil microstructure;water and salt transport
摘要：
Increasing scientific knowledge on the improvement of coastal saline soils is critical for spatially expanding coastal development. Biochar and polyacrylamide (PAM) are popular soil amendments, however, it remains unclear how they affect water and salt transport by regulating soil microstructure characteristics. In this study, we conducted a five-year rice barrel trial and investigated the changes in the aggregates and microstructure of saline soils after adding biochar with three different application rates (B1 = 0%, B2 = 2%, and B3 = 5%, mass ratio) and PAM with three different application rates (P1 = 0%, P2 = 0.4 parts per thousand, and P3 = 1.0 parts per thousand, mass ratio), and simulated the water and salt transport. Results showed that at B1 and B2 treatments, soil mu-CT porosity in 2020 increased by 89.8% and 208.0%, respectively, with respect to that in 2016. The development of soil mesopore structure was promoted at B2 treatments, whereas the P2 and P3 treatments promoted the development of the soil macrostructure. Compared with those of the blank control, soil internal mean water flow rate increased by 22.2% at B2 treatments and 69.2% at P2 treatments, respectively. However, their increases were less pronounced at B3 treatments and the water flow rate decreased by 50.5% at P3 treatments. It might be reasonably attributed to the reason that porous biochar helped the formation of soil pore structure while an excessive amount of biochar blocked soil pores. Furthermore, PAM amendment helped to form soil aggregates while an excessive amount of viscous PAM might block soil pores or form a viscous layer. The time corresponding to the maximum salt concentration was negatively correlated with soil mu-CT porosity (R2 = 0.27) and pore connectivity density (R2 = 0.29). Our findings indicate that appropriate amounts of biochar and PAM can help improve saline soil structure in coastal areas, improve their hydraulic properties, and alleviate salt stress.
期刊：
Global Change Biology,2024年30(1):e17027- ISSN：1354-1013
通讯作者：
Fang, LC
作者机构：
[Fang, Linchuan; Ma, Dengke; Jin, Xiaolian; Fang, LC; Ju, Wenliang; Guo, Liang] Chinese Acad Sci, Inst Soil & Water Conservat, State Key Lab Soil Eros & Dryland Farming Loess Pl, Minist Water Resources, Yangling 712100, Peoples R China.;[Ju, Wenliang] Tsinghua Univ, Sch Environm, Beijing, Peoples R China.;[Fang, Linchuan] Wuhan Univ Technol, Key Lab Green Utilizat Crit Nonmet Mineral Resourc, Minist Educ, Wuhan, Peoples R China.;[Shen, Guoting; Blagodatskaya, Evgenia] UFZ Helmholtz Ctr Environm Res, Dept Soil Ecol, Halle, Saale, Germany.;[Delgado-Baquerizo, Manuel; Zhou, Guiyao] Inst Recursos Nat & Agrobiol Sevilla IRNAS, Lab Biodivers & Funcionamiento Ecosistem, CSIC, Seville, Spain.
通讯机构：
[Fang, LC ] C;Chinese Acad Sci, Inst Soil & Water Conservat, State Key Lab Soil Eros & Dryland Farming Loess Pl, Minist Water Resources, Yangling 712100, Peoples R China.
关键词：
carbon sequestration;grasslands;grazing exclusion;microbial communities and functions;nitrogen and phosphorus accumulation;soil aggregates
摘要：
We linked the soil microscale‐associated microbiomes with the carbon sequestration and biogeochemical cycling of livestock excluded grasslands for up to 36 years. Long‐term grazing exclusion reduced microbial diversity, community stability, and microbial functional genes associated with carbon sequestration and nutrient cycling. Moreover, we emphasize that the interaction between grazing exclusion and longevity as well as the structure of soil aggregates have substantial impacts the grassland biogeochemical cycles and global climate change in which the soil microbiome is involved. Abstract Grazing exclusion alters grassland soil aggregation, microbiome composition, and biogeochemical processes. However, the long‐term effects of grazing exclusion on the microbial communities and nutrient dynamics within soil aggregates remain unclear. We conducted a 36‐year exclusion experiment to investigate how grazing exclusion affects the soil microbial community and the associated soil functions within soil aggregates in a semiarid grassland. Long‐term (36 years) grazing exclusion induced a shift in microbial communities, especially in the <2 mm aggregates, from high to low diversity compared to the grazing control. The reduced microbial diversity was accompanied by instability of fungal communities, extended distribution of fungal pathogens to >2 mm aggregates, and reduced carbon (C) sequestration potential thus revealing a negative impact of long‐term GE. In contrast, 11–26 years of grazing exclusion greatly increased C sequestration and promoted nutrient cycling in soil aggregates and associated microbial functional genes. Moreover, the environmental characteristics of microhabitats (e.g., soil pH) altered the soil microbiome and strongly contributed to C sequestration. Our findings reveal new evidence from soil microbiology for optimizing grazing exclusion duration to maintain multiple belowground ecosystem functions, providing promising suggestions for climate‐smart and resource‐efficient grasslands.
摘要：
Over the past decade, China has experienced a decline in atmospheric reactive nitrogen (Nr) emissions. Given that China's subtropical region is a significant nitrogen (N) deposition hotspot, it is essential to accurately quantify the ten-year variations in dry and wet N depositions in the context of reductions in atmospheric Nr emissions. Here, we evaluated the spatiotemporal variation in N deposition on forest, paddy field and tea field ecosystems in a typical subtropical agricultural catchment from 2011 to 2020. Our findings indicated a significant decrease in total N deposition in both the tea field ecosystem (41.5-30.5kgNha(-1)) and the forest ecosystem (40.8-25.7kgNha(-1)) (P<0.05), but no significant change in the paddy field ecosystem (29.3-32.9kgNha(-1)). Specifically, dry N deposition exhibited significant declines except in the paddy field ecosystem, whereas wet N deposition had no significant change. The reduction in total oxidized and reduced N depositions in forest and tea field ecosystems is attributed to the decrease in NO(x) and NH(3) emissions. Additionally, The ratio of NH(x) deposition to total N deposition all exceeded 0.5 in three ecosystems and the NH(x)/NO(y) ratio had an increasing trend (P<0.05) in the paddy field, indicating that reactive N emissions from agricultural sources were the primary contributor to overall N deposition. Our study emphasizes that despite the decreasing trend in N deposition, it still exceeds the critical loads of natural ecosystems and requires stringent N emissions control, particularly from agricultural sources, in the future.
期刊：
GEOPHYSICAL RESEARCH LETTERS,2024年51(5):e2023GL107316- ISSN：0094-8276
通讯作者：
Yin, GF
作者机构：
[Yin, Gaofei; Yin, GF; Wang, Changjing; Ma, Dujuan; Xie, Jiangliu; Chen, Rui; Wu, Xiaodan] Southwest Jiaotong Univ, Fac Geosci & Environm Engn, Chengdu, Peoples R China.;[Wang, Cong] Cent China Normal Univ, Sch Urban & Environm Sci, Wuhan, Peoples R China.;[Xie, Qiaoyun] Univ Western Australia, Sch Engn, Perth, WA, Australia.
通讯机构：
[Yin, GF ] S;Southwest Jiaotong Univ, Fac Geosci & Environm Engn, Chengdu, Peoples R China.
关键词：
microclimate;phenology;aspects;climate
摘要：
Vegetation growth is influenced by the microclimate driven by aspects, as evident in the asymmetric vegetation greenness on polar-facing slopes (PFS) and equatorial-facing slopes (EFS). However, it remains uncertain whether aspects influence vegetation phenology. To address this question, we defined the aspect-induced phenological differences between PFS and EFS from 2019 to 2022 within each 3 × 3 km2 grid, using average phenological metrics extracted from Sentinel-2 data. We found that the start of the growing season (SOS) occurs earlier on EFS in cold and humid regions, but in arid areas, PFS has an earlier SOS. The end of the growing season (EOS) consistently occurred later on EFS due to radiation limitations in autumn phenology. Employing the space-for-time approach, the observed distribution of phenological differences within the climate space could potentially indicate the phenological trends of different slope orientations in the future. Our study provides valuable insights into topographic regulation on vegetation phenology.
There are significant phenological differences between polar-facing slopes and equatorial-facing slopes
Phenological differences vary under different background climatic conditions
Using the space-for-time approach, the phenological differences in climate space suggest future phenological shifts
Equatorial-facing slopes (EFS) receive more solar radiation than polar-facing slopes (PFS), resulting in contrasting microclimate conditions. Specifically, EFS are warmer and drier, while PFS are colder and wetter. These microclimate differences contribute to variations in vegetation greenness between PFS and EFS. Based on this, we hypothesized that the phenology of grassland in the Three Rivers Source Region on the Tibetan Plateau is influenced by aspects. To test this hypothesis, we calculated the phenological differences between PFS and EFS within each 3 × 3 km2 grid using average phenological metrics derived from Sentinel-2. Our findings reveal that, for the start of the growing season (SOS), EFS exhibited an earlier onset in regions with low temperature and high precipitation, whereas for regions with high temperature, the growing season starts earlier on PFS. In contrast, over 70% of the grassland area on EFS experiences a later end of the growing season (EOS) due to radiation being a major limiting factor of autumn phenology. In addition, we utilized the space-for-time approach to project potential future phenological changes on PFS and EFS. Our study enhances comprehension of vegetation ecological management and carbon sequestration in mountainous areas.
作者机构：
[Yu, Lei; Xu, Yueling; Zhou, Xueyan; Lv, Tianqi; Wang, Caiyun; Huang, Fan] Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat Hubei Prov, Wuhan 430079, Peoples R China.;[Yu, Lei; Xu, Yueling; Zhou, Xueyan; Lv, Tianqi; Wang, Caiyun; Huang, Fan] Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.
通讯机构：
[Yu, L ] C;Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat Hubei Prov, Wuhan 430079, Peoples R China.;Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.
摘要：
This study evaluates the effects of a combined rice-crayfish farming model and compares this model with traditional paddy fields. The focus is on soil aggregate characteristics, organic matter content, and also the distribution of soil aggregates. This research was conducted in Qianjiang, Hubei Province. The surface soil samples were collected from two types of arable land: paddy fields (WR) and rice-crayfish fields (CR). We performed an analysis of soil aggregate distribution and organic matter content. Results reveal that the majority of soil aggregates exceed 2 mm in size (>= 74.94%). The integrated rice-crayfish farming model significantly enhances the presence of large soil aggregates. And these parameters such as the average weight diameter (MWD), average geometric diameter (GWD), and agglomerate stability (PAD) also increase. Moreover, it mitigates agglomerate fragmentation (WASR). However, the net increase in total soil organic matter due to the integrated farming model remains modest. Organic matter content within the agglomerates follows an initial increase followed by a decrease. The highest content occurs in the 0.25-0.5 mm grain size (D4). When examining the distribution of soil aggregates and organic matter, it becomes evident that organic matter primarily originates from grain sizes larger than 2 mm (>= 71.92%). Notably, the rice-crayfish paddy field (CR) exhibits a substantially higher contribution compared to the traditional rice paddy field (WR). This study demonstrates several positive outcomes of the integrated rice-crayfish farming model compared to traditional paddy farming. It promotes the development of larger soil aggregates, enhances the structural integrity of soil aggregates, and improves their mechanical and hydrological stability. Additionally, it marginally increases the organic matter content within each component of soil aggregates. Furthermore, integrated modelling increases the impact of larger soil aggregates on soil organic matter. This improves the quality of the soil and as a result, crop yields are increased. The health of the soil is also improved and this contributes positively to food security.
摘要：
The deteriorating urban thermal environment poses a huge impediment to sustainable urban development, which is closely related to the urban morphology under different urban functional zones (UFZs). By integrating remote sensing and geospatial big data, this work aims to reveal the divergent mechanism behind Urban Heat Island (UHI) across UFZs taking insights from 2D/3D urban morphology. The Minimum Spanning Tree (MST) indicator depicting 3D building distribution was introduced and integrated with the classic indicators. Their impacts on UHI were measured by ensemble learning and SHapley Additive exPlanations (SHAP) model. Taking Wuhan as the study area, the eighteen 2D/3D urban morphology indicators affecting UHI in different locations and UFZs were extensively examined and compared. The results reveal that: 1) The impact of 2D/3D urban morphology indicators on UHI significantly varies across different UFZs, with dominance in transportation zones exhibiting opposite polarity compared to the other types; 2) positive impacts have a decreasing trend from the urban center to the edge, while negative impacts exhibit opposite trend; 3) XGBoost outperforms other classic methods in interpreting the impact of urban morphology on UHI for all UFZ types. The findings improving knowledge of UHI across UFZs will provide a practical guide for urban planning.
期刊：
Journal of Cleaner Production,2024年434:139854 ISSN：0959-6526
通讯作者：
Gong, J
作者机构：
[Gao, Haoran; Ye, Teng; Gong, Jian] China Univ Geosci, Sch Publ Adm, Wuhan 430074, Peoples R China.;[Gao, Haoran; Ye, Teng; Gong, Jian] Minist Nat Resources, Key Lab Land & Resources Law Evaluat Project, Wuhan 430074, Peoples R China.;[Liu, Jiakang] Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430074, Peoples R China.
通讯机构：
[Gong, J ] C;China Univ Geosci, Sch Publ Adm, Wuhan 430074, Peoples R China.;Minist Nat Resources, Key Lab Land & Resources Law Evaluat Project, Wuhan 430074, Peoples R China.
关键词：
Ecological functional areas;Comparative analysis;Quantitatively analyze the drivers;Changes of SOC stocks;Carbon sequestration potential
摘要：
Understanding the process of land use/cover changes (LUCC) can provide experience on the enhancement of soil organic carbon (SOC) stocks and carbon sequestration potential for different areas. This study is uniquely to divide different ecological functional areas, and originally combine the machine learning method and soil carbon pool dataset for regional comparative analysis, to compare and quantitatively analyze the drivers of LUCC and the changes in SOC stocks effected by LUCC over 30 years. The results show that topography and climate changes are the main drivers affecting LUCC in four natural areas, while soil factors and population changes do not cause significant effects. The total SOC stocks in Qinghai was increased by 71.18 Tg C and 107.19 Tg C in 0–30 cm and 0–300 cm layers, respectively, and the highest SOC stocks within 0–300 cm were in Pastoral area. Desert and Gobi area had the lowest SOC stocks in both 0–30 cm and 0–300 cm layers. SOC stocks increased in both 0–30 cm and 0–300 cm layers only in Sanjiangyuan Natural Reserve, while the Desert and Gobi area showed a decrease in both over 30 years. This study emphasizes the significant impact of grassland changes on SOC stocks, indicating the importance of considering these changes in land management and ecological protection policies. The initial and original SOC stocks of pre-LUCC may influence the SOC stocks in post-LUCC. The response of SOC stocks changes to LUCC was varies in different areas. The heterogeneity of different ecological functional areas is affected by multiple factors and SOC stocks will become more complex among these areas in the future. These findings contribute to the development of ecological protection policies and the enhancement of regional land management strategies.
期刊：
Journal for Nature Conservation,2024年:126563 ISSN：1617-1381
通讯作者：
Jing Hu
作者机构：
[Huangting Deng] College of Urban and Environmental Sciences, Central China Normal University, Wuhan 430079, Hubei, China;Wuhan Branch of China Tourism Academy, Wuhan 430079, Hubei, China;[Jing Hu] College of Urban and Environmental Sciences, Central China Normal University, Wuhan 430079, Hubei, China<&wdkj&>Wuhan Branch of China Tourism Academy, Wuhan 430079, Hubei, China
通讯机构：
[Jing Hu] C;College of Urban and Environmental Sciences, Central China Normal University, Wuhan 430079, Hubei, China<&wdkj&>Wuhan Branch of China Tourism Academy, Wuhan 430079, Hubei, China
摘要：
Resource-based cities are an important concern for the construction of ecological civilization in China, and developing tourism is an important direction for the transformation of resource-based cities. Based on the mechanism of the coupling and coordination effect of ecological civilization construction and tourism development, four different types of resource-based cities in China, Wuwei City (growing type), Pingliang City (mature type), Baiyin City (declining type) and Zhangye City (regenerative type), were selected as the research area. Based on the improved entropy weight method, coupling coordination model and obstacle model, the evaluation index system of ecological civilization construction and tourism development in resource-based cities was constructed, and its coupling development status and obstacle factors were analyzed. According to the results: (1) From 2013 to 2020, the comprehensive scores of ecological civilization construction of four different types of resource-based cities were higher than that of tourism development. They were divided into two gradients according to the comprehensive score of ecological civilization construction. The first gradient was the regeneration and maturity of resource-based cities, while the other gradient was growth and decline of resource-based cities. The comprehensive score of tourism development of four resource-based cities were regeneration, maturity, growth and decline in turn. (2) The coupling degree between regenerative and mature resource-based cities was the best. All of them were in the period of coordinated coupling during the study period, and the coupling degree tended to 1. (3) The regenerative resource city had the highest degree of coupling and coordination between the two systems, followed by mature, growing and finally declining type. (4) Among growing, mature, and declining resource-based cities, the obstacle degree of the tourism development system layer was always higher than that of the ecological civilization construction system layer, while the result was the opposite for regenerative resource-based cities.
摘要：
Accurate monitoring of soil organic carbon (SOC) is critical for sustainable management of soil for improving its quality, function, and carbon sequestration. As a nondestructive, efficient, and low-cost technique, mid-infrared (MIR) spectroscopy has shown a great potential in rapid estimation of SOC, despite limited studies of the global scale. The objective of this work was to use a globally distributed topsoil MIR spectral library with 33,039 samples to predict SOC using different modeling methods. Effects of nine fractional-order derivatives (FODs) on the predicted accuracy of SOC were evaluated using four regression algorithms (i.e., ratio index-based linear regression, RI-LR; partial least squares regression, PLSR; Cubist; convolutional neural network, CNN). Square-root transformation to SOC data was performed to minimize the skewness and non-linearity. Results indicated FOD to capture the subtle spectral details related to SOC, leading to improved predictions that may not be possible by the raw absorbance and common integer-order derivatives. Concerning the RI-LR models, the optimal validation result for SOC was obtained by 0.75-order derivative, with the ratio of performance to inter-quartile distance (RPIQ) of 1.85. Regarding the full-spectrum modeling for SOC, the CNN outperformed PLSR and Cubist models, irrespective of raw absorbance or eight FODs; the best-performing CNN model was achieved by 1.25-order derivative (validation RPIQ = 6.33). It can be concluded that accurate estimation of SOC using large and diverse MIR spectral library at the global scale combined with deep-learning CNN model is feasible. This global-scale database is extremely valuable for us to deal with the shortage of soil data and to monitor the soils at different geographical scales.
关键词：
aridity;biogeography;climate change;deep soil;microbial biodiversity and function;soil depth;water heterogeneity
摘要：
Our results contribute to broader and deeper knowledge of climate change microbiology in deep soil environments under future climate scenarios. We proposes a potential mechanism for the association between climate aridity and deep soil microbes; that is, when the external aridity changes, water evapotranspiration (including plant transpiration and soil water evaporation) is directly and indirectly (e.g., changes in rooting depths and soil texture) affected, and a volumetric soil moisture gradient (related to soil porosity) is formed to primarily drive microorganisms in deep soil. Abstract Microbes inhabiting deep soil layers are known to be different from their counterpart in topsoil yet remain under investigation in terms of their structure, function, and how their diversity is shaped. The microbiome of deep soils (>1 m) is expected to be relatively stable and highly independent from climatic conditions. Much less is known, however, on how these microbial communities vary along climate gradients. Here, we used amplicon sequencing to investigate bacteria, archaea, and fungi along fifteen 18‐m depth profiles at 20–50‐cm intervals across contrasting aridity conditions in semi‐arid forest ecosystems of China's Loess Plateau. Our results showed that bacterial and fungal α diversity and bacterial and archaeal community similarity declined dramatically in topsoil and remained relatively stable in deep soil. Nevertheless, deep soil microbiome still showed the functional potential of N cycling, plant‐derived organic matter degradation, resource exchange, and water coordination. The deep soil microbiome had closer taxa–taxa and bacteria–fungi associations and more influence of dispersal limitation than topsoil microbiome. Geographic distance was more influential in deep soil bacteria and archaea than in topsoil. We further showed that aridity was negatively correlated with deep‐soil archaeal and fungal richness, archaeal community similarity, relative abundance of plant saprotroph, and bacteria–fungi associations, but increased the relative abundance of aerobic ammonia oxidation, manganese oxidation, and arbuscular mycorrhizal in the deep soils. Root depth, complexity, soil volumetric moisture, and clay play bridging roles in the indirect effects of aridity on microbes in deep soils. Our work indicates that, even microbial communities and nutrient cycling in deep soil are susceptible to changes in water availability, with consequences for understanding the sustainability of dryland ecosystems and the whole‐soil in response to aridification. Moreover, we propose that neglecting soil depth may underestimate the role of soil moisture in dryland ecosystems under future climate scenarios.
