Łukasz Dylewski, Łukasz Maćkowiak, Marcin K. Dyderski
Linear structures such as woodlots and hedgerows offer many benefits to ecosystems, including enhancing biodiversity, increasing the abundance of plants and animals, and providing a wide range of ecosystem services. However, agriculture expansion has deteriorated and destroyed these elements in the farmland landscape. Human‐made structures like road verges, electricity pylons, or railways may enhance biodiversity in intensive farmland, replacing natural woody elements. We aimed to explore whether abandoned railway lines in agriculture‐dominated landscapes can serve as alternative habitats for plant species. We evaluated the taxonomical, functional, and phylogenetic diversity, along with the community composition of plants, in 25 sites along abandoned railway lines and 25 reference sites in adjacent semi‐natural grasslands. We found no significant difference in species richness and Shannon diversity between grasslands and abandoned railway vegetation, but we observed distinct differences in functional and phylogenetic diversity. Moreover, the vegetation along abandoned railways is not a variant of surrounding semi‐natural grasslands but comprises a novel vegetation type composed of species associated mainly with crops, ruderal, and forest habitats. Abandoned railway lines are characterized by specific abiotic conditions providing a set of opportunities for shaping distinct plant communities in an intensively managed agricultural landscape, fulfilling the concept of a novel ecosystem. Abandoned railways offer a unique opportunity for conservation and can serve as valuable dispersal corridors and habitats for plants, increasing functional and phylogenetic diversity in agricultural landscapes. Combining ecological restoration techniques and sustainable land management practices can help support plant diversity on abandoned railways.
{"title":"Abandoned Railways Support Greater Functional and Phylogenetic Plant Diversity Than Adjacent Grassy Meadows in Agricultural Landscape","authors":"Łukasz Dylewski, Łukasz Maćkowiak, Marcin K. Dyderski","doi":"10.1002/ldr.5383","DOIUrl":"https://doi.org/10.1002/ldr.5383","url":null,"abstract":"Linear structures such as woodlots and hedgerows offer many benefits to ecosystems, including enhancing biodiversity, increasing the abundance of plants and animals, and providing a wide range of ecosystem services. However, agriculture expansion has deteriorated and destroyed these elements in the farmland landscape. Human‐made structures like road verges, electricity pylons, or railways may enhance biodiversity in intensive farmland, replacing natural woody elements. We aimed to explore whether abandoned railway lines in agriculture‐dominated landscapes can serve as alternative habitats for plant species. We evaluated the taxonomical, functional, and phylogenetic diversity, along with the community composition of plants, in 25 sites along abandoned railway lines and 25 reference sites in adjacent semi‐natural grasslands. We found no significant difference in species richness and Shannon diversity between grasslands and abandoned railway vegetation, but we observed distinct differences in functional and phylogenetic diversity. Moreover, the vegetation along abandoned railways is not a variant of surrounding semi‐natural grasslands but comprises a novel vegetation type composed of species associated mainly with crops, ruderal, and forest habitats. Abandoned railway lines are characterized by specific abiotic conditions providing a set of opportunities for shaping distinct plant communities in an intensively managed agricultural landscape, fulfilling the concept of a novel ecosystem. Abandoned railways offer a unique opportunity for conservation and can serve as valuable dispersal corridors and habitats for plants, increasing functional and phylogenetic diversity in agricultural landscapes. Combining ecological restoration techniques and sustainable land management practices can help support plant diversity on abandoned railways.","PeriodicalId":203,"journal":{"name":"Land Degradation & Development","volume":"23 1","pages":""},"PeriodicalIF":4.7,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. G. Velásquez Ramírez, J. C. Nazario Rios, A. Gobin, M. Pillaca, E. Thomas, J. A. Guerrero Barrantes, U. Román, E. Becerra Lira, A. Muñoz Ushñahua, P. Nascimento Herbay, L. Rodriguez Achata, J. Garate‐Quispe, S. Malpica, R. Russo, M. Abril, L. F. S. Dionisio, R. Corvera Gomringer, D. del Castillo Torres
Artisanal and Small‐Scale Gold Mining (ASGM) carried out by individual miners or small enterprises with limited capital, significantly contribute to land degradation and loss of biodiversity‐rich forests in the Amazon. Due to limited information on the edaphic conditions crucial for restoring these degraded areas, a soil evaluation method was employed in representative locations of the Peruvian Amazon, including two native communities and one protected natural area. The categorization of ASGM‐degraded areas into cultural landscape units was confirmed and validated. Sentinel‐2 and UAV remote sensing revealed over 122,000 ha of deforestation since the 1980s. Surface and soil profile assessments identified extreme new soil conditions with low chemical and physical fertility, characterized by coarse texture and rock fragments, which hinder revegetation, especially during prolonged dry seasons. These degraded soils were classified as Entisols and Technosols according to Soil Taxonomy and the World Reference Base. Over time, natural regeneration and plantations improved soil formation, aligning with recognized soil classification systems. Under current management practices, restoration planning should prioritize selected shrub and tree species, and consider soil amendments to initiate soil recovery. This approach aligns with self‐sustaining successional stages and contributes to the objectives of Land Degradation Neutrality, Appropriate Mitigation and Adaptation Actions, and Sustainable Development Goals.
{"title":"Degradation, Classification, and Management of Soils From Alluvial‐Gold Mine Spoils in the Southeastern Peruvian Amazon","authors":"M. G. Velásquez Ramírez, J. C. Nazario Rios, A. Gobin, M. Pillaca, E. Thomas, J. A. Guerrero Barrantes, U. Román, E. Becerra Lira, A. Muñoz Ushñahua, P. Nascimento Herbay, L. Rodriguez Achata, J. Garate‐Quispe, S. Malpica, R. Russo, M. Abril, L. F. S. Dionisio, R. Corvera Gomringer, D. del Castillo Torres","doi":"10.1002/ldr.5365","DOIUrl":"https://doi.org/10.1002/ldr.5365","url":null,"abstract":"Artisanal and Small‐Scale Gold Mining (ASGM) carried out by individual miners or small enterprises with limited capital, significantly contribute to land degradation and loss of biodiversity‐rich forests in the Amazon. Due to limited information on the edaphic conditions crucial for restoring these degraded areas, a soil evaluation method was employed in representative locations of the Peruvian Amazon, including two native communities and one protected natural area. The categorization of ASGM‐degraded areas into cultural landscape units was confirmed and validated. Sentinel‐2 and UAV remote sensing revealed over 122,000 ha of deforestation since the 1980s. Surface and soil profile assessments identified extreme new soil conditions with low chemical and physical fertility, characterized by coarse texture and rock fragments, which hinder revegetation, especially during prolonged dry seasons. These degraded soils were classified as Entisols and Technosols according to Soil Taxonomy and the World Reference Base. Over time, natural regeneration and plantations improved soil formation, aligning with recognized soil classification systems. Under current management practices, restoration planning should prioritize selected shrub and tree species, and consider soil amendments to initiate soil recovery. This approach aligns with self‐sustaining successional stages and contributes to the objectives of Land Degradation Neutrality, Appropriate Mitigation and Adaptation Actions, and Sustainable Development Goals.","PeriodicalId":203,"journal":{"name":"Land Degradation & Development","volume":"246 1","pages":""},"PeriodicalIF":4.7,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In desert ecosystems, afforestation with xerophytic shrubs has the potential to significantly increase soil nutrient levels by mitigating wind and soil erosion. Nevertheless, further investigation is required to elucidate the changes in soil organic carbon (SOC) fractions and stability on different soil depths with afforestation years. We collected soil samples from the 0–20, 20–60, and 60–100 cm depths of three xerophytic shrublands ages (3, 7, and 10 years), with a natural desert as the control, in a hyper‐arid desert region. We investigated the variations of SOC fractions (stable and active C) and stability (stability index and MAOC:POC ratios) after afforestation. The results showed that the rate of increase in SOC fractions and stability did not follow a linear trajectory with afforestation years. Instead, they accelerated around 7 years but then decreased after 10 years. The increase in SOC stability was primarily attributed to the greater increase in stable C within the total SOC pool. Afforestation increased the concentration of ROC from 0.26 to 0.89 g kg−1 and MAOC from 0.11 to 0.78 g kg−1. Afforestation increased SOC stability by 74.36%–231% compared to the CK in the 0–100 cm. SOC stability in the 60–100 cm was higher than that in the 0–20 cm layer, while SOC stability varied insignificantly across soil layers. The strongest direct positive impact on SOC stability was attributed to changes in soil physicochemical properties rather than soil microbial biomass or aggregate stability. These findings contribute to our understanding of the importance of afforestation in increasing SOC stability in desert ecosystems.
{"title":"Afforestation With Xerophytic Shrubs Promoted Soil Organic Carbon Stability in a Hyper‐Arid Environment of Desert","authors":"Guangxing Zhao, Akash Tariq, Zhihao Zhang, Muhammad Nazim, Corina Graciano, Jordi Sardans, Xinping Dong, Yanju Gao, Josep Peñuelas, Fanjiang Zeng","doi":"10.1002/ldr.5387","DOIUrl":"https://doi.org/10.1002/ldr.5387","url":null,"abstract":"In desert ecosystems, afforestation with xerophytic shrubs has the potential to significantly increase soil nutrient levels by mitigating wind and soil erosion. Nevertheless, further investigation is required to elucidate the changes in soil organic carbon (SOC) fractions and stability on different soil depths with afforestation years. We collected soil samples from the 0–20, 20–60, and 60–100 cm depths of three xerophytic shrublands ages (3, 7, and 10 years), with a natural desert as the control, in a hyper‐arid desert region. We investigated the variations of SOC fractions (stable and active C) and stability (stability index and MAOC:POC ratios) after afforestation. The results showed that the rate of increase in SOC fractions and stability did not follow a linear trajectory with afforestation years. Instead, they accelerated around 7 years but then decreased after 10 years. The increase in SOC stability was primarily attributed to the greater increase in stable C within the total SOC pool. Afforestation increased the concentration of ROC from 0.26 to 0.89 g kg<jats:sup>−1</jats:sup> and MAOC from 0.11 to 0.78 g kg<jats:sup>−1</jats:sup>. Afforestation increased SOC stability by 74.36%–231% compared to the CK in the 0–100 cm. SOC stability in the 60–100 cm was higher than that in the 0–20 cm layer, while SOC stability varied insignificantly across soil layers. The strongest direct positive impact on SOC stability was attributed to changes in soil physicochemical properties rather than soil microbial biomass or aggregate stability. These findings contribute to our understanding of the importance of afforestation in increasing SOC stability in desert ecosystems.","PeriodicalId":203,"journal":{"name":"Land Degradation & Development","volume":"11 1","pages":""},"PeriodicalIF":4.7,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Clemence Muitire, Francis Zvomuya, Theresa Adesanya, Inoka Amarakoon, Afua Mante
The construction of underground pipelines negatively impacts soil productivity in various ecosystems. However, the temporal progression in the recovery of soil productivity following the reclamation of cropland impacted by natural gas pipeline rights‐of‐way (ROWs) construction remains unclear. This study examined temporal, post‐reclamation changes in selected soil health indicators and productivity on reclaimed underground natural gas pipeline ROWs on cropland. Soil and crop samples were collected from ROWs ranging in time elapsed since reclamation (TSR) from 6 to 12 years and from adjacent undisturbed locations (off‐ROW) in the same field. The soil samples were analyzed for soil health indicators (permanganate‐oxidizable carbon (POXC), soil respiration, and autoclaved citrate‐extractable (ACE) protein) and selected chemical properties. Crop samples were assessed for grain and total biomass yields as well as grain protein content. Compared to the off‐ROW, soil organic C on the ROWs was 29% (6‐year ROW) and 33% (9‐year ROW) lower than on the off‐ROWs. Soil respiration recovered within 6 years of ROW reclamation, whereas it took 12 years for POXC and ACE protein to recover to off‐ROW levels. Grain and biomass yields 12 years post‐reclamation were still 42% and 36%, respectively, lower on the ROWs than on the off‐ROWs. However, measured soil attributes recovered faster than crop variables, indicating that pipeline construction on cropland has longer‐term impacts on crop yields than on soil attributes. These results indicate that, although underground pipeline construction has detrimental impacts on soil and crop attributes, these attributes would slowly recover to pre‐construction levels with increasing TSR.
{"title":"Temporal Trends in Soil Health and Productivity on Reclaimed Natural Gas Pipeline Rights‐of‐Way on Cropland","authors":"Clemence Muitire, Francis Zvomuya, Theresa Adesanya, Inoka Amarakoon, Afua Mante","doi":"10.1002/ldr.5389","DOIUrl":"https://doi.org/10.1002/ldr.5389","url":null,"abstract":"The construction of underground pipelines negatively impacts soil productivity in various ecosystems. However, the temporal progression in the recovery of soil productivity following the reclamation of cropland impacted by natural gas pipeline rights‐of‐way (ROWs) construction remains unclear. This study examined temporal, post‐reclamation changes in selected soil health indicators and productivity on reclaimed underground natural gas pipeline ROWs on cropland. Soil and crop samples were collected from ROWs ranging in time elapsed since reclamation (TSR) from 6 to 12 years and from adjacent undisturbed locations (off‐ROW) in the same field. The soil samples were analyzed for soil health indicators (permanganate‐oxidizable carbon (POXC), soil respiration, and autoclaved citrate‐extractable (ACE) protein) and selected chemical properties. Crop samples were assessed for grain and total biomass yields as well as grain protein content. Compared to the off‐ROW, soil organic C on the ROWs was 29% (6‐year ROW) and 33% (9‐year ROW) lower than on the off‐ROWs. Soil respiration recovered within 6 years of ROW reclamation, whereas it took 12 years for POXC and ACE protein to recover to off‐ROW levels. Grain and biomass yields 12 years post‐reclamation were still 42% and 36%, respectively, lower on the ROWs than on the off‐ROWs. However, measured soil attributes recovered faster than crop variables, indicating that pipeline construction on cropland has longer‐term impacts on crop yields than on soil attributes. These results indicate that, although underground pipeline construction has detrimental impacts on soil and crop attributes, these attributes would slowly recover to pre‐construction levels with increasing TSR.","PeriodicalId":203,"journal":{"name":"Land Degradation & Development","volume":"73 1","pages":""},"PeriodicalIF":4.7,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142610156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Research on sustainable livelihoods tend to emphasis on objective and macroregional aspects. However, there is space to expand research on the farmers' livelihoods in the context of poverty alleviation and rural revitalization development. This paper uses a field survey on farmers' livelihood efficiency, influencing factors and mechanisms of farmers' livelihood efficiency in the Qinba mountainous areas of southern Shaanxi China. Based on DEA and Tobit approaches, the authors investigate farmer livelihood efficiency and analyze the disparities according to the farm households' socio‐demographics descriptions. Findings of this study show that, livelihood efficiency is a new entry point of sustainable livelihoods for farmers, and currently, the overall livelihood efficiency of farmers in the study area is low, which needs to be further improved. The results also show that the willingness of environmental protection activities, village busses and government financial expenditure have a significant positive impact on the livelihood efficiency, while the abandonment has a significant negative impact on the livelihood efficiency of farmers. These factors have significant differences in the impact of farmers' technical efficiency and scale efficiency. The results further indicate that, utilization and conversion rate of the existing livelihood capital of farmers is low. Livelihood diversification should be stimulated to enhance “livelihood export” and its operation ability of livelihood capital accumulation. The study findings also propose that, there is a need of reform of dual paths to improve the efficiency of farmers' livelihood, and promote farmers' livelihood development with “wide path” and “wide choice.”
对可持续生计的研究往往侧重于客观和宏观的地区方面。然而，在脱贫攻坚和乡村振兴发展的背景下，对农民生计的研究还有拓展的空间。本文通过对陕南秦巴山区农民生计效率、农民生计效率的影响因素和机制进行实地调查。基于 DEA 和 Tobit 方法，作者调查了农民的生计效率，并根据农户的社会人口特征描述分析了差距。研究结果表明，生计效率是农民可持续生计的新切入点，目前研究区农民的总体生计效率较低，有待进一步提高。结果还显示，环保活动意愿、村村通客车和政府财政支出对生计效率有显著的正向影响，而弃耕对农民生计效率有显著的负向影响。这些因素对农户技术效率和规模效率的影响存在显著差异。结果进一步表明，农民现有生计资本的利用率和转化率较低。应鼓励生计多样化，以增强 "生计出口 "及其生计资本积累的运作能力。研究结果还提出，需要通过双路径改革来提高农民生计效率，促进农民生计发展的 "宽路径 "和 "宽选择"。
{"title":"Quantifying farmers' Livelihood Efficiency, Regional Indicators and Its Influencing Factors: Implementing an Improved Sustainable Livelihood Framework","authors":"Fang Su, Bingjie Fan, Nini Song, Shah Fahad","doi":"10.1002/ldr.5374","DOIUrl":"https://doi.org/10.1002/ldr.5374","url":null,"abstract":"Research on sustainable livelihoods tend to emphasis on objective and macroregional aspects. However, there is space to expand research on the farmers' livelihoods in the context of poverty alleviation and rural revitalization development. This paper uses a field survey on farmers' livelihood efficiency, influencing factors and mechanisms of farmers' livelihood efficiency in the Qinba mountainous areas of southern Shaanxi China. Based on DEA and Tobit approaches, the authors investigate farmer livelihood efficiency and analyze the disparities according to the farm households' socio‐demographics descriptions. Findings of this study show that, livelihood efficiency is a new entry point of sustainable livelihoods for farmers, and currently, the overall livelihood efficiency of farmers in the study area is low, which needs to be further improved. The results also show that the willingness of environmental protection activities, village busses and government financial expenditure have a significant positive impact on the livelihood efficiency, while the abandonment has a significant negative impact on the livelihood efficiency of farmers. These factors have significant differences in the impact of farmers' technical efficiency and scale efficiency. The results further indicate that, utilization and conversion rate of the existing livelihood capital of farmers is low. Livelihood diversification should be stimulated to enhance “livelihood export” and its operation ability of livelihood capital accumulation. The study findings also propose that, there is a need of reform of dual paths to improve the efficiency of farmers' livelihood, and promote farmers' livelihood development with “wide path” and “wide choice.”","PeriodicalId":203,"journal":{"name":"Land Degradation & Development","volume":"19 1","pages":""},"PeriodicalIF":4.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142599171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Phosphorus (P) is the key nutritional element in the soil of cut road slopes undergoing ecological restoration, and the transformation of organic P (Po) is a crucial part of the P cycle. However, the role of phoD‐harboring bacteria in driving the mineralization of Po fractions in road slope soil aggregates is unclear. This study analyzed road slope soils that had undergone 7, 11, and 14 years of restoration in the western Sichuan Plateau of China. We examined the differences and associations between the Po fraction content, alkaline phosphatase (ALP) activity, and community composition of rare and abundant phoD‐harboring bacteria in soil aggregates of four particle sizes (0.053–0.25, 0.25–2, 0.053–0.25, and, > 2 mm). The results showed that NaHCO3‐extracted Po (NaHCO3‐Po) content in soil aggregates increased with restoration years, while NaOH‐extracted Po (NaOH‐Po) content decreased. ALP activity in soil aggregates increased with restoration years, but there was no significant relationship between ALP activity with the phoD‐harboring bacterial community. There were significant differences in the composition of rare and abundant phoD‐harboring bacterial communities during slope restoration. Soil moisture, pH, organic carbon, and the C:P ratio in soil aggregates were the primary factors affecting the distribution of the Po fractions and the phoD‐harboring bacterial community. NaHCO3‐Po and NaOH‐Po in soil aggregates were likely the main substrates for ALP‐mediated Po mineralization. More genera were involved in Po mineralization in slope soils restored for 14 years than in soils restored for 7 and 11 years, and rare phoD‐harboring genera were more actively involved in Po mineralization than abundant phoD‐harboring genera. This study provides some theoretical basis for P effectiveness enhancement and P management during slope soil restoration.
磷（P）是正在进行生态恢复的公路边坡土壤中的主要营养元素，而有机磷（Po）的转化是磷循环的关键部分。然而，噬菌体在推动公路边坡土壤团聚体中 Po 部分矿化过程中所起的作用尚不清楚。本研究分析了中国川西高原经过 7 年、11 年和 14 年修复的公路边坡土壤。我们研究了四种粒径（0.053-0.25、0.25-2、0.053-0.25 和 2 mm）土壤团聚体中 Po 组分含量、碱性磷酸酶（ALP）活性以及稀有和丰富 phoD-harboring细菌群落组成之间的差异和关联。结果表明，土壤团聚体中 NaHCO3 萃取的 Po（NaHCO3-Po）含量随着修复年限的增加而增加，而 NaOH 萃取的 Po（NaOH-Po）含量则随着修复年限的增加而减少。土壤团聚体中的 ALP 活性随着恢复年限的增加而增加，但 ALP 活性与 phoD-有害细菌群落之间没有显著关系。在斜坡修复过程中，稀有和丰富的噬菌体群落组成存在明显差异。土壤水分、pH 值、有机碳和土壤团聚体中的碳-磷比例是影响 Po 分馏物和 phoD-噬菌体群落分布的主要因素。土壤团聚体中的 NaHCO3-Po 和 NaOH-Po 可能是 ALP 介导的 Po 矿化的主要底物。与恢复 7 年和 11 年的土壤相比，恢复 14 年的斜坡土壤中有更多的菌属参与了 Po 矿化过程，而且稀有的 phoD-arboring 菌属比丰富的 phoD-arboring 菌属更积极地参与了 Po 矿化过程。这项研究为坡地土壤修复过程中提高磷有效性和磷管理提供了一些理论依据。
{"title":"Rare and Abundant phoD‐Harboring Bacteria Mediate the Mineralization of Organic Phosphorus Fractions in Soil Aggregates During Cut Slope Restoration","authors":"Zongyang Liu, Shenghao Ai, Meihua Sheng, Jingyao Xiao, Fuyun Pei, Yingwei Ai, Xue Jiang, Xiaoyan Ai","doi":"10.1002/ldr.5371","DOIUrl":"https://doi.org/10.1002/ldr.5371","url":null,"abstract":"Phosphorus (P) is the key nutritional element in the soil of cut road slopes undergoing ecological restoration, and the transformation of organic P (Po) is a crucial part of the P cycle. However, the role of <jats:italic>phoD</jats:italic>‐harboring bacteria in driving the mineralization of Po fractions in road slope soil aggregates is unclear. This study analyzed road slope soils that had undergone 7, 11, and 14 years of restoration in the western Sichuan Plateau of China. We examined the differences and associations between the Po fraction content, alkaline phosphatase (ALP) activity, and community composition of rare and abundant <jats:italic>phoD</jats:italic>‐harboring bacteria in soil aggregates of four particle sizes (0.053–0.25, 0.25–2, 0.053–0.25, and, > 2 mm). The results showed that NaHCO<jats:sub>3</jats:sub>‐extracted Po (NaHCO<jats:sub>3</jats:sub>‐Po) content in soil aggregates increased with restoration years, while NaOH‐extracted Po (NaOH‐Po) content decreased. ALP activity in soil aggregates increased with restoration years, but there was no significant relationship between ALP activity with the <jats:italic>phoD</jats:italic>‐harboring bacterial community. There were significant differences in the composition of rare and abundant <jats:italic>phoD</jats:italic>‐harboring bacterial communities during slope restoration. Soil moisture, pH, organic carbon, and the C:P ratio in soil aggregates were the primary factors affecting the distribution of the Po fractions and the <jats:italic>phoD</jats:italic>‐harboring bacterial community. NaHCO<jats:sub>3</jats:sub>‐Po and NaOH‐Po in soil aggregates were likely the main substrates for ALP‐mediated Po mineralization. More genera were involved in Po mineralization in slope soils restored for 14 years than in soils restored for 7 and 11 years, and rare <jats:italic>phoD</jats:italic>‐harboring genera were more actively involved in Po mineralization than abundant <jats:italic>phoD</jats:italic>‐harboring genera. This study provides some theoretical basis for P effectiveness enhancement and P management during slope soil restoration.","PeriodicalId":203,"journal":{"name":"Land Degradation & Development","volume":"95 1","pages":""},"PeriodicalIF":4.7,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142599173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ming‐Xu Zhang, Jin‐Peng Hu, Jia‐Lü Li, Zhuo Che, Li Li, Zhao‐Long Lü, Wan‐Qing Dong, Jian‐Quan Zhang, Tuo Yao, Ting‐Yu Duan, Jin‐Lin Zhang
Legume species are essential components of plant diversity and affect soil biodiversity across various ecosystems. Their effect on the diversity and traits of soil bacteria, particularly in degraded grasslands, remains unknown. This study analysed the relationships among plant diversity, soil traits and legume‐associated rhizobacterial communities in Xiahe (XH) and Maqu (MQ) in Gansu Province, Haibei (HB) in Qinghai Province and Hongyuan (HY) in Sichuan Province in the eastern Qinghai‐Tibetan Plateau (QTP). The diversity index values (coverage, richness, Shannon index and evenness) of legume species were positively correlated with plant diversity. Several soil nutrients (ammonia‐nitrogen, nitrate‐nitrogen, total nitrogen, available potassium, available phosphorus and soil organic matter) and enzymes (urease, sucrase, peroxidase and dehydrogenase) were lower in HB and HY than in XH and MQ. The Shannon index for rhizobacterial diversity was higher in HB and HY than in XH and MQ. In contrast, the diversity index values were higher for geographical locations than for sympatric plant species. Additionally, HB and HY showed 50% fewer positive and negative associations with rhizobacteria than XH and MQ. Functional Annotation of Prokaryotic Taxa analysis indicated a higher relative abundance of nitrate reduction occurred in HB and HY than in XH and MQ, whereas nitrogen fixation occurred at a lower level in HB and HY than in XH and MQ. The Simpson index value for bacterial diversity was positively correlated with plant diversity, legume species diversity and soil multifunctionality. However, the Shannon index value was negatively correlated with these parameters. Changes in the composition of legume‐associated rhizobacteria across different geographical locations are strongly influenced by plant diversity and soil nutrients, reflecting the distribution characteristics of legumes in alpine grasslands.
豆科物种是植物多样性的重要组成部分，影响着各种生态系统的土壤生物多样性。它们对土壤细菌多样性和性状的影响，尤其是对退化草地土壤细菌多样性和性状的影响，仍是未知数。本研究分析了青藏高原东部甘肃省夏河（XH）和玛曲（MQ）、青海省海北（HB）和四川省红原（HY）的植物多样性、土壤性状和豆科相关根瘤菌群落之间的关系。豆科植物的多样性指数值（覆盖度、丰富度、香农指数和均匀度）与植物多样性呈正相关。HB 和 HY 的几种土壤养分（氨氮、硝态氮、全氮、可利用钾、可利用磷和土壤有机质）和酶（脲酶、蔗糖酶、过氧化物酶和脱氢酶）均低于 XH 和 MQ。根瘤菌多样性的香农指数在 HB 和 HY 中高于 XH 和 MQ。相比之下，地理位置的多样性指数值高于同域植物物种的多样性指数值。此外，与 XH 和 MQ 相比，HB 和 HY 与根瘤菌的正负相关要少 50%。原核生物类群功能注释分析表明，HB 和 HY 的硝酸盐还原相对丰度高于 XH 和 MQ，而 HB 和 HY 的固氮水平低于 XH 和 MQ。细菌多样性的辛普森指数值与植物多样性、豆科植物物种多样性和土壤多功能性呈正相关。然而，香农指数值与这些参数呈负相关。豆科植物相关根瘤菌在不同地理位置的组成变化受植物多样性和土壤养分的影响很大，反映了豆科植物在高寒草地的分布特点。
{"title":"Responses of Legume‐Associated Rhizobacterial Communities to Plant Diversity and Soil Traits in Alpine Grassland","authors":"Ming‐Xu Zhang, Jin‐Peng Hu, Jia‐Lü Li, Zhuo Che, Li Li, Zhao‐Long Lü, Wan‐Qing Dong, Jian‐Quan Zhang, Tuo Yao, Ting‐Yu Duan, Jin‐Lin Zhang","doi":"10.1002/ldr.5369","DOIUrl":"https://doi.org/10.1002/ldr.5369","url":null,"abstract":"Legume species are essential components of plant diversity and affect soil biodiversity across various ecosystems. Their effect on the diversity and traits of soil bacteria, particularly in degraded grasslands, remains unknown. This study analysed the relationships among plant diversity, soil traits and legume‐associated rhizobacterial communities in Xiahe (XH) and Maqu (MQ) in Gansu Province, Haibei (HB) in Qinghai Province and Hongyuan (HY) in Sichuan Province in the eastern Qinghai‐Tibetan Plateau (QTP). The diversity index values (coverage, richness, Shannon index and evenness) of legume species were positively correlated with plant diversity. Several soil nutrients (ammonia‐nitrogen, nitrate‐nitrogen, total nitrogen, available potassium, available phosphorus and soil organic matter) and enzymes (urease, sucrase, peroxidase and dehydrogenase) were lower in HB and HY than in XH and MQ. The Shannon index for rhizobacterial diversity was higher in HB and HY than in XH and MQ. In contrast, the diversity index values were higher for geographical locations than for sympatric plant species. Additionally, HB and HY showed 50% fewer positive and negative associations with rhizobacteria than XH and MQ. Functional Annotation of Prokaryotic Taxa analysis indicated a higher relative abundance of nitrate reduction occurred in HB and HY than in XH and MQ, whereas nitrogen fixation occurred at a lower level in HB and HY than in XH and MQ. The Simpson index value for bacterial diversity was positively correlated with plant diversity, legume species diversity and soil multifunctionality. However, the Shannon index value was negatively correlated with these parameters. Changes in the composition of legume‐associated rhizobacteria across different geographical locations are strongly influenced by plant diversity and soil nutrients, reflecting the distribution characteristics of legumes in alpine grasslands.","PeriodicalId":203,"journal":{"name":"Land Degradation & Development","volume":"5 1","pages":""},"PeriodicalIF":4.7,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142599174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The micro‐scale distribution patterns of rocks and soils are crucial to the hydrological processes of karst slopes. However, current research has provided detailed reports only on the aboveground rock–soil patterns, neglecting the role of underground rock–soil patterns. To address this, our study conducted simulated rainfall experiments and runoff supply tests to observe surface runoff, sediment yield and the migration characteristics of subsurface runoff under three types of bedrock topographies: mosaic bedrock topography (MBT), horizontal‐strip bedrock topography (HBT) and smooth bedrock topography (SBT), at rainfall intensities of 30, 60 and 90 mm/h. The results indicated that undulating bedrock topography significantly increases surface runoff and exacerbates surface erosion. The surface runoff yields in HBT and MBT were 184.68% and 131.77% higher, respectively, than in SBT, and their average surface soil losses were 4.56 and 3.35 times greater than those of SBT, respectively. The undulating bedrock topography impeded the movement of subsurface runoff; the average subsurface runoff yield in SBT was 42.36% and 82.86% greater than in MBT and HBT, respectively. The movement of subsurface runoff followed the ‘fill‐and‐spill’ theory, where the undulating bedrock topography controls subsurface runoff transport. Additionally, preferential pathways between bedrock depressions affected the rate of subsurface runoff movement. Similar to rock outcrops, underlying bedrock, influenced by its characteristics and other factors, may play two opposing roles in the erosion process. Therefore, it warrants as much attention as rock outcrops.
{"title":"The Role of Bedrock Topography in the Runoff Process and Soil Erosion on Karst Steep Slopes","authors":"Liman Ao, Yaoqin Wu, Qinxue Xu, Yangchi Zhou, Xiaona Chen, Peining Liang, Zhiyong Fu, Hongsong Chen","doi":"10.1002/ldr.5377","DOIUrl":"https://doi.org/10.1002/ldr.5377","url":null,"abstract":"The micro‐scale distribution patterns of rocks and soils are crucial to the hydrological processes of karst slopes. However, current research has provided detailed reports only on the aboveground rock–soil patterns, neglecting the role of underground rock–soil patterns. To address this, our study conducted simulated rainfall experiments and runoff supply tests to observe surface runoff, sediment yield and the migration characteristics of subsurface runoff under three types of bedrock topographies: mosaic bedrock topography (MBT), horizontal‐strip bedrock topography (HBT) and smooth bedrock topography (SBT), at rainfall intensities of 30, 60 and 90 mm/h. The results indicated that undulating bedrock topography significantly increases surface runoff and exacerbates surface erosion. The surface runoff yields in HBT and MBT were 184.68% and 131.77% higher, respectively, than in SBT, and their average surface soil losses were 4.56 and 3.35 times greater than those of SBT, respectively. The undulating bedrock topography impeded the movement of subsurface runoff; the average subsurface runoff yield in SBT was 42.36% and 82.86% greater than in MBT and HBT, respectively. The movement of subsurface runoff followed the ‘fill‐and‐spill’ theory, where the undulating bedrock topography controls subsurface runoff transport. Additionally, preferential pathways between bedrock depressions affected the rate of subsurface runoff movement. Similar to rock outcrops, underlying bedrock, influenced by its characteristics and other factors, may play two opposing roles in the erosion process. Therefore, it warrants as much attention as rock outcrops.","PeriodicalId":203,"journal":{"name":"Land Degradation & Development","volume":"70 1","pages":""},"PeriodicalIF":4.7,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142597704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hui Guo, Shaomin Fu, Shaoteng Chen, Qindi Zhang, Zongshan Li
Ongoing climate change poses a major threat to forest growth, which in turn accelerates the rate of land degradation. Given the high sensitivity of mountain forests to climate, there is an urgent need for more detailed studies on the dynamics of montane forests affected by climate change. For this study, we selected 20 tree ring width chronologies in the mountainous regions of Northern China, and investigated the responses of tree growth to climate change in the 20th century. The results indicated that the tree growth trends shifted in 1953 in the mountainous regions of Northern China. The tree growth rates exhibited an increasing trend during 1900–1953 (first stage) followed by a significant decreasing trend from 1954 to 2000 (second stage). The temperature exhibited a continuing increasing trend, while precipitation showed an increase and then decrease in two stages, in tandem with the standardized precipitation evapotranspiration index (SPEI). Initially, rising temperatures positively influenced tree radial growth. However, after 1953, continued warming inhibited tree growth, with trees being increasingly constrained by the availability of water (precipitation and SPEI), particularly during the annual growing season. Our findings emphasized that climate warming and drought have been the main causes of tree growth declines in recent decades, which underscores the susceptibility of montane forest ecosystems to warming‐induced water deficits. Our findings can facilitate the conservation of forest ecosystems, reduce land degradation, increase forest cover, as well as gradually improve the regional environment.
{"title":"Shifts in the Climate Sensitivity of Tree Ring Growth in the Mountainous Regions of Northern China Through the 20th Century","authors":"Hui Guo, Shaomin Fu, Shaoteng Chen, Qindi Zhang, Zongshan Li","doi":"10.1002/ldr.5378","DOIUrl":"https://doi.org/10.1002/ldr.5378","url":null,"abstract":"Ongoing climate change poses a major threat to forest growth, which in turn accelerates the rate of land degradation. Given the high sensitivity of mountain forests to climate, there is an urgent need for more detailed studies on the dynamics of montane forests affected by climate change. For this study, we selected 20 tree ring width chronologies in the mountainous regions of Northern China, and investigated the responses of tree growth to climate change in the 20th century. The results indicated that the tree growth trends shifted in 1953 in the mountainous regions of Northern China. The tree growth rates exhibited an increasing trend during 1900–1953 (first stage) followed by a significant decreasing trend from 1954 to 2000 (second stage). The temperature exhibited a continuing increasing trend, while precipitation showed an increase and then decrease in two stages, in tandem with the standardized precipitation evapotranspiration index (SPEI). Initially, rising temperatures positively influenced tree radial growth. However, after 1953, continued warming inhibited tree growth, with trees being increasingly constrained by the availability of water (precipitation and SPEI), particularly during the annual growing season. Our findings emphasized that climate warming and drought have been the main causes of tree growth declines in recent decades, which underscores the susceptibility of montane forest ecosystems to warming‐induced water deficits. Our findings can facilitate the conservation of forest ecosystems, reduce land degradation, increase forest cover, as well as gradually improve the regional environment.","PeriodicalId":203,"journal":{"name":"Land Degradation & Development","volume":" 1","pages":""},"PeriodicalIF":4.7,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142597707","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lucimar de Carvalho Medeiros, Maíse Soares de Moura, Isadora Fonseca Navarro, Luís Felipe Sanches Fernandes, Fernando António Leal Pacheco, Adriana Monteiro da Costa
Accidents involving tailings dams are threatening because of their potential impacts. In many countries, despite the existence of legislation the population lives with the insecurity of potential dam breaks. Using Minas Gerais state in Brazil as an example, the aforementioned insecurity applies to hundreds of tailings dams, specifically the Vargem Grande dam of Vale mining company. The area affected by a dam failure is set through legal‐administrative instruments called “flood patches.” The purpose of this study was to analyze these patches, using the Vargem Grande dam as example, and assess the possible land degradation impacts of a failure, focused on the flooded native vegetation. The assessment resorted to the VERA—Economic Valuation of Environmental Resources method. The results exposed the potential destruction of 200 ha of Atlantic Forest and 55 ha of Cerrado vegetation within the flood patches. However, the simulated outcomes also reveal a significant decline in the flood patches in a short period (from 4.60 km2 in 2022 to 3.05 km2 in 2023), related with dam‐decommissioning risk‐reduction works allegedly implemented or to be implemented by the mining company. This reduction can be misleading because decommissioning works are legal‐administrative issues frequently used by the mining companies to minimize their responsibilities in the case of tailings dam breakup. It is worth mentioning that the patch reduction led to a convenient drop in the VERA results, from nearly 74 to 53 million dollars. Therefore, the official protocol used to delineate the flood patches must be improved to allow a more realistic evaluation. In that regard, the changes to flood patches overtime must be better defined in the legislation, namely through inclusion of potentially affected soil‐ and water‐bearing ecosystem services. Effective monitoring of dam‐decommissioning works is also paramount for a true evaluation of land degradation in the impacted areas.
涉及尾矿坝的事故因其潜在影响而具有威胁性。在许多国家，尽管制定了相关法律，但民众仍生活在潜在溃坝的不安全感中。以巴西米纳斯吉拉斯州为例，数以百计的尾矿坝，特别是淡水河谷矿业公司的 Vargem Grande 大坝，都存在上述不安全因素。受溃坝影响的区域是通过称为 "洪水补丁 "的法律行政手段确定的。本研究的目的是以 Vargem Grande 大坝为例，对这些区域进行分析，并评估溃坝可能造成的土地退化影响，重点是被淹没的本地植被。评估采用了环境资源经济评估法（VERA-Economic Valuation of Environmental Resources）。评估结果表明，在洪水泛滥的区域内，200 公顷的大西洋森林和 55 公顷的 Cerrado 植被可能遭到破坏。然而，模拟结果还显示，洪水斑块在短期内大幅减少（从 2022 年的 4.60 平方公里减少到 2023 年的 3.05 平方公里），这与据称矿业公司已经实施或即将实施的大坝退役风险降低工程有关。这种减少可能会引起误解，因为退役工程是矿业公司经常利用的法律行政问题，以尽量减少其在尾矿坝决堤时的责任。值得一提的是，补丁的减少导致 VERA 结果从近 7 400 万美元下降到 5 300 万美元。因此，必须改进用于划定洪泛区的官方规程，以便进行更切合实际的评估。在这方面，必须在立法中更好地界定洪泛区随时间发生的变化，即纳入可能受影响的土壤和含水生态系统服务。对大坝退役工程进行有效监测对于真正评估受影响地区的土地退化情况也至关重要。
{"title":"The Risk of Land Degradation in Areas Impacted by Tailings Mudflows: A Legal and Economic Assessment","authors":"Lucimar de Carvalho Medeiros, Maíse Soares de Moura, Isadora Fonseca Navarro, Luís Felipe Sanches Fernandes, Fernando António Leal Pacheco, Adriana Monteiro da Costa","doi":"10.1002/ldr.5366","DOIUrl":"https://doi.org/10.1002/ldr.5366","url":null,"abstract":"Accidents involving tailings dams are threatening because of their potential impacts. In many countries, despite the existence of legislation the population lives with the insecurity of potential dam breaks. Using Minas Gerais state in Brazil as an example, the aforementioned insecurity applies to hundreds of tailings dams, specifically the Vargem Grande dam of Vale mining company. The area affected by a dam failure is set through legal‐administrative instruments called “flood patches.” The purpose of this study was to analyze these patches, using the Vargem Grande dam as example, and assess the possible land degradation impacts of a failure, focused on the flooded native vegetation. The assessment resorted to the VERA—Economic Valuation of Environmental Resources method. The results exposed the potential destruction of 200 ha of Atlantic Forest and 55 ha of Cerrado vegetation within the flood patches. However, the simulated outcomes also reveal a significant decline in the flood patches in a short period (from 4.60 km<jats:sup>2</jats:sup> in 2022 to 3.05 km<jats:sup>2</jats:sup> in 2023), related with dam‐decommissioning risk‐reduction works allegedly implemented or to be implemented by the mining company. This reduction can be misleading because decommissioning works are legal‐administrative issues frequently used by the mining companies to minimize their responsibilities in the case of tailings dam breakup. It is worth mentioning that the patch reduction led to a convenient drop in the VERA results, from nearly 74 to 53 million dollars. Therefore, the official protocol used to delineate the flood patches must be improved to allow a more realistic evaluation. In that regard, the changes to flood patches overtime must be better defined in the legislation, namely through inclusion of potentially affected soil‐ and water‐bearing ecosystem services. Effective monitoring of dam‐decommissioning works is also paramount for a true evaluation of land degradation in the impacted areas.","PeriodicalId":203,"journal":{"name":"Land Degradation & Development","volume":"127 1","pages":""},"PeriodicalIF":4.7,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142597703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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