Rangeland Ecology & Management最新文献_第9页

Evaluating Native Plant Community Characteristics After Restoration Efforts in Invaded Tallgrass Prairies 入侵高草草原恢复后乡土植物群落特征评价

IF 2.4 3区环境科学与生态学 Q2 ECOLOGY

Rangeland Ecology & Management

Pub Date : 2024-09-11 DOI: 10.1016/j.rama.2024.07.015

Jessica E. Mingione , Jaime J. Coon , James R. Miller

Invasive grasses reduce native plant diversity in North America's tallgrass prairies and are commonly controlled using herbicide followed by seeding of native plants. Despite the long-term development of plant communities after seeding, evaluations of restoration outcomes rarely exceed 2 yr. Further, plant community development may be influenced by grazing by domestic cattle, a dominant land use in working landscapes that typify the Great Plains, yet this relationship is seldom explored. In the eastern Great Plains, we evaluated plant community characteristics over 8 yr in tallgrass prairies invaded by tall fescue (Schedonorus arundinaceus) after treatment with herbicide followed by seeding native plants. We compared 16 restoration sites seeded once between spring 2014 and 2021 to 2 unrestored, invaded sites and 3 high-diversity reference sites that were not restored. Domestic cattle grazed six restoration sites and one unrestored, invaded site; the remaining sites were ungrazed. In July 2021, we quantified the dominance and cover of herbaceous plants and the composition and richness of seeded species. Annual forb dominance, seeded species establishment and composition, native forb cover, and seeded species richness of older restorations closely resembled references. However, grazed restorations resembled high-quality references less closely than ungrazed restorations. Future studies should consider identifying high-quality reference sites that are grazed because ungrazed references may represent inappropriate target conditions for grazed restorations. The similarities we observed between older restorations and references highlight the importance of long-term evaluations when quantifying restoration outcomes and indicate that treatment with herbicide followed by native seeding has long-lasting positive effects for restoring native plant communities in invaded tallgrass prairies. Enhancing the practicality and effectiveness of restoration efforts in working landscapes is key to supporting grassland restoration.

入侵草减少了北美高草草原的本土植物多样性，通常使用除草剂和本土植物播种进行控制。尽管植物群落在播种后会长期发展，但对恢复结果的评估很少超过2年。此外，植物群落的发展可能受到家畜放牧的影响，这是大平原典型工作景观中主要的土地利用方式，但这种关系很少被探讨。在大平原东部，对高羊茅（Schedonorus arundinaceus）入侵的高草草原进行了8年的植物群落特征评价。我们将2014年春季至2021年春季期间播种过一次的16个恢复点与2个未恢复的入侵点和3个未恢复的高多样性参考点进行了比较。家牛放牧了6个恢复点和1个未恢复的入侵点；其余的地点都没有放牧。在2021年7月，我们量化了草本植物的优势度和覆盖度以及种子物种的组成和丰富度。年际牧草优势度、种子种类的建立和组成、原生牧草盖度和种子物种丰富度与文献相似。然而，放牧恢复与未放牧恢复相比，与高质量参考文献的相似程度较低。未来的研究应考虑确定放牧的高质量参考点，因为未放牧的参考点可能不适合放牧恢复的目标条件。我们观察到的旧修复与文献之间的相似性突出了量化恢复结果时长期评估的重要性，并表明除草剂处理后本地播种对恢复入侵高草草原的本地植物群落具有持久的积极作用。提高工作景观恢复工作的实用性和有效性是支持草地恢复的关键。

{"title":"Evaluating Native Plant Community Characteristics After Restoration Efforts in Invaded Tallgrass Prairies","authors":"Jessica E. Mingione , Jaime J. Coon , James R. Miller","doi":"10.1016/j.rama.2024.07.015","DOIUrl":"10.1016/j.rama.2024.07.015","url":null,"abstract":"<div><div>Invasive grasses reduce native plant diversity in North America's tallgrass prairies and are commonly controlled using herbicide followed by seeding of native plants. Despite the long-term development of plant communities after seeding, evaluations of restoration outcomes rarely exceed 2 yr. Further, plant community development may be influenced by grazing by domestic cattle, a dominant land use in working landscapes that typify the Great Plains, yet this relationship is seldom explored. In the eastern Great Plains, we evaluated plant community characteristics over 8 yr in tallgrass prairies invaded by tall fescue (<em>Schedonorus arundinaceus</em>) after treatment with herbicide followed by seeding native plants. We compared 16 restoration sites seeded once between spring 2014 and 2021 to 2 unrestored, invaded sites and 3 high-diversity reference sites that were not restored. Domestic cattle grazed six restoration sites and one unrestored, invaded site; the remaining sites were ungrazed. In July 2021, we quantified the dominance and cover of herbaceous plants and the composition and richness of seeded species. Annual forb dominance, seeded species establishment and composition, native forb cover, and seeded species richness of older restorations closely resembled references. However, grazed restorations resembled high-quality references less closely than ungrazed restorations. Future studies should consider identifying high-quality reference sites that are grazed because ungrazed references may represent inappropriate target conditions for grazed restorations. The similarities we observed between older restorations and references highlight the importance of long-term evaluations when quantifying restoration outcomes and indicate that treatment with herbicide followed by native seeding has long-lasting positive effects for restoring native plant communities in invaded tallgrass prairies. Enhancing the practicality and effectiveness of restoration efforts in working landscapes is key to supporting grassland restoration.</div></div>","PeriodicalId":49634,"journal":{"name":"Rangeland Ecology & Management","volume":"98 ","pages":"Pages 134-145"},"PeriodicalIF":2.4,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142745709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Recent Spatiotemporal Dynamics of Grasslands in Slovenia: Contribution to Their Preservation and Management 斯洛文尼亚草原的近期时空动态：对其保护和管理的贡献

IF 2.4 3区环境科学与生态学 Q2 ECOLOGY

Rangeland Ecology & Management

Pub Date : 2024-09-10 DOI: 10.1016/j.rama.2024.07.010

Rui Machado , Pedro Santos , Nuno Sousa-Neves , Janez Pirnat

Seminatural European grasslands and pastures have a high conservation value because they provide different goods and services (meat, wool, carbon sequestration, etc.) and harbor diverse communities of plants and animals. These land use systems were created by low- and moderate-intensity use and, nowadays, face threats from both abandonment and overuse. Although less productive or less accessible areas are abandoned, triggering afforestation processes, others are subject to intensive agricultural practices with the addition of production factors and modern management schemes. Neither is comparable with the traditional uses that first formed and maintained these systems for generations, and therefore, it is fundamental to design effective policies to ensure a sustainable territorial coexistence of modern agriculture and traditional pastures and grasslands. In this work, we assessed the recent dynamics of pastures and grasslands in Slovenia. The results show distinct local changes and a nationwide general dynamic of area reduction and loss of patches. After elaborating on how such changes affect the landscape and some species according to their traits, we provide practical recommendations for policy design to contribute to protecting and promoting this land use system. We argue that the two major priorities should be to preserve the most relevant patches and to try to convert other land uses into grasslands, preferably attempting to merge separated patches and thus increasing the mean patch size of grasslands. Overall, by identifying trends, locating the different spatial changes, and complementing with a connectivity analysis, this approach can be valuable in identifying effective measures to protect and improve grasslands. Besides the concrete results obtained from the Slovenian case study, the underlying rationale and workflow can be applied elsewhere to produce similar outputs that help identify land transformation patterns and interpret specific land use category dynamics.

半自然的欧洲草原和牧场具有很高的保护价值，因为它们提供不同的商品和服务（肉、羊毛、碳封存等），并孕育着不同的动植物群落。这些土地利用系统是由低强度和中等强度的使用创造的，现在面临着废弃和过度使用的威胁。虽然放弃了生产力较低或不易进入的地区，引发了造林过程，但其他地区则采用集约化农业做法，并增加了生产因素和现代管理计划。两者都无法与最初形成和维持这些系统的传统用途相比，因此，设计有效的政策以确保现代农业与传统牧场和草原的可持续共存是至关重要的。在这项工作中，我们评估了斯洛文尼亚牧场和草原的最新动态。结果表明，斑块面积减少和损失具有明显的局地变化和全国性的总体动态。在阐述了这些变化如何影响景观和一些物种的特征之后，我们为政策设计提供了实用的建议，以有助于保护和促进这一土地利用系统。我们认为，两个主要的优先事项应该是保护最相关的斑块，并试图将其他土地利用转化为草地，最好是尝试合并分离的斑块，从而增加草地的平均斑块大小。总体而言，通过识别趋势，定位不同的空间变化，并辅以连通性分析，该方法在确定有效的保护和改善草原措施方面具有重要价值。除了从斯洛文尼亚案例研究中获得的具体结果外，其基本原理和工作流程也可以应用于其他地方，以产生类似的产出，帮助确定土地转型模式并解释具体的土地利用类别动态。

{"title":"The Recent Spatiotemporal Dynamics of Grasslands in Slovenia: Contribution to Their Preservation and Management","authors":"Rui Machado , Pedro Santos , Nuno Sousa-Neves , Janez Pirnat","doi":"10.1016/j.rama.2024.07.010","DOIUrl":"10.1016/j.rama.2024.07.010","url":null,"abstract":"<div><div>Seminatural European grasslands and pastures have a high conservation value because they provide different goods and services (meat, wool, carbon sequestration, etc.) and harbor diverse communities of plants and animals. These land use systems were created by low- and moderate-intensity use and, nowadays, face threats from both abandonment and overuse. Although less productive or less accessible areas are abandoned, triggering afforestation processes, others are subject to intensive agricultural practices with the addition of production factors and modern management schemes. Neither is comparable with the traditional uses that first formed and maintained these systems for generations, and therefore, it is fundamental to design effective policies to ensure a sustainable territorial coexistence of modern agriculture and traditional pastures and grasslands. In this work, we assessed the recent dynamics of pastures and grasslands in Slovenia. The results show distinct local changes and a nationwide general dynamic of area reduction and loss of patches. After elaborating on how such changes affect the landscape and some species according to their traits, we provide practical recommendations for policy design to contribute to protecting and promoting this land use system. We argue that the two major priorities should be to preserve the most relevant patches and to try to convert other land uses into grasslands, preferably attempting to merge separated patches and thus increasing the mean patch size of grasslands. Overall, by identifying trends, locating the different spatial changes, and complementing with a connectivity analysis, this approach can be valuable in identifying effective measures to protect and improve grasslands. Besides the concrete results obtained from the Slovenian case study, the underlying rationale and workflow can be applied elsewhere to produce similar outputs that help identify land transformation patterns and interpret specific land use category dynamics.</div></div>","PeriodicalId":49634,"journal":{"name":"Rangeland Ecology & Management","volume":"98 ","pages":"Pages 204-213"},"PeriodicalIF":2.4,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142746893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Responses in the Physical Structure and Density of Bush Clumps on Piosphere Gradients in an Arid Thicket Mosaic, South Africa 南非干旱区灌丛物理结构和密度对大气梯度的响应

IF 2.4 3区环境科学与生态学 Q2 ECOLOGY

Rangeland Ecology & Management

Pub Date : 2024-09-05 DOI: 10.1016/j.rama.2024.06.007

Anton Schmidt , Graham Kerley

The hypothesis that transformation of rangelands by domestic mesoherbivores follows state-and-transition models allows for the prediction that the vegetation could cross an ecological threshold. We examine this hypothesis by attempting to identify structural thresholds in Gamka Thicket, a structurally heterogeneous variation of Albany Thicket in South Africa. We relate the physical structure and density of thicket bush clumps to distance from artificial watering points in four piosphere treatments differing in rangeland management history. Furthermore, we compare the pattern, extent, and variation in transformation at the end regions of our piosphere treatments with each other and with a transformed and untransformed reference site. Changes to the density and leaf mass below 1.5 m of bush clumps indicate that their structure is profoundly altered by mesoherbivores. Nevertheless, the evidence is not sufficient to indicate that irreversible changes in the physical structure of bush clumps have taken place and therefore that structural thresholds have been crossed. A useful addition to our sampling design would be to include exclosure plots along the piosphere gradients.

驯养的中草食动物对牧场的转变遵循状态-过渡模型，这一假设允许植被跨越生态阈值的预测。我们通过试图确定Gamka灌丛的结构阈值来检验这一假设，Gamka灌丛是南非奥尔巴尼灌丛的结构异质变异。在不同的草地管理历史中，我们将灌丛的物理结构和密度与距人工浇水点的距离联系起来。此外，我们还比较了在我们的大气层处理的末端区域转化的模式、程度和变化，并与转化和未转化的参考点进行了比较。丛丛1.5 m以下密度和叶质量的变化表明，中草食动物对丛丛结构产生了深刻的影响。然而，证据还不足以表明灌木丛的物理结构发生了不可逆转的变化，因此已经越过了结构阈值。对我们的抽样设计的一个有用的补充是包括沿大气层梯度的围合图。

{"title":"Responses in the Physical Structure and Density of Bush Clumps on Piosphere Gradients in an Arid Thicket Mosaic, South Africa","authors":"Anton Schmidt , Graham Kerley","doi":"10.1016/j.rama.2024.06.007","DOIUrl":"10.1016/j.rama.2024.06.007","url":null,"abstract":"<div><div>The hypothesis that transformation of rangelands by domestic mesoherbivores follows state-and-transition models allows for the prediction that the vegetation could cross an ecological threshold. We examine this hypothesis by attempting to identify structural thresholds in Gamka Thicket, a structurally heterogeneous variation of Albany Thicket in South Africa. We relate the physical structure and density of thicket bush clumps to distance from artificial watering points in four piosphere treatments differing in rangeland management history. Furthermore, we compare the pattern, extent, and variation in transformation at the end regions of our piosphere treatments with each other and with a transformed and untransformed reference site. Changes to the density and leaf mass below 1.5 m of bush clumps indicate that their structure is profoundly altered by mesoherbivores. Nevertheless, the evidence is not sufficient to indicate that irreversible changes in the physical structure of bush clumps have taken place and therefore that structural thresholds have been crossed. A useful addition to our sampling design would be to include exclosure plots along the piosphere gradients.</div></div>","PeriodicalId":49634,"journal":{"name":"Rangeland Ecology & Management","volume":"98 ","pages":"Pages 1-8"},"PeriodicalIF":2.4,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142746895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Assessing Pastoral Reforms Through the Performance of Agro-Pastoral Community-Based Organizations in South Tunisia 通过南突尼斯农牧社区组织的绩效评估牧区改革

IF 2.4 3区环境科学与生态学 Q2 ECOLOGY

Rangeland Ecology & Management

Pub Date : 2024-09-02 DOI: 10.1016/j.rama.2024.07.008

Mariem Sghaier , Aymen Frija , Julio Postigo , Stijn Speelman , Véronique Alary , Mongi Sghaier

Pastoralism is one of the most important agricultural production systems in drylands worldwide. It plays an important role in both the economy and the cycle of ecosystem goods and services. However, it is vulnerable to climatic challenges such as prolonged drought and socioeconomic pressures such as administrative shortcomings and ineffective governance. Under neoliberal influence, political and economic reforms have been implemented over the last 30 years to address these threats. These reforms have promoted local institutions for rangeland management and agro-pastoral development. In this paper, we assess the impact of these reforms on pastoral devolvement and Community-based natural resource management (CBNRM) by analyzing the performance of agro-pastoral community-based organizations CBOs in the province of Médenine (south-eastern Tunisia). We use a two-step methodology, with the first step focusing on a quantitative typology analysis of the performance of 31 CBOs. In a subsequent qualitative step, data from semi-structured interviews with 21 CBO chairpersons were used to identify the drivers of CBO performance.

Results show that only 10% of the CBOs studied are able to move towards autonomy and proper integration into local and regional institutional networks and development dynamics. About 42% of the CBOs need further support and are in a precarious situation as they are dependent on public support. The remaining 48% have a low growth potential and in the early stages of consolidation. The qualitative analysis suggests that these shortcomings are mainly related to the CBOs' lack of networking skills. In addition, CBOs should improve their reputation and gain more trust from pastoral communities. Our findings suggest that well-functioning institutions do contribute to rural development; however, the design of pastoralist policy and institutional reforms should include long-term complementary support for the institutions created and consideration of the pastoralist community and regional contexts in order to achieve long-lasting transformative outcomes.

畜牧业是世界旱地最重要的农业生产系统之一。它在经济和生态系统产品和服务的循环中都发挥着重要作用。然而，它很容易受到长期干旱等气候挑战和行政缺陷和无效治理等社会经济压力的影响。在新自由主义的影响下，过去30年来实施了政治和经济改革，以应对这些威胁。这些改革促进了牧场管理和农牧发展的地方机构。本文通过分析突尼斯m denine省农牧社区组织cbo的绩效，评估了这些改革对牧区发展和社区自然资源管理（CBNRM）的影响。我们采用两步方法，第一步重点对31家cbo的绩效进行定量类型学分析。在随后的定性步骤中，采用对21位CBO主席进行半结构化访谈的数据来确定CBO绩效的驱动因素。结果表明，在所研究的cbo中，只有10%能够走向自治，并适当融入地方和区域机构网络和发展动态。大约42%的社区组织需要进一步的支持，由于他们依赖于公众的支持，处于不稳定的境地。其余48%的增长潜力较低，处于整合的早期阶段。定性分析表明，这些缺陷主要与cbo缺乏社交技能有关。此外，cbo还应提高自己的声誉，赢得牧区的信任。我们的研究结果表明，运转良好的机构确实有助于农村发展；然而，牧民政策和机构改革的设计应包括对所创建机构的长期补充支持，并考虑到牧民社区和区域情况，以便取得持久的变革成果。

{"title":"Assessing Pastoral Reforms Through the Performance of Agro-Pastoral Community-Based Organizations in South Tunisia","authors":"Mariem Sghaier , Aymen Frija , Julio Postigo , Stijn Speelman , Véronique Alary , Mongi Sghaier","doi":"10.1016/j.rama.2024.07.008","DOIUrl":"10.1016/j.rama.2024.07.008","url":null,"abstract":"<div><div>Pastoralism is one of the most important agricultural production systems in drylands worldwide. It plays an important role in both the economy and the cycle of ecosystem goods and services. However, it is vulnerable to climatic challenges such as prolonged drought and socioeconomic pressures such as administrative shortcomings and ineffective governance. Under neoliberal influence, political and economic reforms have been implemented over the last 30 years to address these threats. These reforms have promoted local institutions for rangeland management and agro-pastoral development. In this paper, we assess the impact of these reforms on pastoral devolvement and Community-based natural resource management (CBNRM) by analyzing the performance of agro-pastoral community-based organizations CBOs in the province of Médenine (south-eastern Tunisia). We use a two-step methodology, with the first step focusing on a quantitative typology analysis of the performance of 31 CBOs. In a subsequent qualitative step, data from semi-structured interviews with 21 CBO chairpersons were used to identify the drivers of CBO performance.</div><div>Results show that only 10% of the CBOs studied are able to move towards autonomy and proper integration into local and regional institutional networks and development dynamics. About 42% of the CBOs need further support and are in a precarious situation as they are dependent on public support. The remaining 48% have a low growth potential and in the early stages of consolidation. The qualitative analysis suggests that these shortcomings are mainly related to the CBOs' lack of networking skills. In addition, CBOs should improve their reputation and gain more trust from pastoral communities. Our findings suggest that well-functioning institutions do contribute to rural development; however, the design of pastoralist policy and institutional reforms should include long-term complementary support for the institutions created and consideration of the pastoralist community and regional contexts in order to achieve long-lasting transformative outcomes.</div></div>","PeriodicalId":49634,"journal":{"name":"Rangeland Ecology & Management","volume":"98 ","pages":"Pages 49-62"},"PeriodicalIF":2.4,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142746788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Ecological Stoichiometry of Multiple Nutrients in Leymus chinensis and Soils Subjected to Long-Term Saline-Sodic Stress in Western Jilin Province, China 中国吉林省西部莱姆斯和长期盐碱胁迫土壤中多种营养元素的生态平衡关系

IF 2.4 3区环境科学与生态学 Q2 ECOLOGY

Rangeland Ecology & Management

Pub Date : 2024-08-31 DOI: 10.1016/j.rama.2024.07.013

Xingyi Wang, Jingfa Zhong, Yuefen Li

L. chinensis is considered an important plant for saline-sodic soil restoration. Ecological stoichiometry of multiple nutrient elements in Leymus chinensis (L. chinensis) and soils subjected to long-term saline-sodic stress remains unclear, which hinders our understanding of the mechanisms regulating nutrient cycling in the plant-soil environment. We examined nutrient element levels in saline-sodic soil and L. chinensis in western Jilin Province. Soil analysis revealed medium to high levels of available N, K, P, Mo, Mn, Fe, Cu, and Zn. The Mn/Fe and N/P ratios exceeded the national soil average of China, while those of Fe/Cu, Fe/Zn, and P/K were comparatively lower. Furthermore, L. chinensis exhibited deficiencies in the Mn, Zn, and P. Mo/Mn, Mo/Zn, and Fe/Zn ratios, which were significantly higher compared to healthy plants, while Mn/Fe and P/K showed the opposite trend. Soil pH had the most significant effect on element stoichiometry in both the soil and in L. chinensis. Particularly, the soil available Mn, Zn, K, along with L. chinensis Mn, Fe, Cu, and P levels exhibited sensitivity to pH fluctuations. Additionally, we observed significant synergistic or antagonistic effects between the soil available element concentration and stoichiometry ratios. Among these, only Mn, Fe, Fe/Zn, Mo/Zn, N/K, and Mo/Fe in L. chinensis were significantly modeled (P < 0.05). The Mo/Fe homeostasis index was the lowest at 0.97, followed by Fe (1.16), N/K (2.28), Mo/Zn (2.59), Fe/Zn (3.38), and Mn (4.92), while other elements and their stoichiometric ratios remained stable. Overall, L. chinensis, as the dominant species in saline-sodic soil, demonstrated high homeostasis.

被认为是恢复盐碱土壤的重要植物。长期遭受盐碱胁迫的土壤中多种营养元素的生态平衡尚不清楚，这阻碍了我们对植物-土壤环境中营养循环调节机制的了解。我们研究了吉林省西部盐碱地土壤中的营养元素水平。土壤分析表明，可利用的氮、钾、磷、钼、锰、铁、铜和锌的含量为中高水平。锰/铁和氮/磷的比率超过了中国全国土壤的平均水平，而铁/铜、铁/锌和磷/钾的比率则相对较低。此外，锰、锌、钾、钼/锰、钼/锌、铁/锌比值均显著高于健康植株，而锰/铁、磷/钾比值则呈相反趋势。土壤 pH 值对土壤和植株中元素的化学计量影响最大。特别是，土壤中可利用的锰、锌、钾以及锰、铁、铜和磷的含量对 pH 值的波动非常敏感。此外，我们还观察到土壤可利用元素浓度与化学计量比之间存在明显的协同或拮抗作用。其中，只有锰、铁、铁/锌、钼/锌、氮/钾和钼/铁之间存在显著的模型效应（< 0.05）。钼/铁平衡指数最低，为 0.97，其次是铁（1.16）、氮/钾（2.28）、钼/锌（2.59）、铁/锌（3.38）和锰（4.92），其他元素及其化学计量比保持稳定。总体而言，作为盐碱地土壤中的主要物种，Ⅴ表现出高度的平衡性。

{"title":"Ecological Stoichiometry of Multiple Nutrients in Leymus chinensis and Soils Subjected to Long-Term Saline-Sodic Stress in Western Jilin Province, China","authors":"Xingyi Wang, Jingfa Zhong, Yuefen Li","doi":"10.1016/j.rama.2024.07.013","DOIUrl":"10.1016/j.rama.2024.07.013","url":null,"abstract":"<div><div><em>L. chinensis</em> is considered an important plant for saline-sodic soil restoration. Ecological stoichiometry of multiple nutrient elements in <em>Leymus chinensis (L. chinensis)</em> and soils subjected to long-term saline-sodic stress remains unclear, which hinders our understanding of the mechanisms regulating nutrient cycling in the plant-soil environment. We examined nutrient element levels in saline-sodic soil and <em>L. chinensis</em> in western Jilin Province. Soil analysis revealed medium to high levels of available N, K, P, Mo, Mn, Fe, Cu, and Zn. The Mn/Fe and N/P ratios exceeded the national soil average of China, while those of Fe/Cu, Fe/Zn, and P/K were comparatively lower. Furthermore, <em>L. chinensis</em> exhibited deficiencies in the Mn, Zn, and P. Mo/Mn, Mo/Zn, and Fe/Zn ratios, which were significantly higher compared to healthy plants, while Mn/Fe and P/K showed the opposite trend. Soil pH had the most significant effect on element stoichiometry in both the soil and in <em>L. chinensis</em>. Particularly, the soil available Mn, Zn, K, along with <em>L. chinensis</em> Mn, Fe, Cu, and P levels exhibited sensitivity to pH fluctuations. Additionally, we observed significant synergistic or antagonistic effects between the soil available element concentration and stoichiometry ratios. Among these, only Mn, Fe, Fe/Zn, Mo/Zn, N/K, and Mo/Fe in <em>L. chinensis</em> were significantly modeled (<em>P</em> < 0.05). The Mo/Fe homeostasis index was the lowest at 0.97, followed by Fe (1.16), N/K (2.28), Mo/Zn (2.59), Fe/Zn (3.38), and Mn (4.92), while other elements and their stoichiometric ratios remained stable. Overall, <em>L. chinensis</em>, as the dominant species in saline-sodic soil, demonstrated high homeostasis.</div></div>","PeriodicalId":49634,"journal":{"name":"Rangeland Ecology & Management","volume":"98 ","pages":"Pages 125-133"},"PeriodicalIF":2.4,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142224907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Indaziflam Provides Long-Term Reduction of Annual Brome Grass (Bromus spp.) in Canada's Mixedgrass Prairie Indaziflam可以长期减少加拿大混合草原一年生雀麦草（雀麦属）的数量

IF 2.4 3区环境科学与生态学 Q2 ECOLOGY

Rangeland Ecology & Management

Pub Date : 2024-08-31 DOI: 10.1016/j.rama.2024.07.011

Anabel Dombro, Lisa Raatz, Edward W. Bork

Annual bromegrasses are some of the most widespread and problematic weeds in North America and present a challenge in managing rangeland, with control options needed. The herbicide indaziflam has shown promise in long-term annual brome reduction on western United States rangeland, though how this strategy applies to northern temperate grasslands, including those of western Canada, remains uncertain. We studied the effect of indaziflam rate (0, 37.5, 75, and 150 g ai ha⁻¹) and timing (fall vs. spring) of application on long-term biomass and density of annual brome at two field sites in Canada's northern Mixedgrass Prairie. Reductions in brome were not evident until the second growing season following treatment. During the third growing season, the current recommended rate (75 g ai ha⁻¹) of indaziflam reduced brome biomass and density by at least 90% at both sites. By the fourth season, indaziflam continued to reduce brome biomass by 11% and 66%, and brome density by 76% and 95%, at the two sites, respectively. While reductions in brome biomass and density occurred at rates as low as 37.5 g ai ha⁻¹, this rate was not as reliable as higher rates of 75 and 150 g ai ha⁻¹. The timing of indaziflam application had little impact on long-term brome reduction. We conclude that a single application of indaziflam can reduce annual brome, including corn brome (Bromus squarrosus L.), in northern Mixedgrass Prairie grasslands for up to 4 years, and therefore provides another tool to manage the spread of these species.

一年生雀稗是北美分布最广、问题最严重的杂草之一，对牧场管理构成挑战，需要采取控制措施。除草剂indaziflam在美国西部牧场显示出长期每年减少溴化的希望，尽管这种策略如何适用于北温带草原，包括加拿大西部的草原，仍然不确定。在加拿大北部混合草原的两个试验点，研究了吲唑氟姆用量（0、37.5、75和150 g / ha - 1）和施药时间（秋季和春季）对一年生溴甲烷长期生物量和密度的影响。溴化物的减少直到处理后的第二个生长季节才明显。在第三个生长季节，目前推荐的用量（75 g / ha - 1）使两个地点的溴甲烷生物量和密度降低了至少90%。到第4季，茚地氟兰继续使两个地点的溴甲烷生物量分别减少11%和66%，溴甲烷密度分别减少76%和95%。虽然溴甲烷生物量和密度的减少速率低至37.5 g / ha - 1，但这一速率不如75和150 g / ha - 1的较高速率可靠。茚地夫仑应用时间对长期溴减少影响不大。研究结果表明，单次施用茚地芬可减少北部混交草草原上的玉米雀麦（Bromus squarrosus L.）等一年生雀麦的数量长达4年，从而为控制这些物种的传播提供了另一种工具。

{"title":"Indaziflam Provides Long-Term Reduction of Annual Brome Grass (Bromus spp.) in Canada's Mixedgrass Prairie","authors":"Anabel Dombro, Lisa Raatz, Edward W. Bork","doi":"10.1016/j.rama.2024.07.011","DOIUrl":"10.1016/j.rama.2024.07.011","url":null,"abstract":"<div><div>Annual bromegrasses are some of the most widespread and problematic weeds in North America and present a challenge in managing rangeland, with control options needed. The herbicide indaziflam has shown promise in long-term annual brome reduction on western United States rangeland, though how this strategy applies to northern temperate grasslands, including those of western Canada, remains uncertain. We studied the effect of indaziflam rate (0, 37.5, 75, and 150 g ai ha<sup>−1</sup>) and timing (fall vs. spring) of application on long-term biomass and density of annual brome at two field sites in Canada's northern Mixedgrass Prairie. Reductions in brome were not evident until the second growing season following treatment. During the third growing season, the current recommended rate (75 g ai ha<sup>−1</sup>) of indaziflam reduced brome biomass and density by at least 90% at both sites. By the fourth season, indaziflam continued to reduce brome biomass by 11% and 66%, and brome density by 76% and 95%, at the two sites, respectively. While reductions in brome biomass and density occurred at rates as low as 37.5 g ai ha<sup>−1</sup>, this rate was not as reliable as higher rates of 75 and 150 g ai ha<sup>−1</sup>. The timing of indaziflam application had little impact on long-term brome reduction. We conclude that a single application of indaziflam can reduce annual brome, including corn brome (<em>Bromus squarrosus</em> L.), in northern Mixedgrass Prairie grasslands for up to 4 years, and therefore provides another tool to manage the spread of these species.</div></div>","PeriodicalId":49634,"journal":{"name":"Rangeland Ecology & Management","volume":"98 ","pages":"Pages 73-82"},"PeriodicalIF":2.4,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142745772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

No Field Evidence of Grass Fuel Structure effects on Postfire Tree Mortality in Juniperus virginiana 没有实地证据表明草燃料结构对杜松火后树木死亡率有影响

IF 2.4 3区环境科学与生态学 Q2 ECOLOGY

Rangeland Ecology & Management

Pub Date : 2024-08-23 DOI: 10.1016/j.rama.2024.07.012

Xiulin Gao , Dylan W. Schwilk , Robin Verble

Prescribed fires are an important management tool for containing woody plant encroachment in rangeland ecosystems. Grasses are the dominant fuel type in rangelands. Past work has shown that grass canopy architecture, which varies among grass species, can influence flammability. Whether variation in grass fuel structure can influence postfire plant responses has not yet been tested. To bridge this gap, we set up field burning experiments with different fuel treatments and examined postfire mortality of Juniperus virginiana L. in a tallgrass prairie in southwestern Missouri. We sampled 60 trees and measured tree height and diameter at breast height before the fire. Fuels surrounding each tree were manipulated to vary independently in both fuel load and fuel structure. Flame temperatures were measured during the fire, and both stem and canopy injuries were evaluated 1 d after the fire. We surveyed tree mortality 7 mo after the fire. We found no effects of either fuel load or fuel structure on postfire mortality or on canopy injury in J. virginiana. Canopy injury was a critical fire severity measurement determining postfire mortality in J. virginiana, and taller trees are more fire resilient. Despite laboratory-observed fuel structure effects on flammability, this study finds no evidence for the importance of grass fuel load and canopy architecture in influencing postfire tree response. This result might arise from the low crown depth and low canopy water content of J. virginiana, which can promote canopy fire and result in a high mortality rate across fuel treatments. Notwithstanding the negative results, testing laboratory-based findings in field settings is important for further examining laboratory observations and upscaling individual-level processes to ecosystems to help identify the key ecological processes determining population dynamics and community assembly. Our study also suggests that prescribed fire is an effective tool to remove encroaching J. virginiana in tallgrass prairies at an early stage.

预设火种是遏制木本植物侵占牧场生态系统的重要管理工具。草是牧场的主要燃料类型。过去的研究表明，不同草种的草冠结构会影响可燃性。至于草地燃料结构的变化是否会影响植物的火后反应，目前尚未进行过测试。为了弥补这一空白，我们在密苏里州西南部的高草草原上进行了不同燃料处理的野外燃烧实验，并考察了L.的火后死亡率。我们对 60 棵树进行了取样，并在火灾前测量了树高和胸径。我们对每棵树周围的燃料进行了处理，使其在燃料负荷和燃料结构方面各不相同。火灾期间测量了火焰温度，火灾 1 d 后评估了茎干和树冠的损伤情况。火灾发生 7 个月后，我们对树木死亡率进行了调查。我们没有发现燃料负荷或燃料结构对火灾后树木死亡率或树冠损伤有任何影响。树冠损伤是火灾严重程度的一个重要衡量标准，它决定了Ⅳ级飓风的火后死亡率，而高大的树木在火灾中的抗灾能力更强。尽管实验室观察到燃料结构对可燃性有影响，但本研究没有发现任何证据表明草地燃料负荷和树冠结构对火后树木反应的重要影响。造成这一结果的原因可能是Ⅳ级草地的树冠深度低、冠层含水量低，这可能会促进冠层着火并导致各种燃料处理的高死亡率。尽管结果是负面的，但在野外环境中检验基于实验室的研究结果对于进一步研究实验室观察结果和将个体水平的过程放大到生态系统非常重要，有助于确定决定种群动态和群落组合的关键生态过程。我们的研究还表明，处方火是一种有效的工具，可以在早期清除高草草原上的蚕食物种。

{"title":"No Field Evidence of Grass Fuel Structure effects on Postfire Tree Mortality in Juniperus virginiana","authors":"Xiulin Gao , Dylan W. Schwilk , Robin Verble","doi":"10.1016/j.rama.2024.07.012","DOIUrl":"10.1016/j.rama.2024.07.012","url":null,"abstract":"<div><div>Prescribed fires are an important management tool for containing woody plant encroachment in rangeland ecosystems. Grasses are the dominant fuel type in rangelands. Past work has shown that grass canopy architecture, which varies among grass species, can influence flammability. Whether variation in grass fuel structure can influence postfire plant responses has not yet been tested. To bridge this gap, we set up field burning experiments with different fuel treatments and examined postfire mortality of <em>Juniperus virginiana</em> L. in a tallgrass prairie in southwestern Missouri. We sampled 60 trees and measured tree height and diameter at breast height before the fire. Fuels surrounding each tree were manipulated to vary independently in both fuel load and fuel structure. Flame temperatures were measured during the fire, and both stem and canopy injuries were evaluated 1 d after the fire. We surveyed tree mortality 7 mo after the fire. We found no effects of either fuel load or fuel structure on postfire mortality or on canopy injury in <em>J. virginiana</em>. Canopy injury was a critical fire severity measurement determining postfire mortality in <em>J. virginiana</em>, and taller trees are more fire resilient. Despite laboratory-observed fuel structure effects on flammability, this study finds no evidence for the importance of grass fuel load and canopy architecture in influencing postfire tree response. This result might arise from the low crown depth and low canopy water content of <em>J. virginiana</em>, which can promote canopy fire and result in a high mortality rate across fuel treatments. Notwithstanding the negative results, testing laboratory-based findings in field settings is important for further examining laboratory observations and upscaling individual-level processes to ecosystems to help identify the key ecological processes determining population dynamics and community assembly. Our study also suggests that prescribed fire is an effective tool to remove encroaching <em>J. virginiana</em> in tallgrass prairies at an early stage.</div></div>","PeriodicalId":49634,"journal":{"name":"Rangeland Ecology & Management","volume":"98 ","pages":"Pages 110-117"},"PeriodicalIF":2.4,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142224909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Patch-Burn Grazing: An Economic Analysis of Pyric Herbivory Rangeland Management by Cow–Calf Producers 烧地放牧：牛-小牛生产者热草地管理的经济分析

IF 2.4 3区环境科学与生态学 Q2 ECOLOGY

Rangeland Ecology & Management

Pub Date : 2024-08-22 DOI: 10.1016/j.rama.2024.07.007

Hannah M. Baker , Hannah E. Shear , Derrell S. Peel , Kellie Curry Raper , Samuel D. Fuhlendorf

Rangeland management decisions require cattle producers to select practices that improve the sustainability of rangelands to maintain cattle production while remaining profitable. The invasion of Eastern red cedar (Juniperus virginiana) across the Great Plains due to fire suppression is limiting grazeable land for cattle. Woody plant encroachment (WPE), combined with drought impacts and high input costs, becomes expensive for cattle producers who are forced to supplement, destock, or both. Patch-burn grazing is a practice based on the understanding of the interaction of fire and grazing (pyric herbivory) that divides a pasture into sections, burning one section rotationally each year. It offers improved rangeland productivity by providing high-quality forages, mitigation for drought impacts, and control of WPE. Despite these benefits, the adoption of patch-burn grazing by cattle producers is limited. Our goal involved increasing awareness of the benefits of patch-burn grazing by estimating the costs and long-term economic benefits and comparing them to those of one of the more traditional approaches of burning an entire pasture every 3 yr. In building an economic analysis, our objectives were to calculate utilization costs and quantify the benefits of high-quality forages and drought impact mitigation.

Results indicated that patch-burn grazing will cost approximately $5.94 more per hectare per year than burning the entire pasture every 3 yr. The benefit of cows having continual access to high-quality forages in recently burned areas results in savings of $20 per head per year in winter supplementation costs. Additionally, utilizing patch-burn grazing before a drought, not burning during a drought, and resuming after the drought reduce supplementation and burn costs by 4.5% and increase future value of savings by $100.21 per cow compared with those caused by traditional management practices after 6 yr. An economic analysis of patch-burn grazing provides beneficial economic information to aid cow–calf producers in the decision-making process of rangeland management.

牧场管理决策要求养牛者选择提高牧场可持续性的做法，以维持牛的生产，同时保持盈利。东部红杉（Juniperus virginia）由于灭火而入侵大平原，限制了牛的放牧用地。木本植物的入侵，再加上干旱影响和高投入成本，对牛生产者来说变得昂贵，他们被迫补充或减少库存，或两者兼而有之。斑块燃烧放牧是一种基于对火和放牧（pyric草食）相互作用的理解的做法，它将牧场分成几个部分，每年轮流燃烧一个部分。它通过提供高质量的牧草、缓解干旱影响和控制WPE来提高牧场生产力。尽管有这些好处，养牛者采用的烧地放牧是有限的。我们的目标是通过估算成本和长期经济效益，并将其与每3年烧毁整个牧场的传统方法进行比较，提高人们对斑块燃烧放牧效益的认识。在构建经济分析时，我们的目标是计算利用成本，量化高质量牧草和缓解干旱影响的效益。结果表明，与每3年烧一次整个牧场相比，每年每公顷烧一次牧场的成本约为5.94美元。在最近被烧过的地区，奶牛可以持续获得高质量的饲料，因此每年每头奶牛的冬季补充成本可节省20美元。此外，在干旱前利用斑块燃烧放牧，干旱期间不燃烧，干旱后恢复，与传统管理做法相比，6年后补充和燃烧成本降低4.5%，每头牛的未来节约价值增加100.21美元。对斑块燃烧放牧的经济分析提供了有益的经济信息，以帮助小牛生产者在牧场管理决策过程中。

{"title":"Patch-Burn Grazing: An Economic Analysis of Pyric Herbivory Rangeland Management by Cow–Calf Producers","authors":"Hannah M. Baker , Hannah E. Shear , Derrell S. Peel , Kellie Curry Raper , Samuel D. Fuhlendorf","doi":"10.1016/j.rama.2024.07.007","DOIUrl":"10.1016/j.rama.2024.07.007","url":null,"abstract":"<div><div>Rangeland management decisions require cattle producers to select practices that improve the sustainability of rangelands to maintain cattle production while remaining profitable. The invasion of Eastern red cedar (<em>Juniperus virginiana)</em> across the Great Plains due to fire suppression is limiting grazeable land for cattle. Woody plant encroachment (WPE), combined with drought impacts and high input costs, becomes expensive for cattle producers who are forced to supplement, destock, or both. Patch-burn grazing is a practice based on the understanding of the interaction of fire and grazing (pyric herbivory) that divides a pasture into sections, burning one section rotationally each year. It offers improved rangeland productivity by providing high-quality forages, mitigation for drought impacts, and control of WPE. Despite these benefits, the adoption of patch-burn grazing by cattle producers is limited. Our goal involved increasing awareness of the benefits of patch-burn grazing by estimating the costs and long-term economic benefits and comparing them to those of one of the more traditional approaches of burning an entire pasture every 3 yr. In building an economic analysis, our objectives were to calculate utilization costs and quantify the benefits of high-quality forages and drought impact mitigation.</div><div>Results indicated that patch-burn grazing will cost approximately $5.94 more per hectare per year than burning the entire pasture every 3 yr. The benefit of cows having continual access to high-quality forages in recently burned areas results in savings of $20 per head per year in winter supplementation costs. Additionally, utilizing patch-burn grazing before a drought, not burning during a drought, and resuming after the drought reduce supplementation and burn costs by 4.5% and increase future value of savings by $100.21 per cow compared with those caused by traditional management practices after 6 yr. An economic analysis of patch-burn grazing provides beneficial economic information to aid cow–calf producers in the decision-making process of rangeland management.</div></div>","PeriodicalId":49634,"journal":{"name":"Rangeland Ecology & Management","volume":"98 ","pages":"Pages 41-48"},"PeriodicalIF":2.4,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142746900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of Dormant Season and Contemporary Spring-Summer Grazing on Plant Community Composition in the Sagebrush Ecosystem 休眠期和当代春夏放牧对山艾属植物群落组成的影响

IF 2.4 3区环境科学与生态学 Q2 ECOLOGY

Rangeland Ecology & Management

Pub Date : 2024-08-22 DOI: 10.1016/j.rama.2024.07.006

Vanessa M. Schroeder , Dustin D. Johnson , Kirk W. Davies , Chad S. Boyd , Rory C. O'Connor

Livestock grazing is the primary land use across sagebrush ecosystems in the western US and its effects have been subject to extensive research and debate. Historical overgrazing, annual grass invasion and associated increase in fire frequency, conifer encroachment, climate change, and human modification have resulted in the loss or degradation of 86% of sagebrush ecosystems, leading to intensified interest in how remaining intact rangelands are managed. Unlike historical, continuous grazing, contemporary practices generally incorporate planned periods of rest and recovery from grazing during the growing season. Dormant season grazing is one such practice that shows promise for improving degraded rangelands and reducing wildfire risk. However, no studies have compared moderate intensity dormant season grazing to contemporary spring-summer grazing and grazing exclusion in sagebrush rangelands dominated by perennial bunchgrasses. We evaluated the effects of contemporary spring-summer grazing, dormant season grazing, and grazing exclusion on plant community characteristics in a Wyoming big sagebrush ecosystem. We expected the effects of dormant season grazing to be comparable to grazing exclusion. Deep-rooted perennial bunchgrass cover and density and shallow-rooted perennial bunchgrass cover in grazed areas did not differ from grazing exclusion (control) sites, and we found no support that grazing altered the deep-rooted perennial bunchgrass community through time. Dormant season grazing reduced native annual forb and sagebrush cover, but increased density of the shallow-rooted perennial bunchgrass. Our results suggest contemporary spring-summer or dormant season grazing are unlikely to lead to a decline in desirable perennial bunchgrasses.

放牧牲畜是美国西部荞属植物生态系统的主要土地利用方式，其影响一直受到广泛的研究和争论。历史上的过度放牧、每年的草入侵和相关的火灾频率增加、针叶树入侵、气候变化和人类改造导致了86%的山艾草生态系统的丧失或退化，导致人们对如何管理剩余的完整牧场的兴趣日益浓厚。与历史上的连续放牧不同，当代的做法通常包括在生长季节放牧后的计划休息和恢复时期。休眠期放牧就是这样一种做法，它有望改善退化的牧场，降低野火风险。然而，在以多年生束草为主的山艾草草地上，尚无研究将中度休眠期放牧与现代春夏放牧和放牧隔离进行比较。研究了当代春夏放牧、休眠期放牧和禁牧对怀俄明州大山艾草生态系统植物群落特征的影响。我们预计休眠期放牧的影响与不放牧相当。放牧区深根多年生丛草盖度、密度和浅根多年生丛草盖度与不放牧（对照）地无显著差异，放牧对深根多年生丛草群落的改变不存在时间上的支持。休眠期放牧减少了本地一年生草本和山艾草的盖度，但增加了多年生浅根束草的密度。我们的研究结果表明，当代春夏或休眠期放牧不太可能导致理想的多年生束草的减少。

{"title":"Effects of Dormant Season and Contemporary Spring-Summer Grazing on Plant Community Composition in the Sagebrush Ecosystem","authors":"Vanessa M. Schroeder , Dustin D. Johnson , Kirk W. Davies , Chad S. Boyd , Rory C. O'Connor","doi":"10.1016/j.rama.2024.07.006","DOIUrl":"10.1016/j.rama.2024.07.006","url":null,"abstract":"<div><div>Livestock grazing is the primary land use across sagebrush ecosystems in the western US and its effects have been subject to extensive research and debate. Historical overgrazing, annual grass invasion and associated increase in fire frequency, conifer encroachment, climate change, and human modification have resulted in the loss or degradation of 86% of sagebrush ecosystems, leading to intensified interest in how remaining intact rangelands are managed. Unlike historical, continuous grazing, contemporary practices generally incorporate planned periods of rest and recovery from grazing during the growing season. Dormant season grazing is one such practice that shows promise for improving degraded rangelands and reducing wildfire risk. However, no studies have compared moderate intensity dormant season grazing to contemporary spring-summer grazing and grazing exclusion in sagebrush rangelands dominated by perennial bunchgrasses. We evaluated the effects of contemporary spring-summer grazing, dormant season grazing, and grazing exclusion on plant community characteristics in a Wyoming big sagebrush ecosystem. We expected the effects of dormant season grazing to be comparable to grazing exclusion. Deep-rooted perennial bunchgrass cover and density and shallow-rooted perennial bunchgrass cover in grazed areas did not differ from grazing exclusion (control) sites, and we found no support that grazing altered the deep-rooted perennial bunchgrass community through time. Dormant season grazing reduced native annual forb and sagebrush cover, but increased density of the shallow-rooted perennial bunchgrass. Our results suggest contemporary spring-summer or dormant season grazing are unlikely to lead to a decline in desirable perennial bunchgrasses.</div></div>","PeriodicalId":49634,"journal":{"name":"Rangeland Ecology & Management","volume":"98 ","pages":"Pages 214-222"},"PeriodicalIF":2.4,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142746894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Appraising Formal and Informal Insurance Approaches Within Pastoralist Social Networks in Northern Kenya 评估肯尼亚北部牧民社会网络中的正式和非正式保险方法

IF 2.4 3区环境科学与生态学 Q2 ECOLOGY

Rangeland Ecology & Management

Pub Date : 2024-08-22 DOI: 10.1016/j.rama.2024.07.005

Brian N. Muchema , Judith S. Mbau , Nzioka J. Muthama

Pastoral resource scarcity resulting from climate shocks, particularly drought, impoverishes and adversely affects pastoralists in arid and semiarid lands. Understanding how pastoralists apply established and contemporary risk management approaches is critical for policy and planning on social protection for vulnerable communities. Hence, this study sought to describe existing informal risk-sharing approaches and explore index-based livestock insurance (IBLI) as a formal risk-sharing approach employed by pastoralists to cope with pastoral resource scarcity. Based on the socioecological and disaster approaches to resilience theory, this research employed a qualitative descriptive design. Using semistructured in-person interviews, data were collected from a sample of 69 household respondents, a focus group discussion, and 4 key informants. This study found that although social networks enhance resource sharing, adverse climate stressors were strangling the traditional resource-sharing structures of pastoralism. As a result, this study noted a potential shift from collective risk sharing to household-based or self-insurance among pastoralists. IBLI uptake was recorded as low at 17% due to low awareness levels, a slowed premium sale supply, and a plausible product trust deficit. This study affirms that formal insurance can leverage informal insurance social networks to assist households in coping better with climate shocks, thus enhancing livelihood resilience. The study recommends establishing a framework that integrates both the traditional and modern approaches to risk sharing. Additionally, a focus on designing formal risk-sharing products that cater to household and collective shock recovery may be promising.

气候冲击，特别是干旱造成的畜牧业资源短缺，使干旱和半干旱地区的牧民陷入贫困并受到不利影响。了解牧民如何应用现有的和现代的风险管理方法，对于脆弱社区的社会保护政策和规划至关重要。因此，本研究试图描述现有的非正式风险分担方法，并探索基于指数的牲畜保险（IBLI）作为牧民应对牧区资源稀缺的正式风险分担方法。本研究以社会生态学和灾害理论为基础，采用定性描述设计。采用半结构化的面对面访谈，从69个家庭受访者、焦点小组讨论和4个关键线人中收集数据。研究发现，尽管社会网络促进了资源共享，但不利的气候压力因素正在扼杀传统的畜牧业资源共享结构。因此，本研究指出，牧民可能从集体分担风险转向以家庭为基础或自我保险。由于认知度低、溢价销售供应放缓以及可信的产品信任赤字，IBLI的使用率低至17%。本研究证实，正规保险可以利用非正规保险社会网络，帮助家庭更好地应对气候冲击，从而增强生计复原力。该研究建议建立一个框架，将传统和现代的风险分担方法结合起来。此外，注重设计适合家庭和集体冲击恢复的正式风险分担产品可能是有希望的。

{"title":"Appraising Formal and Informal Insurance Approaches Within Pastoralist Social Networks in Northern Kenya","authors":"Brian N. Muchema , Judith S. Mbau , Nzioka J. Muthama","doi":"10.1016/j.rama.2024.07.005","DOIUrl":"10.1016/j.rama.2024.07.005","url":null,"abstract":"<div><div>Pastoral resource scarcity resulting from climate shocks, particularly drought, impoverishes and adversely affects pastoralists in arid and semiarid lands. Understanding how pastoralists apply established and contemporary risk management approaches is critical for policy and planning on social protection for vulnerable communities. Hence, this study sought to describe existing informal risk-sharing approaches and explore index-based livestock insurance (IBLI) as a formal risk-sharing approach employed by pastoralists to cope with pastoral resource scarcity. Based on the socioecological and disaster approaches to resilience theory, this research employed a qualitative descriptive design. Using semistructured in-person interviews, data were collected from a sample of 69 household respondents, a focus group discussion, and 4 key informants. This study found that although social networks enhance resource sharing, adverse climate stressors were strangling the traditional resource-sharing structures of pastoralism. As a result, this study noted a potential shift from collective risk sharing to household-based or self-insurance among pastoralists. IBLI uptake was recorded as low at 17% due to low awareness levels, a slowed premium sale supply, and a plausible product trust deficit. This study affirms that formal insurance can leverage informal insurance social networks to assist households in coping better with climate shocks, thus enhancing livelihood resilience. The study recommends establishing a framework that integrates both the traditional and modern approaches to risk sharing. Additionally, a focus on designing formal risk-sharing products that cater to household and collective shock recovery may be promising.</div></div>","PeriodicalId":49634,"journal":{"name":"Rangeland Ecology & Management","volume":"98 ","pages":"Pages 160-169"},"PeriodicalIF":2.4,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142745711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0