Pub Date : 2022-01-02DOI: 10.2989/10220119.2021.2016965
Abraham N Dabengwa, S. Archibald, J. Finch, L. Scott, L. Gillson, W. Bond
African grassy biomes evolved together with fire and have a long history of human manipulation of fire, yet few rangeland studies acknowledge the role of prehistoric fire in shaping contemporary ecological patterns. Nevertheless, prehistoric fire records have been used elsewhere as invaluable environmental contexts for practitioners in fire management, ecosystem restoration and climate change. Therefore, our aim is to collate prehistoric sedimentary charcoal studies from southern African grassy biomes and bring them to the attention of practitioners. We discuss how long-term data contribute to fire ecology and ecosystem functioning. Importantly, this contribution aims to give a reference point for stakeholders working at different temporal and spatial scales to improve our understanding and management of grassy ecosystems.
{"title":"Sedimentary charcoal studies from southern Africa’s grassy biomes: a potential resource for informing the management of fires and ecosystems","authors":"Abraham N Dabengwa, S. Archibald, J. Finch, L. Scott, L. Gillson, W. Bond","doi":"10.2989/10220119.2021.2016965","DOIUrl":"https://doi.org/10.2989/10220119.2021.2016965","url":null,"abstract":"African grassy biomes evolved together with fire and have a long history of human manipulation of fire, yet few rangeland studies acknowledge the role of prehistoric fire in shaping contemporary ecological patterns. Nevertheless, prehistoric fire records have been used elsewhere as invaluable environmental contexts for practitioners in fire management, ecosystem restoration and climate change. Therefore, our aim is to collate prehistoric sedimentary charcoal studies from southern African grassy biomes and bring them to the attention of practitioners. We discuss how long-term data contribute to fire ecology and ecosystem functioning. Importantly, this contribution aims to give a reference point for stakeholders working at different temporal and spatial scales to improve our understanding and management of grassy ecosystems.","PeriodicalId":50841,"journal":{"name":"African Journal of Range & Forage Science","volume":"72 1","pages":"27 - 43"},"PeriodicalIF":1.4,"publicationDate":"2022-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90295991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2022-01-02DOI: 10.2989/10220119.2022.2033322
J. Puttick, M. Timm Hoffman, T. O’Connor
Fire is a key regulator of tree cover in grassy ecosystems, but century-long changes in fire regimes have not been explicitly quantified in South Africa. This study aimed to determine changes in the fire regimes of South Africa’s grassy biomes over the past century in response to widespread human-induced changes. Using spatially explicit data, we employed random forest models to examine the importance of climatic and human drivers on the extent, frequency and intensity of fire. We then modelled how fire regimes are likely to have changed over the past century using historical trends in key human drivers (population growth, livestock density, road density and land cover change) as inputs. Results showed that human drivers, particularly land transformation and human population density, were important determinants of fire regime. Random forest predictions showed a decline in burnt area (mean of 10.5% in 1910 to 5.1% in 2020), and a shift to fire regimes with smaller burnt areas, longer fire return intervals and lower intensity fires over the past century, particularly in the mesic east. These dynamics have important implications for our understanding of the widespread increases in woody cover observed in the region over this period.
{"title":"The effect of changes in human drivers on the fire regimes of South African grassland and savanna environments over the past 100 years","authors":"J. Puttick, M. Timm Hoffman, T. O’Connor","doi":"10.2989/10220119.2022.2033322","DOIUrl":"https://doi.org/10.2989/10220119.2022.2033322","url":null,"abstract":"Fire is a key regulator of tree cover in grassy ecosystems, but century-long changes in fire regimes have not been explicitly quantified in South Africa. This study aimed to determine changes in the fire regimes of South Africa’s grassy biomes over the past century in response to widespread human-induced changes. Using spatially explicit data, we employed random forest models to examine the importance of climatic and human drivers on the extent, frequency and intensity of fire. We then modelled how fire regimes are likely to have changed over the past century using historical trends in key human drivers (population growth, livestock density, road density and land cover change) as inputs. Results showed that human drivers, particularly land transformation and human population density, were important determinants of fire regime. Random forest predictions showed a decline in burnt area (mean of 10.5% in 1910 to 5.1% in 2020), and a shift to fire regimes with smaller burnt areas, longer fire return intervals and lower intensity fires over the past century, particularly in the mesic east. These dynamics have important implications for our understanding of the widespread increases in woody cover observed in the region over this period.","PeriodicalId":50841,"journal":{"name":"African Journal of Range & Forage Science","volume":"86 1","pages":"107 - 123"},"PeriodicalIF":1.4,"publicationDate":"2022-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83571263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2022-01-02DOI: 10.2989/10220119.2021.2016966
Nicola Findlay, A. Manson, J. P. Cromsigt, P. Gordijn, Cathy Nixon, M. Rietkerk, G. Thibaud, M.J.infoeu-repo Wassen, M. Beest
Fire has been an integral evolutionary force shaping and maintaining grassy biomes, such as the Afromontane grasslands of South Africa. Afromontane grasslands represent a large carbon reservoir, but it is uncertain how fire affects their long-term C storage. We investigated the effect of fire regime on soil organic C and N (SOC; SON) in a long-term (39-year) burning experiment in the Maloti-Drakensberg Park, South Africa. We compared SOC and SON sampled in 2004 and 2019 from six treatments differing in fire frequency (annual, biennial, five-year, infrequent) and season (spring, autumn). Average SOC increased significantly between 2004 and 2019. Average SON increased slightly, resulting in a significant increase in C:N ratio, indicating that soil organic matter is becoming less N-eutrophic. Importantly, burning annually in spring increased SOC and SON. This unexpected response is attributed to the aluandic (acidic, high organic matter) properties of Drakensberg soils. Burning in autumn did not increase SOC and SON. The lowest C stocks were observed in infrequently burnt plots. Average C sequestration across all fire treatments was 0.30 Mg ha−1 y−1. The observed increase in SOC under frequent fires is contrary to many findings from other studies in grassy ecosystems and notably driven by fire season.
火一直是形成和维持草类生物群落的一种不可或缺的进化力量，例如南非的非洲山地草原。非洲山地草原代表着一个巨大的碳库，但不确定火如何影响它们的长期碳储存。研究了不同火种对土壤有机碳、氮(SOC)的影响;SON)在南非的Maloti-Drakensberg公园进行了一项长期(39年)燃烧实验。我们比较了2004年和2019年6个不同火灾频率(一年生、两年生、五年、不常见)和季节(春季、秋季)处理的SOC和SON样本。2004年至2019年间，平均SOC显著增加。平均SON略有增加，导致C:N比值显著增加，表明土壤有机质富营养化程度降低。重要的是，每年春季的燃烧增加了SOC和SON。这种意想不到的反应归因于德拉肯斯堡土壤的酸性(酸性，高有机质)特性。秋季燃烧对土壤的SOC和SON没有增加作用。碳储量最低的是不常烧毁的地块。所有五个处理的平均碳固存量为0.30 Mg ha - 1 y - 1。观察到的频繁火灾下有机碳的增加与其他草地生态系统研究的许多结果相反，主要是由火灾季节驱动的。
{"title":"Long-term frequent fires do not decrease topsoil carbon and nitrogen in an Afromontane grassland","authors":"Nicola Findlay, A. Manson, J. P. Cromsigt, P. Gordijn, Cathy Nixon, M. Rietkerk, G. Thibaud, M.J.infoeu-repo Wassen, M. Beest","doi":"10.2989/10220119.2021.2016966","DOIUrl":"https://doi.org/10.2989/10220119.2021.2016966","url":null,"abstract":"Fire has been an integral evolutionary force shaping and maintaining grassy biomes, such as the Afromontane grasslands of South Africa. Afromontane grasslands represent a large carbon reservoir, but it is uncertain how fire affects their long-term C storage. We investigated the effect of fire regime on soil organic C and N (SOC; SON) in a long-term (39-year) burning experiment in the Maloti-Drakensberg Park, South Africa. We compared SOC and SON sampled in 2004 and 2019 from six treatments differing in fire frequency (annual, biennial, five-year, infrequent) and season (spring, autumn). Average SOC increased significantly between 2004 and 2019. Average SON increased slightly, resulting in a significant increase in C:N ratio, indicating that soil organic matter is becoming less N-eutrophic. Importantly, burning annually in spring increased SOC and SON. This unexpected response is attributed to the aluandic (acidic, high organic matter) properties of Drakensberg soils. Burning in autumn did not increase SOC and SON. The lowest C stocks were observed in infrequently burnt plots. Average C sequestration across all fire treatments was 0.30 Mg ha−1 y−1. The observed increase in SOC under frequent fires is contrary to many findings from other studies in grassy ecosystems and notably driven by fire season.","PeriodicalId":50841,"journal":{"name":"African Journal of Range & Forage Science","volume":"10 2 1","pages":"44 - 55"},"PeriodicalIF":1.4,"publicationDate":"2022-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81109787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2022-01-02DOI: 10.2989/10220119.2022.2030408
T. Hamilton, S. Archibald, S. Woodborne
Southern Africa is dominated by fire-prone arid and semi-arid landscapes that are expected to experience increased maximum temperatures, rainfall variation and frequency of extreme rainfall events in the future. These conditions will affect fire and vegetation dynamics, but feedback and interactions among fire, rainfall and woody cover limit our ability to predict future ecosystem changes. Moreover, human activities can also drive changes in these components and their interactions. There are few long-term datasets available to monitor these changes over ecologically relevant time-scales. Here the combined analysis of a rainfall proxy, developed from a baobab tree core (Adansonia digitata) and fire proxy, from a sediment core, in the savanna-woodland transition zone in South Central Africa elucidates the history of two major drivers of savanna structure for the past 600 years. They show a system that oscillates between wooded and grassy vegetation states over time, as well as a change in the spatial scale of fires, which could be linked to human activities and recent fire management legislation.
{"title":"Historic changes in the fire-rainfall relationship at a woodland-savanna transition zone in southern Africa","authors":"T. Hamilton, S. Archibald, S. Woodborne","doi":"10.2989/10220119.2022.2030408","DOIUrl":"https://doi.org/10.2989/10220119.2022.2030408","url":null,"abstract":"Southern Africa is dominated by fire-prone arid and semi-arid landscapes that are expected to experience increased maximum temperatures, rainfall variation and frequency of extreme rainfall events in the future. These conditions will affect fire and vegetation dynamics, but feedback and interactions among fire, rainfall and woody cover limit our ability to predict future ecosystem changes. Moreover, human activities can also drive changes in these components and their interactions. There are few long-term datasets available to monitor these changes over ecologically relevant time-scales. Here the combined analysis of a rainfall proxy, developed from a baobab tree core (Adansonia digitata) and fire proxy, from a sediment core, in the savanna-woodland transition zone in South Central Africa elucidates the history of two major drivers of savanna structure for the past 600 years. They show a system that oscillates between wooded and grassy vegetation states over time, as well as a change in the spatial scale of fires, which could be linked to human activities and recent fire management legislation.","PeriodicalId":50841,"journal":{"name":"African Journal of Range & Forage Science","volume":"100 1","pages":"70 - 81"},"PeriodicalIF":1.4,"publicationDate":"2022-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80308287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2022-01-02DOI: 10.2989/10220119.2022.2028187
Simon Pooley
This paper provides a history of attempts to understand and manage fire in the grasslands and savannas of eastern and southern Africa from c. 1900 to 2010. Given the brevity of the paper and the author’s expertise, there is a focus on science and management in South Africa, though wider networks of research and expertise across the region are discussed. There is a focus on a few key figures like Charles Swynnerton, John Phillips and Winston Trollope, with references provided for other important historical figures like John William Bews. The emphasis is on scientific research and expert-led thinking on fire and fire management in vegetation, with brief discussion of African approaches and the extent to which they have been ignored or have influenced scientific thinking. Fire in relation to invasive species is not covered.
{"title":"A historical perspective on fire research in East and Southern African grasslands and savannas","authors":"Simon Pooley","doi":"10.2989/10220119.2022.2028187","DOIUrl":"https://doi.org/10.2989/10220119.2022.2028187","url":null,"abstract":"This paper provides a history of attempts to understand and manage fire in the grasslands and savannas of eastern and southern Africa from c. 1900 to 2010. Given the brevity of the paper and the author’s expertise, there is a focus on science and management in South Africa, though wider networks of research and expertise across the region are discussed. There is a focus on a few key figures like Charles Swynnerton, John Phillips and Winston Trollope, with references provided for other important historical figures like John William Bews. The emphasis is on scientific research and expert-led thinking on fire and fire management in vegetation, with brief discussion of African approaches and the extent to which they have been ignored or have influenced scientific thinking. Fire in relation to invasive species is not covered.","PeriodicalId":50841,"journal":{"name":"African Journal of Range & Forage Science","volume":"56 1","pages":"1 - 15"},"PeriodicalIF":1.4,"publicationDate":"2022-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83548821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2021-12-10DOI: 10.2989/10220119.2021.1918247
M. Trytsman, Francuois L Muller, C. Morris, A. E. van Wyk
The ecological and economical importance of African grasses in sustaining animal production prompted studies to quantify the wealth of grass genetic resources indigenous to southern Africa. Plant collection and occurrence data were extracted from two southern African datasets, BODATSA and PHYTOBAS, and analysed to establish biogeographical patterns in the grass flora indigenous to South Africa, Lesotho and Eswatini. A total of 1 648 quarter degree grid cells, representing 674 grass species, were used in an agglomerative hierarchical clustering to determine biogeographical units being referred to as grasschoria. Six distinct groups formed, mainly following existing biome vegetation units, termed the Grassland, Indian Ocean Coastal Belt, Fynbos, Savanna, Central Arid Region and Succulent Karoo grasschoria. The description focuses on associated phytochoria, floristic links, key species, climate and soil properties. The main gradient distinguishing grasschoria was a rainfall-temperature gradient. The collection, conservation and breeding of pasture grass species adapted to especially arid and semi-arid environments, could be managed more efficiently by using these results, but also calling on the need to describe and label infraspecific genetic variants, including ecotypes.
{"title":"Biogeographical patterns of grasses (Poaceae) indigenous to South Africa, Lesotho and Eswatini","authors":"M. Trytsman, Francuois L Muller, C. Morris, A. E. van Wyk","doi":"10.2989/10220119.2021.1918247","DOIUrl":"https://doi.org/10.2989/10220119.2021.1918247","url":null,"abstract":"The ecological and economical importance of African grasses in sustaining animal production prompted studies to quantify the wealth of grass genetic resources indigenous to southern Africa. Plant collection and occurrence data were extracted from two southern African datasets, BODATSA and PHYTOBAS, and analysed to establish biogeographical patterns in the grass flora indigenous to South Africa, Lesotho and Eswatini. A total of 1 648 quarter degree grid cells, representing 674 grass species, were used in an agglomerative hierarchical clustering to determine biogeographical units being referred to as grasschoria. Six distinct groups formed, mainly following existing biome vegetation units, termed the Grassland, Indian Ocean Coastal Belt, Fynbos, Savanna, Central Arid Region and Succulent Karoo grasschoria. The description focuses on associated phytochoria, floristic links, key species, climate and soil properties. The main gradient distinguishing grasschoria was a rainfall-temperature gradient. The collection, conservation and breeding of pasture grass species adapted to especially arid and semi-arid environments, could be managed more efficiently by using these results, but also calling on the need to describe and label infraspecific genetic variants, including ecotypes.","PeriodicalId":50841,"journal":{"name":"African Journal of Range & Forage Science","volume":"13 1","pages":"S73 - S89"},"PeriodicalIF":1.4,"publicationDate":"2021-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87765377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2021-12-03DOI: 10.2989/10220119.2021.2000025
M. Mangwane, I. Madakadze, FV Nherera-Chokuda, S. Dube, M. Mndela
Certain grasses show potential for the rehabilitation of coalmine spoils. Species selection and evaluation are used to guide the choice of the most appropriate grass species. This study evaluated the germination performance of seven forage grass species, with some represented by two varieties, under varying salinity conditions of 0 (distilled H2O), 100, 200, 400, 600, 800 and 1 000 mS m−1 of NaCl. Cumulative germination, final germination percentage (FG%), and time taken to reach 50% of the final germination (T50) were determined for each species–treatment combination. Species × salinity interaction was significant (p < 0.01) for cumulative germination, FG% and T50. Cumulative germination increased gradually up to 17 days and thereafter declined. The highest FG% for all grass species was attained under distilled water (0 mS m−1), ranging from 38% to 94%, and declined significantly (p < 0.01) with an increase in salinity. T50 increased with increasing salinity for all grass species. Eragrostis curvula var. Ermelo and Lolium multiflorum var. Archie were the quickest to germinate and attained significantly (p < 0.01) higher values of FG%, of 45% and 50%, respectively, at 600 mS m−1, indicating higher salt tolerance than the other species. Overall, increasing salinity reduced the germination performance of all grass species tested; however, Archie and Ermelo showed higher potential for rehabilitation of coalmine spoils irrigated with saline water.
某些草显示出恢复煤矿废墟的潜力。物种选择和评价用于指导选择最合适的草种。在0(蒸馏水)、100、200、400、600、800和1 000 mS m−1 NaCl不同盐度条件下，对7种牧草(部分为2个品种)的萌发性能进行了研究。测定了各处理组合的累积发芽率、最终发芽率(FG%)和达到最终发芽率50%所需时间(T50)。累积发芽率、成果率和T50与种与盐度的交互作用极显著(p < 0.01)。累积发芽率在第17天逐渐上升，之后逐渐下降。在蒸馏水(0 mS m−1)条件下，各草种的成虫率最高，为38% ~ 94%，随盐度的增加呈极显著下降(p < 0.01)。T50随盐度的增加而增加。在600 mS m−1处理下，黑麦和多花Lolium multiflorum var. Archie的萌发速度最快，分别达到45%和50% (p < 0.01)，表明其耐盐性高于其他品种。总体而言，盐度增加降低了所有被试草的发芽性能;而Archie和Ermelo在盐碱水灌溉的煤矿废弃地恢复中表现出较高的潜力。
{"title":"Germination performance of different forage grass species at different salinity (NaCl) concentrations","authors":"M. Mangwane, I. Madakadze, FV Nherera-Chokuda, S. Dube, M. Mndela","doi":"10.2989/10220119.2021.2000025","DOIUrl":"https://doi.org/10.2989/10220119.2021.2000025","url":null,"abstract":"Certain grasses show potential for the rehabilitation of coalmine spoils. Species selection and evaluation are used to guide the choice of the most appropriate grass species. This study evaluated the germination performance of seven forage grass species, with some represented by two varieties, under varying salinity conditions of 0 (distilled H2O), 100, 200, 400, 600, 800 and 1 000 mS m−1 of NaCl. Cumulative germination, final germination percentage (FG%), and time taken to reach 50% of the final germination (T50) were determined for each species–treatment combination. Species × salinity interaction was significant (p < 0.01) for cumulative germination, FG% and T50. Cumulative germination increased gradually up to 17 days and thereafter declined. The highest FG% for all grass species was attained under distilled water (0 mS m−1), ranging from 38% to 94%, and declined significantly (p < 0.01) with an increase in salinity. T50 increased with increasing salinity for all grass species. Eragrostis curvula var. Ermelo and Lolium multiflorum var. Archie were the quickest to germinate and attained significantly (p < 0.01) higher values of FG%, of 45% and 50%, respectively, at 600 mS m−1, indicating higher salt tolerance than the other species. Overall, increasing salinity reduced the germination performance of all grass species tested; however, Archie and Ermelo showed higher potential for rehabilitation of coalmine spoils irrigated with saline water.","PeriodicalId":50841,"journal":{"name":"African Journal of Range & Forage Science","volume":"128 1","pages":"S98 - S103"},"PeriodicalIF":1.4,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87956409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2021-12-02DOI: 10.2989/10220119.2021.2005146
P. Novellie
{"title":"Shaping Addo: The Story of a South African National Park","authors":"P. Novellie","doi":"10.2989/10220119.2021.2005146","DOIUrl":"https://doi.org/10.2989/10220119.2021.2005146","url":null,"abstract":"","PeriodicalId":50841,"journal":{"name":"African Journal of Range & Forage Science","volume":"1 1","pages":"300 - 300"},"PeriodicalIF":1.4,"publicationDate":"2021-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78711072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2021-11-26DOI: 10.2989/10220119.2021.1965026
A. El Aich, S. Ghassan, C. Alados, S. El Aayadi, L. Baamal
Livestock grazing intensity gradients associated with sheep holder shelters influenced the longevity of rangelands vegetation. This study aimed to examine the effects of livestock grazing pressure on vegetation structure and diversity with distance from herder shelters. Six shelters were sampled. From each herder shelter, a grazing gradient was set aligned to the contour lines. Along each grazing gradient, we surveyed seven 100-m transects between 10 and 800 m from the herder shelter. The standing crop biomass (dry matter = DM) along the gradient from the shelters, bare soil, cover of vegetation functional groups and plant species diversity were determined using the point intercept method along each transect. Bare soil cover increased as we approached herder shelter. The total standing crop biomass (DM) (in g DM m−2) increased with the distance from the shelter. Shrub biomass decreased when approaching shelters, as so did the percentage of shrub cover. Cover of perennial forbs and grass also increased with distance from shelter, whereas annual cover increased as we approached the shelter. Species richness and diversity increased when moving away from the shelter. Changes in vegetation structure were not linear. Strong changes were detectable within the first 200 m, whereas little responses were found behind this threshold. The 200 m threshold should be used to monitor the main keystone species that preserved these rangelands.
{"title":"Changes in plant vegetation structure and diversity with distance from herder shelters in the Middle Atlas Mountains","authors":"A. El Aich, S. Ghassan, C. Alados, S. El Aayadi, L. Baamal","doi":"10.2989/10220119.2021.1965026","DOIUrl":"https://doi.org/10.2989/10220119.2021.1965026","url":null,"abstract":"Livestock grazing intensity gradients associated with sheep holder shelters influenced the longevity of rangelands vegetation. This study aimed to examine the effects of livestock grazing pressure on vegetation structure and diversity with distance from herder shelters. Six shelters were sampled. From each herder shelter, a grazing gradient was set aligned to the contour lines. Along each grazing gradient, we surveyed seven 100-m transects between 10 and 800 m from the herder shelter. The standing crop biomass (dry matter = DM) along the gradient from the shelters, bare soil, cover of vegetation functional groups and plant species diversity were determined using the point intercept method along each transect. Bare soil cover increased as we approached herder shelter. The total standing crop biomass (DM) (in g DM m−2) increased with the distance from the shelter. Shrub biomass decreased when approaching shelters, as so did the percentage of shrub cover. Cover of perennial forbs and grass also increased with distance from shelter, whereas annual cover increased as we approached the shelter. Species richness and diversity increased when moving away from the shelter. Changes in vegetation structure were not linear. Strong changes were detectable within the first 200 m, whereas little responses were found behind this threshold. The 200 m threshold should be used to monitor the main keystone species that preserved these rangelands.","PeriodicalId":50841,"journal":{"name":"African Journal of Range & Forage Science","volume":"36 1","pages":"159 - 172"},"PeriodicalIF":1.4,"publicationDate":"2021-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82452552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2021-11-26DOI: 10.2989/10220119.2021.2001570
Robyn Nicolay, S. Jeffery, N. Randall
Contemporary evidence shows biotic factors play a prominent role in the soil health and the provision of soil functions. Herbaceous grassland species differ in their modulation of soil communities, effects on soil components, as well the processes they interact with or regulate. In this study, we aimed to investigate the impact of different plant species communities on soil health, as quantified by soil physical (water infiltration), chemical (soil organic matter) and biological (Collembola community data) indicators. Data was collected from an existing long-term field trial in the UK, planted to either forb-dominated composition, grass species dominated composition or a multipurpose mixture of forb and grass species. Results showed that plant community can determine soil water infiltration rates, particularly with observed increased soil organic matter (SOM) and epigeic Collembola abundances. The results presented here add evidence that plant communities planted as vegetative buffer strips can be specifically tailored to support soil health development and maintenance.
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