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Biblioteca (s) : |
INIA Treinta y Tres. |
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Fecha : |
18/04/2022 |
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Actualizado : |
18/04/2022 |
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Tipo de producción científica : |
Artículos en Revistas Indexadas Internacionales |
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Autor : |
LEZAMA, F.; PARUELO, J. |
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Afiliación : |
FELIPE LEZAMA, Department of Environmental Systems, Faculty of Agronomy, University of República, Montevideo, Uruguay.; JOSÉ PARUELO, Institute of Ecology and Environmental Sciences, Faculty of Sciences, UDELAR, UY. Department of Quantitative Methods and Information Systems, FAGRO, UY. INIA (Instituto Nacional de Investigación Agropecuaria), Uruguay. |
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Título : |
Regional assessment of stocking rate effects on uruguayan rangelands: a ranch-level study. |
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Fecha de publicación : |
2022 |
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Fuente / Imprenta : |
Rangeland Ecology & Management, 2022, volume 82, pages 58-65. Doi: https://doi.org/10.1016/j.rama.2022.02.005 |
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DOI : |
10.1016/j.rama.2022.02.005 |
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Idioma : |
Inglés |
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Notas : |
Article history: Received 27 April 2021 // Revised 9 February 2022 // Accepted 16 February 2022. |
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Contenido : |
We analyzed the variation of plant composition, forage production, and livestock diet across a broad stocking rate gradient on Eastern Hills rangelands of Uruguay. Our approach encompassed five ranches subjected to mixed sheep-cattle grazing and combined field surveys, microhistological fecal analysis, and remote sensing techniques. We hypothesized that selectivity would decrease as stocking rate increased. Vegetation data and fecal samples were obtained in 17 paddocks in 2008. To investigate the role of stocking rate on vegetation, we focused on dominant species and forage type cover. Diet composition was analyzed at forage type level. Annual net primary productivity was estimated for each paddock using the normalized difference vegetation index derived from the MODIS (Moderate Resolution Imaging Spectroradiometer) sensor. We found a clear relationship between the variation in stocking rate and floristic and forage type composition, both suggesting a deterioration of grassland conservation status. Cool season grass cover varied from 25% to 5%, from low to high stocking rates. Dicot cover showed an opposite trend, with values around 15% in the low and moderate stocking levels and reaching 35% on high-stocked paddocks. Diet composition and diet overlap between herbivores also showed clear patterns of response to stocking rate. On the other hand, livestock selectivity interacted with herbivore type. While cattle showed the expected pattern, sheep did not decrease selectivity in winter as stocking rate increased. Contrary to expectations, annual net primary productivity was similar across the different stocking rate levels and the month of maximum productivity was generally March. Our study provides strong evidence of marked rangeland degradation; however, the lack of response in terms of ANPP and the ability of sheep to maintain selectivity under high stocking rates could help to explain the lack of responsiveness in the adoption of generalized stocking adjustments by the ranchers. MenosWe analyzed the variation of plant composition, forage production, and livestock diet across a broad stocking rate gradient on Eastern Hills rangelands of Uruguay. Our approach encompassed five ranches subjected to mixed sheep-cattle grazing and combined field surveys, microhistological fecal analysis, and remote sensing techniques. We hypothesized that selectivity would decrease as stocking rate increased. Vegetation data and fecal samples were obtained in 17 paddocks in 2008. To investigate the role of stocking rate on vegetation, we focused on dominant species and forage type cover. Diet composition was analyzed at forage type level. Annual net primary productivity was estimated for each paddock using the normalized difference vegetation index derived from the MODIS (Moderate Resolution Imaging Spectroradiometer) sensor. We found a clear relationship between the variation in stocking rate and floristic and forage type composition, both suggesting a deterioration of grassland conservation status. Cool season grass cover varied from 25% to 5%, from low to high stocking rates. Dicot cover showed an opposite trend, with values around 15% in the low and moderate stocking levels and reaching 35% on high-stocked paddocks. Diet composition and diet overlap between herbivores also showed clear patterns of response to stocking rate. On the other hand, livestock selectivity interacted with herbivore type. While cattle showed the expected pattern, sheep did not decrease selectivity i... Presentar Todo |
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Palabras claves : |
(NDVI); EASTERN HILLS; FORAGE TYPES; LIVESTOCK DIET; MICROHISTOLOGICAL TECHNIQUE; NORMALIZED DIFFERENCE VEGETATION INDEX; PLANT COMPOSITION. |
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Asunto categoría : |
F40 Ecología vegetal |
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Marc : |
LEADER 02892naa a2200241 a 4500
001 1063033
005 2022-04-18
008 2022 bl uuuu u00u1 u #d
024 7 $a10.1016/j.rama.2022.02.005$2DOI
100 1 $aLEZAMA, F.
245 $aRegional assessment of stocking rate effects on uruguayan rangelands$ba ranch-level study.$h[electronic resource]
260 $c2022
500 $aArticle history: Received 27 April 2021 // Revised 9 February 2022 // Accepted 16 February 2022.
520 $aWe analyzed the variation of plant composition, forage production, and livestock diet across a broad stocking rate gradient on Eastern Hills rangelands of Uruguay. Our approach encompassed five ranches subjected to mixed sheep-cattle grazing and combined field surveys, microhistological fecal analysis, and remote sensing techniques. We hypothesized that selectivity would decrease as stocking rate increased. Vegetation data and fecal samples were obtained in 17 paddocks in 2008. To investigate the role of stocking rate on vegetation, we focused on dominant species and forage type cover. Diet composition was analyzed at forage type level. Annual net primary productivity was estimated for each paddock using the normalized difference vegetation index derived from the MODIS (Moderate Resolution Imaging Spectroradiometer) sensor. We found a clear relationship between the variation in stocking rate and floristic and forage type composition, both suggesting a deterioration of grassland conservation status. Cool season grass cover varied from 25% to 5%, from low to high stocking rates. Dicot cover showed an opposite trend, with values around 15% in the low and moderate stocking levels and reaching 35% on high-stocked paddocks. Diet composition and diet overlap between herbivores also showed clear patterns of response to stocking rate. On the other hand, livestock selectivity interacted with herbivore type. While cattle showed the expected pattern, sheep did not decrease selectivity in winter as stocking rate increased. Contrary to expectations, annual net primary productivity was similar across the different stocking rate levels and the month of maximum productivity was generally March. Our study provides strong evidence of marked rangeland degradation; however, the lack of response in terms of ANPP and the ability of sheep to maintain selectivity under high stocking rates could help to explain the lack of responsiveness in the adoption of generalized stocking adjustments by the ranchers.
653 $a(NDVI)
653 $aEASTERN HILLS
653 $aFORAGE TYPES
653 $aLIVESTOCK DIET
653 $aMICROHISTOLOGICAL TECHNIQUE
653 $aNORMALIZED DIFFERENCE VEGETATION INDEX
653 $aPLANT COMPOSITION
700 1 $aPARUELO, J.
773 $tRangeland Ecology & Management, 2022, volume 82, pages 58-65. Doi: https://doi.org/10.1016/j.rama.2022.02.005
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Registro completo
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Biblioteca (s) : |
INIA La Estanzuela. |
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Fecha actual : |
27/04/2021 |
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Actualizado : |
12/08/2021 |
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Tipo de producción científica : |
Artículos en Revistas Indexadas Internacionales |
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Circulación / Nivel : |
Internacional - -- |
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Autor : |
BIRU, F.N; ISLAM, T.; CIBILS-STEWART, X.; CAZZONELLI, CH.I.; ELBAUM, R.; JOHNSON, S.N. |
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Afiliación : |
FIKADU N. BIRU, Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia.; TARIKUL ISLAM, Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia; XIMENA CIBILS-STEWART, INIA (Instituto Nacional de Investigación Agropecuaria), Uruguay./ Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia.; CHRISTOPHER I. CAZZONELLI, Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia.; RIVKA ELBAUM5, R H Smith Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem, Rehovot, Israel.; SCOTT N. JOHNSON, Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia. |
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Título : |
Anti-herbivore silicon defences in a model grass are greatest under Miocene levels of atmospheric CO2. |
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Fecha de publicación : |
2021 |
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Fuente / Imprenta : |
Global Change Biology, Volume 27, Issue 12, Pages 2959-2969, June 2021. Doi: https://doi.org/10.1111/gcb.15619 |
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DOI : |
10.1111/gcb.15619 |
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Idioma : |
Inglés |
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Notas : |
Article history: Received: 8 February 2021/Accepted: 12 March 2021./ First published: 27 March 2021: Email: f.biru@westernsydney.edu.au. |
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Contenido : |
Abstract:
Silicon (Si) has an important role in mitigating diverse biotic and abiotic stresses in plants, mainly via the silicification of plant tissues. Environmental changes such as atmospheric CO2 concentrations may affect grass Si concentrations which, in turn, can alter herbivore performance. We recently demonstrated that pre?industrial atmospheric CO2 increased Si accumulation in Brachypodium distachyon grass, yet the patterns of Si deposition in leaves and whether this affects insect herbivore performance remains unknown. Moreover, it is unclear whether CO2?driven changes in Si accumulation are linked to changes in gas exchange (e.g. transpiration rates). We therefore investigated how pre?industrial (reduced; rCO2, 200 ppm), ambient (aCO2, 410 ppm) and elevated (eCO2, 640 ppm) CO2 concentrations, in combination with Si?treatment (Si+ or Si?), affected Si accumulation in B. distachyon and its subsequent effect on the performance of the global insect pest, Helicoverpa armigera. rCO2 increased Si concentrations by 29% and 36% compared to aCO2 and eCO2 respectively. These changes were not related to observed changes in gas exchange under different CO2 regimes, however. The increased Si accumulation under rCO2 decreased herbivore relative growth rate (RGR) by 120% relative to eCO2, whereas rCO2 caused herbivore RGR to decrease by 26% compared to eCO2. Si supplementation also increased the density of macrohairs, silica and prickle cells, which was associated with reduced herbivore performance. There was a negative correlation among macrohair density, silica cell density, prickle cell density and herbivore RGR under rCO2 suggesting that these changes in leaf surface morphology were linked to reduced performance under this CO2 regime. To our knowledge, this is the first study to demonstrate that increased Si accumulation under pre?industrial CO2 reduces insect herbivore performance. Contrastingly, we found reduced Si accumulation under higher CO2, which suggests that some grasses may become more susceptible to insect herbivores under projected climate change scenarios. MenosAbstract:
Silicon (Si) has an important role in mitigating diverse biotic and abiotic stresses in plants, mainly via the silicification of plant tissues. Environmental changes such as atmospheric CO2 concentrations may affect grass Si concentrations which, in turn, can alter herbivore performance. We recently demonstrated that pre?industrial atmospheric CO2 increased Si accumulation in Brachypodium distachyon grass, yet the patterns of Si deposition in leaves and whether this affects insect herbivore performance remains unknown. Moreover, it is unclear whether CO2?driven changes in Si accumulation are linked to changes in gas exchange (e.g. transpiration rates). We therefore investigated how pre?industrial (reduced; rCO2, 200 ppm), ambient (aCO2, 410 ppm) and elevated (eCO2, 640 ppm) CO2 concentrations, in combination with Si?treatment (Si+ or Si?), affected Si accumulation in B. distachyon and its subsequent effect on the performance of the global insect pest, Helicoverpa armigera. rCO2 increased Si concentrations by 29% and 36% compared to aCO2 and eCO2 respectively. These changes were not related to observed changes in gas exchange under different CO2 regimes, however. The increased Si accumulation under rCO2 decreased herbivore relative growth rate (RGR) by 120% relative to eCO2, whereas rCO2 caused herbivore RGR to decrease by 26% compared to eCO2. Si supplementation also increased the density of macrohairs, silica and prickle cells, which was associated with reduced he... Presentar Todo |
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Palabras claves : |
Climate change; Defence trade-offs; Insect herbivore; INSECTO HERBIVORO; Plant defences; Silicon. |
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Thesagro : |
CAMBIO CLIMÁTICO. |
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Asunto categoría : |
-- |
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Marc : |
LEADER 03125naa a2200289 a 4500
001 1061999
005 2021-08-12
008 2021 bl uuuu u00u1 u #d
024 7 $a10.1111/gcb.15619$2DOI
100 1 $aBIRU, F.N
245 $aAnti-herbivore silicon defences in a model grass are greatest under Miocene levels of atmospheric CO2.$h[electronic resource]
260 $c2021
500 $aArticle history: Received: 8 February 2021/Accepted: 12 March 2021./ First published: 27 March 2021: Email: f.biru@westernsydney.edu.au.
520 $aAbstract: Silicon (Si) has an important role in mitigating diverse biotic and abiotic stresses in plants, mainly via the silicification of plant tissues. Environmental changes such as atmospheric CO2 concentrations may affect grass Si concentrations which, in turn, can alter herbivore performance. We recently demonstrated that pre?industrial atmospheric CO2 increased Si accumulation in Brachypodium distachyon grass, yet the patterns of Si deposition in leaves and whether this affects insect herbivore performance remains unknown. Moreover, it is unclear whether CO2?driven changes in Si accumulation are linked to changes in gas exchange (e.g. transpiration rates). We therefore investigated how pre?industrial (reduced; rCO2, 200 ppm), ambient (aCO2, 410 ppm) and elevated (eCO2, 640 ppm) CO2 concentrations, in combination with Si?treatment (Si+ or Si?), affected Si accumulation in B. distachyon and its subsequent effect on the performance of the global insect pest, Helicoverpa armigera. rCO2 increased Si concentrations by 29% and 36% compared to aCO2 and eCO2 respectively. These changes were not related to observed changes in gas exchange under different CO2 regimes, however. The increased Si accumulation under rCO2 decreased herbivore relative growth rate (RGR) by 120% relative to eCO2, whereas rCO2 caused herbivore RGR to decrease by 26% compared to eCO2. Si supplementation also increased the density of macrohairs, silica and prickle cells, which was associated with reduced herbivore performance. There was a negative correlation among macrohair density, silica cell density, prickle cell density and herbivore RGR under rCO2 suggesting that these changes in leaf surface morphology were linked to reduced performance under this CO2 regime. To our knowledge, this is the first study to demonstrate that increased Si accumulation under pre?industrial CO2 reduces insect herbivore performance. Contrastingly, we found reduced Si accumulation under higher CO2, which suggests that some grasses may become more susceptible to insect herbivores under projected climate change scenarios.
650 $aCAMBIO CLIMÁTICO
653 $aClimate change
653 $aDefence trade-offs
653 $aInsect herbivore
653 $aINSECTO HERBIVORO
653 $aPlant defences
653 $aSilicon
700 1 $aISLAM, T.
700 1 $aCIBILS-STEWART, X.
700 1 $aCAZZONELLI, CH.I.
700 1 $aELBAUM, R.
700 1 $aJOHNSON, S.N.
773 $tGlobal Change Biology, Volume 27, Issue 12, Pages 2959-2969, June 2021. Doi: https://doi.org/10.1111/gcb.15619
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