Aridity and grazing as convergent selective forces: an experiment with an Arid Chaco bunchgrass
It has been proposed that aridity and grazing are convergent selective forces: each one selects for traits conferring resistance to both. However, this conceptual model has not yet been experimentally validated. The aim of this work was to experimentally evaluate the effect of aridity and grazing, a...
| Autores principales: | , , , |
|---|---|
| Formato: | info:ar-repo/semantics/artículo |
| Lenguaje: | Inglés |
| Publicado: |
Wiley
2021
|
| Materias: | |
| Acceso en línea: | http://hdl.handle.net/20.500.12123/9412 https://esajournals.onlinelibrary.wiley.com/doi/10.1890/09-0641.1 https://doi.org/10.1890/09-0641.1 |
| _version_ | 1855036208611065856 |
|---|---|
| author | Quiroga, Raul Emiliano Golluscio, Rodolfo Angel Blanco, Lisandro Javier Fernandez, Roberto J. |
| author_browse | Blanco, Lisandro Javier Fernandez, Roberto J. Golluscio, Rodolfo Angel Quiroga, Raul Emiliano |
| author_facet | Quiroga, Raul Emiliano Golluscio, Rodolfo Angel Blanco, Lisandro Javier Fernandez, Roberto J. |
| author_sort | Quiroga, Raul Emiliano |
| collection | INTA Digital |
| description | It has been proposed that aridity and grazing are convergent selective forces: each one selects for traits conferring resistance to both. However, this conceptual model has not yet been experimentally validated. The aim of this work was to experimentally evaluate the effect of aridity and grazing, as selective forces, on drought and grazing resistance of populations of Trichloris crinita, a native perennial forage grass of the Argentinean Arid Chaco region. We collected seeds in sites with four different combinations of aridity and grazing history (semiarid/subhumid × heavily grazed/lightly grazed), established them in pots in a common garden, and subjected the resulting plants to different combinations of drought and defoliation. Our results agreed with the convergence model. Aridity has selected T. crinita genotypes that respond better to drought and defoliation in terms of sexual reproduction and leaf growth, and that can evade grazing due to a lower shoot : root ratio and a higher resource allocation to reserves (starch) in stem bases. Similarly, grazing has selected genotypes that respond better to drought and defoliation in terms of sexual reproduction and that can evade grazing due to a lower digestibility of leaf blades. These results allow us to extend concepts of previous models in plant adaptation to herbivory to models on plant adaptation to drought. The only variable in which we obtained a result opposite to predictions was plant height, as plants from semiarid sites were taller (and with more erect tillers) than plants from subhumid sites; we hypothesize that this result might have been a consequence of the selection exerted by the high solar radiation and soil temperatures of semiarid sites. In addition, our work allows for the prediction of the effects of dry or wet growing seasons on the performance of T. crinita plants. Our results suggest that we can rely on dry environments for selecting grazing-resistant genotypes and on high grazing pressure history environments for selecting drought-resistant ones. |
| format | info:ar-repo/semantics/artículo |
| id | INTA9412 |
| institution | Instituto Nacional de Tecnología Agropecuaria (INTA -Argentina) |
| language | Inglés |
| publishDate | 2021 |
| publishDateRange | 2021 |
| publishDateSort | 2021 |
| publisher | Wiley |
| publisherStr | Wiley |
| record_format | dspace |
| spelling | INTA94122021-05-21T13:13:16Z Aridity and grazing as convergent selective forces: an experiment with an Arid Chaco bunchgrass Quiroga, Raul Emiliano Golluscio, Rodolfo Angel Blanco, Lisandro Javier Fernandez, Roberto J. Forrajes Pastoreo Zona Arida Sequía Defoliación Forage Grazing Arid Zones Drought Defoliation Bunchgrass Aridity Trichloris crinita Aridez Región Chaco Arido, Argentina It has been proposed that aridity and grazing are convergent selective forces: each one selects for traits conferring resistance to both. However, this conceptual model has not yet been experimentally validated. The aim of this work was to experimentally evaluate the effect of aridity and grazing, as selective forces, on drought and grazing resistance of populations of Trichloris crinita, a native perennial forage grass of the Argentinean Arid Chaco region. We collected seeds in sites with four different combinations of aridity and grazing history (semiarid/subhumid × heavily grazed/lightly grazed), established them in pots in a common garden, and subjected the resulting plants to different combinations of drought and defoliation. Our results agreed with the convergence model. Aridity has selected T. crinita genotypes that respond better to drought and defoliation in terms of sexual reproduction and leaf growth, and that can evade grazing due to a lower shoot : root ratio and a higher resource allocation to reserves (starch) in stem bases. Similarly, grazing has selected genotypes that respond better to drought and defoliation in terms of sexual reproduction and that can evade grazing due to a lower digestibility of leaf blades. These results allow us to extend concepts of previous models in plant adaptation to herbivory to models on plant adaptation to drought. The only variable in which we obtained a result opposite to predictions was plant height, as plants from semiarid sites were taller (and with more erect tillers) than plants from subhumid sites; we hypothesize that this result might have been a consequence of the selection exerted by the high solar radiation and soil temperatures of semiarid sites. In addition, our work allows for the prediction of the effects of dry or wet growing seasons on the performance of T. crinita plants. Our results suggest that we can rely on dry environments for selecting grazing-resistant genotypes and on high grazing pressure history environments for selecting drought-resistant ones. EEA La Rioja Fil: Quiroga, Raul Emiliano. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Rioja; Argentina Fil: Golluscio, Rodolfo A. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de investigación Fisiológicas y Ecológicas Vinculado a la Agricultura; Argentina. Fil: Golluscio, Rodolfo A. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de investigación Fisiológicas y Ecológicas Vinculado a la Agricultura; Argentina. Fil: Blanco, Lisandro Javier. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Rioja; Argentina Fil: Fernandez, Roberto J. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de investigación Fisiológicas y Ecológicas Vinculado a la Agricultura; Argentina. Fil: Fernandez, Roberto J. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de investigación Fisiológicas y Ecológicas Vinculado a la Agricultura; Argentina. 2021-05-21T13:08:56Z 2021-05-21T13:08:56Z 2010-10 info:ar-repo/semantics/artículo info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion http://hdl.handle.net/20.500.12123/9412 https://esajournals.onlinelibrary.wiley.com/doi/10.1890/09-0641.1 1939-5582 https://doi.org/10.1890/09-0641.1 eng info:eu-repo/semantics/restrictedAccess application/pdf Wiley Ecological Applications 20 (7) : 1876-1889 (October 2010) |
| spellingShingle | Forrajes Pastoreo Zona Arida Sequía Defoliación Forage Grazing Arid Zones Drought Defoliation Bunchgrass Aridity Trichloris crinita Aridez Región Chaco Arido, Argentina Quiroga, Raul Emiliano Golluscio, Rodolfo Angel Blanco, Lisandro Javier Fernandez, Roberto J. Aridity and grazing as convergent selective forces: an experiment with an Arid Chaco bunchgrass |
| title | Aridity and grazing as convergent selective forces: an experiment with an Arid Chaco bunchgrass |
| title_full | Aridity and grazing as convergent selective forces: an experiment with an Arid Chaco bunchgrass |
| title_fullStr | Aridity and grazing as convergent selective forces: an experiment with an Arid Chaco bunchgrass |
| title_full_unstemmed | Aridity and grazing as convergent selective forces: an experiment with an Arid Chaco bunchgrass |
| title_short | Aridity and grazing as convergent selective forces: an experiment with an Arid Chaco bunchgrass |
| title_sort | aridity and grazing as convergent selective forces an experiment with an arid chaco bunchgrass |
| topic | Forrajes Pastoreo Zona Arida Sequía Defoliación Forage Grazing Arid Zones Drought Defoliation Bunchgrass Aridity Trichloris crinita Aridez Región Chaco Arido, Argentina |
| url | http://hdl.handle.net/20.500.12123/9412 https://esajournals.onlinelibrary.wiley.com/doi/10.1890/09-0641.1 https://doi.org/10.1890/09-0641.1 |
| work_keys_str_mv | AT quirogaraulemiliano aridityandgrazingasconvergentselectiveforcesanexperimentwithanaridchacobunchgrass AT gollusciorodolfoangel aridityandgrazingasconvergentselectiveforcesanexperimentwithanaridchacobunchgrass AT blancolisandrojavier aridityandgrazingasconvergentselectiveforcesanexperimentwithanaridchacobunchgrass AT fernandezrobertoj aridityandgrazingasconvergentselectiveforcesanexperimentwithanaridchacobunchgrass |