Estrategias de uso y adquisición de recursos en plantas y su efecto sobre procesos ecosistémicos asociados a los ciclos del carbono y nitrógeno en ecosistemas áridos
In arid environments, limiting resources can act as filters that modulate plant strategies, and ultimately lead to changes in community structure. The fast-slow plant economics spectrum hypothesis (fs-PES) states that in areas with more nutrient availability, plants should exhibit a fast resource ac...
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| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2020 |
| País: | Chile |
| OAI Identifier: | oai:repositorio.anid.cl:10533/246549 |
| Acceso en línea: | https://hdl.handle.net/10533/246549 |
| Access Level: | acceso abierto |
| Palabra clave: | Ciencias Naturales Otras Ciencias Naturales |
| Sumario: | In arid environments, limiting resources can act as filters that modulate plant strategies, and ultimately lead to changes in community structure. The fast-slow plant economics spectrum hypothesis (fs-PES) states that in areas with more nutrient availability, plants should exhibit a fast resource acquisition strategy, whereas in resource-poor environments plants should exhibit a slow resource acquisition strategy, which prioritizes conservation of resources over growth. Changes in plant acquisition strategy may also influence soil microbial composition and activity. This latter would be linked to differences in the quantity and quality of leaf and root litter that different plant species entering into the soil. Finally, this plant-soil interaction can have profound effects on ecosystem functionality, for example, over the control of the decomposition process. The main objective of this study is to test the generality of the fs-PES in shrub communities of the Atacama Desert distributed along nutrients gradients, their effects on soil microorganisms and finally on the decomposition of organic matter. I characterized different above- and below-ground functional traits of 10 to 15 dominant shrub species in four sites with similar climatic conditions, but located in different soil types at the least arid locality. I estimate the abundance and enzymatic activity of soil microbes under the four most abundant species of each site. Finally, I conducted a field decomposition experiment using the leaf and root litter of the most abundant plant species of the community. In the nutrient gradient, leaf changes were associated with the fs-PES, shifting from communities with more acquisitive strategies to communities with more conservative strategies with increasing nutrient limitation. No such pattern of co-variation was observed for roots. Both bacterial and fungal abundance and their metabolic activity were connected to changes in the resource acquisition strategies of plants communities. Particularly, I found a greater abundance of bacteria associated with a fast strategy. Finally, the decomposition of leaf and root litter was linked to soil nutrient availability, the nutrient content of leaf and root litter and Fungi:Bacteria ratio. |
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