Browsing by Author "Guerrero-Gatica, Matias"

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    An Eltonian proxy for restoring a lost browser-tree interaction
    (2024) Root-Bernstein, Meredith; Guerrero-Gatica, Matias; Rossle, Andoni Elorrieta; Fleming, Jory; Aguillar, Jorge Ramos; Rochefort, Benjamin Silva; Charles-Dominique, Tristan; Armesto, Juan; Jaksic, Fabian M.
    Many South American dry woodlands lack good historical or paleoecological baseline data to inform restoration and conservation. However, functionalist approaches such as those popularized by rewilding suggest that functional interactions producing target ecosystem processes are valid even without data confirming compositionalist values such as a long coevolutionary histories or known historical range overlaps of target species. In central Chile, the guanaco (Lama guanicoe) has been extirpated but is known to browse trees in other regions of South America, and the tree Vachellia [Acacia] caven shows adaptations to browsing but has no extant browsers within its Chilean range. Both species are native to Chile but there are no data to assess their historical levels of interaction. Here we test the hypothesis that they can act as mutual "Eltonian proxy" species: interacting species for which we lack sufficient data (the Eltonian shortfall) to prove they are not proxies. Specifically we predict that they have complementary adaptations such that guanacos will browse Vachellia [Acacia] caven and the latter will show adaptive responses to their browsing. We introduced five guanacos into an enclosure of Vachellia [Acacia] caven "espinal" woodland, and over two years measured the growth responses of individual branches, compared to branches of trees in an area without browsing. We predicted that Vachellia [Acacia] caven would show compensatory growth in response to guanaco browsing resulting in an increase in branching. Guanacos browsed throughout the two years. In the presence of guanaco browsing, Vachellia [Acacia] caven branches grew longer, grew more sub-branches, and showed more densely streamlined branch architectures. These results indicate that guanacos could be used to substitute anthropogenic pruning as a restoration and management technique in Vachellia [Acacia] caven "espinal" woodlands. However, other extinct megaherbivores or extirpated deer may also be key components of a past herbivore community to which Vachellia [Acacia] caven was adapted. Further attention to a network of multiple interacting browsers, and their indirect and nontrophic effects, is an area for further research.
  • No Thumbnail Available
    Item
    Local Territorial Practices Inform Co-Production of a Rewilding Project in the Chilean Andes
    (2023) Guerrero-Gatica, Matias; Reyes, Tamara Escobar; Rochefort, Benjamin Silva; Fernandez, Josefina; Elorrieta, Andoni; Root-Bernstein, Meredith
    Co-production of conservation projects is favored by incorporating local ecological knowledge into project design and implementation. Using a mixed method approach, we asked how the territorial practices and knowledge of cowboys and livestock farmers inform their attitudes to this proposed project. We predicted that cowboy territorial practices would be reduced in diversity compared to the past, and that this may be associated with a reduction in coping or adaptation capacity in the face of environmental challenges. We further predicted that due to growing environmental and social pressures reducing traditional livelihood opportunities for this group, they are likely to see the guanaco reintroduction project in a conflictual and negative light. We additionally predicted that they would perceive local carnivorous species in a conflictual and negative way. We found that territorial practices among the sample had indeed decreased in diversity. The sample coped with changing socio-ecological conditions by taking up other jobs. However, we also found that they had majority favorable views on the guanaco reintroduction project. Yet their knowledge of current guanaco behavior led them to believe that the project would fail. However, they also observed that pumas and condors changed their behaviors. We suggest that there are opportunities to co-produce knowledge about the possibility of flexible and adaptive guanaco behavior, which may lead to restoration and create more sustainable future scenarios, by engaging with the territorial practices and local ecological knowledge of cowboys and livestock farmers.