δ13C and δ15N variation on guanacos in Tierra del Fuego: references for terrestrial foodwebs in a high-latitude island

Kochi, Sayuri; Tessone, Augusto; Zangrando, Atilio Francisco Javier; Ugan, Andrew; Alunni, Daniela Verónica; Salemme, Mónica; Santiago, Fernando; Vázquez, Martín

doi:10.1007/s12520-020-01011-7

Cited by 12 publications

(7 citation statements)

References 70 publications

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“…Low–medium grazing intensity, by contrast, may not be a strong enough pressure to generate an immediate response on native dicots. Native herbivores such as guanacos have led to a grazing pressure exerted by native species (Kochi et al, 2020), shaping the local vegetation.…”

Section: Discussionmentioning

confidence: 99%

Herbivores regulate native–alien plants dynamics in sub‐Antarctic beech (Nothofagus antarctica) forests of Tierra del Fuego, Argentina

Soler¹,

Bustamante²,

Cruz‐Alonso

et al. 2023

Applied Vegetation Science

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Questions What is the role of native and domestic herbivores in native–alien vegetation changes in sub‐Antarctic forests? Does herbivory suppression increase native while reducing alien species diversity? Location Central–eastern Tierra del Fuego Island, Argentina. Methods In four sites, we set up three different treatments: excluded grazing by livestock (cattle), by livestock and native (guanaco) herbivores, and grazed control plots in Nothofagus antarctica forests. We then monitored the dynamics of understorey native and alien plants (species richness, abundance) of dicots, monocots, and ferns over 6 years. Generalized Linear Mixed Models were used to determine the effects of herbivore exclusion and time on species richness and abundance. In addition, we calculated the abundance rate of change to quantify temporal dynamics. Results Overall species richness did not change in the exclusion plots, but native and alien abundances were affected by herbivory and time since exclusion. The abundance of native monocots changed after herbivore exclusion, increasing its dominance significantly inside exclusion plots. However, the cessation of herbivory did not reduce alien species in general. Only alien dicots significantly declined in the livestock exclusion treatment. Further, we found that the two dominant alien grass species (Holcus lanatus and Poa pratensis) respond differently to grazing exclusion, and their response was modulated by forest basal area. Conclusions Our results indicate that cattle and guanaco grazing had variable effects on native and alien plants, and that herbivore exclusion has a substantially positive effect on native grasses. However, the magnitude of temporal changes was more significant for vegetation richness and abundance than the effect of exclusion treatments. Herbivore exclusions can initiate a rapid recovery of compositional attributes of native vegetation in N. antarctica forests grazed by livestock.

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Section: Discussionmentioning

confidence: 99%

Herbivores regulate native–alien plants dynamics in sub‐Antarctic beech (Nothofagus antarctica) forests of Tierra del Fuego, Argentina

Soler¹,

Bustamante²,

Cruz‐Alonso

et al. 2023

Applied Vegetation Science

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“…We evaluate guanaco isotopic niche size between different time periods and habitats with Bayesian-based Standard Ellipse Areas (SEA b ) using the SIBER package in R (Jackson et al, 2011; R Core Team, 2022; Supplemental Material 2). This technique offers a robust way to compare isotopic variability between different assemblages (Kochi et al, 2020; Santana-Sagredo et al, 2020; Szpak et al, 2015; Szpak and Valenzuela, 2020; Tessone, 2022; Tessone et al, 2023). Here, we use 4,0004000 different Bayesian model iterations to calculate the ellipse area.…”

Section: Methodsmentioning

confidence: 99%

Dietary change of North Patagonian guanacos: A historical ecology perspective through the study of stable isotopes

Gil,

Otaola,

Dombrosky

et al. 2024

The Holocene

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This paper presents the results of a study on the isotopic ecology of guanacos in central western Argentina. We examine the historical population ecology of guanacos using stable isotope analysis of bone collagen from pre-Hispanic and modern guanaco populations ( n = 129), considering variability in two ecoregions: the Monte hot desert and the Andean-Patagonian cold desert. Our study addresses the consistency of guanaco diets over time, evaluating palaeoecology to provide information for conservation of this taxon. We found significant differences in isotopic niche size between modern and archaeological guanacos. When analyzed by ecoregion, there were significant differences in niche size through time, indicating that guanacos had distinctive dietary habits and occupied different ecological niches across the ecoregions. Comparing Standard Ellipse Areas (SEA) through time and across space, we observed that the archaeological SEA for guanacos is smaller than its modern counterpart in the Andean-Patagonia ecoregion. Conversely, in Monte, the archaeological SEA is larger than the one established for modern samples. The contrast between pre-Hispanic and modern populations highlight the impact of human activity and conservation efforts on the distribution and ecology of guanacos. These findings have important implications for understanding guanaco ecology with consequences for conservation policies.

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“…Within this volume, two research pieces study dietary composition and changes in the guanaco populations of Argentina through stable isotope analysis, a research field in constant expansion in South America (Barberena et al, 2009; Kochi et al, 2020; Tessone et al, 2014). Guanaco ( Lama guanicoe ), a wild South American camelid, has been an important resource for past human populations in southern South America (e.g.…”

Section: Isotopic Insights Into Guanaco Populationsmentioning

confidence: 99%

Zooarchaeological perspectives in the framework of the Anthropocene: Contributions to ecological, environmental and conservation studies from South America

Mignino,

López,

Samec

2024

The Holocene

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This special volume considers major recent changes in southern South American animal communities. Eleven papers consider megafauna, pinnipeds, marine mammals, small terrestrial mammals and birds and are grouped under four sub-headings: (1) Isotopic insights into guanaco populations; (2) Historical sources and marine ecosystem change; (3) Changes in small mammal communities and human impacts; and (4) megafaunal extinction, domestication, avifauna and recent interactions with humans. Although some of these contributions include changes that occurred earlier in the Holocene, many highlight a current decrease in the taxonomic diversity of communities and ecosystems in different environments, which are likely to have been caused by modern human activities. The Anthropocene concept is seen as providing a useful framework for understanding and mitigation of such adverse human impacts.

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δ13C and δ15N variation on guanacos in Tierra del Fuego: references for terrestrial foodwebs in a high-latitude island

Cited by 12 publications

References 70 publications

Herbivores regulate native–alien plants dynamics in sub‐Antarctic beech (Nothofagus antarctica) forests of Tierra del Fuego, Argentina

Herbivores regulate native–alien plants dynamics in sub‐Antarctic beech (Nothofagus antarctica) forests of Tierra del Fuego, Argentina

Dietary change of North Patagonian guanacos: A historical ecology perspective through the study of stable isotopes

Zooarchaeological perspectives in the framework of the Anthropocene: Contributions to ecological, environmental and conservation studies from South America

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