Browsing by Autor "Daniel Renison"

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Climate change and the distribution and conservation of the world's highest elevation woodlands in the South American Altiplano
(Elsevier BV, 2015) Griet An Erica Cuyckens; Duncan A. Christie; Alejandra I. Domic; Lucio R. Malizia; Daniel Renison
Distribución y estado de conservación de las poblaciones de árboles y arbustos del género Polylepis (Rosaceae) en las montañas de Argentina
(2013) Daniel Renison; Giet A. E. Cuyckens; Silvia Pacheco; Gustavo F. Guzmán; H. Ricardo Grau; Paula I. Marcora; Gerardo Robledo; Ana M. Cingolani; Julio Dominguez; Marcos A. Landi
The genus Polylepis is endemic to the mountains of South America. Species of this genus frequently dominate the canopy of forests and shrublands whose conservation and restoration is a priority at a continental scale. The five species described for Argentina are distributed in the mountains central and northwestern Argentina. Their distribution, threats and conservation status are poorly described and the degree to which humans have impacted their cover, structure and distribution is controversial. We modeled the distribution per species. Models suggest an area of 14800 km2 environmentally suitable for at least one of the five species. We surveyed 490 plots of 3600 m2 distributed in 43 locations and for each species we describe the best preserved forests which could tentatively be used as reference sites when determining conservation and restoration goals. In three of the species we recorded fire evidences in over 60% of the visited plots. Soil erosion was evident in several localities and many forests presented low cover and structural complexity. Argentina provides good opportunities for the conservation and restoration of these forests as there still remain extensive forests, numerous relicts, and in many areas human impacts have been decreasing. It is important to reduce fire events, establish more and better protected areas, to have a better knowledge on the ecology of each species and to develop methods to restore forests, especially in northwestern Argentina.
Forest recovery of areas deforested by fire increases with elevation in the tropical Andes
(Elsevier BV, 2013) Denis Lippok; Stephan Beck; Daniel Renison; Silvia C. Gallegos; Francisco Saavedra; Isabell Hensen; Matthias Schleuning
La Red de Restauración Ecológica de la Argentina (REA): Avances, vacíos y rumbo a seguir
(2018) Daniel Roberto Pérez; Paula Meli; Daniel Renison; Fernando R. Barri; Adriana Beider; Gabriel Burgueño; A. Dalmasso; Sebastián Dardanelli; Manuel de Paz; Fernando M. Farinaccio
In a Latin American and national context of increasing environmental degradation, we describe the perception of the members of the REA on the current state of the restoration in Argentina, and we identify the current prospect of progress and achievements in order to suggest ecological restoration actions in the country. The REA was formalized in 2012 and held its first national organizational meeting in 2017. It currently has 198 members distributed in eight regional nodes. Analyses carried out at this meeting indicate relatively few restoration initiatives at the institutional and landscape level. Most of the actions are carried out at the local level by scientists who contribute through research and practitioners who promote the activity in a wide range of social and ecological contexts. Restoration practitioners, (i.e., those who execute projects in the field) use information generated by the scientific, social, private and government sectors. Among other deficiencies, they mention the limited availability of basic ecological information, the inexistence or inadequacy of legal frameworks, institutional and technical capacities. We hope the consolidation of the REA will allow all those interested and involved in the ecological restoration of the country to share experiences and generate links to contribute to the continuity of a multidisciplinary, participatory work, integrated to the socio-environmental problems of the country, at different scales and with a long-term perspective.https://doi.org/10.25260/EA.18.28.2.0.659
Pleistocene climatic oscillations rather than recent human disturbance influence genetic diversity in one of the world's highest treeline species
(Wiley, 2015) Yanling Peng; Susanne Lachmuth; Silvia C. Gallegos; Michael Kessler; Paul M. Ramsay; Daniel Renison; Ricardo Suarez; Isabell Hensen
Our study shows that, unlike the case for other Andean treeline species, recent human activities have not affected the genetic structure of P. tarapacana, possibly because its inhospitable habitat is unsuitable for agriculture. The current genetic pattern of P. tarapacana points to a historically more widespread distribution at lower altitudes, which allowed considerable gene flow possibly during the glacial periods of the Pleistocene epoch, and also suggests that the northern Argentinean Andes may have served as a refugium for historical populations.
Topography and edge effects are more important than elevation as drivers of vegetation patterns in a neotropical montane forest
(Wiley, 2013) Denis Lippok; Stephan Beck; Daniel Renison; Isabell Hensen; Amira Apaza‐Quevedo; Matthias Schleuning
Abstract Aims The high plant species diversity of tropical mountain forests is coupled with high habitat heterogeneity along gradients in elevation and topography. We quantified the effects of elevation, topography and forest edge on habitat conditions and woody plant diversity of tropical montane forest fragments. Location Tropical montane forest fragments, ‘ Y ungas’, B olivia. Methods We measured microclimate and sampled soil properties and woody vegetation at forest edges and in the forest interior on ridges and in gorges along an elevational gradient of 600 m. We analysed effects of elevation, topography and forest edge on habitat conditions (i.e. microclimate, soil properties and forest structure), species richness, evenness and composition with linear mixed effects models and detrended correspondence analysis ( DCA ). Results Changes in habitat conditions were weaker along the elevational gradient than between forest interior and forest edge and between different topographies. Species richness was not affected by any gradient, while species evenness was reduced at forest edges. All three gradients affected species composition, while effects of topography and forest edge were stronger than that of elevation. Conclusions In general, effects of the 600‐m elevational gradient were weak compared to effects of forest edge and topography. Edge effects shifted species composition towards pioneer species, while topographical heterogeneity is particularly important for generating high diversity in montane forests. These results underscore that edge effects have severe consequences in montane forest remnants and that small‐scale variation between topographical microhabitats should be considered in studies that predict monotonous upslope migrations of plant species in tropical montane forests due to global warming.