4 research outputs found
Biodiversity potential of Nothofagus forests in Tierra del Fuego (Argentina): tool proposal for regional conservation planning
Tree-Growth Variations of Nothofagus antarctica Related to Climate and Land Use Changes in Southern Patagonia, Argentina
Isolated forest patches of Nothofagus antarctica (ñire) are frequent in the Patagonian forest-steppe ecotone. These remnants, also called relicts (R), are separate from the continuous forests (C). Over the past century, these ecotonal forests have been impacted by anthropogenic activities, including fires, logging, and cattle ranching. In order to identify in N. antarctica ring-width records the variations in tree growth associated with documented changes in land use, five sites were selected in Santa Cruz, Argentina. In each site, increment cores from R and C were collected. We developed individual chronologies, and the relationships between regional climate variations and N. antarctica growth were established for each forest type and site. The similarities/differences between site-paired chronologies (R-C) were estimated by calculating moving correlation coefficients lagged by 1 year. N. antarctica regional growth was directly related to precipitation during the current growing season (NovemberâDecember; r = 0.34, n = 62, p < 0.01), and inversely related to temperature (DecemberâMarch; r = â0.58, n = 62, p < 0.001). Since the middle of the twentieth century, a progressive decrease has been recorded in regional radial growth, consistent with an increase in summer temperature and a decrease in spring precipitation. In the context of this regional response of N. antarctica to climate, differences in growth patterns between R and C were associated with past changes in land use. Overall, the largest differences between R and C chronologies were concurrent with the settlement of cattle ranches and the associated use of forests. Conversely, similarities between R and C records increased after the establishment of protected areas and during the implementation of similar management practices in both forest types. Our research provides the first dendrochronological records from Nothofagus antarctica for the Argentinean Patagonia and represents one of the first efforts to identify in tree-rings past changes in livestock practices in southern South America.EEA Santa CruzFil: Vettese, Evangelina S. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. CIT Santa Cruz; Argentina.Fil: Villalba, Ricardo. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto Argentino de NivologĂa, GlaciologĂa y Ciencias Ambientales; Argentina.Fil: Orellana Ibåñez, Ivonne A. Universidad Nacional de la Patagonia San Juan Bosco. Facultad de Ciencias Naturales y Ciencias de la Salud; Argentina.Fil: Peri, Pablo Luis. Instituto Nacional de TecnologĂa Agropecuaria (INTA). EstaciĂłn Experimental Agropecuaria Santa Cruz; Argentina.Fil: Peri, Pablo Luis. Universidad Nacional de la Patagonia Austral; Argentina.Fil: Peri, Pablo Luis. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina
The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project
The PREDICTS project-Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)-has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity