Tree-growth responses across environmental gradients in subtropical Argentinean forests

Abstract

Subtropical forests in montane ecosystems grow under a wide range of environmental conditions. However, little is known about the growth responses of subtropical trees to climate along ecological gradients. To assess how, and to what extent climate controls tree growth, we analyzed tree responses to climate for 15 chronologies from 4 different species (Schinopsis lorentzii, Juglans australis, Cedrela lilloi, Alnus acuminata) across a variety of environments in subtropical forests from northwestern Argentina (22-28°S, 64-66°W). Using correlation and principal component analysis, site and species differences in tree-growth responses to precipitation and temperature were determined along the elevation gradient from the dry-warm Chaco lowlands to the wet-cool montane Yungas. Our results show that species responses differ according to the severity in climate conditions along the elevation gradient. At sites with unfavorable conditions, mainly located at the extremes of the environmental gradient, responses of different species to climate variations are similar; in contrast, at sites with relatively mild conditions, tree growth displays a large variety of responses reflecting differences in both local environmental conditions and species physiology. Our research suggests that individualistic responses to environmental variability would determine differences in the type and timing of the responses of dominant trees to climate, which ultimately may shift species' assemblages in montane subtropical regions of South America under future climate changes.

Tree-ring based reconstruction of Río Bermejo streamflow in subtropical South America

“…Many of these records were recently updated and new chronologies developed from other subtropical species such as Schinopsis lorentzii (Ferrero and Villalba, 2009;Ferrero et al, 2013). Currently we have an extended network of chronologies available from the subtropical montane forests of northwestern Argentina (Boninsegna et al, 2009) that can potentially be used to develop reconstructions of river flows in subtropical areas of South America.…”

“…Previous studies showed that tree growth in northwestern Argentinean forests is mostly influenced by precipitation and to a lesser extent by temperature variations 9 (Villalba et al, 1992;Ferrero, 2011;Ferrero et al, 2013). A principal component analysis (PCA) of the tree-ring chronology network showed that the first principal component, which explains 26% of the total variability in the chronologies, is strongly connected with precipitation variations in subtropical northwestern Argentina (Ferrero, 2011).…”

Forest type and height are important in shaping the altitudinal change of radial growth response to climate change

“…ref. 9–11 ) and latitude 2,12,13 . However, many studies have included only one forest zone or examined the different growth response of a single species across elevations (e.g.…”

“…This is similar to the latitudinal gradient and thus more useful in understanding the different growth response to climate change at broad scales. Other studies have found that different forest types (species) under a similar climate may show contrasting growth response to climate change, suggesting that species identity is another key factor leading to different growth response 4,11,17,18 . Thus, different forest types distributed along elevational gradients may contribute to the altitudinal change of RWI-climate relationship, but its relative effect vs. climate gradient has not been well quantified.…”

Neotropical seasonally dry forests: response of soil fungal communities to anthropogenic actions

“…During several years the studies on these areas have been developed especially in plants, soil carbon and ecosystem services. 10,34,35,[37][38][39] In the last years, studies on microbial ecology have increased in these areas. Their main objectives among others were a) evaluation of loss diversity, b) impact of anthropogenic management, c) forest clearance and d) functionality of soil community.…”