Large-scale patterns of turnover and Basal area change in Andean forests.

Selene Báez,Cecilia Blundo,Ricardo Grau,Karina Garcia‐Cabrera ,Jürgen Homeier,Oliver L. Phillips,Kenneth J. Feeley,Francisco Cuesta,Zhofre Aquirre,Miles R. Silman,Carlos Reynel,Nikolay Aguirre,Esteban Álvarez,William Farfán-Ríos,Julieta Carilla,Oriana Osinaga,Álvaro Duque,Omar Melo Cruz,Manuel Jiménez Aguilar ,Lucio R. Malizia,Agustina Malizia,Reynaldo Linares-Palomino

doi:10.1371/journal.pone.0126594

Abstract

General patterns of forest dynamics and productivity in the Andes Mountains are poorly characterized. Here we present the first large-scale study of Andean forest dynamics using a set of 63 permanent forest plots assembled over the past two decades. In the North-Central Andes tree turnover (mortality and recruitment) and tree growth declined with increasing elevation and decreasing temperature. In addition, basal area increased in Lower Montane Moist Forests but did not change in Higher Montane Humid Forests. However, at higher elevations the lack of net basal area change and excess of mortality over recruitment suggests negative environmental impacts. In North-Western Argentina, forest dynamics appear to be influenced by land use history in addition to environmental variation. Taken together, our results indicate that combinations of abiotic and biotic factors that vary across elevation gradients are important determinants of tree turnover and productivity in the Andes. More extensive and longer-term monitoring and analyses of forest dynamics in permanent plots will be necessary to understand how demographic processes and woody biomass are responding to changing environmental conditions along elevation gradients through this century.

Highlights

Our understanding of the responses of tropical forests to environmental factors is still limited [1,2,3]
Our results indicate that combinations of abiotic and biotic factors that vary across elevation gradients are important determinants of tree turnover and productivity in the Andes
Our results showed that forest demography in this region was affected by the environmental variation captured in Principal Components Analysis (PCA) 2

Summary

Introduction

Our understanding of the responses of tropical forests to environmental factors is still limited [1,2,3]. General patterns of forest dynamics and productivity in the Andes Mountains in particular remain poorly characterized due to the scarcity of studies, as well as the complexity of environmental variation in these topographically complex systems [4,5,6]. This lack of knowledge is troubling since the Andes are among the most important areas for biological conservation in the world [7] and deliver valuable environmental services (e.g., water provision and carbon storage) to large human populations [8, 9]. Trees in the Peruvian Andes have shifted their distributions upslope over the past decades potentially in response to rising temperatures [21]

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Conclusion