Exposed roots as indicators of geomorphic processes: A case-study from Polylepis mountain woodlands of Central Argentina

MARCELO PABLO CHARTIER, CÉSAR MARIO ROSTAGNO, FIDEL ALEJANDRO ROIG; GIANTOMASI, M.A.; RENISON, DANIEL; FIDEL A ROIG

Dendrochronologia

ELSEVIER GMBH, URBAN & FISCHER VERLAG

Lugar: ALEMANIA; Año: 2016 p. 57 - 63

1125-7865

<!-- /* Font Definitions */@font-face{font-family:Times;panose-1:2 0 5 0 0 0 0 0 0 0;mso-font-charset:0;mso-generic-font-family:auto;mso-font-pitch:variable;mso-font-signature:3 0 0 0 1 0;}@font-face{font-family:"ＭＳ 明朝";panose-1:0 0 0 0 0 0 0 0 0 0;mso-font-charset:128;mso-generic-font-family:roman;mso-font-format:other;mso-font-pitch:fixed;mso-font-signature:1 134676480 16 0 131072 0;}@font-face{font-family:"ＭＳ 明朝";panose-1:0 0 0 0 0 0 0 0 0 0;mso-font-charset:128;mso-generic-font-family:roman;mso-font-format:other;mso-font-pitch:fixed;mso-font-signature:1 134676480 16 0 131072 0;}@font-face{font-family:Cambria;panose-1:2 4 5 3 5 4 6 3 2 4;mso-font-charset:0;mso-generic-font-family:auto;mso-font-pitch:variable;mso-font-signature:3 0 0 0 1 0;} /* Style Definitions */p.MsoNormal, li.MsoNormal, div.MsoNormal{mso-style-unhide:no;mso-style-qformat:yes;mso-style-parent:"";margin:0cm;margin-bottom:.0001pt;mso-pagination:widow-orphan;font-size:12.0pt;font-family:Cambria;mso-ascii-font-family:Cambria;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:"ＭＳ 明朝";mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:Cambria;mso-hansi-theme-font:minor-latin;mso-bidi-font-family:"Times New Roman";mso-bidi-theme-font:minor-bidi;}.MsoChpDefault{mso-style-type:export-only;mso-default-props:yes;font-family:Cambria;mso-ascii-font-family:Cambria;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:"ＭＳ 明朝";mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:Cambria;mso-hansi-theme-font:minor-latin;mso-bidi-font-family:"Times New Roman";mso-bidi-theme-font:minor-bidi;}@page WordSection1{size:595.0pt 842.0pt;margin:70.85pt 3.0cm 70.85pt 3.0cm;mso-header-margin:35.4pt;mso-footer-margin:35.4pt;mso-paper-source:0;}div.WordSection1{page:WordSection1;}-->Soil erosion is a serious problema of landdegradation in many parts of the world, and particularly in mountain rangelands.To understand this process it is necessary to develop methods to assess soil erosionrate in a quick, economic and accurate manner. Based on the analysis of exposedPolylepis australis roots, we tested a dendrogeomorphological method for determiningsoil loss rate in rills and gullies. Few studies considered non-coniferous treerings in soil erosion analysis and we used, for the first time, an experimentalprocedure of root exposure and provided a comparison with roots exposed by gullyerosion. Our main results showed that as a consequence of soil erosion, exposedroots changed from root-like to a more stem-like Wood anatomical structure. Thepercentage of vessel área per tree-ring área decreases by an average of 22% to 43%during the first and second year after exposure, respectively. Moreover, and duringthe same time interval, the mean vessel área decreased 32% and 65%, and the numberof vessels increased 7% and 48%, respectively. Scars formed at the upper side ofthe exposed roots are coincident with changes in Wood anatomy, and both evidencesmay be applied to reconstruct an erosion process. This study confirms that the Woodanatomy analysis of partially exposed roots can be used to determine the year inwhich roots are exposed and provides a useful tool to monitor soil erosion rateswith a high accuracy.