Ecological Rehabilitation Indicators for One Eucalyptus Reforestation With an Oak Forest as Reference

Abstract

The evaluation of reforestation for ecological restoration purposes in an area requires the comparison of similarity indicators with nearby reference forests. The objective of this study was to compare the vegetal composition, structure, falling debris, and their decomposition in the soil of a reforestation site of Eucalyptus camaldulensis Dehnh, planted more than 50 years ago, and a neighbouring forest dominated by Quercus deserticola Trel. and Q. laeta Liebm (used as reference), in an area of the State of Mexico; and obtain quantitative indicators of the trajectory of rehabilitation through the use of non-native species of Mexico. In reforestation and oak forest, we established 12 sampling sites where the composition, structure and two ecological processes (falling debris and decomposition) were determined. In addition, solar radiation was estimated by taking zenith photos of the canopy, using a hemispherical lens. When data was within normal distribution, we used the Student test, and when it was not, the Wilcoxon test was used to compare the variables studied. The reference forest outperformed reforestation (p ≤ 0.05) in: richness (68 and 50 species); diversity (Simpson index, 1.6-2.6 and 0.7-2.3); normal diameter (21.3 and 13.7 cm), accumulated leaf litter (18.2 and 9.2 Mg ha-1), detritus fall (0.606 and 0.321 Mg ha-1 per month), and litter decomposition (0.443 and 0.251 Mg ha-1 per month). Reforestation had a higher total radiation (5384 vs. 4376 MJ m-2 year-1) and tree height (8.1 vs. 7.4 m). The percentage values of importance were 32.8 and 26.9 % for Quercus deserticola and Q. laeta in the oak forest, and 70 % for E. camaldulensis in the reforestation. After 50 years, reforestation still showed statistical differences from forest in composition, structure, and soil processes.