Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Accueil du site → Master → Pays Bas → 2019 → Quantifying the effect of ecological restoration on soil development : constructing a SOC chronosequence in the Baviaanskloof, South Africa

Wageningen University (2019)

Quantifying the effect of ecological restoration on soil development : constructing a SOC chronosequence in the Baviaanskloof, South Africa

Koster, Jip

Titre : Quantifying the effect of ecological restoration on soil development : constructing a SOC chronosequence in the Baviaanskloof, South Africa

Auteur : Koster, Jip

Université de soutenance : Wageningen University

Grade : Master of Science (MS) 2019

Résumé
Ecological restoration has the potential to tackle major global problems, but knowledge to predict its effects are currently limited due to a lack of available multidisciplinary monitoring methods, such as mapping soil organic carbon. Therefore, this research aims at constructing a method to quantify soil development as a result of ecological restoration. This is done in the semi-arid Baviaanskloof catchment, South Africa. This area offered the possibility to derive a 13-year chronosequence using 50 soil samples, which were analyzed on SOC. Further analyses of these samples, local legacy data and remote sensing derivatives were used to 1) investigate the main drivers of soil development in this study area by applying a principal component analyses and investigating the effects of the single soil forming factors, 2) assess the suitability of a mechanistic model approach to predict the spatial distribution of the observed SOC fractions and thereby the current soil development state, 3) assess the potential to predict the temporal development of the soil state as a result of ecological restoration, and 4) assess the suitability of established carbon models for quantifying soil development (RothC and Carbon Benefit Project) by comparing them with the chronosequence findings. This study shows that SOC was an appropriate indicator for quantifying soil development, in contrast to the NDVI. The most important drivers were parent material and livestock, while the contribution of erosion and climate to soil development were hard to quantify. Moreover, the mechanistic model was successful in the prediction of the measured distribution of SOC (R 2 = 0.67 and thereby improved the original model (R 2 = 0.41). Given these models limitations are addressed, the mechanistic approach has the potential to be applied for the monitoring of restoration practices. The use of a chronosequence approach for predicting temporal development resulted in an identification of divergence, an alternative state and the soil development state. Although these identifications involved large uncertainties, the contribution to the currently scarce knowledge on the behavior of soil development to ecological restoration is profound. Moreover, the existing carbon models turned out to overestimate and misjudge this temporal behavior of SOC, which means their limitations are critical for the prediction of SOC development. This study concludes that despite its complex behavior, the importance of soil forming processes in driving the ecological system, teaches us that a multidisciplinary method, such as applied in this research, are crucial in the application of restoration practices, monitoring and modelling scenarios

Présentation

Version intégrale ( 1 Mb)

Page publiée le 1er novembre 2019