Abstract
Forest plantations with exotic species are planted extensively in the southern hemisphere for soil conservation and shallow landslide mitigation. The extent to which these are suitable for fulfilling their protection goals is the subject of debate. A biogeomorphic framework was applied to link land use, soil conservation and natural hazards. It consists of a feedback loop with the two effect pathways hillslope stability and vegetation fitness. The study site is located in Chilean Patagonia, where thixotropic Andosols are widespread and Pinus plantations were planted initially in conservation areas, and later on private land. We were testing the hypothesis whether soil stability differs between primary and secondary forests, Pinus plantations, wildfire sites (ex. plantations) and pastures. Shear strength, liquid limit, consolidation degree and available water capacity were used as soil stability indicators and set as dependent variables using non-metrical multidimensional scaling (NMDS), representing mechanical and hydrological biogeomorphic interactions. Soil texture, topographic and vegetation properties were post-hoc correlated as independent variables. Vegetation assemblage correlates most strongly with soil indicator variance. The soils under secondary native Nothofagus forests have significantly higher liquid limits than Pinus plantations (41 ± 4.9% vs. 31 ± 14%, p < 0.1, A Horizon). Consolidation degree is higher under secondary forests than in Plantations (A and B Horizon), due to a significantly higher root abundance. Primary forests provide landscape by maintaining the water cycle balance and biodiversity. Secondary forests establish the biogeomorphic feedback loop through mechanical effects and enhancing vegetation fitness. Pinus plantations cause a slight improvement in soil stability properties, but with trade-offs in water balance and vegetation fitness. Landscape resilience is thus impaired by the higher risk of wildfires, erosion and landslides. Pastures show good values in the soil stability parameters, but their biogeomorphic interactions are unlikely to rebuild landscape resilience.
| Original language | English |
|---|---|
| Article number | 106364 |
| Pages (from-to) | 1-20 |
| Number of pages | 20 |
| Journal | Catena |
| Volume | 216 |
| Issue number | Part A |
| DOIs | |
| Publication status | Published - Sept 2022 |
Bibliographical note
Funding Information:We would like to thank: the Ministerio de Minería de Chile for supporting the project organizationally and logistically as well as the partial financing of laboratory costs; Paulo Andrés (Subdirección del Ministerio de Minería de Chile) for organizational and logistical support; Alex Fajardo (CIEP) and Neal Stolpe (INA) for advice on local conditions during our field research; Marcelo Dorner (CONAF) for administrative support; The Pioneer Corps of the Chilean Army for logistical support.
Funding Information:
The field research was supported by grants from the federal state of Baden-Württemberg, the Federal Republic of Germany and the KIT. This work was also supported by the Ministerio de Minería de Chile for soil laboratory costs. Funding had no influence on study design; in the collection, analysis and interpretation of data; in the writing of the report; and in the decision to submit the article for publication.
Publisher Copyright:
© 2022 Elsevier B.V.
Funding
We would like to thank: the Ministerio de Minería de Chile for supporting the project organizationally and logistically as well as the partial financing of laboratory costs; Paulo Andrés (Subdirección del Ministerio de Minería de Chile) for organizational and logistical support; Alex Fajardo (CIEP) and Neal Stolpe (INA) for advice on local conditions during our field research; Marcelo Dorner (CONAF) for administrative support; The Pioneer Corps of the Chilean Army for logistical support. The field research was supported by grants from the federal state of Baden-Württemberg, the Federal Republic of Germany and the KIT. This work was also supported by the Ministerio de Minería de Chile for soil laboratory costs. Funding had no influence on study design; in the collection, analysis and interpretation of data; in the writing of the report; and in the decision to submit the article for publication.
Keywords
- Biogeomorphology
- Ecological landslide mitigation
- Forest plantation
- Hillslope stability
- Land use
- Nothofagus pumilio
- Patagonia
- Pinus contorta
- Pinus ponderosa
- Water erosion
