Abstract

Stream-riparian networks are subject to multiple human pressures that threaten key functions of aquatic and terrestrial ecosystems, drive habitat and diversity losses, affect riparian connectivity and cause stakeholder conflicts. Designing riparian landscapes in a way that they can simultaneously meet multiple competing demands requires a clear understanding of existing trade-offs, and a landscape-scale perspective on the planning of reforestation measures. This study applied a landscape optimization algorithm for allocating riparian forest management measures in the intensively used agricultural catchment of the Zwalm River (Belgium). We optimized forest allocation to improve stream ecological quality (EPT index), functional diversity (diatoms) and riparian carbon processing (cotton-strip assay), while minimizing losses in agricultural production potential. Regression models were developed to predict the target indicators for 489 segments of the Zwalm riparian corridor, using spatial variables on three different scales. For each riparian segment, we developed spatially explicit management measures, representing different intensities of riparian reforestation. The allocation and combination of these measures in the riparian corridor were optimized to identify (a) trade-offs among the target indicators, (b) priority regions for reforestation actions and (c) the required reforestation intensity. The results showed that all target indicators were affected by the area share of riparian forests and its landscape-scale configuration. Reforestation of the Zwalm riparian corridor could significantly improve indicators for biodiversity and ecosystem functioning (e.g. up to +96% for EPT index), but would lead to a strong trade-off with agricultural production. By optimizing the placement of management measures, we showed how these trade-offs could be best balanced. The headwater regions of the Zwalm were identified as priority regions for reforestation actions. Facilitating connectivity among and further expansion of existing forest patches in the Zwalm headwaters showed to improve ecosystems with minimized trade-offs. Synthesis and applications. This study demonstrates, for the first time, the potential of landscape optimization algorithms to support the management and design of multifunctional stream-riparian networks. We identified riparian reforestation solutions that minimized trade-offs between specific natural values and societal needs. Our spatially explicit approach allows for an integration into spatial planning and can inform policy design and implementation.

Keywords

biodiversity; ecosystem functioning; ecosystem services; forest riparian buffers; multi-objective optimization; riparian management; spatial planning; trade-off

Published in

Journal of Applied Ecology
2022, Volume: 59, number: 6, pages: 1456-1471
Publisher: WILEY

SLU Authors

• Burdon, Francis

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    
  • University of Waikato

• Mckie, Brendan

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

Sustainable Development Goals

Protect, restore and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation and halt biodiversity loss


UKÄ Subject classification

Ecology
Environmental Sciences related to Agriculture and Land-use


Publication identifier

DOI: https://doi.org/10.1111/1365-2664.14176

Permanent link to this page (URI)

https://res.slu.se/id/publ/117055