Optimizing the effectiveness of connectivity modifiers to reduce dryland degradation

Authors: Young, Kristina; EDWARDS, BRANDON - New Mexico State University; DUNIWAY, MICHAEL - Us Geological Survey (USGS); Webb, Nicholas

Submitted to: Restoration Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/20/2025
Publication Date: 5/23/2025
Citation: Young, K.E., Edwards, B., Duniway, M., Webb, N.P. 2025. Optimizing the effectiveness of connectivity modifiers to reduce dryland degradation. Restoration Ecology. Article e70055.
DOI: https://doi.org/10.1111/rec.70055

Interpretive Summary: When drylands become degraded, essential resources such as soil, seeds, and nutrients, become lost more easily from the landscape. To combat this loss, restoration practitioners and land managers often use physical structures, such as piles of branches and mulch, to reduce the likelihood of resource loss. Connectivity Modifiers, or ConMods are low-profile galvanized metal structures that were designed specifically to retain resources in degraded areas. However, it is unclear how best to optimize ConMod design and configuration on the landscape to capture the most benefits. In this study, we used modeling, specifically the Aeolian EROsion (AERO) model, to determine the best configurations of ConMods on the landscape to reduce horizontal movement of wind-blown sediment. We found that there are multiple configurations of ConMods, including manipulating the height, spacing, and porosity, that can result in substantial reductions in sediment movement. These findings allow land managers and restoration practitioners to optimize their limited resources to gain the largest increases in site stability when using ConMods, or other techniques that reduce resource loss.

Technical Abstract: Dryland degradation from unsustainable land use and increasing aridity often manifests as bare, interconnected areas that facilitate the loss or redistribution of resources (soil, seeds, and nutrients) through wind and run-off. Physical structures like branches and stick bundles, which disrupt these pathways and retain resources, are crucial for rehabilitation and restoration. Connectivity modifiers or ConMods, which are galvanized mesh structures that mimic low stature vegetation, are tools specifically designed to interrupt connected pathways and help reinforce overall site stability. Yet, how to effectively and consistently use ConMods to achieve site stability has not been thoroughly tested. Here, we used the Aeolian EROsion model to investigate the combined effects of ConMod height, porosity, and spacing on simulated horizontal sediment flux, a key indicator of site stability. We assessed ConMod performance as percent reduction in predicted sediment flux versus a bare, unvegetated 10,000'm2 area for a range of horizontal sediment flux. Additionally, in a field experiment, ConMods increased litter retention by up to 15.6'mm compared to bare ground plots, demonstrating their potential to enhance both soil stabilization and resource retention. These findings underscore the potential of ConMods as flexible, cost-effective tools that interrupt positive feedbacks to degradation and provide measurable benchmarks for restoration success.