‘Branching’ with complex coarse woody debris reduces herbivory on recovering erosion scalds

Abstract

SummaryCoarse woody debris (CWD) has many benefits in restoration, including protecting seedlings from herbivory, and it is often reintroduced where CWD is depauperate. At Calperum Station on the Murray River floodplain, artificially applied CWD (‘branching’) is being trialled to restore erosion scalds. At two erosion scalds, we applied 900 m2 of branching and created a 900 m2 branching‐free control. We predicted that branching would protect seedlings from browsing by mammalian herbivores. We planted Nitre Goosefoot (Chenopodium nitrariaceum) seedlings in each treatment and measured the number of terminal ends affected by herbivory and plant height for 8 weeks. Branching reduced the number of terminal ends affected by herbivory by ~80% and plant height loss by ~60%. Remote cameras detected some browsing by kangaroos, the most abundant herbivores on the Calperum floodplain, although cameras were too few to directly observe much of the browsing that occurred. We did not detect an effect of site browsing pressure on overall herbivory or the effectiveness of the branching. Despite the small sample size, our results suggest that branching can effectively reduce herbivory. It is likely that the effectiveness of branching in reducing herbivory is conditional on a range of factors, such as browsing pressure (i.e. scat density), so a large‐scale trial is required to clarify the role branching has on reducing herbivory in relation to these complex interactions.