Canadian Forest Service Publications

Increased reliance of stream macroinvertebrates on terrestrial food sources linked to forest management intensity. 2019. Erdozain, M.; Kidd, K.; Kreutzweiser, D.P.; Sibley, P. Ecological Applications 29(4): e01889.

Year: 2019

Issued by: Great Lakes Forestry Centre

Catalog ID: 39785

Language: English

Availability: PDF (request by e-mail)

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Plain Language Summary

The study was conducted in the Black Brook forest area of New Brunswick, and applied techniques in stable isotope analyses to determine the influences of forest management on the food web structure and function of forest streams. This is an advanced method to assess sustainability of forest management. Aquatic primary production contributed substantially to the biomass of invertebrates in these headwater streams, contrary to expectations from the literature. However, the contribution of algae to food webs decreased as forest management intensity (road density and associated sediments, water cations/carbon and dissolved organic matter humification) and conifer dominance increased, and as canopy openness decreased. This trend was probably due to an increase in the delivery of organic and inorganic terrestrial materials (dissolved and in suspension) in areas of greater harvesting intensity and road density, which resulted in more heterotrophic biofilms. Overall this suggests that catchment disturbance from forest management can affect stream food web structure via changes in energy flows despite the presence of riparian buffers. This indicates that increased protection should be directed at minimizing ground disturbance in areas with direct hydrological connection to streams and reducing dissolved and particulate matter inputs from roads and stream crossings in catchments with high degrees of management activity.