hydrology Article Impact of Urbanization on Large Wood Sizes and Associated Recruitment Zones Matthew T. Allen 1 and Philippe G. Vidon 2,* 1 Atlantic States Rural Water & Wastewater Association, 11 High St., Suite 204, Suffield, CT 06078, USA;
[email protected] 2 Department of Sustainable Resources Management, State University of New York College of Environmental Science and Forestry (SUNY-ESF), 1 Forestry Drive, Syracuse, NY 13210, USA * Correspondence:
[email protected] Received: 14 October 2020; Accepted: 13 November 2020; Published: 16 November 2020 Abstract: Although the presence of large wood (LW) has long been recognized to enhance watershed function, land use impact on LW remains poorly understood. Using a series of six watersheds, we investigate the relationships between LW recruitment zones, LW size, and LW jam occurrence and land use. Although the results in general show urban land use to severely limit LW, they also stress that agricultural land use may be positively correlated to LW. Occurrence of potentially productive LW recruitment zones is nevertheless best correlated to total forest land cover and forested riparian area. However, the lack of mature forest due to previous widespread deforestation linked to historical agricultural land use is likely a limiting legacy effect. Since the pattern of land use seen in the study area is typical of much of the developed world, our results suggest the limiting of LW may be a major way in which watersheds are impacted in many regions. Accordingly, reintroduction of LW represents a significant opportunity to restore watersheds on a broad scale. Specifically, we propose a mix of passive conservation and active restoration of LW sources and that the targeting of these tactics be planned using the spatial analysis methods of this study.