Biochar Amendment on a Coastal Ecosystem: Effectiveness of Biochar on Stormwater Infiltration in Upland and Nutrient Removal in Living Shoreline

Delaware's Inland Bays face challenges due to excess of nutrients and considerable shoreline erosion. Additionally, stormwater runoff has emerged as a significant contributor to pollution to the bays, leading to compromised water quality for both aquatic ecosystems and recreational purposes. To challenge these issues, constructed living shorelines offers a natural approach to stabilize the shorelines, reduce erosion, and improve water quality. In our study, we applied biochar, a substance resembling charcoal produced from pyrolysis of wood waste, at two locations: an Upland area and a recently constructed Living Shoreline. We designated these locations as S1 and S2, respectively. Both S1 and S2 were divided into alternating treatment sections of 4% (w/w) biochar, and 0% (w/w) biochar (control). For S1, characterized by a 12-hour tidal cycle, the focus was on examining the impact of the biochar amendment on plant growth, nitrogen removal, and erosion reduction. The S2 site represents a meadow ecosystem where we planted a combination of native wildflowers and warm-season grasses. Unlike S1, S2 is unaffected by tidal cycles and the study aims to discern variations in infiltration rates with and without biochar. To our knowledge this is the first field application of biochar to a meadow ecosystem for studying the enhanced capture of overland flow.

特拉华州内陆海湾（Delaware's Inland Bays）正面临营养盐过剩与严重岸线侵蚀的双重挑战。此外，雨水径流已成为该海湾污染的重要来源，导致水生生态系统与休闲用水的水质均出现恶化。为应对这些问题，人工生态护岸（constructed living shorelines）提供了一种自然解决方案，可实现岸线稳定、侵蚀减缓与水质改善。本研究中，我们在两处场地施加了生物炭（biochar）——一种由木材废弃物经热解制得的类炭物质：一处为高地（Upland）区域，另一处为新近建成的人工生态护岸场地。我们将这两处场地分别命名为S1与S2。S1与S2均被划分为交替布设的处理区段：施加4%（质量分数）生物炭的实验组，以及施加0%（质量分数）生物炭的对照组。S1场地具有12小时的潮汐周期，本研究重点考察了生物炭改良对植物生长、氮素去除与侵蚀减缓的影响。S2场地为草甸生态系统，我们在此种植了本土野花与暖季草本植物的混合群落。与S1不同，S2不受潮汐周期影响，本研究旨在辨析施加与未施加生物炭时的入渗率差异。据我们所知，本研究是首次将生物炭应用于草甸生态系统，以探究其对地表径流强化截留的效果。