Gần đây, Hội đồng Nghiên cứu Quốc gia Hoa Kỳ (2001) đề nghị sử dụng một quan điểm đầu nguồn cùng với khoa học, quy trình đánh giá nhanh chóng để theo dõi giảm nhẹ và phục hồi đất ngập nước. Các công cụ đánh giá nhanh có thể được sử dụng như một dấu hiệu cảnh báo để cung cấp cho một ý tưởng nhanh chóng của tình trạng đất ngập nước và xác định các trang web cần đánh giá thêm hoặc bảo vệ ngay lập tức. Nhiều tiểu bang Hoa Kỳ có hoặc đang phát triển quy. | 14 Evaluation of Rapid Assessment Techniques for Establishing Wetland Condition on a Watershed Scale Vanessa L. Lougheed Christian A. Parker and R. Jan Stevenson INTRODUCTION Recently the . National Research Council 2001 recommended utilizing a watershed perspective together with science-based rapid assessment procedures to track wetland mitigation and restoration. Rapid assessment tools can be used as a warning sign to give a quick idea of wetland condition and determine sites in need of further assessment or immediate protection. Many . states have or are developing three-tiered assessment procedures that include an initial landscape-scale assessment using aerial imagery tier 1 followed by a rapid condition assessment tier 2 and a more intensive monitoring program tier 3 . Miller and Gunsalus 1999 Mack 2001 Fennessy et al. 2004 . Wetlands can be significantly impacted by a variety of physical chemical and biological factors and although a single environmental factor can sometimes be implicated as the primary stressor to a wetland ecosystem King and Richardson 2003 it is more likely that a combination of factors result in wetland degradation on a landscape scale Danielson 2001 . Furthermore spatial and temporal variability in chemical stressor levels can make it difficult to diagnose one specific nutrient causing impairment especially for sites sampled just once in landscape-scale assessments. In such cases multistressor axes can be used to ensure assessments reflect a greater number of stressors . Mack 2001 Lougheed et al. 2001 . In particular one encounters a variety of wetland classes in a single watershed . lacustrine riverine and isolated wetlands and these different classes may respond differently to a variety of stressors Fennessy et al. 2004 . Multistressor axes may therefore have a greater utility for a suite of wetlands in a landscape setting than does any one individual measure. Existing rapid assessment methods generally combine .
