Two years of monitoring health and growth of planted seedlings in a floodplain forest at Kains Switch South

Abstract

The study site is within the Kains Switch South (KSS) forest management site, a U. S. Army Corps of Engineers’ forest management site located on the western edge of the Upper Mississippi River floodplain between river miles 668.2 and 670.3 and within navigation Pool 9. The site is approximately 5 miles (8 km) south of New Albin, IA, and the Minnesota/Iowa border in Allamakee County, IA. Nine plots were established at KSS spanning an elevation gradient, with three plots per elevation quantile (high, 626.5 to 628.5 ft [190.9 to 191.6 m]; intermediate, 624.5 to 626.5 ft [190.3 – 190.9 m]; and low, 622.5 to 624.5 ft [189.7 to 190.3 m]). A total of 64 seedlings were planted in each plot in an 8 x 8 grid with 10 ft x 10 ft cell sizes (3 by 3 m), with 16 individuals representing each of the following species: swamp white oak (Quercus bicolor Willd.), silver maple (Acer saccharinum L.), sycamore (Platanus occidentalis L.), and hackberry (Celtis occidentalis L.). Orientation of the grid was north/south. Species’ cell assignments were random and placement within the 10 ft x 10 ft (3 by 3 m) cell was also random. Initial measurements of species, basal diameter, height, and initial notes regarding seedling vigor and health and evidence of herbivory occurred in June 2020. End-of-growing-season measurements (same as initial variables) occurred in September 2020 and October 2021 and included the same measurements as the initial measurements. An additional survival assessment occurred in June 2021.