Macrophytes in shallow lakes: Relationships with water, sediment and watershed characteristics

Abstract

We examined macrophyte-environment relationships in shallow lakes located within the Prairie Parkland and Laurentian Mixed Forest provinces of Minnesota. Environmental variables included land cover within lake watersheds, and within-lake, water and sediment characteristics. CCA indicated that sediment fraction smaller than 63 μm (f<63), open water area, turbidity, and percent woodland and agricultural cover in watersheds were significant environmental variables explaining 36.6% of variation in macrophyte cover. When Province was added to the analysis as a spatial covariate, these environmental variables explained 30.8% of the variation in macrophyte cover. CCA also indicated that pH, f<63, percent woodland cover in watersheds, open water area, emergent vegetation area, and organic matter content were significant environmental variables explaining 43.5% of the variation in macrophyte biomass. When Province was added to the analysis as a spatial covariate, these environmental variables explained 39.1% of the variation in macrophyte biomass. The f<63 was the most important environmental variable explaining variation for both measures of macrophyte abundance (cover and biomass) when Province was added as a spatial covariate to the models. Percent woodland in watersheds, turbidity, open water area, and Ca+Mg explained 34.5% of the variation in macrophyte community composition. Most species showed a negative relationship with turbidity and open water area except for Potamogeton richardsonii, Stuckenia pectinata, and filamentous algae. Our study further demonstrates the extent to which macrophyte abundance and community composition are related to site- and watershed-scale variables including lake morphology, water and sediment characteristics, and percent land cover of adjacent uplands.

Emergent Macrophytes Alter the Sediment Composition in a Small, Shallow Subtropical Lake: Implications for Methane Emission

“…These holes accumulate OM, producing a heterogeneous sediment, as evidenced by the higher standard deviation at this station ( Table 1). These alterations in the sediment can cause variations in macrophyte cover in aquatic ecosystems [30], which can determine the distribution of this community in aquatic ecosystems. Methane concentrations in the water column varied between minimum values of 0.30 ± 0.02 µM and maximum values of 1.92 ± 0.1 µM ( Table 2).…”

Multi-Elements in Waters and Sediments of Shallow Lakes: Relationships with Water, Sediment, and Watershed Characteristics

“…Six of the PP lakes (west-central lakes) and all of the LMF lakes were sampled in 2010, while 20 PP lakes (south-western lakes) were sampled in 2011. The lakes occurred within watersheds ranging from 8–1384 ha, were from 1.8–59 ha in basin area, and averaged 1.4±0.6 m deep (Kissoon et al 2013). Extensive areas of conifer forests, mixed hardwood, conifer bogs, and swamps exist throughout the LMF province (Minnesota Department of Natural Resources 1999).…”

“…Water samples were collected at 10 locations within the perimeter of each lake, approximately equidistant from each other and at least 4 m from shore (Kissoon et al 2013). Water samples were collected directly above vegetation, approximately 25 cm below the water’s surface.…”

“…Macrophyte communities in shallow lakes are influenced by a combination of within-lake and watershed variables (Kissoon et al 2013). Here, we examined concentrations of multiple elements in waters and sediments of shallow lakes of varying turbidities in the Prairie Parkland and Laurentian Mixed Forest provinces of Minnesota, to determine relationships with various environmental variables.…”

“…Earlier shallow lake studies focused on regime shifts, carbon, phosphorus and nitrogen cycling, phytoplankton biomass, and macrophyte abundance (Scheffer and Jeppesen 1998; Hansel-Welch et al 2003; Schippers et al 2006; Bayley et al 2007, 2013; Zimmer et al 2009; Brothers et al 2013; Llames et al 2013; Zhang et al 2013; Robin et al 2014). Most of these earlier works focused on influences of various environmental variables on water quality and chemistry, but few have considered physical or chemical aspects of shallow lake sediments (Barko and James 1998; Sahuquillo et al 2012; Kissoon et al 2013; Wu et al 2014). Our study adds to findings from these earlier reports in several ways.…”