Primary determinants of macrophyte community structure in 62 marshes across the Great Lakes basin: latitude, land use, and water quality effects

Abstract

We collected water quality, land use, and aquatic macrophyte information from 62 coastal and inland wetlands in the Great Lakes basin and found that species richness and community structure of macrophytes were a function of geographic location and water quality. For inland wetlands, the primary source of water quality degradation was inputs of nutrients and sediment associated with altered land use, whereas for coastal wetlands, water quality was also influenced by exposure and mixing with the respective Great Lakes. Wetlands within the subbasins of the less developed, more exposed upper Great Lakes had unique physical and ecological characteristics compared with the more developed, less sheltered wetlands of the lower Great Lakes and those located inland. Turbid, nutrient-rich wetlands were characterized by a fringe of emergent vegetation, with a few sparsely distributed submergent plant species. Highquality wetlands had clearer water and lower nutrient levels and contained a mix of emergent and floating-leaf taxa with a diverse and dense submergent plant community. Certain macrophyte taxa were identified as intolerant of turbid, nutrient-rich conditions (e.g., Pontederia cordata, Najas flaxilis), while others were tolerant of a wide range of conditions (e.g., Typha spp., Potamogeton pectinatus) occurring in both degraded and pristine wetlands. Résumé : Des données recueillies sur la qualité de l'eau, l'utilisation des terres et les macrophytes aquatiques dans 62 terres humides des régions côtières et intérieures du bassin des Grands Lacs indiquent que la richesse spécifique et la structure des communautés de macrophytes dépendent de la situation géographique et de la qualité de l'eau. Dans les terres humides intérieures, la source principale de dégradation de la qualité de l'eau est l'apport de nutriments et de sédiments causé par les changements dans l'utilisation des terres, alors que, dans les terres humides côtières, la qualité de l'eau est aussi influencée par le contact avec le Grand Lac adjacent et les mélanges d'eau qui s'y produisent. Les terres humides des sous-bassins des Grands Lacs d'amont, qui ont subi moins de développement et qui sont plus exposés, possèdent des caractéristiques physiques et écologiques tout à fait particulières, par comparaison avec les terres humides des Grands Lacs d'aval qui sont plus développés et moins protégés, et les terres humides intérieures. Les terres humides turbides et riches en nutriments sont caractérisées par le développement d'une ceinture de végétation émergente et la présence sporadique de quelques plantes submergées. Les terres humides de grande qualité possèdent une eau plus claire, des concentrations plus faibles de nutriments et une combinaison de taxons de plantes émergentes et de plantes à feuilles flottantes, d'une part, et d'une communauté diversifiée et dense de plantes submergées, d'autre part. Certains taxons de macrophytes se sont révélés intolérants aux conditions de turbidité et de richesse en éléments nutritifs élevées (e.g., Pontederia cordata...

Factors affecting the distribution patterns of aquatic macrophytes

“…A number of studies have found these to be the most significant factors governing the abundance, composition and distribution of macrophytes (Bini et al 1999;Lougheed et al 2001;Pandit 2002). It is well documented that the underwater light plays an important role in determining the depth distribution of different groups of aquatic macrophytes (Sculthorpe 1971;Chambers and Kalff 1985;Dale 1986;Chambers and Prepas 1988;Hrivnak et al 2006).…”

“…A lot of research has been done from time to time to evaluate the effects of water quality, sediment characteristics and geological formations on aquatic macrophyte distribution (Kaul 1971;Chambers 1987;Gopal 1987;Barko et al 1991;Heegaard et al 2001;Lougheed et al 2001;Mir 2009;Birk and Willby 2010;Alahuhta 2011;Uedeme-Naa et al 2011;Tamire and Mengistou 2012;Gecheva et al 2013; Sossey-Alaoui and Rosillon 2013). Riis et al (2000) while examining the relationship between environmental factors and aquatic plant composition in Danish streams found that alkalinity was the most important factor in predicting plant distribution.…”

“…Several studies have established that the nutrient enrichment can cause significant changes in the density, species composition and richness of aquatic vegetation in lakes (Toivonen and Huttunen 1995;Findlay and Houlahan 1997;Bini et al 1999;Magee et al 1999;Lougheed et al 2001;Rosset et al 2010;Alahuhta 2011). There is a possibility that the elevated nutrient concentrations might hamper climate-driven distribution patterns of macrophytes (Rosset et al 2010).…”

Migrating and breeding bird use of restored shallow lakes in Iowa

“…had their greatest frequencies in older restorations, particularly in 2017. This variation and decline could be due to grazing from waterfowl (Lauridsen et al 1993), water level fluctuations (Chow-Fraser 2005), changes in light conditions (Bini et al 1999), temperature (Minc 1997, Smith andMoelyowati 1998), or changes in nutrient inputs (Lougheed et al 2001). …”

The prediction of macrophyte species occurrence in Swiss ponds

“…The distribution of macrophytes is often related to water chemistry, especially as influenced by eutrophication (e.g., Lehmann & Lachavanne, 1999). The significance of parameters such as morphometry, water levels, perturbations and disturbances, composition of bottom substrates, land-use in the catchment and surroundings, connectivity between water bodies, as well as interactions with the fish fauna has also been demonstrated (e.g., Jupp & Spence, 1977;Rørslett, 1991;Wright et al, 1992;Bornette & Amoros, 1996;Lehmann et al, 1997;Lougheed et al, 2001;Oertli et al, 2002). Many of these studies are concerned with the relationships between species richness of aquatic macrophytes and environmental variables but few involve study of a high number of individual species (e.g., Heegaard et al, 2001;Bio et al, 2002).…”