The biogeography of aquatic macrophytes in North America since the Last Glacial Maximum

Abstract

Aim To document the post‐glacial migration of the major aquatic macrophytes of North America. Location North America north of Mexico. Methods Aquatic macrophyte pollen were extracted from the North American Pollen Database. The modern pollen distribution was mapped and related to the climate to document the geographical and climatic constraints on these taxa. The fossil pollen were mapped at 2‐ka intervals for the past 21 ka. Results Numerous genera were present in ice‐free Alaska during the Last Glacial Maximum, and south of the Laurentide Ice Sheet in the southeast. Those taxa with the widest modern climatic ranges migrated rapidly into ice‐marginal areas, first in the west and then in the east of North America. Subsequent changes in the range and abundance were smaller. Main conclusions There were four migration routes of aquatic macrophytes during the late‐glacial and post‐glacial periods: a southward migration from Alaska between 14–13 and ka, a northern migration in the west at the same time into the ice‐free Cordilleran region, and movements east and west of Appalachia as early as 19 ka for some taxa into the lower Mississippi and into the upper Mississippi and Great Lakes by 11 ka. As the Laurentide ice sheet wasted, aquatic taxa with the broadest contemporary temperature tolerances rapidly occupied ice‐marginal environments.

Response of aquatic plants to abiotic factors: a review

“…Santamaria et al 2003), and (2) their dispersal capacity, enabling them to escape the unfavourable conditions and reach more favourable sites. Recolonization of North America by aquatic plants after the last glacial period was shown to be very rapid (Sawada et al 2003), and many invasive species are aquatic plants (Murphy 1988) able to colonize new sites efficiently and rapidly (Brown and Eckert 2005). However, the rate of climate change risks to be much more rapid than aquatic plant dispersal, and the enormous past and present man-made alterations of aquatic ecosystems (area decrease, changes in function and connectivity, Millenium-Ecosystem-Assessment 2005) may strongly disfavour such migrations.…”

Species sorting determines variation in the community composition of common and rare macrophytes at various spatial extents

“…This resulted in a total of 240 study lakes at the state extent. The lake macrophytes within each province formed a metacommunity based on characteristics of the provinces, historical development of lakes (Yu, 2000;Sawada et al, 2003) and good dispersal capabilities of aquatic plants (Santamaria, 2002;Soons et al, 2008;Viana et al, 2013). Illustration of different hypotheses (metacommunity dynamics vs. rarity theory), and how common and rare species should respond to environmental and spatial processes according to these theories and along with variable spatial extent.…”

Rapid Lateglacial tree population dynamics and ecosystem changes in the eastern Baltic region

“…Warmthdemanding taxa such as Nymphaea, Typha and Najas were present instead of more cold-tolerant species like Myriophyllum. The beginning of the Holocene was commonly the time when aquatic plants rapidly colonised lakes, but responses to the climatological and hydroecological changes seem to have been lake-specific (Birks, 2000;Sawada et al, 2003;Väliranta, 2006). …”