Effects of soil water on seed production and photosynthesis of pink smartweed (Polygonum pensylvanicum L.) in playa wetlands

  • Published source details Haukos D.A. & Smith L.M. (2006) Effects of soil water on seed production and photosynthesis of pink smartweed (Polygonum pensylvanicum L.) in playa wetlands. Wetlands, 26, 265-270.


This study is summarised as evidence for the following.

Action Category

Actively manage water level: freshwater marshes

Action Link
Marsh and Swamp Conservation
  1. Actively manage water level: freshwater marshes

    A controlled study in 1993 of four depressional freshwater marshes in Texas, USA (Haukos & Smith 2006) found that marshes kept wetter over the growing season supported greater above-ground biomass of pink smartweed Polygonum pensylvanicum, at the end of the growing season, than drier marshes. This was true for marshes kept permanently flooded to 3–5 cm depth (12,497 kg/ha), marshes kept permanently wet but not flooded (9,010 kg/ha), and marshes that fluctuated between flooded, wet and dry (6,816 kg/ha). In permanently dry marshes, with plants wilting during day, above-ground biomass of pink smartweed was only 4,706 kg/ha. Methods: Four marshes (6.1 ha average size) were kept saturated in spring to promote germination of pink smartweed. Between June and August, three marshes were managed with increased water levels and one marsh was left dry. In September, smartweed was cut from twelve 0.25-m2 quadrats/marsh. Seeds were removed, then the vegetation was dried and weighed.

    (Summarised by: Nigel Taylor)

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