Rapid colonization of a human-made wetland by Mariana common moorhen on Guam

Published source details Ritter M.W. & Sweet T.M. (1993) Rapid colonization of a human-made wetland by Mariana common moorhen on Guam. The Wilson Bulletin, 105, 685-687.
Share Tweet Email

Actions

This study is summarised as evidence for the following.

	Action	Category
	Excavate freshwater pools Action Link
	Directly plant non-woody plants: freshwater wetlands Action Link
	Restore or create inland wetlands Action Link
	Transplant or replace wetland soil: freshwater marshes Action Link

Excavate freshwater pools

A before-and-after study in 1992–1993 on a tourist resort in Guam (Ritter & Sweet 1993) reported that a freshwater pool created by excavation, lining with wetland soil and planting herb species contained two of the four planted species after one year, and four additional species. The two planted species present after one year were spikerush Eleocharis dulcis (60% cover) and rusty flatsedge Cyperus oderatus (<1% cover). Four additional species were present after one year: two rushes, one grass and one forb (<1–10% cover). Methods: In January 1992, a 600-m² wetland was excavated on a natural valley slope, lined with wetland soil (30 cm deep) and planted with four herbaceous species (120 spikerush, an unclear number of rusty flatsedge, 20 taro, 5% cover of water lettuce). The study does not distinguish between the effects of these interventions on non-planted vegetation. The wetland was fed by ground and surface water, and had a stable 20–60 cm water depth. Final vegetation cover was estimated in January 1993.

(Summarised by: Nigel Taylor)
Directly plant non-woody plants: freshwater wetlands

A before-and-after study in 1992–1993 on a tourist resort in Guam (Ritter & Sweet 1993) reported that a freshwater pool created by excavation, lining with wetland soil and planting herb species contained two of the four planted species after one year, and four additional species. The two planted species present after one year were spikerush Eleocharis dulcis (60% cover) and rusty flatsedge Cyperus oderatus (<1% cover). All planted taro Colocasioa esculenta died; the study suggests it was “excessively flooded”. Planted water lettuce Pistia stratioides was deliberately removed after five months, when it had reached 20% cover. Four additional species were present after one year: two rushes, one grass and one forb (<1–10% cover). Methods: In January 1992, a 600-m² wetland was excavated on a natural valley slope, lined with wetland soil (30 cm deep) and planted with four herbaceous species (120 spikerush, an unclear number of rusty flatsedge, 20 taro, 5% cover of water lettuce). The study does not distinguish between the effects of these interventions on non-planted vegetation. The wetland was fed by ground and surface water, and had a stable 20–60 cm water depth. Final vegetation cover was estimated in January 1993.

(Summarised by: Nigel Taylor)
Restore or create inland wetlands

A before-and-after study in 1992 on Guam, South Pacific (Ritter & Sweet 1993), found that Mariana common moorhens Gallinula chloropus guami colonised a newly-created wetland within five months of its creation, with two adults and at least four chicks being seen. The wetland was 20-60 cm deep, 45 m long and up to 27 m wide and created using an excavator in January 1992. Spikerush Eleocharis dulcis, water lettuce Pistia stratiotesm, taro Colocasia esculenta and rusty flatsedge Cyperus odoratus were planted, although the taro died, probably because of excessive flooding.
Transplant or replace wetland soil: freshwater marshes

A before-and-after study in 1992–1993 on a tourist resort in Guam (Ritter & Sweet 1993) reported that a freshwater pool created by excavation, lining with wetland soil and planting herb species contained two of the four planted species after one year, and four additional species. The two planted species present after one year were spikerush Eleocharis dulcis (60% cover) and rusty flatsedge Cyperus oderatus (<1% cover). All planted taro Colocasioa esculenta died; the study suggests it was “excessively flooded”. Planted water lettuce Pistia stratioides was deliberately removed after five months, when it had reached 20% cover. Four additional species were present after one year: two rushes, one grass and one forb (<1–10% cover). Methods: In January 1992, a 600-m² wetland was excavated on a natural valley slope, lined with wetland soil (30 cm deep) and planted with four herbaceous species (120 spikerush, an unclear number of rusty flatsedge, 20 taro, 5% cover of water lettuce). The study does not distinguish between the effects of these interventions on non-planted vegetation. The wetland was fed by ground and surface water, and had a stable 20–60 cm water depth. Final vegetation cover was estimated in January 1993.

(Summarised by: Nigel Taylor)