Polyembryony in Sphagnum

Polyembryony in Armadillos

O travelers passing through the southern US. may be struck by the unusual appearance of the ninebanded armadillo (Dasypus novemcinctus). This animal, which is about threequarters of a meter long, canbe identified by the leathery plates of armor that cover it nearly from the tip of its nose to the end of its tail. It also has a seriesof transverse plates that wrap around its midsection, giving i...

Polyembryony in Hierochloe Odorata (l.) Beauv

The evolution of polyembryony in parasitoid wasps.

Polyembryony has evolved independently in four families of parasitoid wasps. We review three main hypotheses for the selective forces favouring this developmental mode in parasitoids: polyembryony (i) reduces the costs of egg limitation; (ii) reduces the genetic conflict among offspring; and (iii) allows offspring to adjust their numbers to the quality of the host. Using comparative data and ve...

Mobility of Pb in Sphagnum-derived peat

One important assumption in applying 210Pb-dating is that atmospherically deposited 210Pb is immobilized in the peat or sediment column. This assumption has been challenged widely, but has never been evaluated experimentally. We evaluated Pb mobility and the chemical forms in which Pb is stabilized in peat profiles by adding either soluble or particulate Pb to intact peat cores that were mainta...

Acidophilic methanotrophic communities from Sphagnum peat bogs.

Highly enriched methanotrophic communities (> 25 serial transfers) were obtained from acidic ombrotrophic peat bogs from four boreal forest sites. The enrichment strategy involved using media conditions that were associated with the highest rates of methane uptake by the original peat samples, namely, the use of diluted mineral medium of low buffering capacity, moderate incubation temperature (...