New project aims to establish C. acaule population

by:  Carla Zelmer   Mar. 2002

Establishment of new populations of orchids may be desirable for many reasons, including the utilization of already-protected lands as orchid habitat, as insurance against destruction of existing populations and to escape disease pressures in existing sites. There is little other than anecdotal information on the ability of northern terrestrial orchids to establish when seeded into suitable habitat.

In the summer of 2001, Bud Ewacha, Carla Zelmer and Tony Szumigalski began a scientific study to determine the feasibility of seeding C. acaule into an area of appropriate habitat that does not presently support C. acaule plants (Cat Hills, MB). This seeding project has been funded by several sources including the Federal and Provincial Governments.

To aid in tracking the seedlings, an unusual, darkly-coloured variant of C. acaule was used as the seed source for the study. The plant was hand pollinated with its own pollen, resulting in large capsules containing thousands of viable seeds.

Split plots were set up in replicate at the site and marked for relocation over many growing seasons (photo 5, 6,.7). Half of each split plot was planted with a known weight of C. acaule seeds mixed with sand (to help distribute the tiny seeds). Only the sand was added to the other half as a check for existing seedlings.

The sites will be monitored for the next 5 years for the appearance of seedlings. For the first one to several years of a northern terrestrial orchid's life, the seedlings live underground, provided with food by a symbiotic relationship with fungi. Eventually a leaf is produced above ground, and the plants begin to photosynthesize. Monitoring seedling emergence is therefore a long-term proposition. Little is known about the time to emergence in suitable wild habitats because date of seeding is usually not known.

Although the site appears to be favorable for C. acaule growth at this new site, the presence of the symbiotic fungi is not assured. To our knowledge, this study is the first of its kind with C. acaule, which can be germinated in culture but rarely survives planting out into the natural environment. Correspondence with researchers in the USA and Europe indicate that there is interest in undertaking similar studies in several countries.

Photo 4. Rare, darkly pigmented variant of C. acaule used for seeding project.

Photo 5. Bud Ewacha at the perimeter of one of the seeding plots.

Photo 6. Tony Szumigalski and Carla Zelmer seeding the plots.

Photo 7. Sites are marked for relocation over a number of seasons to track the emergence of the C. acaule seedlings.