Richardson's Needlegrass Trial


Richardson's Needlegrass (Stipa richardsonii) seed was collected in the fall of 1996.  A relatively pure stand was found (only a few plants of rough fescue) so the contractor was able to make use of their specialised equipment (see photo insert) instead of hand stripping.  The contractor then cleaned the seed later in the fall.  Some of the seed was cleaned once and another portion was cleaned four times.

The seed was then handed over to the Ministry of Forests Skimikin Nursery at Tappen, B.C. for cultivation in styrofoam blocks.  A pinch of seed was dropped into each cell to allow for variability in germination.  Germination was very high so the resulting grass plugs consisted of at least four plants.  The plants were delivered to Invermere Forest District on May 2, 1997.  The grass plugs were stored under the same conditions as regular tree planting stock.

An experiment was then designed to test the survival of the grass plugs under operational conditions.  The site chosen has been previously established as an experimental plot (Findlay Exclosure) to test germination and survival of native plants and was fenced in order to eliminate livestock, elk and deer grazing.

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INSIDE EXCLOSURE:

Four different treatments were seeded within the Findlay exclosure on May 8, 1997. Plot size was 2m x 1.2m. and each treatment had five replicates for a total of twenty plots. The treatments were as follows:

Treatment 1.- 25 nursery grown plugs planted within the plot area

Treatment 2.- 15 nursery grown plugs planted within the plot area

Treatment 3.- locally collected seed that had been cleaned once seeded at 25 kg./ha

Treatment 4.- locally collected seed that had been cleaned four times seeded at 25 kg./ha.

The plugs were planted with regular tree planting shovels at roughly equal distances apart.  Crowns were to be level with the soil and firmed after planting.  The seeded plots were lightly raked first to disturb the area, then seeded and lightly raked again.  The plots were not watered or fertilized when planted or during the summer.

The following results were observed on October 15, 1997:

Treatment 1.- 95.2% survival (119 out of 125 plugs survived). Some of the individual plants within the plug may have died, but at least one survived. Usually there was a very high survival of most of the individual plants making up the plug.

Treatment 2.- 93.3% survival (70 out of 75 plugs survived). Same survival of individuals within the plug as treatment 1.

Treatment 3.- No sign of any germination.

Treatment 4.- No sign of any germination.

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OUTSIDE EXCLOSURE:

Only grass plugs were planted on May 21, 1997 outside of the Findlay Exclosure.  Six rows each 40 m. long were set out in a north-south direction to the west of the exclosure.  The first two rows were planted at one half meter intervals.  The remaining four rows were planted at one meter intervals.  Row 1, was nearest the fence.

Row 1. – 80 plugs @ m. spacing.

Row 2. – 80 plugs @ m. spacing.

Row 3. – 40 plugs @ m. spacing.

Row 4. – 40 plugs @ m. spacing.

Row 5. – 40 plugs @ m. spacing.

Row 6. – 40 plugs @ m. spacing.

This arrangement was put in place so that the grass plugs in the first two rows would take the brunt of the prevailing winds and shelter the remaining plants.

Survival was as follows:

Row 1. – 21.3% (17/80 plants).

Row 2. – 38.8% (31/80 plants).

Row 3. – 67.5% (27/40 plants).

Row 4. – 37.5 % (15/40 plants).

Row 5. – 77.5% (31/40 plants).

Row 6. – 57.5% (23/40 plants).

The area outside of the exclosure was grazed by livestock from June 24 to July 1, 1997.

There are numerous guesses as to why the survival rates were lower outside than inside the exclosure. Possible reasons for the lower survival rate were:

  • Livestock trampling was a factor since all the stakes marking the plot were knocked down and the orchard grass in the area was heavily grazed.
  • Planting variability (depth, compaction) is most likely a factor as well. Row 2 had most of the crowns of the plugs above the ground. It will be interesting to note how well these plugs survive the winter versus the ones that were planted deeper.
  • As storage time increased, viability may have decreased. These plugs were stored 13 days longer than the ones planted in the exclosure. By this time, some of the plugs were showing signs of mildew at the base of their stems and may have not been able to recover. As well, in many cases, only one individual survived out of a plug, while the other three or four stems died.