Mass blooming Calochortus

Kipp McMichael
Mon, 21 May 2012 15:18:51 PDT


  I would posit that the mass growth & bloom was a result of the reduced competition for sunlight and moisture but I would further posit that seed-setting is comparatively more limited by trace elements than by sunlight/moisture. It would be interesting to test this by comparing the seed-set (rather than merely the vegetative growth or flowers) of two populations that experience manual vs. fire-induced clearing (assuming there is some truth to the idea that fire returns nutrients to the soil!).


> Date: Mon, 21 May 2012 14:45:44 -0700
> From:
> To:
> Subject: [pbs] Mass blooming Calochortus
> I was in the Sierra foothills about a month ago for my usual trip to see 
> the wildflowers.  Last year I was very dismayed to see that virtually 
> all vegetation in one area had been cleared in on both sides of the road 
> to a depth of about 20 feet.  This went on for some miles, and was 
> probably for fire control.  In a completely different area, similar 
> clearing of manzanita had taken place.  This spring there was a mass 
> blooming of Calochortus tolmiei in one place and C. monophyllus in 
> another.  In both areas (which I know very well) I have never seen 
> blooming like this, and in some places I have never seen them blooming 
> at all.  This was not a good year for bulb flowers due to the two month 
> dry spell we had, so these two areas really stood out.  It has been 
> postulated that mass blooming of bulbs after fire could be due to smoke 
> penetrating the ground, or to nutrients from the ash, but there were 
> neither, just the removal of dense shrubby vegetation, so maybe it isn't 
> anything mysterious at all, just the removal of competition, thereby 
> making available to the existing bulbs more moisture and nutrients in 
> the soil.  I went back this weekend for seed, and another thing struck 
> me was that the percentage of plants that set seed in colonies like this 
> is very small.  The flowering was amazing, but seed was fairly sparse, 
> not even 10% of the individuals producing seed.  the C. monophyllus (it 
> is not spotted) literally covers square miles in this area, and the C. 
> tolmiei is almost as abundant.
> Diana
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