Concerning data on regrowth involving multiple pups it is important to understand that there is not necessarily a direct 1:1 correspondence between sequential figures for individual pups within a single plant.
 It was not uncommon for some or all pups to be partly or entirely covered so some photos illustrate the pre-uncovery state.

Images of the tags can be viewed via the links for the tag numbers in the first column.


Images of regrowth for the actual plants that were harvested in our study can be viewed using the links in the column headed "Regrowth as number of pups".

Images of the regrowth plants that were reharvested in the second and third phases of this study can be viewed using the links in the comments column.

On 8 March 2010 the second phase of this study began with the two year old regrowth of half the original harvested plants being reharvested. Those twenty plants were rooted for replanting and the mother plants are now part of a subgroup in the study. 

On 13 March 2012 the third phase of this study began with the two-year old regrowth of half the reharvested plants being reharvested yet again (the third harvest of those plants in four years). The harvested buttons from those twenty plants were dried and saved for a study to determine the mescaline content of small regrowth buttons compared to crown tissue from eight-ribbed mature plants from the same population, and the mother plants are now part of a subgroup in the study. Both the thrice harvested plants and the once harvested plants had four dead or missing plants.

The results from our March 2009–2012 visits concerning those 20 individuals.

          On 10 March 2014, we returned for a follow-up visit and an additional reharvest of half of the two-yr old regrowth.

During 14-15 March 2016, we returned for another follow-up visit. We were challenged by multiple occurrences of photographic equipment failure (including the death of our primary camera early on the first morning of shooting), a lack of half of our anticipated help and a narrow window of access. We deliberately omitted  some of our subjects on day 1 if they had previously been established to be dead. It was our intention to search for their tags after we had located all of the living subjects. It was a sound decision as we barely completed our tasks of locating, counting, measuring and photographing the rest of the subjects before running out of time and needing to vacate the property before wild pig hunters arrived (we left with only 30 minutes to spare).
    Rabbit activity was noted to be higher than in previous years but the damages experienced by the peyotes was very limited.

  nd   – No data available.
       –    – Missing data.

The plants being surveyed are part of a larger population occurring on private land in South Texas. The area of the survey site itself is defined with a transect of 17-gauge electric fence wire secured with steel stakes — the locations of which are recorded with a high resolution GPS. The transect zigzags through the study site with all plants in the study being located within approximately one-half meter of the wire. The area of the study site has not yet been accurately measured but we estimate it to be around half a hectare.

    We also tagged and measured a control group of 50 plants on 23 NOV 2008, which in future monitoring will give us an idea of the magnitude of natural mortality not associated with harvesting. {The results from our visits concerning those 50 individuals serving as our control group.}

    An additional 20 plants (#201-220) were harvested during the November 2008 monitoring to make up for what was believed to be lost plants from the original group of 50 harvested plants. {The results from our visits concerning those twenty individuals.}


7 March 2009 update:
    Interestingly we found the same number of harvested study plants (with their tags) but as can be seen in the table above these were not entirely the same plants & tags as had been located on 23 November 2008.
    On this visit we used a Trimble high-resolution GPS instrument to record the location of all tags and/or plants located.
    Complete or partial burial of plants and their tags was sometimes encountered. To aid in future visits we added a rebar stake near each tagged plant.


6 March 2010 update:
    A number of our tags and plants were completely buried and hence provided missing data in 2009. In 2010, thanks to the use of a high powered metal detector, we located our tags, stakes and plants except in the instances where the plants and their tag were totally missing from the study site.

A new seedling in the study population. 

   

    If you would like to help support additional studies of this type, designed to answer basic questions that are critical to the optimal stewardship/management of vulnerable cactus species, please send a contribution, of $25 USD or whatever amount you can afford, to the Cactus Conservation Institute, 909 E. Sul Ross Ave., Alpine, TX 79830.
    We also now accept donations via PayPal.