Kramer adds details & proposals regarding the mountain beaver hypothesis

I just sent out a link to the shared drive spreadsheet containing the fern data. If you wish to play around with this data, copy and paste it onto another spreadsheet so that none of the numbers get out of place. I do have a backup document but wish for the one posted to stay nice and organized. 

I agree with Tristan that the mountain beavers appear to be having more and more of an impact on the fern population as we continue to further explore around the forests at Seward Park. We came across one section today that looked as if it had been mauled by a pack of mountains beavers. Numerous ferns were completely smashed and flattened as if they had been trampled by a large animal, but the only sign of disturbance appeared to be from mountain beavers. As the surrounding vegetation was not disturbed and countless fronds had been snipped from the smashed ferns. 

Today it seemed that nearly everywhere we walked, we were coming across active mountain beaver dens. We were also thinking that if the system of dens is extensive enough and shallow enough beneath the surface, that this could possible pose problems for increased drought stress on the plants present through disturbing the soil layers and reducing the soils ability to retain moisture throughout the summer. 

As posed numerous times by Tim, I also believe that 5 to 10 exclosure plots in areas where we know mountain beavers are present would be the most effective way to collect quantitative data on the mountain beavers interaction with the sword ferns. Possibly, using the same protocols we have been using for the current 20 plots, we could set up 3x3 exclosure plots inside of larger 5x5 vegetative plots. 

This way we could have an initial data collection on the health of all ferns within the 5x5 plot and then leave the 3x3 exclosure in place for multiple months and come back and re survey the plot and quantify the impact of the mountain beavers on the sword fern population by comparing the amount of fronds removed from the ferns within the 3x3 exclosure and outside of the 3x3 exclosure. 

Many things to ponder here, but seeing that nothing significant is coming from the soil and root samples, testing other hypothesis now may be very worthy. 

Thank you, 

     Kramer