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The MEM Report Presentation of Courtney Johnson -FR and SJ

Author: myUNB News

Posted on Apr 24, 2018

Category: News and Notices

The MEM Report Presentation of Courtney Johnson will be held on Wednesday, April 25, at 4 p.m. in Forestry & Geology Building Room 202 - Dean's Conference Room 

Report Presentation Chaired By:  Dr. B. Leblon, FOREM
Supervisor(s):  Dr. J. Nocera, FOREM, Mr. J. Ogilvie, FOREM
Report Title: Model for Predicting Vernal Pools in New Brunswick from High Resolution LiDAR

Abstract: In New Brunswick, vernal pools represent important habitat for amphibians who use these predator-free temporary pools for reproduction. These pools can often be overlooked in forest management planning and face threats from forestry operations, which can affect the hydroperiod of these pools and create an ecological trap for breeding amphibians. To preserve these habitats it is important to locate and protect them quickly and easily at the large spatial scales at which most forest planning is undertaken. No such tool exists for predicting the large scale occurrence of vernal pools in the Acadian forest in Canada. The recent availability of high resolution LiDAR for NB allowed us to develop a model within the Acadian Research Forest (ARF) to predict the location of vernal pools within one widely accessible program (ArcGIS). To predict vernal pool locations, we first created a Stochastic Depression Analysis tool in ArcGIS to successfully identify small surface depressions with minimal error. We classified vernal pools with certain parameters based on previous remote-sensing and vernal pool research; we defined vernal pools as having a minimum surface area of 10m2 and minimum depth of 0.15m. To isolate depressions with vernal pool habitat characteristics we then incorporated distance from water course, flow accumulation thresholds (10x and 20x vernal pool area), canopy height (<6m, >6m),  and canopy density (<50%, >50%) parameters. We identified ~4500 surface depressions within the ARF.  However, the number of depressions that showed vernal pool characteristics was significantly less; we predicted 739 vernal pools within the 20x flow accumulation threshold and 467 within the 10x threshold.  Patterns were consistent within each threshold where half of the predicted pools occurred within a canopy height <6m and="">50% canopy density, and a third of the pools occurred within a canopy height >6m and >50% canopy density. Although preliminary calibration shows the model to have high accuracy (6 out of 7 known vernal pools predicted), this model now needs to be evaluated through extensive ground truthing.


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