Tree Hugging for Science!

Tree inventories tell us about our forests. They tell the story of our trees by providing clues about past conditions, telling us about the current circumstances and health of the forest and hinting at what the forest may look like in the future. Inventories are vital to understanding our forests and in helping us manage them.


A cottonwood looming over the river.

By regularly inventorying the trees, we can evaluate the success of our management and restoration efforts.

The importance of inventories struck home after the National Park Service’s Inventory and Monitoring Network traveled to the Mississippi National River and Recreation Area (MNRRA) do conduct a vegetation survey that revealed surprising news – they could find no young cottonwoods in the floodplain.

This shocked everyone. Who would have guessed the trees that release millions of seeds that float through the air like snowfall in June aren't regenerating? Thanks to the inventory, the Mississippi River Fund is working with the National Park Service and other partners to seek out a solution to this problem.

With the impact of the last park-wide inventory in mind, we are excited to start a tree inventory program at Coldwater.  This is a new activity for both the Mississippi River Fund and MNRRA  staff so when Suzy and Jessica, leaders of the 2011 park-wide inventory from the Inventory and Monitoring Network, offered to train me and Christine, a biological science technician here at MNRRA, we happily accepted.

Suzy and Jessica explained that they collect data around transects, randomly selected lines that are called transects. These transects are 50 meters long. After they lay out a tape measure showing where the transect lies, they record information on the species, diameter, and general health of all trees are 3 meters or less away from the line. They then regularly stop along the line to record what tree seedlings, shrubs, and non-woody plants they see in the transect.

Compass skills were a must for the inventory.
Laying the line.

After that, it was a hands-on training. Christine and I practiced our compass skills to help record the beginning and end points of the transects and make sure the line was straight.

Once the line was established we got to work taking data on the plants within the transect.

After training with Suzy and Jessica, Christine and I were ready to lay out transects at Coldwater Spring and get started.

It’s a lot of work to take data on so many plants. We are excited to have a team of volunteers from the Tree Care Advisor program, a fellow MN GreenCorps member, a Teacher Ranger Teacher and a UWCA Intern put their tree knowledge to use as inventory volunteers for the Mississippi River Fund and MNRRA. Over the last few weeks, we have been tromping up and down the slopes of Coldwater Spring collecting valuable information about the forest that will tell us about the condition of the forest, inform our management plan and provide baseline data that will help us evaluate the success of our restoration efforts.

Volunteers identified trees and noted their size by measuring the diameter at breast height. 


Checking to make sure the tree is in the transect.
Meticulously identifying trees.

Sometimes to find the appropriate height to measure at they have to get very cozy with the trees and do some serious tree hugging!


Team work was sometimes required to measure the especially large trees.


We counted every tree in the transect that was alive, no matter how unusual the situation. One  poor tree was pinned to the ground by a larger tree that had fallen on it. It was still alive so it still needed to be counted and measured!

Laying on the ground to measure the pinned tree.

With the data the Tree Inventory Team collected, we will soon know more about the forests at Coldwater, which will help us in creating a tailored forest restoration and management plan. We will be completing a follow up inventory in a few years and by comparing data from the inventories we will also be able to measure the success of our restoration efforts.


Tree Inventory Team 2014

Thank you inventory volunteers!