Monday, November 24, 2014

Cottonwoods going dormant, what a year!

Who would have guessed what a whirlwind year of cottonwoods this turned out to be. We've been blown away by enthusiasm and support. 

We have some preliminary results to share, but first here's a quick refresher on the project this year.
At Lilydale with partners planning the cottonwood experiment

I worked with closely with staff from St. Paul Parks and Recreation and the National Park Service as well as researchers associated with the University of Minnesota to design a cottonwood planting experiment that will help us determine the best way for public landowners to plant them in the national park. We went out in the dead of winter to evaluate planting sites and start planning. Special thanks to US Army Corps of Engineers.

Implementing the project was a blast! Volunteers were out in the dead of winter collecting cuttings with foresters from the Army Corps of Engineers and rangers from the National Park Service. We teamed up with the City of St. Paul's Parks and Recreation to plant cottonwoods at Lilydale Regional Park with the help of city employees, a youth crew and volunteers.

Measuring height of plants

Counting leaves to measure vigor
Then youth from Urban Roots helped collect data so we can start answering questions:

1. Do planted cottonwoods grow best in forest openings or fields?
2. Are the cottonwoods sufficiently shielded from deer browse when they're in fencing, tree tubes, or left exposed?

For each of those questions we also looked at whether this was true for trees planted from seed and as unrooted and rooted cuttings. 
The tree in the foreground was unprotected
and clearly has fewer leaves than the tree
directly in front of a tree tube in the
background that was pulled out of the tube

None of the seeds germinated and produced seedlings. This was not surprising because if they would have been successful we would not be worried about their populations. We will study cottonwood germination further next spring.

The cuttings we collected last winter show no visible signs of growth. This is because they started out simply as sticks without roots. Trees need roots before they can begin growing leaves and twigs. By the end of the season these trees had produced roots, so they'll be ready to leaf out next spring. We will be able to compare unrooted and rooted cutting growth next year.

Since the seeds and unrooted cuttings did not grow but the rooted cuttings did, the data shown for this year is only for rooted cuttings. 

Rooted cuttings that were protected by tubing or fencing had more new stem growth at the end of the summer and did not show signs of deer browse. It is likely that the deer eating new growth on the trees that had no fencing or tubing to protect them is the cause.

Only the trees with no form of protection were browsed.

Rooted cuttings grew more stem and leaves when growing in tubing. Those in fencing were in second place for growth an leaves and those without fencing grew the least, likely due to browsing pressure.

Trees in the field grew vigorously
We found that rooted cuttings growing in the field grew more in terms of amount of new growth and number of leaves produced. The trees in the field grew nearly twice as much new stem as those in the forest. Leaf production wasn't dramatically different, but more did grow on field trees. 

It will take another year or two of data to confirm these findings but this year's data yields a few preliminary findings that suggest what conditions make cottonwood plantings most successful: 

1. Cottonwoods showed less growth at the end of the season when they were not protected from deer. Of the protected trees, those with tubing grew the most.
2. Cottonwoods grown in fields grew more than those in the forest.

We will monitor the plots though August 2016 and draw final conclusions then. At that time, we will be more confident in our conclusions  because we will have data from more growing seasons and sites. 

The cottonwood trees are going dormant after a busy year, but the project is not. The McKnight Foundation gave the Mississippi River Fund a grant to keep this work going after my Minnesota GreenCorps position ended. This means I'm spending the winter working with the Minneapolis Park and Recreation Board and Three Rivers Park District to organize a cottonwood planting at North Mississippi Regional Park in Minneapolis, and working with the National Wildlife Federation to identify other areas along the river that need cottonwood restoration. 

Wednesday, November 19, 2014

Seeing a park's past and future through the trees

 By Kate Havelin
The leaves are gone; the snow is here. Without the distraction of splashy wild flowers or dramatic foliage and grasses, what stands out is the steadiness of trees. My eye is drawn is the beauty of bare bark, trunks rooted in earth and the past, stretching to the sky and future.

Standing on the steps at Coldwater Spring, I look north to the oak grove, a graceful grouping of mature trees. They seem like the park’s grandparents, watching over the park and all who come here. I think of the many volunteers who donated hundreds of hours to clear invasive buckthorn that once shrouded the oaks. Thanks to their efforts, we can see and savor this grove. I scan east and south to the oak savanna prairie and the bluff top woodlands. The trees frame sun, sky, clouds and park.

A few hundred years ago, oak savannas made up ten percent of Minnesota’s landscape. Today, oak savannas are rare. My eyes sweep over the restored prairie and the trees, old and new. I get a sense of what was and will be. The trees that volunteers have planted in the past few years will grow to shade visitors not yet born.

Since the park opened in 2012, volunteers have planted six hundred trees, including elms, ironwoods, hackberries, and many oaks. I hope my children and future generations will one day walk along Coldwater as I do today. I hope they stop to gaze at an oak savanna prairie grown vigorous after decades of tending. Trees hint at decades and lifetimes.

For now, the mature trees define Coldwater’s landscape. Modest ash trees, supporting players on the park's stage, usher visitors on toward the spring house. Just south of the springhouse, an aging but still statuesque cottonwood bends like a dancer to her audience. Stoic evergreens stand as western sentries, holding the highway and train line at bay. Fallen trees show us yet another angle in trees' long lifelines.  The massive burly oak at the south end of the property anchors Coldwater, an entity unto himself.

Nearby stands a black maple, a supplicant with its many arms overhead forlornly. In a park full of trees, there’s just this one black maple, an uncommon tree this far north in Minnesota. Every tree has a story. Some trees are planted in honor of loved ones. But every tree is a gift -- for now and the future.

From spring's buds through summer's shade canopy and fall's foliage, trees give us gifts in every season. Winter may be trees' finest hour. It's now, when so much is dormant, that we can see trees as the beacons they are, beckoning us in a white-blanketed landscape. Come see Coldwater's trees. This Saturday, November 22, from 1 PM to 2 PM, you can take a tree walk with a ranger to see and hear more about Coldwater’s trees, old and new, past, present, and future.
Coldwater Tree Walk
Tour Coldwater Spring with a National Park Service ranger. No registration needed; just show up.

Thursday, November 13, 2014

CARP: Invasive Outlaws

By Danielle Quist, Park Ranger with the Mississippi National River and Recreation Area

On October 1st, a 19 pound silver carp was captured within our park just upriver from Lock and Dam 2 in Hastings, MN.  This was a surprise to many, but it wasn’t the first time invasive carp have been caught there. Earlier this summer, on July 17, commercial fishermen under contract by the Minnesota Department of Natural Resources (DNR) caught a bighead carp weighing 40 pounds and a silver carp weighing just under 20 pounds (similar to the one caught in October). Both fish were fertile females possibly carrying thousands or even millions of eggs. These recent and subsequent captures may indicate that there is a chance these invasive fishes are establishing a sustainable population in the area.  If this were to happen, these fishes would wreak havoc, causing big problems for human health, the economy, and the environment.

Bighead carp. Photo courtesy of USGS.
Silver carp and bighead carp are invasive species, meaning they have special adaptions and advantages that allow them to aggressively outcompete most native species. They can tolerate very low oxygen levels, and, although, bighead carp seem to prefer a temperate of around 77° F, silver carp can tolerate a wide range of temperatures from 32-104° F. These adaptions allow the fishes to survive in many different water bodies within the United States. Both species of carp are prolific, reproducing in large quantities.  A bighead carp can produce up to 1 million eggs and a silver carp can produce up to 2 million eggs in one spawning season! Therefore, once a few fertile carp are introduced to a lake or river, they can populate it quickly. Also, since neither species is native to the Mississippi River, they don’t have many natural predators to keep their populations in check.  Without predators, these fish get extremely large in size. Both silver and bighead carp have been documented to reach sizes of greater than 3 feet in length and up to 70-80  pounds.  The largest bighead carp was documented at a shocking 110 pounds! Carp are filter feeders that can eat up 5 to 20% of their body weight in plankton each day.

Plankton, small/microscopic organisms that drift and float within the water column, is an important food source for many of our native fishes, especially during their early life stages. It is sort of like their ‘baby food’. Other fish, such as paddlefish and gizzard shad, depend solely on plankton as their food source during all of their life stages.  Invasive carp tend to hog all the plankton causing these native fishes to seek food elsewhere or even die off. Populations of native piscivores, or fish eaters, that rely on juvenile or small fish as their food source, like largemouth bass which prefer to feed on gizzard shad, may also decrease. Invasive carp also harm native mussel populations, which depend not only on plankton as a food source, but on native fish as hosts for their glochidia, microscopic mussel larvae.

Silver and bighead carp not only negatively affect and disrupt freshwater ecosystems and their foodwebs, but they also cause economic and physical harm to humans. Establishment of large, self-sustaining populations of carp on the lower Mississippi River have decreased native fish populations and have forced many commercial and recreational fishermen to seek these fish elsewhere or change professions and/or hobbies. Silver carp jump up to heights of 10 feet when spooked by motorboats or even a canoe paddle. A 20-40 pound jumping fish can cause tremendous amounts of damage to a boat and great harm to boaters and paddlers. Loss of recreational activities, such as boating, paddling, and fishing, caused by the introduction and establishment of these carp populations could greatly harm local economies within Minnesotan communities that rely on these activities to bring in visitors and support local outdoor and recreational shops and jobs.

Silver carp jump when the water is disturbed. Photo courtesy of USFWS,
With all these negative effects invasive carp have had on freshwater ecosystems and local economies, one might ask how these invasive outlaws got here in the first place?  These fish were first introduced in the United States from Asia to benefit fish farms in Arkansas.  Silver and bighead carp were initially used to control plankton blooms within aquaculture and sewage ponds. It has been presumed that some of these carp escaped these ponds possibly during floods in the late 1970s. High water levels may have allowed some spillover of water, fertilized eggs, and fishes into our freshwater lakes and streams, including the Mississippi River. The carp and their fertilized eggs may have then been transported up river, to other tributaries, and lakes by innocent and unknowing fishermen and boaters as stowaways in bait buckets, boats and/or trailers. Two other invasive carp may have also escaped and been transported in a similar matter with in the United States. Grass and black carp have different food preferences than silver and bighead carp, but can also wreak havoc on freshwater ecosystems and local economies. They are both making their way up the Mississippi River, too.

St. Anthony Falls. Photo courtesy of NPS.

Coon Rapids Dam. Photo courtesy of NPS.

Coon Rapids Dam. Photo courtesy of NPS.
These carp may seem to bring impending doom, but there is hope! Research is currently being done to learn more about the life cycle of these invasive fishes. Methods to stop or at least slow down their advancement up the Mississippi River are being investigated and many are already being applied. Scientists search the water for eDNA, or DNA put in the environment by fish feces, mucus and other parts of the fish. This early detection could help stop huge infestations from occurring and help us create a trajectory of their spread as well as predict where they may end up next. Electronic barriers have been used to zap carp and their eggs, stopping them from traveling from the Illinois River into the Great Lakes. University of Minnesota researcher and professor, Dr. Peter Sorenson and his team from the Minnesota Aquatic Invasive Species Center have found ways to deter carp from entering locks by playing a high frequency noise underwater that scares these invasive fish away when the locks are being used by recreational and commercial boat traffic.  Coon Rapids Dam, near Anoka, MN, is being repaired and built up higher in order to create a physical barrier to the upstream advancement of these carp. 

On June 11th, President Barack Obama signed a bill calling for the closure of St Anthony Falls Lock and Dam by June of 2015. Without the lock system, the falls themselves would be a natural barrier, since they do reach a height of almost 50 feet, too high for most invasive as well as native fishes to travel up. This seems like a logical solution since there is little boat traffic (both commercial and recreational) that uses this lock, but work and research is being done to help those few who do. A possible portage route is even being investigated for canoeists and kayakers who wish to paddle this section of the river.

Closing the St. Anthony Dam will protect the river upstream from invasive carp. Photo courtesy of NPS.

Not only are preventive tactics being applied to keep carp out of our lakes and rivers, but solutions to eradicating carp from already infested waters downstream are also investigated. These fish don’t have many native predators. However, there may be one important predator that we may be overlooking, us. Current research is being done on ways to make these super bony fish, specifically silver carp, more marketable to humans as tasty treats such as fish cakes, salami, bologna, and jerky. Gastronomists and foodies have been partaking in carp tasting at various locations across the United States, like the “Taste of Chicago”, and to the surprise of many, silver carp have ranked high on many of these taste tests. Most people are usually turned away at the thought of eating carp because there is a misconception that all carp are bottom feeders, but that’s just not the case. Silver carp are filter feeders and therefore feed within the water column. They also have more Omega-3 fatty acids then salmon. These fish can not only be healthy, but pretty tasty if cooked and seasoned correctly. Byproducts such as fish bones, skin, and guts can also be used to create fertilizer. Therefore, the whole fish can be used with little to no waste. Establishing a market for these fish may help eradicate these fish from our infested waterways and help return commercial fishermen (and women) to their jobs. However, there is fear about the long-term effects to keep up with supply and demand which scientists and economists are currently researching.
Boaters can prevent the spread of invasives. 
Photo courtesy of the Stop Aquatic Hitchhikers Campaign. 

Fishing tournaments have also been another tool used to inform people about invasive carp as well as help deplete some of their populations. Last year’s commercial fishing tournament in Kentucky, entitled “Carp Madness” brought in almost 83,000 pounds of carp!  The winning team harvested 28,669 pounds and took home the $10,000 grand prize. Another fishing tournament down in Bath, Illinois has been also gaining some publicity; the Redneck Fishing Tournament provides a more entertaining experience and a few less rules then a commercial fishing tournament. Boaters and fishermen dressed in costume do whatever it takes to catch as much carp as they can, some even using bats to hit one into the boat (or out of the river). There’s even a cash reward for the team that catches the most carp and a prize for best costume.

Check your boat for aquatic invasives. Photo courtesy of the Stop Aquatic Hitchhikers Campaign.

You can help eradicate and prevent the spread of these invasive fish within our park, too! Make sure to clean, drain, and dry your boat after use, especially after being in infested waters. Don’t move water, bait, or fish from one body of water to another. Sometimes juvenile carp or eggs may be hiding in your bait bucket or be misidentified as a minnow, so it’s best to dispose of unwanted bait into the trash. Invasive carp can hitch a ride in locks when used by commercial and recreational boat traffic, so try to minimize use of these locks to inhibit them from catching a free ride from you. Also, make sure to report sightings of silver and bighead carp to your DNR division, and if you catch one bring it to your local DNR office.