…To Revive a Forest

Why bother to remove invasive plants? They’ll just grow back again, right? Seems like a fruitless endeavor with few rewards. But I can still remember when a small band of Louisville Nature Center forest volunteers first decided to tackle Bush Honeysuckle, Lonicera maackii at the recently created Beargrass Creek State Nature Preserve (early ’80’s). In those pre info-at-your-fingertips days, we really didn’t know what we were doing, or what would happen. We bravely cut and stump-painted with Roundup, hoping for the best. I’m sure it all grew back again very soon, but it was a start.

Fast forward to 2012, when I returned to the LNC. Invasive plants were still being eradicated, thanks particularly to one determined volunteer, Mike Smith, who just wouldn’t give up. But he also couldn’t keep up, considering the astounding growth rate that is a hallmark of most invasive plants. The seedbank was packed with mostly invasive seeds, ensuring the next generation. We seemed to be locked into a cycle of cut them – then they regrow, over and over again. Our efforts reminded me of Sisyphus pushing his rock up the mountain, only to watch it roll back down.

Was there any way to break this cycle? I began to puzzle over what it would take to return diversity to this forest. Maybe under current conditions invasive plants had no competition, considering how sparse were the populations of herbaceous and shrubby native plants. Maybe we needed to find those few areas where native plant diversity was better, and intensively encourage them to spread, by seed or runners, into the surrounding areas. One plant in particular, Spicebush Lindera benzoin, was showing the ability to produce great amounts of seed when released from the shade of Bush Honeysuckle (if you’ve walked through our forest in winter, you’ve likely seen multitudes of little orange tags, attached to young Spicebush plants that sprang from seed).

And sure enough, this revival strategy is proving to work! Rather than wandering over the forest cutting things randomly, we try to focus intensively on smaller areas with great potential.  It’s one of the most rewarding feelings imaginable (for a plant nut like me) to see how quickly an area can recover it’s biological diversity.

But all this revival comes at a price. To be exact, $56.00 – the price of 2.5 gallons of generic Roundup  (lasts a couple of months).  If you feel that nature shouldn’t have chemicals sprayed all over it, you may not like this part of the story. To keep the revival on track, all those new invasive plants that keep springing from the seedbank need to be pulled or sprayed. One thing I’ve learned – most invasive plants grow awfully fast and are very hard to kill. After all, these aren’t any old plants, but the finest varieties of their kind, selected for landscaping based on their vigor and hardiness!

Consider Porcelainberry, Ampelopsis brevipedunculata, (pic below) which likely resides in some sunny neglected corner of your backyard. It’s unbelievably alluring-to-birds pink, purple, and blue berries are its ticket to everywhere. Vines can grow 20 plus feet in one season, and Roundup foliar spray doesn’t even work on it. Though it’s exploded into prominence fairly recently, it’s nickname of “mini-Kudzu” says it all.

This sea of Porcelainberry exploded in a sunny area where Bush Honeysuckle was removed

So one thing leads to another, and we are moving into a new phase of revival, which will be detailed in the next post, “Opening Pandora’s Box”. Warning, it may be a bit dry compared to all the pics of lovely plants and animals I usually offer. But they are the  reason we do what we do.