Abbie Judice, Moncus Park Environmental Coordinator, organized a Conservation Club activity on Wednesday, March 22 to learn about, and help to remove, invasive plant species from a small wooded area of the park. Invasive plant species are defined as plants that are not native to the ecosystem, and cause environmental and economic damage where they have been introduced. ANPP's Lawrence Rozas assisted in this park activity by giving to the members of the Conservation Club a general introduction to invasive plants and speaking about our past work in identifying invasive plants within the park.
It is important to know that not all non-native plants are invasive, but it’s also important to understand that about 15% of all introduced non-native species have become invasive and damaging to the environment. Sadly, even today, some of the many non-native plants available at commercial plant nurseries are invasive, so it’s important to do a little research before purchasing plants. Purchase only native plant species or non-invasive, non-natives to avoid contributing to the problem of invasive species infesting the natural areas of Acadiana and beyond. Invasive plants cause environmental harm by spreading uncontrollably and replacing native plants, upon which native wildlife depends. Many of the non-native plants that become invasive here are native to Asia where the climate and other environmental conditions are similar to ours. These non-native plants also lack the herbivores and competitors found in their native habitat, so they thrive here in Louisiana and other parts of the U.S. Attempting to control invasive plants once they become established here is costly and time consuming. The costs of monitoring and controlling invasive species, and their damage to crops, fisheries, forests, and native wildlife are estimated to exceed $130 billion each year in the U.S. alone.
Invasive Plants of Moncus Park
Two years ago, the Acadiana Native Plant Project (ANPP) conducted a survey of the plants in the 23-acre wooded Ravine Area of Moncus Park. We identified all the plants we encountered on each survey day and marked the invasive species with brightly colored plastic flagging. In total, we identified 95 plant species native to Louisiana and 34 invasive plant species.
The top six invasive plant species in terms of abundance we termed the “Dirty Half Dozen” were: Chinese Privet (Ligustrum sinensis), Glossy Privet (L. lucidum), Wax Leaf Ligustrum (L. japonicum), Coralberry (Ardisia crenata), and Chinese Tallow (Triadica sebifera). Other commonly observed invasive plants were: Chinese or Drake Elm (Ulmus parvifolia), Nandina (Nandina domestica), Camphor Tree (Cinnamomum camphora), and Japanese Plum (Eriobotrya japonica). Invasive vines were: Bushkiller (Cayratia japonica) and Japanese Honeysuckle (Lonicera japonica).
Control of Invasive Plants in Moncus Park
The Conservation Club concentrated its control efforts on two of the Dirty Half Dozen, Chinese Privet and Glossy Privet, which were abundant at the site we chose to work. We first separated plants into two size categories based on stem or trunk diameter (Small: 2 – 3 inches and Large: greater than 3 inches). Most Chinese Privet fell into the small size category. The control method we used for small stems was the “Cut Stump Treatment”. This method employs both a mechanical and chemical means of control. We used hand saws and loppers to cut plant stems as close to the ground as practical. The exposed stumps were brushed to remove sawdust, then treated with an herbicide to kill the roots. The cut stems were piled up outside the wooded area to be taken away later and composted. Composting is an option because the stems contain no seeds at this time of the year.
Most of the Glossy Ligustrum fell into the large stem category, and we marked these plants with plastic flagging. Park personnel are to return later with chain saws to cut down these plants, treat the stumps with herbicide, remove the cut stems from the wooded area, and haul them away.
This effort by the Conservation Club and Moncus Park personnel was a good start to address the invasive plant problem in the park. This initial effort, however, focused only on a relatively small part of the wooded area of the park due to personnel and budgetary limitations. It’s important to understand that to control invasive plants successfully, the entire 23-acre wooded area of the park would need to be managed for invasive plant species. Furthermore, following the initial treatment of this 23-acre area, the entire area would have to be periodically revisited to remove any seedlings derived from seeds already in the soil or that birds deposit in the area after having fed on seeds in nearby areas infested with invasive plants. The control and management of invasive species is a long-term process that may require years of work, but the amount of work required should gradually diminish each year as the invasive plant populations in the park are reduced. Planting native plants in the area may help to heal the wooded area damaged by invasive plant infestations and speed up the recovery process.