As summer winds down and fall approaches, let’s focus on research projects completed by park rangers and naturalists with the help of other Iowa County Conservation Department staff.
As part of our efforts to conduct science-based research to support management decision-making by ICC staff in the natural landscape of our sites, this research project was designed to address a topic we often address: invasive species. Focused on removal.
…An alien species is known as a species that has invaded an area where it does not naturally occur, and its presence in an ecosystem has a greater ecological, economic, or human impact than its absence. Cause or ultimately cause harm.
In our case, we mainly deal with invasive plant species, the biggest culprits being Amurbush honeysuckle and autumn olive.
This research project will focus specifically on controlling yellowfin honeysuckle using three different removal techniques to determine which of the three techniques is most effective in reducing honeysuckle density in a given area. did.
The aim of the study was to compare physical control methods by brushing, chemical control methods by foliar spraying, and a combination of physical and chemical control methods by stump spraying. We will collect yellowfin honeysuckle from the forest environment of Iowa Lake Park and observe the rate of honeysuckle reduction after implementing each removal method to determine which method is most effective.
The hypothesis of this study was that the most effective eradication treatment for yellow-bellied honeysuckle from woodlands in Iowa Lake Park would be through stump removal.
This study…was conducted in a mid-oak-hickory-dominated forest area at Lake Iowa Park, just northwest of Lake Iowa Park Beach.
Here, nine square plots of 8 × 8 meters were created. These nine plots were then divided into three treatment groups, and each group consisted of three subsequent plots to reproduce the experiment.
Treatment groups were…randomly assigned to one of three eradication methods and labeled A, B, or C.
Treatment group A was designated as a foliar spray treatment group, using a herbicide designed to kill the target species and spraying it on the leaves or foliage of the plants.
Treatment group B was designated as a mowing treatment group in which the target species were cut using a forestry brushcutter and cut as low as possible to the ground.
Finally, treatment group C was designated as the stump treatment group. This group uses some type of cutting tool, such as a chainsaw, blade power saw, etc., to cleanly cut the target species at the base of the main stem. Next, apply the herbicide to the clean, fresh stump using an herbicide designed to kill the target species.
All honeysuckle stems were counted for each plot to obtain pre-treatment honeysuckle density measurements. After treatment, the resprouting of each stem was counted again to obtain the post-treatment density.
It is important to note that the post-processing density count resulted in two different density measurements. One dataset is called “resprouting” and counts whether previously treated stems resprouted (regardless of the number of stems that resprouted). The other dataset is called “Stems” and counts each new stem that grows from a previously processed stem. .
Because no resprouting was observed within the time allotted for completion of this research project, we were able to collect both data sets for all treatment methods except for the foliar spray treatment.
In this example, we could only collect data related to the number of previously treated sprouted stems, not the number of new stems that grew from previously treated stems.
Once the data was collected, the numbers were used to determine the rate of honeysuckle reduction for each treatment. The mean percentage of honeysuckle reduction by treatment group was used to compare effectiveness between eradication methods. Here are the results using both dataset collections:
From the results, we can conclude that our hypothesis was correct. From both datasets, the most effective eradication method was stump treatment. … Honeysuckle density decreased by an average of 83.7% in the shoot dataset and 73.7% in the stem dataset.
Not considered in this study are the numerous variables that can influence land managers’ management decisions.
Again, each of these processing methods has its own advantages and disadvantages, including access to equipment, site conditions, time, management objectives, individual/agency vision, and stakeholder best interests. It can be more or less effective depending on individual administrator variables. .
To expand on these findings and really understand what the most effective eradication methods for yellowtail honeysuckle are that best suit the goals of land managers, we need more information to find further solutions. research must be completed.
If you are interested in more information about this study, please email ghazenfabor@iowacounty.iowa.gov.
