I love the woods. I was born and raised in Vermont and Connecticut where the woods were my play ground. As the population around America increases it has become necessary to set aside natural areas to preserve native plant and animal communities. Tract K, which was set aside as a school property, is now being considered for a park. If properly managed and planted it could become a large natural area. There is also another passive park area along Winterberry Drive which now has a few trees planted with some lovely native flowers along a winding shell walkway to take you through the area. With some well placed under story plants, this could become another native habitat for Marco Island wildlife. There are other areas which could become Marco Island natural areas for local wildlife. Two communities, Key Marco and Hideaway Beach, have set aside large areas which are to remain in their natural state. Both communities have problems with invasive exotics which are causing harm to the native plants meant to be protected and preserved. These special areas should shelter and provide habitat for our dwindling wildlife population but may not be able to if the invasive exotics take over.
You must manage natural areas to control these invasive species and minimize damage to native vegetation and soil. It takes time and caution to clear these natural areas of invasive species. Current methods being used to manage these nonnative plants include manual removal, mechanical removal, physical controls, herbicides and biological control. Each control can be used independently or in combination with one another.
The spread of invasive vegetation can be reduced by educating the public and local government on the identity and control of these invasive plants. It is the responsibility of those who are aware of the problems caused by invasive nonnative plants to educate others about their impact and control to prevent further ecological damage of natural ecosystems. I hope this column helps.
Integrated Pest Management is an important tool for control involving the introduction of reproducing foreign insects or diseases as biological controls for natural areas. However, their development can take years and cannot be expected to solve all the problems.
Manual removal is time consuming and costly but is often a major component of invasive plant control. Seedlings should be repeatedly pulled from the ground as tenacious roots continue to sprout.
Mechanical removal involves the use of bulldozers or other special equipment. This method can disturb the soil creating conditions for re-growth of the invasive species. This method should not be considered in natural areas where non target vegetation could be damaged by the use of the equipment.
Fire is a normal part of Florida’s ecosystem. Many native specimens have evolved with varying degrees of fire tolerance. The suppression of fire alters historical plant communities by encouraging less fire tolerant species. This lack of maintenance around the country is one of the reasons we are experiencing so many out of control wild fires. Closer to home our many hurricanes over the last decade downed many trees in our local natural areas that have not been removed. These downed trees and under story plants are now drying out and becoming a fuel load for local wild fires. We all need to be extra vigilant with cigarettes, parking in tall grass, barbecues and any other potential source of fire when near any of these natural areas.
The invasion of trees and plants by exotic vines and other climbing plants can often result in the suffocation and death of mature trees and plants. They also increase the danger of canopy fires and the resulting death of more mature trees.
Reestablishment of natural plant species by planting native plants in areas of nonnative species removal can be an effective, though expensive, way to reduce the re-invasion of exotic species. If plant material is introduced to the natural habitat, screening for unwanted pests, plant or animal, should occur. Also, the establishment phase of newly planted natives can affect the management practices of a natural area. When you disturb the soil to plant or add temporary irrigation to water new plants you create an invasive plant management technique into a native area. Little is known about natural areas tolerance to these intrusive practices. It is always best to allow these areas ample time to regenerate naturally.
Herbicide uses have been approved by the Environmental Protection Agency for use in natural areas. These approved chemicals are for specific sites, i.e., crops, terrestrial non-crop or aquatic sites. The herbicides recommended for invasive plant control are systemic. They are absorbed by foliage, roots or bark. It is very important to choose and properly use the correct herbicide so as not to harm non target plants near by which may be more sensitive to the herbicide.
Following are three examples of severely damaging invasive plants in our area.
Air potato ( Dioscorea bulbifera) – Air potato is a vine which can quickly engulf native vegetation in natural areas, climbing high into mature tree canopies. It produces bulbils, which help it spread and make it extremely difficult to eliminate because new plants sprout from every bulbil. When the vines are growing up into trees, the vines should be cut and destroyed. Herbicide applications and removal of as many bulbils as possible must occur to prevent the spread of the vines into new areas. It can require successive years of follow up maintenance to bring this invasive plant under control in native areas.
Brazilian pepper (schinus terebinthifolius) – Brazilian pepper is a small shrub-like tree at 15 to 30 feet high which aggressively invades Florida’s disturbed habitats, hammocks, pine lands, mangrove forests and canal banks Florida. Their bright red seeds are dispersed by racoons, opossums and birds. Brazilian pepper forms a dense forest that shades out all other plant life and provides poor habitat for wildlife populations. This small tree can spread, kill and destroy natural areas near by and should be encouraged to be removed where ever it is found.
Australian-pine (Casuarina equisetifolia L.) – This tall, fast growing pine was introduced to Florida in the late 1800’s as windbreaks and shade trees. Seeds germinate easily and it spreads rapidly. Its rapid growth, dense shade, dense litter accumulation and other competitive advantages make it extremely destructive to native vegetation. It encourages beach erosion by displacing deep rooted natives like sea oats and interferes with nesting sea turtles and the American crocodile. It is sensitive to fire, loses branches easily and topples easily in high winds. It produces compounds in the soil that inhibits growth of other plants much like the Brazilian pepper.
Invasive plants are a problem as big as the invasive animals that have been in the news lately. Learn to identify them and remove them before they can spread.