Invasive and Native Plants on Duke Farms

Eastern shadbush, Amelanchier Canadensis, a native fruiting shrub

As spring warms the air and soil at Duke Farms, the plant life on the property is greening and even beginning to bloom in some parts. The non-native plants that also call our region home can be generally broken up into two categories, non-native-non-invasive, and non-native-invasive. Non-invasive-non-native plants are in most cases plant species from Europe and Asia that have been deliberately planted but do not easily spread into the surrounding environment in our region. Plants like ginkgo trees, daffodils, Japanese tree lilacs, Norway spruce and European beech grow where they are planted, but otherwise do not invade the surrounding habitat and out-compete native plant species. However, many of these species that show a lesser tendency to grow and invade a habitat in our area can still be a major problem other parts of the USA and even NJ. A good example is Paulownia tomentosa, aka Princess tree; this tree was planted on the property in the eighties for specialty wood used in cabinetry, and while few survive to this day on our property this same species of tree is a major invader of the Palisades in Northeastern NJ and other mountainous regions of the USA.

Japanese Lilac Tree, Syringa reticulata, a non-native non-invasive tree that was planted in the landscape

The non-native plants that also call our region home can be generally broken up into two categories, non-native-non-invasive and non-native-invasive. Non-invasive-non-native plants are in most cases plant species from Europe and Asia that have been deliberately planted but do not easily spread into the surrounding environment in our region. Plants like ginkgo trees, daffodils, Japanese tree lilacs, Norway spruce and European beech grow where they are planted, but otherwise do not invade the surrounding habitat and outcompete native plant species. However, many of these species that show a lesser tendency to grow and invade a habitat in our area can still be a major problem other parts of the USA and even NJ. A good example is Paulownia tomentosa, aka Princess tree; this tree was planted on the property in the eighties for specialty wood used in cabinetry, and while few survive to this day on our property this same species of tree is a major invader of the Palisades in Northeastern NJ and other mountainous regions of the USA.

Callery Pear, Pyrus calleryana, a non-native invasive tree thats still in use in some areas as a landscape tree. Note the thorns Callery Pear, Pyrus calleryana, a non-native invasive tree thats still used by NJ landscapers despite being very invasive and prone to winter storm damage Managing the vegetation on the property is approached from a variety of directions; the most significant factor in allowing habitats to cope with the number of invasive plants has been managing deer on the property. Prior to fencing off the 650 core acres of property, deer in densities of 200+/sq mile would browse on native plants growing on the property while giving invasive plants a pass due to being less palatable. This non-stop selection of native plants for food gave non-native/invasive plants a strong competitive advantage in woodlands and meadows. By excluding deer from the property and managing the population to levels where native plants arent browsed out of existence, native flora have come back in many areas, especially in wooded areas. Even in areas of the property where no deer fence is erected, native plants have begun to grow back in areas previously devoid of native vegetation.

comparison of native vegetation growing in area protected from overabundant deer (on right) and areas exposed to overabundant deer The battle between native and invasive plants is an ongoing process here at Duke Farms and while complete eradication of established invasive plants is daunting, we can manage the ratios of native to invasive plants and help foster a healthier, more diverse habitat for wildlife to return to.

Spring beauty, Claytonia virginica, a native woodland wildflower that thrives in undisturbed forest understories. This flower relies on the presence of ants in the forest to help spread its seeds