Document: JEN-3-63-21

Construction cost and plant invasibility: Comparing Purple Loosestrife (Lythrum salicaria) with its non-invasive neighbors along disturbed ponds.

NAGEL, J.M.* and K.L.GRIFFIN

Columbia University, Palisades, NY 10964 USA ¹

Abstract:
Successful plant invasions can alter dramatically both the community structure and processes of a variety of ecosystems, so identifying potential invasive plant species would be ecologically advantageous. While habitat disturbance is much cited as a trigger of plant invasions, not all plant species found within disturbed habitats are invasive. This indicates plant physiology must ultimately influence species invasibility. Many studies examining particular species growing in particular environments have produced situation-specific analyses of existing invasions. However, more general omnispecific physiological traits of invasive plants that could be used to evaluate the potential invasibility of any given species have not yet been identified. Due to the great interspecific variety of physiological structures and processes in plants, identifying such common traits seems impossible. Yet these various structures and processes are all commonly influenced by energy partitioning, allocation and content, making energy a viable means of making physiological comparisons between different plant species each with their own unique set of physiological structures and processes. Construction cost, a quantifiable measurement of the amount of energy invested by plants to construct their various morphological structures, can be indirectly related to plant resource-use efficiency. Given the increased competitive ability of invasive plants, we hypothesize invasive plants may require less energy to construct their structures than non-invasive plants, giving them a competitive growth advantage within their communities. By measuring ash content, organic nitrogen content and heat of combustion, we calculated leaf construction costs of purple loosestrife (Lythrum salicaria), a Eurasian emergent species spreading throughout temperate North America, with its five most abundant neighboring non-invasive species along the banks of three artificial ponds in southeastern New York. Correlations between high species abundance and low leaf construction costs were found, indicating the competitive success of purple loosestrife over its neighbors may be influenced by lower leaf construction costs.

Keywords: plant invasions, construction cost, purple loosestrife

This abstract is being presented at: 10:30 AM in session:
RESTORATION ECOLOGY AND INVASIONS