PARENT SESSION
Oral Session 2 / Sesion Orales 2: Invasive Species / Invasivas
Moderated by: Mooney, Hal,
Thursday, January 12 / Jueves, 12 de Enero, 8:30 am - 12:30 pm, Salon Kabah, Level 1, Holiday Inn
The temporal effects of Ulex europaeus on soil properties, modeling impact of invasive species with respect to time, and possible consequences of soil property changes.
Scott, Bronwyn*,1, Reichard, Sarah1, 1 University of Washington, Seattle, WA, USA
ABSTRACT- Invasive plants contribute to biodiversity loss and cause extensive economic damage and costs. Understanding the ecological impacts of invaders and why they are capable of displacing other species and communities is a priority. Much emphasis has been placed on the effects of invasives on ecosystem, community and population levels at a single point in time. However, these plants can continue to have effects as they stay resident. Gorse (Ulex europaeus) is invasive in many parts of the world. This research examined gorse's ability to alter the soil properties, and was done on the Washington coast, where gorse is found growing on sand. In order to determine the age of gorse stands, the progression of invasion over time was assessed by counting annual rings in the stems. Invaded and univaded areas were compared, and gorse plants were selected randomly. From ring count, the gorse established in this area around 26 years ago. Significant linear regressions were found of soil properties over time, clearly showing that key soil properties, such as organic matter, pH and nitrogen had changed in a relatively short period of time. These unique results are part of the empirical evidence needed to treat modeling impact as a discrete, not a continuous event. In addition, invasive plant species management and ecosystem restorations are often considered together. Changes by invasive plants not only need to be taken into account for restoration, but often are difficult to reverse. In particular, build up of soil nitrogen can increase the likelihood of invasion, and the increase can linger for long periods of time. Some low nutrient systems are appreciably changed just from the presence of nitrogen, which makes it different for the native plants to thrive. With improvements in understanding invasion effects, better recommendations can be made for more precise prediction, assessment and management of invasives as well as improved recovery of ecosystem processes to facilitate easier restoration once invasives are removed.
SPANISH ABSTRACT- .