Influences of climate variability on the initial stages of pine invasion: Searching tools for cost/effective management strategies in Patagonia

IGLESIAS, A; NUÑEZ, M; PARITSIS, J

Dublin

Conferencia; 10th International Conference on Biological Invasions; 2018

Pines are one of the biggest invasive plant management problemsin the world. Limited resources are available to control for pineinvasions in northwestern Patagonia where escaped individualsfrom plantations are steadily increasing. Thus, there is urgentneed to implement cost/effective pine management measuresin this region where invasions are still controllable. Furthermore,climate change projections for the area suggest warmer anddrier conditions that may affect pine establishment altering theinvasion process. Our primary objective was to evaluate responses(germination and survival) of pines (Pinus ponderosa and P.contorta) to altered temperature and precipitation in a climatechange context. We conducted a manipulative experiment plantingseeds and 3-year-old seedlings in the field. We implemented afull factorial experimental design with pines growing in warmed(Open Top Chamber), watered, warmed and watered, andcontrol treatments. Water addition had a negative effect on seedgermination of both species, and P. ponderosa presented lessgermination than P. contorta. The survival of the germinants wasnot significantly affected by climatic variables, and P. ponderosahad mayor survival than P. contorta in all treatments. Temperaturehad a negative effect on the survival of P. contorta seedlings buthad no significant effect on the survival of P. ponderosa. Finally, P.contorta seedlings exhibited a higher mortality in all treatmentscompared to P. ponderosa. Our findings suggest that climatevariability may be used as a predictive tool for successful pineestablishment forecasting but that is key to consider speciesidentity and ontogenetic stage. This may optimize early controlmeasures by focusing control actions on favourable climatic yearsfor pine establishment. More research is needed; however, to refineclimate effects on pine establishment and evaluate the influencesof other critical factors, such as masting and seed predation.