title: Parthenium weed (Parthenium hysterophorus L.) and climate change: the effect of CO2concentration, temperature, and water deficit on growth and reproduction of two biotypes.
abstract: Climate change will have a considerable impact upon the processes that moderate weed invasion, in particular to that of parthenium weed (Parthenium hysterophorus L.). This study evaluated the performance of two Australian biotypes of parthenium weed under a range of environmental conditions including soil moisture (100 and 50% of field capacity), atmospheric carbon dioxide (CO2) concentration (390 and 550 ppm), and temperature (35/20 and 30/15 °C/day/night). Measurements were taken upon growth, reproductive output, seed biology (fill, viability and dormancy) and soil seed longevity. Parthenium weed growth and seed output were significantly increased under the elevated CO2concentration (550 ppm) and in the cooler (30/15 °C) and wetter (field capacity) conditions. However, elevated CO2concentration could not promote growth or seed output when the plants were grown under the warmer (35/20 °C) and wetter conditions. Warm temperatures accelerated the growth of parthenium weed, producing plants with greater height biomass but with a shorter life span. Warm temperatures also affected the reproductive output by promoting both seed production and fill, and promoting seed longevity. Dryer soil conditions (50% of field capacity) also promoted the reproductive output, but did not retain high seed fill or promote seed longevity. Therefore, the rising temperatures, the increased atmospheric CO2concentration and the longer periods of drought predicted under climate change scenarios are likely to substantially enhance the growth and reproductive output of these two Australian parthenium weed biotypes. This may facilitate the further invasion of this noxious weed in tropical and sub-tropical natural and agro-ecosystems.
authors.affiliation: School of Agriculture and Food Sciences, The University of Queensland, St Lucia, QLD, Australia.|Department of Ecology and Evolutionary Biology, University of Science, Ho Chi Minh City, Vietnam.
authors.forename: Thi
authors.initials: T
authors.lastname: Nguyen
authors.affiliation: School of Agriculture and Food Sciences, The University of Queensland, St Lucia, QLD, Australia. a.bajwa@uq.qdu.au.
authors.forename: Ali Ahsan
authors.initials: AA
authors.lastname: Bajwa
authors.affiliation: IVM Group Pty. Ltd., PO Box 545, Varsity Lakes, QLD, Australia.
authors.forename: Sheldon
authors.initials: S
authors.lastname: Navie
authors.affiliation: School of Agriculture and Food Sciences, The University of Queensland, St Lucia, QLD, Australia.
authors.forename: Chris
authors.initials: C
authors.lastname: O'Donnell
authors.affiliation: School of Agriculture and Food Sciences, The University of Queensland, St Lucia, QLD, Australia.
authors.forename: Steve
authors.initials: S
authors.lastname: Adkins
mesh_terms: D019659:Asteraceae / Q000187:drug effects; D001315:Australia; D002245:Carbon Dioxide / Q000494:pharmacology; D057231:Climate Change; D013696:Temperature; D014867:Water
chemical_list: D014867:Water; D002245:Carbon Dioxide
keywords: Carbon dioxide; Climate change; Longevity; Parthenium weed; Reproductive capacity; Weed science