Multiple scale analysis of factors influencing the distribution of an invasive aquatic grass

• Published in: Biological invasions Vol. 11; no. 8; pp. 1903 - 1912
• Main Authors: Loo, Sarina E, Mac Nally, Ralph, O'Dowd, Dennis J, Thomson, James R, Lake, P. S
• Format: Journal Article
• Language: English
• Published: Dordrecht Dordrecht : Springer Netherlands 01-10-2009; Springer Netherlands; Springer Nature B.V
• Subjects: Aquatic ecology; Aquatic plants; aquatic weeds; Biomedical and Life Sciences; Carbon; climatic factors; continental scale; Decision making; Developmental Biology; ecological invasion; Ecological models; Ecology; Environmental effects; Environmental factors; freshwater; Freshwater & Marine Ecology; Freshwater environments; geographical distribution; Geology; Glyceria maxima; grass weeds; Grasses; hydrologic factors; Indigenous species; Introduced species; Invasions; Invasive species; Life Sciences; local scale; Mathematical models; Nitrogen; Nonnative species; Organic carbon; Organic phosphorus; Original Paper; Phosphorus; Plant populations; Plant Sciences; prediction; Regional analysis; Regional planning; regional scale; Riparian vegetation; Sampling; Soil; soil nutrients; Soils (organic); spatial distribution; spatial scale; Threatened species; Vegetation; Weeds; Australia; GARP; Biological invasion; Invasive species; Spatial scale; Aquatic weeds
• ISSN: 1387-3547; 1573-1464
• DOI: 10.1007/s10530-008-9368-1

With the expected increase in the spread of invasive species, examination of factors controlling distributions at multiple spatial scales and ecological modelling of their potential distributions are important analyses for informed decision-making. The scale-dependence of mechanisms influencing invasion by non-native species has been shown previously, indicating that studies of key factors affecting invasive species distributions at multiple spatial scales are critical for successful management. Freshwater systems are particularly vulnerable to invasive species, yet few studies have examined the environmental factors influencing distributions of invasive species at multiple spatial scales. We examined the effect of environmental variables on the predicted distribution of the invasive aquatic grass Glyceria maxima over continental, regional and local scales in Australia. We undertook an initial critical evaluation of which predictor variables were most appropriate to use at each scale, largely considering prior knowledge. On a continental scale, climatic, topographic and hydrological variables predicted well the potential distribution of G. maxima, identifying temperate regions as most susceptible to invasion. The regional analysis found that dense, woody, riparian vegetation has a strong negative impact on the occurrence of G. maxima, especially at intermediate elevations. The invasive grass was found less often on biotite granite and on fluvial geology. At a local scale, occurrence of G. maxima was related positively to soil phosphorus and nitrogen, and negatively related to soil organic carbon. The identification of key factors affecting invasive species distributions at multiple spatial scales will inform prevention schemes, assist targeted field sampling for the development of monitoring programs, and allow prioritization of control methods.