Distribution of non-native wetland plants is facilitated by urbanization and roads in the Chicago region

wetlands;halophytes;non-native species distribution;dissimilarity

Skultety, Dennis Phillip ; Matthews ; Jefferey W.

关键词: wetlands;    halophytes;    non-native species distribution;    dissimilarity;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/89107/SKULTETY-THESIS-2015.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Human modification of the landscape, including urbanization and road construction, has facilitated the spread and establishment of non-native plant species.Urban areas have often been introduction points for species and have a combination of factors making them susceptible to invasion; including reduced habitat area, loss of unique habitat types, and increased nutrient run-off. Roads facilitate the spread of non-native plant species by providing locally disturbed habitat and a corridor for propagule dispersal.I conducted two analyses to assess how changes in the environment through urbanization and road construction facilitate the distribution of non-native plant species.For these analyses I used species occurrence data from over 2000 wetlands within the Chicago region.In the first analysis I examined the influence of urbanization and roads on the occurrences of 15 non-native plant species.I found that species, or groups of species, responded differently to the effects of urbanization and roads.For example, occurrences of halophyte species were best predicted by road variables; halophytes were more commonly associated with major roads such as interstates and federal highways, road types that are likely to receive greater applications of de-icing salts.For the second analysis I examined non-native species composition and identified non-native-dominated community types; I then conducted a similarity-based analysis to show that these novel communities are repeated across the landscape in a predictable way.I evaluated the contribution of surrounding land cover, roads, and geographic distances among wetlands to the similarity of plant communities.Non-native species were found to be widespread across the region.I found that non-native species similarity was most strongly correlated with similarity of land cover within 100 m of wetlands.This analysis was repeated for identified community types.My findings that similar changes to the landscape have resulted in similar combinations of non-native species is evidence that anthropogenic drivers are creating novel habitats and ultimately novel community types.Together my analyses have implications for understanding and managing non-native plant species within urban areas.