Functional trait perspective on suitable habitat distribution of invasive plant species at a global scale

Abstract Plant invasion has been proved to threaten biodiversity conservation and ecosystem maintenance at a global scale. It is a challenge to project suitable habitat distributions of invasive plant species (IPS) for invasion risk assessment at large spatial scales. Interaction outcomes between native and invasive plant species are dependent as a function of trait context, which may contribute to suitable habitat distributions of IPS. Here, we explored the effect of functional trait context on suitable habitat distribution of invasive plant species at a global scale. The plant functional trait context was quantified based on the community mean values of specific leaf area, leaf nitrogen concentration, height, and woody density. Habitat suitability modeling was used to project suitable habitat distributions of IPS based on functional trait and abiotic (climate, soil, and human footprint) contexts. There were significant differences in contexts between functional traits and abiotic conditions for IPS across different biomes at a global scale. Community mean functional traits, particularly, height could contribute to habitat suitability of IPS. The functional trait context could have a large effect on the habitat suitability of IPS in Boreal forests/Taiga, Tropical and subtropical grasslands, savannas and shrublands, Tundra, Mediterranean forests, woodlands and scrub, and Mangroves. Functional trait context could affect suitable habitat distributions of IPS at a global scale, indicating that functional trait context should be used as the input for modeling habitat suitability of IPS. The study provided new insights into the application of habitat suitability modeling on plant invasion risk assessment

Machinery investment decision and off-farm employment in rural China

This paper investigates the linkages between farmers' machinery investment decision and off-farm employment in China. Both the theoretical model and the empirical results based on a survey of 453 households in Anhui Province indicate that agricultural labor input and small-size machinery investment are gross complements rahter tha substitutes when machinery service is available in the market. Consequently, farmers with small machinery are more likely to reduce their off-time employment time. --Small-size Machinery,Off-Farm employment,Complements,China