Pollinator Interactions with Yellow Starthistle (Centaurea solstitialis) across Urban, Agricultural, and Natural Landscapes
نویسندگان
چکیده
Pollinator-plant relationships are found to be particularly vulnerable to land use change. Yet despite extensive research in agricultural and natural systems, less attention has focused on these interactions in neighboring urban areas and its impact on pollination services. We investigated pollinator-plant interactions in a peri-urban landscape on the outskirts of the San Francisco Bay Area, California, where urban, agricultural, and natural land use types interface. We made standardized observations of floral visitation and measured seed set of yellow starthistle (Centaurea solstitialis), a common grassland invasive, to test the hypotheses that increasing urbanization decreases 1) rates of bee visitation, 2) viable seed set, and 3) the efficiency of pollination (relationship between bee visitation and seed set). We unexpectedly found that bee visitation was highest in urban and agricultural land use contexts, but in contrast, seed set rates in these human-altered landscapes were lower than in natural sites. An explanation for the discrepancy between floral visitation and seed set is that higher plant diversity in urban and agricultural areas, as a result of more introduced species, decreases pollinator efficiency. If these patterns are consistent across other plant species, the novel plant communities created in these managed landscapes and the generalist bee species that are favored by human-altered environments will reduce pollination services.
منابع مشابه
Practical Challenges in Private Stewardship of Rangeland Ecosystems: Yellow Starthistle Control in Sierra Nevadan Foothills
Private landowners are often de facto stewards of biodiversity and ecosystem services. In California’s Sierra Nevada foothills, ranchers frequently present the only defense against biological invasions in private rangelands. Although ranchers’ land management goals (e.g., the desire to control invasive species) can be consistent with ecosystem protection, practical constraints often limit their...
متن کاملA Structural Growth Model of the Invasive Weed Species Yellow Starthistle, Centaurea solstitialis L
Yellow starthistle (Centaurea solstitialis L.) is a summer-flowering annual plant of the family Asteraceae, and a significant weed of roadsides, pasture and grasslands in California. It is also distributed, though with less economic and ecological significance, throughout the US and in other temperate parts of the world. Yellow starthistle grows vigorously during the dormant period for most nat...
متن کاملBiological Control of Yellow Starthistle (Centaurea solstitialis) in the Salmon River Canyon of Idaho
متن کامل
In situ volatile collection, analysis, and comparison of three Centaurea species and their relationship to biocontrol with herbivorous insects.
Centaurea solstitialis, commonly known as yellow starthistle, is an invasive plant listed as a noxious weed in the western areas of North America and is the target of classical biological control, which involves release of herbivores known to be specific to this plant. These insects often choose their host plant on the basis of the volatile organic compounds (VOCs) emitted. Accordingly, volatil...
متن کاملEstimating Yellow Starthistle (Centaurea solstitialis) Leaf Area Index and Aboveground Biomass with the Use of Hyperspectral Data
Hyperspectral remote-sensed data were obtained via a Compact Airborne Spectrographic Imager-II (CASI-II) and used to estimate leaf-area index (LAI) and aboveground biomass of a highly invasive weed species, yellow starthistle (YST). In parallel, 34 ground-based field plots were used to measure aboveground biomass and LAI to develop and validate hyperspectral-based models for estimating these me...
متن کامل