Planktonic foraminifera constitute a core component of marine plankton communities and play a vital role in the global carbon cycle. With a worldwide distribution, extreme sensitivity to environmental fluctuations, and calcareous shells capable of exceptional preservation across geological timescales, they serve as ideal proxy organisms for reconstructing how marine ecosystems respond to climate change.Previous research has mostly centered on individual dominant species or adopted low-resolution, morphology-driven global distribution analyses. Few studies have adopted high-resolution observation frameworks to systematically research global distribution patterns, key environmental drivers, and interspecific interactions within plankton assemblages from a functional group perspective.This work combines two major high-resolution datasets for analysis: (1) the FORCIS database, which contains dense, globally distributed sampling records documenting foraminiferal responses to climate; (2) satellite-derived high-resolution ocean environmental datasets at a 0.25° × 0.25° spatial grid from WOA23 and biogeochemical hindcast for global ocean, covering sea surface temperature (SST), sea surface salinity (SSS), nutrient concentrations, and mixed layer depth (MLD).
Using the merged multi-source dataset, we build species distribution models to systematically map the global biogeography of distinct functional groups and quantify impacts of diverse environmental variables on their spatial ranges, further disentangling their underlying response mechanisms. Additionally, this paper investigates ecological associations between major planktonic functional groups in marine food webs. Spinose carnivorous planktonic foraminifera rely primarily on copepods as food resources, whereas symbiont-bearing and herbivorous foraminifera depend heavily on diatoms for nutrition. We further analyze trophic linkages as well as potential competitive interactions between planktonic foraminifera and these two dominant plankton groups.By coupling global species occurrence records with satellite-based environmental predictors, this study forecasts future range shifts of foraminiferal functional groups under climate change. It is expected that this study will clarify the functional position of planktonic foraminifera in marine food webs, advance the understanding of inter-group competition mechanisms among plankton, establish a high-resolution data analysis paradigm applicable to marine ecological research, and offer theoretical support for subsequent studies.