Conference Agenda

Understanding the mechanisms shaping species distributions is crucial for deciphering biodiversity patterns. While correlative models like ecological niche models (ENM) and species distribution models (SDM) have been valuable in predicting potential distributions across various scales, process-explicit models offer a more nuanced understanding of distribution causes, abundance predictions, and dispersal dynamics. These models vary in algorithmic nature and input data requirements. I will discuss the distinctions between correlative and process-explicit models, illustrating with a case study on the invasive ambrosia beetle Xyleborus glabratus, a vector of Raffaelea lauricola causing laurel wilt disease in the southeastern USA. Facing challenges due to lack of demographic data, we developed a process-explicit model in the lab. Our simulations align spatio-temporally with known invasion dynamics and provide superior dispersal estimates compared to correlative approaches. Predictions highlight Mexico's favorable conditions for beetle establishment, particularly in the central west. These findings have implications for agricultural, forestry, and economic decision-making, emphasizing the value of multidisciplinary approaches. I will discuss process-explicit model advantages and limitations, encouraging further exploration in diverse research contexts.

The extraordinary species richness and endemism of the Indo-Australian Archipelago exists in one of the most geologically dynamic regions of the planet. Application of the biogeographic history and developed processes-based approaches has stimulated an increasing biogeographic work for aboveground animals and plants in this region. But it is basically unknown how the degree of biogeographic isolation may lead to differences in belowground biodiversity. Here, we used geographic distance and beta diversity partitioning to analyze the influence of biogeographic isolation on soil oribatid mite assemblages in eleven regions in the Indo-Australian Archipelago. On average, oribatid mite richness in the eleven regions showed pronounced endemism. The soil oribatid mites’ zoogeographic distribution pattern changed gradually from the west and east sides to the central regions, consisted with the combination of Weber’s line, Lydekker’s line and Holt’s line. That dissimilarity pattern, in which species turnover was the most critical driving process, was closely correlated with geographic distance, underlining the importance of biogeographic isolation in soil animal biogeography. Our results, for the first time, elucidate the processes-based soil biodiversity patterns in the Indo-Australian Archipelago and emphasize how long-lasting vicariance structure divergent diversity in this biodiversity hotspot region.

Environmental filtering processes are revealed by trait variation in communities, with the community-weighted mean (CWM) being a common metric to indicate optimal adaptive strategy of taxa and directionality of filtering processes. Proximity to CWM indicates of higher fitness, and deviations from this optimal value result in changes in relative abundances of coexisting species. We investigated patterns of intraspecific trait variation in four coexisting carrion beetle (Silphidae) species across elevational gradients in temperate forest ecosystems with distinct natural vegetation zones ranging from 950 m to 1700 m a.s.l.. For seven of the 12 traits, most of the variation was attributed to intraspecific variation. Niche breadth was positively correlated with relative species abundance for most traits. In addition, CWMs of traits associated with long-distance dispersal decreased with elevation, while those associated with microhabitat use showed opposite trends. Soil temperature influenced tibia length after controlling for species identity effects. Nicrophorus quadripunctatus and N. tenuipes supported the CWM-optimality hypothesis for body width and thorax width, while N. maculifrons and N. vespilloides showed an opposite pattern for body width and thorax length. Our study suggests that some functional traits are highly variable, which is likely to help carrion beetles adapt across elevations and vegetation types.