**Abstract:** This study explores the relationship between conspecific spatial aggregation and abundance in forests across different latitudes, aiming to understand the mechanisms that contribute to species coexistence. Using data from 21 temperate, subtropical, and tropical forest plots in the CTFS-ForestGEO network, researchers found that species with lower abundance tend to be more aggregated than those with higher abundance. However, the nature of this relationship varies significantly with latitude. Tropical forests exhibit a weak negative relationship between aggregation and abundance, while temperate forests show a strong negative relationship. This latitudinal gradient in the aggregation–abundance relationship is closely linked to the prevalence of animal seed dispersal and mycorrhizal associations, with tropical forests dominated by arbuscular mycorrhizal (AM) species and temperate forests by ectomycorrhizal (EM) species. The study proposes that in tropical forests, animal seed dispersal leads to the formation of clusters away from conspecific adults, whereas in temperate forests, clusters form close to adults due to the protective effects of EM associations. The researchers developed a mathematical model to integrate these spatial patterns and ecological processes, focusing on the impact of conspecific aggregation on the rare species advantage required for coexistence. The model considers the survival of individual trees as influenced by local tree density, through competition for resources or predation by pathogens, and reproduction as density-independent. By incorporating the observed spatial patterns into the model, the study demonstrates that spatial patterns have a stabilizing effect on species coexistence, challenging the notion that spatial structures alone cannot promote coexistence. The analysis reveals that both tropical and temperate forests satisfy the spatial invasion criterion required for coexistence, but they do so through different mechanisms. Tropical forests, with their weaker negative aggregation–abundance relationships, can have higher risk factors, while temperate forests, with stronger negative relationships, have lower risk factors. This balance suggests that the ability of rare species to invade and persist is influenced by the interplay between aggregation, abundance, and niche differences. The study also investigates the effects of niche differences and a small constant immigration rate on the per capita population growth rate. Niche differences, approximated by phylogenetic dissimilarity, and immigration both enhance the rare species advantage, but their effects diminish as species abundance increases. The researchers conclude that an integrated understanding of the forces shaping forest diversity and composition, including seed dispersal, mycorrhizal associations, and spatial patterns, is essential for advancing ecological theory and predicting species coexistence dynamics. **Key Events and Elements:** - **Research Focus:** Investigating the relationship between conspecific spatial aggregation and abundance in forests across latitudes. - **Data Source:** 21 forest plots from the CTFS-ForestGEO network, ranging in latitude from 6° 40′ N to 48° 08′ N. - **Findings:** - Species with lower abundance tend to be more aggregated. - Tropical forests show a weak negative relationship between aggregation and abundance. - Temperate forests show a strong negative relationship. - The latitudinal gradient is linked to the prevalence of animal seed dispersal and mycorrhizal associations. - **Proposed Mechanisms:** - In tropical forests, animal seed dispersal leads to clusters forming away from conspecific adults. - In temperate forests, ectomycorrhizal associations facilitate clusters forming close to adults. - **Mathematical Model:** - Incorporates spatial patterns and ecological processes. - Demonstrates that spatial patterns have a stabilizing effect on species coexistence. - Challenges the assumption that spatial patterns alone cannot promote coexistence. - **Invasion Criterion:** - Both tropical and temperate forests satisfy the spatial invasion criterion. - Tropical forests can have higher risk factors due to weaker negative relationships. - Temperate forests have lower risk factors due to stronger negative relationships. - **Additional Factors:** - Niche differences and a small constant immigration rate enhance the rare species advantage. - These effects are more significant for less abundant species. - **Conclusion:** - An integrated approach considering seed dispersal, mycorrhizal associations, and spatial patterns is crucial for understanding forest diversity and composition. - The study highlights the need for new theories to account for the spatial context in coexistence dynamics.