Differential response of community biomass temporal- and spatial- stabilities to nitrogen addition in an alpine meadow on the Tibetan Plateau

The concept of community stability encompasses two independent aspects, including both temporal and spatial dimensions. While considerable progress has been made in understanding temporal stability at the community level (referred to as α temporal stability), along with its interplay with temporal stability at smaller scales and the broader scales of β and γ temporal stability, there remains a notable gap in our understanding of spatial stability at the community level (referred to as α spatial stability) and its relationships with spatial stability and asynchrony at smaller species scales. Drawing on five years of data from a nitrogen addition experiment conducted in an alpine meadow on the Tibetan Plateau, we examine the impacts of nitrogen addition on both temporal and spatial stabilities of community biomass, considering species richness, asynchrony and stability of all species, dominant, and other non-dominant species. Our findings demonstrate that nitrogen addition impacts the temporal and spatial stabilities of community biomass in alpine meadow mainly through its influence on the temporal and spatial asynchrony of dominant species and on the temporal and spatial asynchrony at the overall species level. Furthermore, we indicate that in the high species richness alpine meadow on the Tibetan Plateau, temporal stability of community biomass increases rather than decreases in response to nitrogen addition as species richness declines, while spatial stability of community biomass remains unchanged. Our study offers a comprehensive perspective for theoreticians, empiricists, and policymakers, highlighting the importance of integrating the multidimensional nature of ecological stability into research, policy development, and decision-making processes in the face of global change.