Introduction
Temporal changes in community composition are a facet of biodiversity change and are referred to as temporal beta diversity (Hatosy et al., 2013; Baselga, Bonthoux, & Balent, 2015; Legendre, 2019). Recently, the focus of temporal beta-diversity studies has expanded to multiple sites and a large spatial scale, that is, to macroecological contexts (Brice, Cazelles, Legendre, & Fortin, 2019; Gotelli et al., 2022). Macroecological patterns of temporal beta diversity have gained increasing attention during the ongoing biodiversity crisis resulting from various anthropogenic disturbances and climate change impacts (Dornelas et al., 2014; Brice et al., 2019; Magurran, Dornelas, Moyes, & Henderson, 2019). Although the use of beta-diversity indices in temporal beta-diversity studies is generally identical to that in spatial beta-diversity studies, no one has seriously studied how temporal beta diversity differs from spatial beta diversity. Therefore, so far, temporal beta-diversity studies have been conducted based on various uncertain assumptions dependent on spatial knowledge. This lack of basic knowledge about temporal beta diversity could lead to inaccurate assessments of biodiversity changes. Thus, revealing the basic properties of temporal beta-diversity patterns is an urgent issue.
The unified neutral theory proposed by Hubbell (2001) demonstrated that various types of common biodiversity patterns (e.g. species abundance distribution) are reproduced under both ecological neutrality and zero-sum assumptions (Rosindell, Hubbell, & Etienne, 2011; Shinohara, Nakadai, Suzuki, & Terui, 2023). The neutral model would provide valuable base knowledge under the simplest conditions as a starting point (Rosindell et al. 2011; Rosindell, Hubbell, He, Harmon, & Etienne, 2012; Takeuchi, Ohtsuki, & Innan, 2022). The dynamics under a neutral model (i.e. neutral dynamics) would provide basic knowledge regarding temporal beta-diversity studies just as they have provided so far for other biodiversity patterns. Rosindell et al. (2011) argued that studying dynamics under a neutral model is a future challenge. Several previous studies (Dornelas et al., 2014; Sgardeli, Zografou, & Halley, 2016) related to temporal beta diversity have used predictions under neutral dynamics as a baseline to quantify targeted factors (i.e. climate change impacts). However, the effect of each parameter on the general temporal beta-diversity pattern under neutral dynamics remains unexplored. The present study aimed to reveal the basic properties of temporal beta-diversity patterns under neutral dynamics and identify their differences from those of spatial beta-diversity patterns. Specifically, the parameter dependency of four variables, viz., fundamental biodiversity number, local community size, mortality rate, and immigration rate, were examined.