Herb layer species abundance distribution patterns in different seasons in an old-growth temperate forest in Changbai Mountain, China

Abstract

The herbaceous layer is an important component of forest ecosystems and plays an important role in maintaining forest biodiversity. To understand the mechanisms shaping the forest herb community patterns over multiple growing seasons, we used herbaceous data collected in a 25 ha broad-leaved Korean pine (Pinus koraiensis) mixed forest plot in Changbai Mountain, Northeast China and fitted species abundance distributions (SADs) using different models. We used both pure statistical models including log-normal, log-series, and mechanistic models, including two niche models (broken-stick and niche preemption) and two neutral models (metacommunity zero-sum multinomial distribution and Volkov model). Further, we applied the AIC and Kolmogorov-Smirnov tests to compare the goodness-of-fit of these models. Our results showed: (1) The observed SADs of the herb layer varied by season. While there were similar proportions of rare and common species in spring, there were more species with moderate abundances in summer and more rare species in autumn. (2) The best-fitting models of SADs were similar in different seasons. In our analyses, the log-series model was the best pure statistical model across the three seasons. For the mechanistic models, neutral models •森林动态监测样地专题•

Responses of species abundance distribution patterns to spatial scaling in subtropical secondary forests

“…For example, niche models were suitable for explaining the distribution mechanisms in a Pinus tabulaeformis forest, but the neutral model failed to explain any vegetation layer, though it was suitable for explaining either northern broad‐leaved or conifer and broad‐leaved mixed forest communities (Gao, Bi, & Yan, ). Other research suggests the random process of the neutral model at different successional stage of conifer and broad‐leaved mixed forest communities is the main ecological driver determining their SADs patterns at moderate and large sampling scales, and that SADs patterns can vary over growing seasons for the herb layer, for which neutral models performed better than niche models in the broad‐leaved Korean pine mixed communities of north temperate forests of the Changbai Mountains (Yan, Zhang, & Zhao, ; Zhang et al, ). Accordingly, every vegetation community may be located at some point along this continuum based on the relative contributions of niche and neutral processes to its composition (Bar‐Massada et al, ).…”

The Relative Importance of Niche Process and Neutral Process in the Community Assembly of Subtropical Karst Forest: A Perspective on the Changes of Species Distribution Patterns at Different Scales

“…where α represents the species diversity of the community, which is similar to the concept of species richness (McGill, 2010). X is a constant (0 <X ≤ 1), related to the size of the community (Zhang et al, 2015).…”

“…The niche preemption model assumes that the most dominant species in the community first occupies k shares of the total niche, and the subdominant species occupies the remaining k shares, namely k(1-k), and so on, until the remaining resources can no longer sustain a species (Motonura, 1932;Cheng et al, 2011;Zhang et al, 2015). This model guarantees that dominant species have priority in the use of resources, and all species clearly form a hierarchy in niche occupation.…”