Foundation species across a latitudinal gradient in China

Abstract

Foundation species structure forest communities and ecosystems but are difficult to identify without long‐term observations or experiments. We used statistical criteria––outliers from size‐frequency distributions and scale‐dependent negative effects on alpha diversity and positive effects on beta diversity––to identify candidate foundation woody plant species in 12 large forest‐dynamics plots spanning 26 degrees of latitude in China. We used these data (1) to identify candidate foundation species in Chinese forests, (2) to test the hypothesis––based on observations of a midlatitude peak in functional trait diversity and high local species richness but few numerically dominant species in tropical forests––that foundation woody plant species are more frequent in temperate than tropical or boreal forests, and (3) to compare these results with data from the Americas to suggest candidate foundation genera in northern hemisphere forests. Using the most stringent criteria, only two species of Acer, the canopy tree Acer ukurunduense and the shrubby treelet Acer barbinerve, were identified in temperate plots as candidate foundation species. Using more relaxed criteria, we identified four times more candidate foundation species in temperate plots (including species of Acer, Pinus, Juglans, Padus, Tilia, Fraxinus, Prunus, Taxus, Ulmus, and Corlyus) than in (sub)tropical plots (the treelets or shrubs Aporosa yunnanensis, Ficus hispida, Brassaiopsis glomerulata, and Orophea laui). Species diversity of co‐occurring woody species was negatively associated with basal area of candidate foundation species more frequently at 5‐ and 10‐m spatial grains (scale) than at a 20‐m grain. Conversely, Bray‐Curtis dissimilarity was positively associated with basal area of candidate foundation species more frequently at 5‐m than at 10‐ or 20‐m grains. Both stringent and relaxed criteria supported the hypothesis that foundation species are more common in mid‐latitude temperate forests. Comparisons of candidate foundation species in Chinese and North American forests suggest that Acer be investigated further as a foundation tree genus.

Selective logging destabilizes the functioning and composition of forest ecosystems at multiple spatial scales

“…Investigating stability across spatial scales requires defining a local (α) scale and a larger (γ) spatial scale (Zhang et al 2019, Hautier et al 2020). In the study of forest ecosystems, different spatial grains are commonly used to define spatial scales (Chisholm et al 2013, Qiao et al 2021b, Reu et al 2022). In our study, each 10 × 10 m larger quadrat represents the larger (γ) spatial scale, and each of the four non‐overlapping 5 × 5 m local quadrats represents the local (α) spatial scale (Supporting information).…”

Insights into the tussock growth form with model–data fusion

“…Rhizomatous grass and sedge species often form clumps of individual tillers that result in the formation of tussocks (Wein, 1973; Oliva et al ., 2005; Lawrence & Zedler, 2011; Derner et al ., 2012). Tussock‐forming species are often considered ecosystem engineers or foundation species and influence a variety of ecosystem properties, including micro‐topography, soil moisture, soil carbon (C) accumulation, and species diversity (Crain & Bertness, 2005; Peach & Zedler, 2006; Benscoter & Vitt, 2008; Varty & Zedler, 2008; Eldridge et al ., 2010; Balke et al ., 2012; Elumeeva et al ., 2017; Qiao et al ., 2020). This is especially true in the Arctic, where tussock cottongrass ( Eriophorum vaginatum L.) forms elevated mounds of root necromass as a strategy to escape the poor growing conditions of waterlogged anoxic soils (Fig.…”

Trait Response to Nitrogen and Salinity in Rhizophora mangle Propagules and Variation by Maternal Family and Population of Origin

“…Further, foundation species modulate fluxes of nutrients and energy in their ecosystem (Ellison, 2019). Hence, these species disproportionately contribute to maintaining habitat integrity and ecosystem resilience (Bertness and Callaway, 1994;Keith et al, 2017;Ellison, 2019;Bertness, 2020;Qiao et al, 2021). Understanding how these species cope with challenges from anthropogenic impacts is key to preserving the ecosystems they create and define (Gedan et al, 2009(Gedan et al, , 2011Guo et al, 2021).…”