Linking Changes to Intraspecific Trait Diversity to Community Functional Diversity and Biomass in Response to Snow and Nitrogen Addition Within an Inner Mongolian Grassland

Abstract

In recent years, both the intraspecific and interspecific functional diversity (FD) of plant communities have been studied with new approaches to improve an understanding about the mechanisms underlying plant species coexistence. Yet, little is known about how global change drivers will impact intraspecific FD and trait overlap among species, and in particular how this may scale to impacts on community level FD and ecosystem functioning. To address this uncertainty, we assessed the direct and indirect responses of specific leaf area (SLA) among both dominant annual and subordinate perennial species to the independent and interactive effects of nitrogen and snow addition within the Inner Mongnolian steppe. More specifically, we investigated the consequences for these responses on plant community FD, trait overlap and biomass. Nitrogen addition increased the biomass of the dominant annual species and as a result increased total community biomass. This occurred despite concurrent decreases in the biomass of subordinate perennial species. Nitrogen addition also increased intraspecific FD and trait overlap of both annual species and perennial species, and consequently increased the degree of trait overlap in SLA at the community level. However, snow addition did not significantly impact intraspecific FD and trait overlap of SLA for perennial species, but increased intraspecific FD and trait overlap of annual species, of which scaled to changes in community level FD. We found that the responses of the dominant annual species to nitrogen and snow additions were generally more sensitive than the subordinate perennial species within the inner Mongolian grassland communities of our study. As a consequence of this sensitivity, the responses of the dominant species largely drove impacts to community FD, trait overlap and community biomass. In total, our study demonstrates that the responses of dominant species in a community to environmental change may drive the initial trajectories of change to community FD and functioning.

Intraspecific trait variation drives grassland species richness and productivity under changing precipitation

“…2014, Mao et al. 2017). Generally, external filtering involves assembly processes that operate at a larger spatial scale including climate and soil conditions, and tends to select species with similar functional traits in similar habits, which leads to community traits converging into a small range (Laughlin et al.…”

“…Various abiotic (such as environmental conditions) and biotic (such as competition and parasitism) factors can induce intraspecific variation, which provides the rough material for natural selection by filtering processes (Violle et al 2012, Abakumova et al 2016. Therefore, in a given community, a group of species is the result of external and internal filtering on community traits variation (Chesson 2000, Violle et al 2012, Jung et al 2014, Mao et al 2017. Generally, external filtering involves assembly processes that operate at a larger spatial scale including climate and soil conditions, and tends to select species with similar functional traits in similar habits, which leads to community traits converging into a small range (Laughlin et al 2012, Kraft et al 2015) (Fig.…”

Effect of Nutrient Addition on the Productivity and Species Richness of Grassland Along With an Elevational Gradient in Tajikistan

“…Increase in nitrogen is known to significantly increase the above-ground biomass (AGB) and reduce the species diversity (Zhao et al, 2019;Gao et al, 2021). However, some studies have shown that although nitrogen addition reduced the species diversity, it increased the functional richness (Niu et al, 2014;Mao et al, 2017). Enrichment with phosphorus fertilizer has been shown to have either increased or no effect on ecosystem productivity and species diversity (Menge and Field, 2007;Gao et al, 2021).…”

Effects of nitrogen addition on plant-soil-microbe stoichiometry characteristics of different functional group species in Bothriochloa ischemum community

“…However, excessive N input increases the risk of soil acidification and nutrient leaching, causing a series of ecological problems, such as reduced productivity, species diversity loss, and ecosystem degradation (Wei et al, 2013). The responses of functional groups to environmental changes often vary due to their different functional traits and species characteristics (Mao et al, 2017). Studies have illustrated that N addition exerts opposite effects on the underground biomass of gramineous herbs and forbs (Song et al, 2012).…”