Mowing alters nitrogen effects on the community-level plant stoichiometry through shifting plant functional groups in a semi-arid grassland

Abstract

Land-use practices such as mowing and nitrogen (N) fertilization can have significant impacts on plant stoichiometry. However, the interactive effects of mowing and N fertilization on the community-level plant stoichiometry and the underlying processes are not well understood. We examined the impacts of mowing (once a year) and N fertilization (12 g N m−2 yr−1) on the community-level plant stoichiometry in a semi-arid grassland on the Loess Plateau. Results obtained showed that mowing alone had no effect on the community-level plant N or phosphorus (P) concentration. N fertilization alone significantly reduced the community-level plant P concentration, but did not affect the community-level plant N concentration, leading to an enhancement of plant N:P ratio. However, mowing altered the effects of N fertilization, leading to a higher plant N (and P) concentration than the fertilization-only plots. Also, mowing significantly reduced soil nitrate (NO3 −), but increased soil temperature, photosynthetic active radiation, plant diversity, richness and gross ecosystem productivity. In addition, mowing and N fertilization significantly affected plant community composition through shifting dominant plant functional groups (PFGs) (e.g. asteraceae, forbs and grass). Further, our structural equation modeling analysis showed that shifts in PFGs played an important role in regulating plant stoichiometry under mowing and N fertilization. Together, these results illustrate that effective management of mowing and N fertilization may induce changes in soil limiting nutrients and shifts in plant community composition, potentially altering plant N:P stoichiometry at the community level.

The two sides of resistance–resilience relationship in both aboveground and belowground communities in the Eurasian steppe

“…However, we suggest that mowing destabilizes the plant community by reducing both resistance and resilience to N. The reduced resistance may simply be related to the interaction between mowing and N addition. Since the improved plant growth through extra N inputs would be further accelerated by mowing due to the stimulation and regrowth of plant roots (Giese et al ., 2013; S. Li et al ., 2020). On the other side, persistent seed banks are an important indicator of high resilience (Ma et al ., 2019).…”

Integrating herbivore assemblages and woody plant cover in an African savanna to reveal how herbivores respond to ecosystem management

“…Alternatively, our observed pattern of low use in artificial grasslands may be linked with food availability and/or quality. The management approach of tree clearing and annual mowing reduces grass biomass (i.e., food availability) and could negatively influence the species composition of the herbaceous layer (i.e., food quality) [ 65 , 66 ], which may make these areas undesirable for grazing herbivores. Thus, it is likely that food availability and/or quality also plays a role in driving our observed patterns of low use in artificial grasslands.…”

Mulching in lowland hay meadows drives an adaptive convergence of above- and below-ground traits reducing plasticity and improving biomass: A possible tool for enhancing phytoremediation

“…However, for the same vegetation type and climatic conditions, the decomposition time of the organic matter is four weeks circa ( Moog et al., 2002 and references therein), indicating a lack of effects related to the litter accumulation. Finally, mulching reduces water evaporation and increases infiltration ( Gupta and Gupta, 1986 ), generally enhancing soil water conservation ( Jun et al., 2014 ; Li et al., 2020 ). These new ecological conditions characterizing the MU area, in our study may be related to optimal condition for the spread of competitive and invasive species such as Sorghum halepense ( Table 2 ; Dalle Fratte et al., 2019a ).…”