Livestock grazing promotes ecosystem multifunctionality of a coastal salt marsh

Abstract

Livestock grazing is extensively practiced in grasslands worldwide (Bardgett & Wardle, 2010;Briske, 2017). Grazing exerts strong ecosystem-level impacts primarily by disturbing soil abiotic properties (e.g. soil moisture) and changing resource input from plants to the soil (such as quality and quantity of litter input and root ex-

The Nitrogen Removal Ability of Salt Marsh Improved After Grazing Prohibition

“…Nitrogen removal capacity potential is facilitated by grazing prohibition, probably through enhanced biomass production via increases in nutrient and carbon sources into the soil. In addition, previous studies on the ecosystem multifunctionality of salt marshes have mainly focused on the variables related to the operating rates of ecosystems but often ignored variables related to ecosystem services (Jing et al, 2015;Zhang et al, 2021). Therefore, it is necessary to integrate indicators related to ecosystem function and ecosystem services when conducting research on salt marsh ecosystem multifunctionality.…”

“…Although studies in grassland ecosystems had demonstrated that grazing prohibition could have a significant effect on the nitrogen cycle through changes in soil physicochemical properties (Li et al, 2021a), microbial community composition (Song et al, 2019) and soil nutrient content (Walker et al, 2009 ;, and some of these effects are positive and some are negative. However, salt marshes have distinct environmental characteristics that vary from those of terrestrial grasslands, such as high salinity, low redox potential, and the occurrence of periodic tidal inundation (Zhang et al, 2021 ;Martin and Reddy, 1997). These discrepancies may result in different responses of salt marshes to grazing prohibition, and the regulator of grazing prohibition impacts may differ between these ecosystems.…”

Different effects of grazing and nitrogen addition on ecosystem multifunctionality are driven by changes in plant resource stoichiometry in a typical steppe

“…Grassland ecosystems typically experience defoliation and eutrophication simultaneously due to the accumulation of herbivore excrement and atmospheric nitrogen (N) deposition (Stevens 2019;Borer et al 2020). Growing evidence suggests that anthropogenic N input and the effects of herbivores together are altering global grassland ecosystem processes and functions, including productivity and biodiversity stability, and biogeochemical cycles (Cui et al 2020;Zhang et al 2021a;Zheng et al 2021). So far, insufficient field evidence supports the interactive effects of grazing and N enrichment on multiple ecosystem functions (multifunctionality, EMF) in grasslands.…”

“…Biodiversity loss caused by herbivores or N enrichment can interfere or even decrease multiple ecosystem functions (Allan et al 2015) by two mechanisms, i.e., directly loss of species functions and indirectly decline of resource utilization efficiency (Dib et al 2020;Zhang et al 2021aZhang et al , b, 2022. Plant species diversity and aboveground biomass are usually promoted at a moderate stocking rate due to reduced resource contention and increased plant compensatory growth, but they may decrease at a high stocking rate because of the aggravating resource limitation (i.e., nutrient availability) (Ren et al 2018).…”

“…Grazing and N enrichment usually have either similar or converse effects on ecosystem structure and functions. For example, moderate stocking rate and N enrichment may increase soil N availability and plant N concentration (Li et al 2019;Liu et al 2020;Yang et al 2018;Zhang et al 2021a). Plant productivity generally increases with the increase in N addition rate (Liu et al 2021;Zheng et al 2021), but decreases with the increase in stocking rate (Zhang et al 2022).…”