Grazing-induced changes in plant species composition affect plant and soil properties of grassland mesocosms

Abstract

Grazing-induced floristic changes in plant communities may accelerate or reduce plant and soil processes through changes in litter quality. Here, we intended to elucidate if the joint action of live and senescing plant tissue of palatable and non-palatable species differentially influences soil processes and properties. We conducted a 1-year experiment with mesocosms from a subhumid grassland. Mesocosms were monocultures of palatable or non-palatable species and a multispecific control. Palatable species included a legume and annual and perennial grasses, whereas non-palatable species included a perennial grass and annual and perennial forbs. Palatable monocultures showed greater soil mineral nitrogen, soil bacterial diversity, and lower soil pH than nonpalatable monocultures. These differences were not accounted for by differences in plant biomass. The multispecific control treatment only exhibited greater shoot biomass than the monocultures, and lower root biomass than the palatable monocultures. Our results suggest that the whole (live + dead plant tissue) had a specific imprint on soil system even when variation was not very apparent in terms of plant biomass, and that this effect was associated with plant palatability to domestic large herbivores.

Grazing depresses soil carbon storage through changing plant biomass and composition in a Tibetan alpine meadow

“…There is a range of potential indirect mechanisms through which soil carbon may be affected by increased grazing (Bardgett and Wardle 2003, De Deyn et al 2008, Semmartin et al 2010. Firstly, in the present study both RAB (P < 0.001, n = 120; Figure 3a) and root biomass (P < 0.001, n = 120; Figure 3b) were found to have a significantly positive correlation with SOC storage over three years, which suggests that the decrease of SOC storage with increased grazing can be attributed to grazing-induced decreases in plant biomass.…”

“…Grazing directly influences soil carbon dynamics and turnover by removing biomass but also returning carbon in the form of dung and urine deposition; trampling may also have direct effects (Bardgett and Wardle 2003). Grazing can also indirectly influence soil carbon storage in several ways (Bardgett and Wardle 2003, De Deyn et al 2008, Semmartin et al 2010. First, herbivores regulate the quantities of resources that are returned to the soil through changing biomass allocation patterns Wardle 2003, De Deyn et al 2008).…”

“…First, herbivores regulate the quantities of resources that are returned to the soil through changing biomass allocation patterns Wardle 2003, De Deyn et al 2008). Second, herbivores could alter soil carbon storage through changes in plant species composition (Bardgett and Wardle et al 2003, De Deyn et al 2008, Semmartin et al 2010, which was demonstrated to influence litter quality and decomposability (Bardgett and Wardle 2003). Although the mechanisms of grazing impact on soil carbon storage were extensively studied in a wide range of ecosystems worldwide (Ingram et al 2008, Piňeiro et al 2010, few studies examined the linkage between SOC storage and grazing-induced vegetation changes in Tibet (Wu et al 2010).…”

Mehlich 3 extractant used for the evaluation of wheat-available phosphorus and zinc in calcareous soils

“…Grazing can directly influence soil C stock dynamics by removing plant biomass and returning C through dung and urine input (Deng et al 2014a). Additionally, grazing can indirectly influence soil C stock from two aspects (Semmartin et al 2010). Firstly, livestock changes plant biomass allocation patterns and thus regulate much resources that are returned to the soil (De Deyn et al 2008); secondly, livestock changes plant species composition and thus alters soil C stock (Semmartin et al 2010), which demonstrated to impact on litter quality and decomposability (Bardgett and Wardle 2003).…”

“…Additionally, grazing can indirectly influence soil C stock from two aspects (Semmartin et al 2010). Firstly, livestock changes plant biomass allocation patterns and thus regulate much resources that are returned to the soil (De Deyn et al 2008); secondly, livestock changes plant species composition and thus alters soil C stock (Semmartin et al 2010), which demonstrated to impact on litter quality and decomposability (Bardgett and Wardle 2003). Although mechanisms of the grazing effect on soil C stock were extensively studied in a wide range of ecosystems worldwide, little studies had examined the linkage between soil C stock and grazing-induced vegetation changes on the Loess Plateau.…”