00569nas a2200157 4500008004100000245012900041210006900170300001400239490000700253100001800260700001700278700001900295700001700314700001900331856006100350 2019 eng d00aPhosphorus and mowing improve native alfalfa establishment, facilitating restoration of grassland productivity and diversity0 aPhosphorus and mowing improve native alfalfa establishment facil a647 - 6570 v301 aZhou, Jiqiong1 aWilson, G.T.1 aCobb, Adam, B.1 aYang, Gaowen1 aZhang, Yingjun uhttps://onlinelibrary.wiley.com/doi/abs/10.1002/ldr.325102146nas a2200217 4500008004100000245012800041210006900169300001400238490000700252520144500259100001601704700001701720700001701737700001901754700002801773700001701801700001901818700001901837700001701856856005501873 2018 eng d00aLong-term effects of grazing and topography on extra-radical hyphae of arbuscular mycorrhizal fungi in semi-arid grasslands0 aLongterm effects of grazing and topography on extraradical hypha a117 - 1270 v283 a

Grazing and topography have drastic effects on plant communities and soil properties. These effects are thought to influence arbuscular mycorrhizal (AM) fungi. However, the simultaneous impacts of grazing pressure (sheep ha-1) and topography on plant and soil factors and their relationship to the production of extra-radical AM hyphae are not well understood. Our 10-year study assessed relationships between grazing, plant species richness, aboveground plant productivity, soil nutrients, edaphic properties, and AM hyphal length density (HLD) in different topographic areas (flat or sloped). We found HLD linearly declined with increasing grazing pressure (1.5-9.0 sheep ha-1) in sloped areas, but HLD was greatest at moderate grazing pressure (4.5 sheep ha-1) in flat areas. Structural equation modeling indicates grazing reduces HLD by altering soil nutrient dynamics in sloped areas, but non-linearly influences HLD through plant community and edaphic changes in flat areas. Our findings highlight how topography influences key plant and soil factors, thus regulating the effects of grazing pressure on extra-radical hyphal production of AM fungi in grasslands. Understanding how grazing and topography influence AM fungi in semi-arid grasslands is vital, as globally, severe human population pressure and increasing demand for food aggravate the grazing intensity in grasslands.

1 aRen, Haiyan1 aGui, Weiyang1 aBai, Yongfei1 aStein, Claudia1 aRodrigues, Jorge, L. M.1 aWilson, G.T.1 aCobb, Adam, B.1 aZhang, Yingjun1 aYang, Gaowen uhttp://link.springer.com/10.1007/s00572-017-0812-x02177nas a2200241 4500008004100000245014500041210006900186300001200255490000800267520142800275100001701703700001601720700001301736700001901749700001901768700001701787700001401804700001301818700001401831700001801845700001701863856005501880 2018 eng d00aPlant functional group influences arbuscular mycorrhizal fungal abundance and hyphal contribution to soil CO2 efflux in temperate grasslands0 aPlant functional group influences arbuscular mycorrhizal fungal  a157-1700 v4323 a

Background and aims: Arbuscular mycorrhizal (AM) fungi are abundant in grassland ecosystem. We assessed AM hyphal contributions to soil CO2 efflux across plant functional groups to better quantify AM fungal influences on soil carbon dynamics.


Methods: We conducted a field experiment using in-growth mesocosms to partition soil CO2 efflux from roots, AM hyphae, and free-living soil microbes associated with C3 grasses, C4 grasses, forbs, and diverse plant communities from May to August in 2017.


Results: AM hyphae contributed <10% to total soil respiration in forb communities and diverse plant communities but accounted for as much as 32% in C3 grasses. Plant functional groups differed in hyphal production efficiencies (the ratio of AM hyphal length to aboveground biomass), with the lowest in C3 grasses (0.47?±?0.15 m g-1) and the greatest in forbs (3.27?±?0.55 m g-1). Mowing reduced hyphal production efficiency of C4 grasses and forbs but did not affect total soil respiration. AM hyphal and microbial respiration peaked at the middle of the growing season, however there was no significant seasonal variation in root respiration.


Conclusion: AM hyphal respiration is an important pathway of carbon flux from plants to atmosphere. Shifts in plant community composition can influence soil carbon processes by regulating hyphal production and respiration.

1 aGui, Weiyang1 aRen, Haiyan1 aLiu, Nan1 aZhang, Yingjun1 aCobb, Adam, B.1 aWilson, G.T.1 aSun, Xiao1 aHu, Jian1 aXiao, Yan1 aZhang, Fengge1 aYang, Gaowen uhttp://link.springer.com/10.1007/s11104-018-3789-002922nas a2200205 4500008004100000245012500041210006900166300000800235490000600243520225200249100001802501700001702519700001902536700001702555700001802572700001702590700001702607700001902624856007302643 2018 eng d00aTrichoderma biofertilizer links to altered soil chemistry, altered microbial communities, and improved grassland biomass0 aTrichoderma biofertilizer links to altered soil chemistry altere a8480 v93 a

In grasslands, forage and livestock production results in soil nutrient deficits as grasslands typically receive no nutrient inputs, leading to a loss of grassland biomass. The application of mature compost has been shown to effectively increase grassland nutrient availability. However, research on fertilization regime influence and potential microbial ecological regulation mechanisms are rarely conducted in grassland soil. We conducted a two-year experiment in meadow steppe grasslands, focusing on above- and belowground consequences of organic or Trichoderma biofertilizer applications and potential soil microbial ecological mechanisms underlying soil chemistry and microbial community responses. Grassland biomass significantly (p = 0.019) increased following amendment with 9,000 kg ha−1 of Trichoderma biofertilizer (composted cattle manure + inoculum) compared with other assessed organic or biofertilizer rates, except for BOF3000 (fertilized with 3,000 kg ha−1 biofertilizer). This rate of Trichoderma biofertilizer treatment increased soil antifungal compounds that may suppress pathogenic fungi, potentially partially responsible for improved grassland biomass. Nonmetric multidimensional scaling (NMDS) revealed soil chemistry and fungal communities were all separated by different fertilization regime. Trichoderma biofertilizer (9,000 kg ha−1) increased relative abundances of Archaeorhizomyces and Trichoderma while decreasing Ophiosphaerella. Trichoderma can improve grassland biomass, while Ophiosphaerella has the opposite effect as it may secrete metabolites causing grass necrosis. Correlations between soil properties and microbial genera showed plant-available phosphorus may influence grassland biomass by increasing Archaeorhizomyces and Trichoderma while reducing Ophiosphaerella. According to our structural equation modeling (SEM), Trichoderma abundance was the primary contributor to aboveground grassland biomass. Our results suggest Trichoderma biofertilizer could be an important tool for management of soils and ultimately grassland plant biomass.

1 aZhang, Fengge1 aHuo, Yunqian1 aCobb, Adam, B.1 aLuo, Gongwen1 aZhou, Jiqiong1 aYang, Gaowen1 aWilson, G.T.1 aZhang, Yingjun uhttp://journal.frontiersin.org/article/10.3389/fmicb.2018.00848/full