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With growing recognition of the ecological importance of grasslands, efforts to prevent their degradation, enhance the soil quality, and maintain ecological balance have become central to temperate grassland management. However, many temperate grasslands experience varying intensities and modes of grazing. Effective grazing management is crucial to avoid damage and promote the sustainable development of temperate grasslands. This study adopts a variety of research methods. Firstly, through the collection and sorting of data, it is clear that the research content mainly focuses on more than 70 response variables. Secondly, the comprehensive effects of different grazing intensity, grazing mode, and grazing history on these response variables were studied, and then detailed studies were conducted to analyze the effects of different grazing intensity and grazing mode under different temperate grassland types on these response variables. According to the analysis of the comprehensive effects and effects of different temperate grassland types, significant heterogeneity was found in 13 response variables (H, R, E, Height, Coverage, Density, TB, PB-PF, SWC, TK, OK, and N(20–60 cm)). Finally, in order to study the source of heterogeneity of these 13 response variables, subgroup analysis was carried out to analyze whether it was caused by environmental factors (MAP, MAT, MAP ×MAT), and then publication bias test and Egger's test were carried out to prove the reliability of the research results. The results showed that the heterogeneity of 12 response variables (R, H, E, height, coverage, density, TB, PB, PF, SWC, OK and N(20–60 cm)) was attributed to environmental factors. However, due to insufficient data after subgroup analysis, the heterogeneity of TK cannot be determined. • Conduct comprehensive effect analysis and result synthesis from three perspectives. • Refine the grazing effect into grassland types and study its impact on the ecosystem. • Analyze the heterogeneity and sources of response variables in the grassland ecosystem. • Conduct subgroup analysis on MAT, MAP and their combined effects. • Verify the results from heterogeneous sources and analyze publication bias to ensure accuracy. [ABSTRACT FROM AUTHOR]

The temperate steppe in Inner Mongolia is China’s largest steppe. Heavily intensified grazing has been widely used in an Inner Mongolia grasslands. However, the effects of the grazing on fine root demography have been little studied in grassland ecosystems. In this study, we conducted in situ field measurements for root production, mortality, and standing crop in Inner Mongolia steppe under both ungrazed and heavily intensified grazed conditions using the improved rhizotron techniques. Our results showed that root production and mortality in the steppe displayed seasonal dynamic patterns, whereas no clear seasonal dynamic patterns for the standing crop were detected. Long-term heavily intensified grazing did not alter seasonal dynamic patterns of root production, mortality and standing crop. Root production, mortality and standing crop distributed in different soil layers responded to livestock grazing differently. The grazing increased root production, mortality and standing crop in 0–10 cm soil layer, while it reduced root production, mortality and standing crop in 10–20 and 20–30 cm soil layers, with an overall reduction in the three variables across 0–30 cm soil layer. The grazing-induced reduction in root production, mortality and standing crop was mainly accounted for by reductions in aboveground biomass and soil water contents. These results indicate that long-term heavily intensified grazing can lead to the loss of soil organic matters and nutrients in the steppe. Thus, appropriate measures have to be taken for an effective management of the livestock grazing in Inner Mongolia steppe. [ABSTRACT FROM AUTHOR]

Abstract: The impact of climate change (i.e. warming and changes in precipitation patterns) on carbon (C) sequestration in the continental steppe is currently disputed and uncertain. We conducted a six-year field experiment in the temperate grassland ecosystem in Inner Mongolia, China. We found that C storage in the 0–30cm soil layer significantly decreased by 129.3gCm−2 under warming (W) but significantly increased by 145.9gCm−2 with increased precipitation (P), with no apparent interaction of W×P. The effects of W and P on soil C sequestration varied in different soil fractions (labile vs. recalcitrant soil organic matter) and layers (topsoil vs. subsoil), which complicated the prediction of the short- and long-term effects of soil C sequestration in climate change scenarios. Furthermore, C:nitrogen (N) ratios in soils with increasing C and N were asynchronous under W, P, and W+P treatments, suggesting that the limiting effect of N on soil C sequestration would be intensified under W with P conditions. Our findings suggest that, without an increase in precipitation or concurrent P and W, the semiarid Inner Mongolian grasslands may potentially act as a net C source in the future. [Copyright &y& Elsevier]

Abstract: Temperate grasslands of Argentina are extensively grazed by domestic livestock. Primary production follows a seasonal pattern, with maximum vegetation growth in late spring and minimum in winter. During the last decade, winter forage productivity has been encouraged by promoting the growth of cool-season annual grasses through late summer applications of glyphosate. The aim of this study was to describe structural changes in grassland vegetation associated with glyphosate treatments, as applied in a commercial livestock farm in the Flooding Pampa. Vegetation composition was assessed from spring 2006 to late summer 2008, in three paddocks that had never been exposed to any kind of herbicide, and three other paddocks treated with glyphosate in late summer in the previous 5 years. In the paddocks treated with glyphosate, basal cover of cool-season annual grasses and forage value in spring were greater but basal cover of cool-season perennial grasses, warm-season tussock grasses, warm-season legumes, total basal vegetation cover and forage value in summer were much lower respect to untreated paddocks. The shift in floristic composition resulted in less rich and even assemblages, dominated by an annual species and impoverished in native and perennial species. These structural changes may alter ecosystem processes through the increase of soil salinization and water losses in summer, may affect the seasonal pattern of productivity and may threaten biodiversity conservation and sustainability of wild life. [Copyright &y& Elsevier]

Abstract: Greenhouse gas budgets as well as the productivity of grassland systems are closely related to the carbon (C) and nitrogen (N) cycles. Within the framework of the CarboEurope and NitroEurope projects we have measured C and N exchange on the field scale at the grassland site Oensingen previously converted from arable rotation. The site is located on the Swiss Central Plateau and consists of two parallel fields of equal size. One field was subjected to intensive management with average nitrogen input of 230kg-Nha−1 year−1 and 4–5 cuts per year, and the other to an extensive management with no fertilisation and less frequent cutting. The total C budget of the fields was assessed by measuring the CO2 exchange by eddy covariance and analysing the carbon import by manure application and export by harvest. The N budget of the managed grassland is more complex. Besides the management related import and export, it includes gaseous exchange in many different forms (NO, NO2, HNO3, N2O, NH3, N2) needing different analytical techniques, as well as input by rain and leaching of N-compounds with the soil water. The main (“level-3”) field sites in the NitroEurope project are supposed to measure 95% of the N fluxes at the field scale. For several of the N fluxes specific measurements have been performed for 1 year or longer at the site. Some of the remaining N budget components (dry and wet deposition) could be estimated from results of a national deposition network, while other components (NH3 and N2 emission) were estimated based on literature parameterisations. However, we found indications that the (systematic) uncertainties of these estimated N-fluxes are large and that it is important to make site-specific measurement for all relevant budget components. The suitability of corresponding experimental methods is discussed. Analysis of the C budget over a 6-year period (2002–2007) showed a significant mean difference between the two newly established grassland fields with a likely net carbon loss for the extensive management and a net sequestration for the intensive management. Since the C/N ratio of the soil organic matter of the grassland is constrained in a rather narrow range around 9.3, the change in the soil carbon pool is supposed to be accompanied by a corresponding change in the N storage. This approach provided an alternative method to check the N budget of the two grassland fields derived from the individual N fluxes. [Copyright &y& Elsevier]

Abstract: Eutrophication of waterways through delivery of phosphorus (P) and nitrogen (N) from farmland is a problem in many countries. Loss of nutrients from grazed grassland via overland flow is well demonstrated, but the sources of these nutrients and the processes controlling their mobilization into water are not well understood. Much of the nutrient loss in overland flow from grazed pastures may be due to generally increased fertility of the soil–plant system (i.e. background or ‘systematic’ nutrient loss) rather than to immediate loss after fertilizer application [Nash, D., Clemow, L., Hannah, M., Barlow, K., Gangaiya, P., 2005. Modelling phosphorus exports from rain-fed and irrigated pastures in southern Australia. Aust. J. Soil Res. 43, 745–755]. The main aim of this study was to measure the effects of long-term (25 years) superphosphate (Ca(H2PO4)2 +2CaSO4) fertilizer application (0–23kg/(hayear)) on P and N in soil, plants, and potential background P and N movement in overland flow (generated using a rainfall simulator) from sheep-grazed pastures in southern Australia. Measurements were taken in autumn, under dry soil conditions, and in winter, under wet soil conditions, 12 and 15 months after the last fertilizer applications, respectively. Superphosphate application caused a strong increase in plant P, soil total P, Olsen P, and Colwell P; and a weaker increase in plant N, soil total N, and inorganic N (ammonium and nitrate). Soil P and N were concentrated in the surface 25mm of soil. Soil water-extractable P, calcium chloride-extractable P, and calcium chloride organic P were in general only poorly associated with fertilizer application. The concentration of P and, to a lesser extent, the concentration of N in overland flow increased with increasing fertilizer application and showed strong seasonal differences (0.06–0.77mgP/L and 0.6–5.5mgN/L in autumn; 0.04–0.20mgP/L and 0.4–1.7mgN/L in winter). The P in overland flow was predominantly dissolved reactive P in autumn and particulate P in winter. The N in overland flow contained significant proportions of dissolved organic N, dissolved inorganic N (ammonium and nitrate), and particulate N. The concentrations of P and N in overland flow usually exceeded State water quality targets (<0.04mgP/L and <0.90mgN/L), suggesting that background losses of nutrients from these pasture systems could contribute to the eutrophication of waterways. [Copyright &y& Elsevier]

Abstract: The carbon exchange of managed temperate grassland, previously converted from arable rotation, was quantified for two levels of management intensities over a period of 3 years. The original field on the Swiss Central Plateau had been separated into two plots of equal size, one plot was subjected to intensive management with nitrogen inputs of 200kgha−1 year−1 and frequent cutting, and the other to extensive management with no fertilization and less frequent cutting. For both plots, net CO2 exchange (NEE) was monitored by the eddy covariance technique, and the flux data were submitted to extensive quality control and gap filling procedures. Cumulative NEE was combined with values for carbon export through biomass harvests and carbon import through application of liquid manure (intensive field only) to yield the annual net carbon balance of the grassland ecosystems. The intensive management was associated with an average net carbon sequestration of 147 (±130)gCm−2 year−1, whereas the extensive management caused a non-significant net carbon loss of 57 (+130/−110)gCm−2 year−1. Despite the large uncertainty ranges for the two individual systems, the special design of the paired experiment led to a reduced error of the differential effect, because very similar systematic errors for both parallel fields could be assumed. The mean difference in the carbon budget over the 3-year study period was determined to be significant with a value of 204 (±110)gCm−2 year−1. The difference occurred in spite of similar aboveground productivities and root biomass. Additional measurements of soil respiration under standardized laboratory conditions indicated higher rates of soil organic carbon loss through mineralization under the extensive management. These data suggest that conversion of arable land to managed grassland has a positive effect on the carbon balance during the initial 3 years, but only if the system receives extra nitrogen inputs to avoid carbon losses through increased mineralization of soil organic matter. [Copyright &y& Elsevier]

Environmental management often lacks a harmonization across scales and beyond boundaries of the land with changed use. As an example, extensive areas of Uruguayan grassland have been transformed into crop and timber plantations in the past decades, but little is known about the possible impacts of these changes on neighboring native forests. We explore how the diversity of native forests differs in relation to land-use change trajectories, from grassland to monocultures, in the surrounding landscapes. We recorded woody species in 32 different native forest plots in Uruguay. Using Landsat images, we created land-use maps in a buffer of 3 km around each plot for the years 1986/1987, 1996/1997, 2006/2007 and 2016/2017. We calculated trajectories of changes regarding the percentage of cover per land use, the landscape shape and aggregation index for native forests, grassland, timber plantations and crops. Trajectories were explored based on the slope of the generalized linear model correlated with woody species composition. Landscape covered by native forests, timber plantations and crops increased whereas grassland cover decreased. Large and interconnected native forests in a landscape dominated by grasslands harbor a high diversity of woody species. Disaggregation of grassland resulted in a decrease in richness and diversity of woody species. The history of surrounding landscape determines diversity of native forests. We observed cross boundary effects of neighboring land uses on native forests. These effects have to be considered in all measures of environmental management to reduce the trade-offs between biodiversity conservation and economic profit. Nevertheless, other parameter such as climate and soil interplay, override and alter the effects of land use history and management. [Display omitted] • We reveal large cross-boundary effects from neighboring land on native forests. • Landscape change legacy shapes the diversity of woody species. • There is an urgent need for an environmental management beyond boundaries. [ABSTRACT FROM AUTHOR]

Grazing exclusion (GE) is widely considered to be an important strategy for restoring overgrazed grasslands and promoting carbon (C) storage. However, the changes in the components of ecosystem C with GE and their related drivers remain largely unexplored. Here, we investigated the effects of GE on the ecosystem C components (plant and soil C stocks) and their key driving factors through sampling inside and outside 15 grazing exclosures across the Inner Mongolia arid and semiarid grasslands in northern China. Our results showed that, except for dead root C, GE significantly promoted plant C stocks. The increase of C stocks in AGB and litter resulted from the increases of both biomass and C concentration, while the increase in live root C stock was mainly attributed to biomass accumulation. GE also promoted the topsoil (0–10 cm) C stocks but had little effect on the subsoil (10–30 cm) C stocks. Overall, GE had no significant effect on total ecosystem C stocks. Our results further indicated that across the grasslands, GE likely enhanced C accumulation in AGB, litter and live root in more humid and/or fertile sites. We also found that the increases of C stocks in AGB and litter were driven by the direct effects of GE and its indirect effects mediated by soil water content. The increases of C stocks in live root and topsoil with GE were linked to only high soil water contents. The generalizability of the soil water effect was confirmed by a meta-analysis which further revealed that across the grasslands of China, the responses of ecosystem C components to GE were associated with changes in soil water conditions. Therefore, our study highlighted the important role of soil water in regulating ecosystem C dynamics with GE at the national scale. Overall, our results showed that across arid and semiarid grasslands, GE is generally beneficial for plant and topsoil C accumulation. However, GE effects mediated by soil water on ecosystem C components may change to some extent due to altered soil water conditions under climate change. ● Grazing exclusion promoted plant carbon stocks except for dead root carbon. ● Grazing exclusion increased topsoil carbon but had little effect on subsoil carbon. ● The responses of plant carbon were contingent on climate and in situ soil fertility. ● Carbon increase was linked to higher soil water content after grazing exclusion. ● Soil water effect on carbon response can be generalized to the national scale. [ABSTRACT FROM AUTHOR]