Understanding the functional diversity relationship between biomass and plants is a key issue in biodiversity-ecosystem functionality and the utility of grassland. We conducted a five-year mowing experiment to examine the effects of the mowing frequency on biomass, plant species, and functional diversity of a natural plant community in a semiarid region of Inner Mongolia. A secondary objective was to test whether unmowed refuge areas within plots would mitigate the disturbance effect of mowing. The result showed that mowing disturbance reduced biomass by the greatest amount with mowing once every year (M1) and the least with M2. The biomass composition of M2 consisted of a greater mass of perennial species than in the other mowing treatments but was equivalent to the control (CK). However, mowing disturbances increased the plant species richness and M2 had the largest number of species. The community-weighted means (CWM) indices indicated that M2 produced the least detrimental effects on the grassland. Retaining unmowed refuge areas appeared to be ineffective in promoting beneficial community traits under M1 mowing regimes. Based on our results, we recommend that the semi-arid grassland be mowed every other year in order to optimize sustainable production.Sustainability 2020, 12, 1507 2 of 11 preparing winter feed for livestock production in the semi-arid regions in northern China, Mongolia, and east Russia [12]. The Typical Steppe is the most widely distributed type of native grassland suitable for mowing in the pastoral regions in Inner Mongolia [13]. Rotational mowing dates and frequencies [14] have a small effect on the reproduction of grassland community plants and can avoid the excessive use of grassland resources [15]. From this perspective, mowing may be an effective grassland management practice and substitute for grazing for semi-arid natural grasslands [1,3,8].Moreover, mowing has also been found to enhance the growth, and thus the relative abundance, of C4 species in natural grassland [16], producing higher light saturation point [17], photosynthetic rate [18], and water use efficiency [19].An appropriate mowing regime can maintain high plant species richness [15] and reduce competition [20] by inhibiting tall plant species [3], thereby allowing short species to persist. However, mowing disturbances can also have negative impacts on species richness and plant traits that alter the community's structure and function [2], including its productivity [21]. Therefore, Roel et al. [22] suggested keeping an unmowed refuge zone within the grassland to increase species diversity in grasslands. Based on theoretical and empirical evidence, Doležal et al. [23] argued that seasonal mowing shifts community composition, which may reduce competitive interactions and promote the coexistence of dominant and subordinate species.Plant functional traits not only determine how plants respond to environmental factors [24], but also represent important indicators of ecological strategies that affect the attributes of plant c...

Soybean (Glycine max L.) is the most important legume crop in the world, and provides protein and oil for human consumption and animal feed. Cold and waterlogging or flooding are abiotic stress that are commonly encountered during soybean germination in short-season growing conditions in the Northern latitudes. Imbibition of cold water during the germination disrupts the cell membranes and increases leakage of their contents and makes seeds vulnerable to biotic stress. The cold tolerance is associated with the ability of cells to avoid or repair the damage to their membranes and organelles, restoring membrane function, metabolism and managing the reactive oxygen species (ROS) generated during the process. Excess moisture impedes aerobic respiration by oxygen deprivation and increases the likelihood of soil-borne diseases further reducing the germination rate. Tolerance to waterlogging is associated with mechanisms that slow the rate of water uptake and help maintain efficient anaerobic metabolism. The QTL mapping, transcriptomics, and proteomic studies have revealed several genes and pathways that likely play a role in seed response to cold and waterlogging stress. This review discusses the effects of cold and waterlogging on soybean seed germination at the physiological level, the molecular mechanisms involved and provides an overview of soybean waterlogging and cold tolerance research. The methodologies commonly used to study the molecular mechanisms controlling tolerance to waterlogging and cold stress also are reviewed and discussed.

Mowing removes plant photosynthetic organs, thus decreasing plant biomass and nutrients in the community. Responses of community functional diversity, biomass and nutrient status to mowing plays a crucial role in the restoration and sustainable use of degraded grasslands, but have not been well studied. Our study linked functional diversity with forage biomass and nutrition in a semi-arid grassland. We found that annual mowing reduced community biomass, in particular significantly reduced the dominant plants biomass, which was maintained with biennial mowing. In addition, this study showed that functional diversity could be maintained at a high level under biennial mowing compared to unmowed, but significantly decreased under annual mowing. Structural equation modeling indicated that annual mowing reduced dominant plants biomass by reducing community functional diversity. Mowing decreased dominant plants nutrients by decreasing community functional diversity and soil nutrients, but had no significant effect on nutrients of community and non-dominant plants.Furthermore, there was a strong positive correlation between community functional diversity with forage production and nutrition. In conclusion, our study demonstrated that biennial mowing increases community biomass, litter mass, and dominant plant nutrition by regulating functional diversity. Therefore, biennial mowing can provide better conservation of grassland ecosystems and is a suitable 4 grassland management practice in semi-arid grasslands.