Humans are born with the ability and the need for affection, but communicating affection as a social behavior is historically bound. Based on the digitized books of Google Ngram Viewer from 1960 through 2008, the present research investigated affectionate communication (AC) in China and the United States, and its changing landscape along with social changes from collectivist to individualistic environments. In particular, we analyzed the frequency in terms of verbal affection (e.g., love you, like you), non-verbal affection (e.g., hug, kiss), and individualism (indicated by the use of first-person singular pronouns such as I, me, and myself) in Chinese and American books. The results revealed an increasing trend for AC in recent decades, although the frequency of affection words was lower in Chinese than in American books. Further, individualism was positively related to the frequency of affection words in both Chinese and American books. These results demonstrate the effect of cultural changes on AC, in that affection exchange becomes popular in adaptation to individualistic urban environments. These findings exemplify a cross-cultural difference in the expression of love and the cultural universality of social change in Eastern and Western societies.

Background: With the profound changes in the global climate, the issue of grassland degradation is becoming increasingly prominent. Grassland degradation poses a severe threat to the carbon cycle and carbon storage within grassland ecosystems. Additionally, it will adversely affect the sustainability of food production. The grassland ecosystem in the northwest region of Liaoning Province, China, is particularly vulnerable due to factors such as erosion from the northern Horqin Sandy Land, persistent arid climate, and issues related to overgrazing and mismanagement of grassland. The degradation issue is especially pronounced in this ecological environment. However, previous research on the carbon density of degraded grasslands in Northeast China has predominantly focused on Inner Mongolia, neglecting the impact on the grasslands in the northwest of Liaoning Province. Therefore, this experiment aims to assess the influence of grassland degradation intensity on the vegetation and soil carbon density in the northwest of Liaoning Province. The objective is to investigate the changes in grassland vegetation and soil carbon density resulting from different degrees of grassland degradation. Methodology: This study focuses on the carbon density of grasslands at different degrees of degradation in the northwest of Liaoning Province, exploring the variations in vegetation and soil carbon density under different levels of degradation. This experiment employed field sampling techniques to establish 100 × 100 m plots in grasslands exhibiting varying degrees of degradation. Six replications of 100 × 100 m plots per degradation intensity were sampled. Vegetation and soil samples were collected for analysis of carbon density. Results: The results indicate that in the context of grassland degradation, there is a significant reduction in vegetation carbon density. Furthermore, it was found that root carbon density is the primary contributor to vegetation carbon density. In comparison to mildly degraded grasslands, moderately and severely degraded grasslands experience a reduction in vegetation carbon density by 25.6% and 52.6%, respectively. However, with regard to the impact of grassland degradation on soil carbon density, it was observed that while grassland degradation leads to a slight decrease in soil carbon density, there is no significant change in soil carbon density in the short term under the influence of grassland degradation. Conclusions: Therefore, grassland degradation has exerted a negative impact on aboveground vegetation carbon density, reducing the carbon storage of above-ground vegetation in grasslands. However, there was no significant effect on grassland soil carbon density.

The mixed salt stress is common in nature. Salt stress always affects plant growth. Different plant species have different adaptive capacity to salty soils. Leymus chinensis is an herbaceous plant with different leaf colors. However, little research was conducted to explore the different tolerance mechanisms to salt stress among the three different leaf colour genotypes of Leymus chinensis (grey green, transitional color, yellow green). Pot experiments for Leymus chinensis in three leaf colors were conducted under mixed salt treatments in 2010. Malondialdehyde (MDA) and protein concentrations, and the activity of various antioxidant enzymes [i.e., superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR), dehydroascorbate reductase (DHAR) and monodehy- droascorbate reductase (MDHAR)] were determined and compared among the three leaf color genotypes of Leymus chinensis. The concentrations of MDA and protein, and the activity of antioxidant enzymes showed an increasing trend with increasing pHs in almost all three leaf colors, and all of them became highest when salt stress and pH values were also highest. Moreover, antioxidant enzymes were the highest in the grey-green leaf color, and the lowest in the yellow green leaf color after exposure to the same pH treatment. The results suggested that all three leaf colors of Leymus chinensis were tolerant to salt stress, and the salt-tolerance declined according to the order of grey green > transitional color > yellow green of Leymus chinensis. This study can give us a better understanding of the intra-species adaptation to mixed salt soils.

Climate can shape plant genetic diversity and genetic structure, and genetic diversity and genetic structure can reflect the adaptation of plants to climate change. We used rbcl and trnL-trnF sequences to analyze the genetic diversity and genetic structure of C. squarrosa under the influence of different environmental factors in Inner Mongolia grassland. The results showed that the genetic diversity of this species was low. (The trnL-trnF sequences have higher genetic diversity than rbcl sequences.) C. squarrosa had low genetic diversity compared to other prairie plants, but had a more pronounced genetic structure. The haplotype network diagram of the combined sequences could be divided into two categories, and the results of the NJ, MP, and ML trees also showed that the haplotypes were divided into two branches. The results of genetic structure analysis showed that that the populations located in the desert steppe fall into exactly one cluster, and the populations located in the typical steppe fall into exactly another cluster. The neutrality tests were all negative and the mismatch distribution also showed a single peak across the population, suggesting that C. squarrosa had undergone population expansion and was well adapted to the local environment. The results of the mantel test showed that climate had a greater influence on the genetic distance of C. squarrosa, with annual precipitation having a higher influence than mean annual temperature. This study provided basic genetic information on the genetic structure of C. squarrosa and contributes to the study of genetic adaptation mechanisms in grassland plants.