[Trait-based responses and adaptation of Artemisia sacrorum to environmental changes].

The paper focused on Artemisia sacrorum in the stable natural plant community in three vegetation zones (forest, forest steppe and steppe) in the Yanhe River catchment. The following plant functional traits were measured at each sample site, i.e., specific leaf area (SLA), leaf tissue density (LTD), leaf nitrogen concentration (LNC), leaf phosphorus concentration (LPC), leaf nitrogen phosphorus ratio (LNP), specific root length (SRL), root tissue density (RTD), root nitrogen concentration (RNC), root phosphorus concentration (RPC) and root nitrogen phosphorus ratio (RNP). These 10 plant functional traits were chosen because they were easily measurable and adequately reflected plant survival strategies. We analyzed intraspecific differences in A. sacrorum functional traits in the different habitat zones, and the influence of climate and terrain factors on A. sacrorum functional traits. We also studied the relationships among A. sacrorum plant functional traits. The results showed that some A. sacrorum functional traits were significantly different among sample sites, such as LPC, LNP, SRL, RTD and RNP, while the other 5 functional traits had no significant differences. The functional traits were not significantly different between sites with different slopes and aspects. SLA was very significantly negatively correlated with LTD, SRL was significantly negatively correlated with RTD and RNP, RTD was significantly positively correlated with RNC and RNP, and there were no significant relationships among LTD, LNC and LNP and the other functional traits. This showed that A. sacrorum adapted to the environment by coordinating adjustment among leaf and root functional traits. Different climate factors had different effects on plant traits, with the effects of mean annual precipitation > mean annual temperature > annual average evaporation capacity.

[Relationships among leaf traits and their expression in different vegetation zones in Yanhe River basin, Northwest China].

This article selected zonal plant communities as the research objects in different vegetation zones in Yanhe River basin. We measured six leaf traits of the dominant species and main accompanying species in each community, and then analyzed the relationships and their changes along with environmental gradients between these traits in order to understand the plant adaptation strategies to the environment changes. The results showed that the specific leaf area was significantly negatively correlated to leaf tissue density, area-based leaf nitrogen and phosphorus concentrations, and significantly positively correlated to mass-based leaf phosphorus concentration. Both the scaling relationships among these traits and plant life strategies were different among the three vegetation zones, the scaling-dependent relationship between leaf tissue density and specific leaf area was stronger in steppe and forest-steppe zones than in forest zone, but the correlations among area-based leaf nitrogen/phosphorus concentrations and specific leaf area and leaf tissue density were more significant in forest zone than in steppe zone. In the arid grassland and forest-steppe zone, plants give priority to defensive and stress resistance strategies, and in relatively moist nutrient-rich forest zone, plants give priority to fast growth and resource optimization allocation strategies.

[Responses of plant functional traits to micro-topographical changes in hilly and gully region of the Loess Plateau, China].

Plant functional traits are closely tied to the performance of plants in specific microenvironments, and reflect their ability to adapt to those microenvironments. In areas with complex topography, analyzing the responses of plant functional traits to microtopographical changes is crucial to understanding the adaptive strategies of plants in diverse environments. This paper analyzed fluctuations in soil nutrients as well as correlations between plant functional traits and changes in topography at the family and community levels in selected natural vegetation communities in the foreststeppe zone of the loess hilly and gully region in Loess Plateau of China. Significant differences in plant functional traits were primarily driven by the phylogenetic background or species composition of the community. Slope aspect exerted less impact while slope positions had no significant effect on plant traits at the community level. No significant changes in plant functional traits were observed with changes in topography at the community level. However, leaf nitrogen and root nitrogen contents of Leguminous and Compositae species differed significantly With slope positions. The root tissue density of Graminaceous species differed significantly with slope positions. Root density exhibited significant positive correlations with soil nutrient and carbon contents at the community level. Both leaf nitrogen and root nitrogen contents of Leguminous species were positively correlated with soil phosphorus content, while leaf nitrogen and root nitrogen contents of both Graminaceous and Compositae species were significantly positively related to soil nitrogen content. The results demonstrate the different responses of species of different families to changes in micro-topography and their distinctive adaptive strategies to the environment.