Plant Nutrient Contents Rather Than Physical Traits Are Coordinated Between Leaves and Roots in a Desert Shrubland

Abstract

Although leaf economics spectrum (LES) has been extensively tested with regional and global datasets, the correlation among functional traits of desert plants remains largely unclear. Moreover, examinations on whether and how leaf and root traits are coordinated have yielded mixed results. We investigated variations in leaf and fine-root traits across 48 species in a desert community of northern China to test the hypotheses that (1) the leaf-trait syndrome of plant species in desert shrublands follows the predictions of the global LES, and is paralleled by a similar root-trait syndrome, (2) functional traits related to nutrient contents and resource uptake are tightly coordinated between leaves and fine roots in desert ecosystems where plant growth is limited primarily by dry and nutrient-poor conditions, and (3) traits as well as their relationships vary among functional groups. Our results partially supported the LES theory. Specific leaf area (SLA) was correlated with leaf tissue density, phosphorus content, and carbon-to-nitrogen ratio, but not with leaf nitrogen content. Specific root length (SRL) was not correlated with other fine-root traits, and fine-root traits were largely independent of each other. Therefore, fine-root traits did not mirror the leaf-trait syndrome. Fine-root nitrogen and phosphorus contents, nitrogen-to-phosphorous ratio, and carbon-to-nitrogen ratio all increased with analogous leaf traits, whereas SRL was not correlated with SLA. After phylogenetic effects were considered, nutrient contents and their ratios still displayed stronger coordination between leaves and fine roots than did SRL and SLA. The overall pattern of trait variations and relationships suggested differentiation among functional groups. Our results suggest that despite the absence of a root-trait syndrome, fine-root functions in the studied desert community were probably coordinated with leaf functions with respect to nutrient allocation and use.

Varying Relationship Between Vascular Plant Leaf Area and Leaf Biomass Along an Elevational Gradient on the Eastern Qinghai-Tibet Plateau

“…Then, the length, width, and area of the blade were measured by the Image J. We then measured LFW and dried the leaves in a ventilated oven at 105°C for 15 min and turned to 75°C until achieving a constant dry weight (i.e., LDW) ( Huang et al, 2019a ; Guo et al, 2021 ; Jiang et al, 2021 ). LFW and LDW were both measured using an electronic balance (0.0001 g, Zhuojing Experimental Equipment Co. Ltd., BMS, Shanghai, China).…”

“…Previous studies have confirmed that leaf size spans six orders of magnitude ( Milla and Reich, 2007 ; Wright et al, 2017 ), and this variation in leaf size is the basis for maintaining biodiversity ( Mi et al, 2021 ). For leaves, abiotic factors (e.g., altitude) are one of the driving forces of variation ( Chen et al, 2021 ; Jiang et al, 2021 ; Ren et al, 2021 ). The scaling relationship between leaf traits caused by leaf size may affect leaf biomass and element allocation, and this relationship has also been proven to be one of the strategies for species to acquire resources, and even affect species coexistence and community construction ( Li et al, 2008 ; Ren et al, 2021 ).…”

Divergent nitrogen and phosphorus allocation strategies in terrestrial plant leaves and fine roots: A global meta‐analysis

“…Empirical evidence indicates that leaf traits are coordinated with analogous fine root traits that follow evolutionary and biophysical constraints (Reich, 2014; Weigelt et al, 2021). For example, specific leaf area and specific root length were strongly correlated (Jiang et al, 2021; Withington et al, 2006). The same holds for the N and P concentrations correlation between leaves and fine roots, which was found to be strongly positive (Freschet et al, 2010; Geng et al, 2014; Tjoelker et al, 2005).…”

Coordinated variation in root and leaf functional traits of Hippophae rhamnoides treated at different stump heights in feldspathic sandstone areas of Inner Mongolia

“…stand for the ratio of dry weight to volume of leaves, and the ratio of dry weight to volume of fine roots respectively (Jiang et al, 2021). The dried leaves and fine roots were ground into powder using a PULVERISETTE 5 high flow ball milling system (Fritsch, Munich, Germany), which was passed through a 0.149 mm sieve for chemical analysis.…”