Differential resource acquisition strategies of herbaceous and woody plants in temperate forests

Functional traits are pivotal indicators of plant ecological strategies, regulating resource acquisition and allocation through traits trade-offs. However, few studies have explored how trait coordination underlying resource-use strategies vary across plant life-forms from different trait dimensionalities. In this study, we examined 14 leaf functional traits in 81 plant species (27 herbaceous and 54 woody species) from the southwestern Qinling Mountains, including 6 structural traits (leaf area, leaf thickness, leaf mass per area, leaf dry matter content, leaf tissue density, and leaf volume), 4 chemical traits (leaf carbon, nitrogen, and phosphorus concentrations and nitrogen-to-phosphorus ratio), and 4 photosynthetic traits (maximum net photosynthetic rate, stomatal conductance, internal-to-ambient carbon dioxide ratio, and photosynthetic nitrogen use efficiency).

Our findings revealed divergent distribution ranges between herbaceous and woody plants along the leaf economics spectrum, with herbaceous plants at the resource acquisition end (e.g., high nutrient concentration and photosynthesis rate) and woody plants at the resource conservation end (e.g., high tissue density). Furthermore, herbaceous plants exhibited higher connectivity in their trait networks, with leaf area as the hub trait, emphasizing efficient resource utilization through optimized light interception. In contrast, woody plants showed greater modularity, with leaf dry mass content as the hub trait, reflecting enhanced flexibility to environmental pressures by prioritizing maintenance and defense.

These findings advance our understanding of how trait coordination mediates plant adaptative strategies across multiple dimensions and underscore the functional importance of plant hub traits in modulating resource use strategy across plant life-forms.