# Differences in Fine Root Traits of Quercus rehderiana Between Rocky and Nonrock Desertification Forests in Southwest China

## TL;DR

This study compares fine root traits of Quercus rehderiana in rocky and nonrocky desertification forests in China to understand how environmental conditions influence resource acquisition and conservation strategies.

## Contribution

The study reveals distinct adaptive strategies in fine root traits of Quercus rehderiana in response to rocky versus nonrocky desertification environments.

## Key findings

- Quercus rehderiana in rocky desertification forests showed higher root length, volume, and nutrient concentrations like nitrogen, calcium, and magnesium.
- Nonrocky desertification forests had higher phosphorus and potassium concentrations in fine roots.
- Rocky desertification forests favored resource-acquisition strategies, while nonrocky ones favored resource-conserving strategies.

## Abstract

Fine roots (diameter < 2 mm) play a crucial role in plants' acquisition of soil water and nutrients. Their morphological and chemical traits, which reflect resource utilization strategies, have garnered significant global research attention. However, the extent to which these traits are influenced by environmental conditions remains unclear. In this study, we measured 14 morphological and chemical traits from nine Quercus rehderiana individuals in both rocky and nonrocky desertification forest habitats. Our objectives were to identify the key factors shaping fine root traits and elucidate their adaptive strategies in the arid, nutrient‐poor conditions of rocky desertification forest ecosystems. The results revealed that Quercus rehderiana fine roots in rocky desertification forests exhibited higher root length (RL), root volume (RV), nitrogen (N), calcium (Ca), and magnesium (Mg) concentrations, along with an elevated nitrogen‐to‐phosphorus ratio (N:P ratio), compared to those in nonrocky desertification forests. Conversely, fine roots in nonrocky desertification forests showed greater phosphorus (P) and potassium (K) concentrations. Correlation analysis indicated that in rocky desertification forests, specific root length (SRL) and specific root area (SRA) were positively correlated with root P concentration, while root N concentration exhibited synergistic relationships with P and K. In contrast, nonrocky desertification forests displayed trade‐offs: SRL and SRA were negatively correlated with RV, root diameter (RD), and root tissue density (RTD), and root carbon (C) concentration was inversely related to Ca and Mg. Principal component analysis further demonstrated that rocky desertification forests favored a resource‐acquisition strategy, characterized by enhanced morphological traits and nutrient concentrations, whereas nonrocky desertification forests leaned toward a resource‐conserving strategy, prioritizing P and K accumulation. These findings highlight that Quercus rehderiana adapts to divergent environments through distinct resource allocation mechanisms, with its unique traits in rocky desertification forests underscoring its suitability for ecological restoration efforts.

Fine roots (< 2 mm in diameter) play an important role in plants acquiring soil water and nutrient resources. Their morphological and chemical traits linked to resource strategies have received much attention in the world. However, whether the traits related to resource strategies are affected by environmental conditions or phylogeny is still unclear. In this study, 14 fine root traits (morphological and chemical traits) of Quercus rehderiana were measured in 9 individuals in forests with rocky and nonrocky desertification. The objective was to analyze the factors influencing fine root morphological and chemical traits and their strategies of adaptation to arid and poor environments in forests with rocky desertification. The results showed that Quercus rehderiana fine roots in forests with rocky desertification had higher root length, root volume, nitrogen concentration, calcium concentration, magnesium concentration, and nitrogen phosphorus ratio than in forests with nonrocky desertification. Quercus rehderiana fine roots in forests with nonrocky desertification had a greater phosphorus concentration and potassium concentration than in forests with rocky desertification. The results of principal component analysis showed that forests with rocky desertification tended to show resource‐acquisition strategies with higher fine root morphological traits and nutrient concentrations, while forests with nonrocky desertification tended to show resource‐conserving strategies with greater phosphorus and potassium concentrations. We inferred that the fine root morphological traits are determined by phylogeny, while nutrient concentration is influenced by the availability of soil mineral nutrients.