Geology topics

Xiaotao Lü

Publications and source records attributed to Xiaotao Lü.

3 recordsLinked to original sources

USGS2021

Global resorption efficiencies of trace elements in leaves of terrestrial plants

Leaf nutrient resorption is a critical nutrient conservation strategy. Previous studies focus mainly on resorption patterns of macronutrients, but resorption patterns of trace elements remain poorly understood. A meta-analysis was conducted to explore the general patterns of the leaf resorption of eight trace elements [i.e. copper (Cu), molybdenum (Mo), zinc (Zn), boron (B), manganese (Mn), sodium (Na), aluminium (Al) and iron (Fe)], and a macronutrient [i.e. sulphur (S)] using data collected from 53 published studies. Sulphur (49.6%) had the highest average resorption efficiency followed by Cu (30.3%), Mo (29.5%), Zn (19.5%) and B (17.6%). Two structural elements, Na and Mn, were not resorbed, whereas two potentially toxic elements, Al (−55.6%) and Fe (−25.4%), were accumulated in senesced leaves. Both climatic factors and growth types affected leaf nutrient resorption efficiency, but the magnitudes and directions of the effects differed greatly between S and the trace elements. The resorption efficiencies of S, Cu, Mo and Zn decreased as leaf nutrient concentrations increased, but the structural or potentially toxic elements (i.e. B, Mn, Na, Fe and Al) presented no response or opposite trends. Our results provide global mean resorption efficiencies of trace elements for the first time, and highlight that structural and potentially toxic elements have relatively lower or no leaf resorption, which should be fully considered in biogeochemical models.

Functional Ecology↗

USGS2021

Coexistence of multiple leaf nutrient resorption strategies in a single ecosystem

Leaf resorption is critical for considerations of how plants use and recycle nutrients, but fundamental unknowns remain regarding the controls over plant nutrient resorption. Empirical studies suggest at least three basic types of resorption control, including (i) stoichiometric control, (ii) nutrient limitation control, and (iii) nutrient concentration control strategies. However, which strategies are adopted in given conditions and whether multiple strategies coexist in an ecosystem are still open questions. To address these unknowns, leaf nitrogen (N) and phosphorus (P) resorption efficiency (NRE and PRE) and proficiency were measured for seven woody species at a nutrient-rich but potentially N-limited secondary forest and a nutrient-poor and potentially P-limited secondary forest. NRE was higher in the N-limited forest while PRE was higher in the P-limited forest, suggesting that plants responded to nutrient limitation with preferential resorption of the more limiting nutrient. NRE:PRE was positively related to leaf N:P ratios within each forest, demonstrating a role for stoichiometric control. Nutrient concentration controls were also found, with higher nutrient resorption proficiency in the nutrient-poor forest than in the nutrient-rich forest. The controls of stoichiometry and nutrient concentration were community-wide, but the nutrient limitation control was species-specific. Our results highlight the coexistence of multiple nutrient resorption strategies in a single ecosystem, and suggest these strategies are scale-dependent.

Science of the Total Environment↗

USGS2020

Scaling responses of leaf nutrient stoichiometry to the lakeshore flooding duration gradient across different organizational levels

Most wetlands have been subject to changes in flooding regimes by climate change and human activities, resulting in widespread alteration of wetland plants at different organizational levels. However, scaling the responses of wetland plants to changes in flooding regimes is still challenging, because flooding could indirectly affect wetland plants through affecting environment factors (e.g. soil properties). During the non-flooding period, we investigated leaf N and P stoichiometry at three organizational levels (intra-species, inter-species, inter-community) along a flooding duration gradient in a lakeshore meadow of Poyang Lake floodplain, China. At the intra-species level, leaf N and P stoichiometry showed species-specific responses to flooding duration. At the inter-species level, leaf N or P contents or N:P ratio showed no significant response to flooding duration. At the inter-community level, leaf N and P contents significantly increased with flooding duration, while leaf N:P ratio decreased. At each organizational level, leaf N and P stoichiometry showed poor correlation with soil N and P stoichiometry. Moreover, intra-specific responses of leaf N and P contents to flooding duration and soil nutrient content increased with mean flooding duration of species distribution, which was the index of species hydrological niche. Intraspecific variation had lower contribution than species turnover to variations in community leaf nutrient stoichiometry. In all, flooding duration affected leaf N and P stoichiometry mainly through direct pathway at the intra-species and inter-community level, rather than the indirect pathway via soil nutrient stoichiometry. Therefore, our results have implications for scaling up from environmental conditions to ecosystem processes via wetland plant communities.

Science of the Total Environment↗